[Objectives]To explore the effects of chlorogenic acid from honeysuckle on the secretion enzymes,lipoxygenase A4(LXA4),and blood biochemical indicators in mice with aluminum induced Alzheimer's disease(AD).[Method...[Objectives]To explore the effects of chlorogenic acid from honeysuckle on the secretion enzymes,lipoxygenase A4(LXA4),and blood biochemical indicators in mice with aluminum induced Alzheimer's disease(AD).[Methods]Chlorogenic acid was extracted from hon-eysuckle by ultrasound assisted alcohol extraction method.Seventy mice were randomly divided into normal group,model group,and low,me-dium and high dose groups of honeysuckle chlorogenic acid.All the mice in each group except for the normal group were given maltol aluminum by intraperitoneal injection to establish models of aluminum induced AD,continuously injected for 5 d and stopped for 2 d,totally poisoned for 8 weeks.Starting from the 5^(th) week of poisoning,the low,medium and high dose groups of honeysuckle chlorogenic acid were given honeysuck-le chlorogenc acid solution 40,80 and 160 mg/kg by gavage,respectively,while the normal group and the model group were fed with an equal volume of distilled water,all once daily,continuously gavaged until the end of the 8^(th) week.At the end of the experiment,the learning memory ability of the mice was tested by Y-type waler maze,and the number of tests required to reach the learning standard,the number of memory er-rors in 20 tests and the error rate of the mice were recorded.The brains of mice were taken to determine the contents of β-secretase,α-secre-tase,γ-secretase,LXA4 and acetylcholinesterase(AchE)in the homogenates of brain tissues by ELISA,and their blood was taken to deter-mine the biochemical indexes.[Results]Compared with the normal group,the number of learning tests,number of memory errors,error rate and the contents of β-secretase,γ-secretase and AchE in brain tissue of the mice in the model group were all significantly increased(all P<0.05),the contents of LXA4 in brain tissue were significantly decreased(all P<0.05),and the contents of α-secretase did not change significantly(all P>0.05);compared with the model group,the number of learning tests,the number of memory errors,the error rate and the content of β-secretase,γ-secretase and AchE in brain tissue were all significantly reduced(all P<0.05),the content of LXA4 in brain tissue of the high dose group of honeysuckle chlorogenic acid was significantly increased(P<0.05),and there was no significant change in the content of α-secretase in brain tissue of all groups of honeysuckle chlorogenic acid(all P>0.05).Compared with the normal group,the levels of blood glucose,TC,TG,ALT,BUN,Cr and UA in the model group and the levels of TC,TG and BUN in the low-and medium-dose groups of honeysuckle chlorogenic acid were significantly increased(all P<0.05),and the level of HDL-C in the model group and the levels of UA in the medium-and high-dose groups of honeysuckle chlorogenic acid were significantly decreased(all P<0.05);compared with the model group,the levels of blood glucose,ALT,BUN,UA in each group of honeysuckle chlorogenic acid,the levels of TC and Cr in medium and high dose groups of honeysuckle chlorogenic acid,and the level of TG in the high dose group of honeysuckle chlorogenic acid were all signifi-cantly lower(all P<0.05),while the level of HDL-C in the medium and high dose groups of honeysuckle chlorogenic acid and the level of to-tal protein in the high dose group of honeysuckle chlorogenic acid were all significantly higher(all P<0.05).[Conclusions]Chlorogenic acid from honeysuckle may improve AD induced by aluminum exposure via regulating related secretory enzymes,LXA4,and various biochemi-cal indicators.展开更多
A study was conducted to explore the defense response in woody plants after insect herbivory. The activities of two enzymes, lipoxygenase （LOX）, a key enzyme ofjasmonate （JA） pathway, and phenylalanine ammonia lya...A study was conducted to explore the defense response in woody plants after insect herbivory. The activities of two enzymes, lipoxygenase （LOX）, a key enzyme ofjasmonate （JA） pathway, and phenylalanine ammonia lyase （PAL）, a rate-limiting enzyme of phenyl- propanoid pathway, were measured in the leaves of one-year-old poplar （Populus simonii × P. pyramidalis ＇Opera 8277＇） cuttings after Clostera anachoreta larvae attack. The results show that the increased activities of LOX and PAL were found not only in the leaves wounded by C. anachoreta larvae but also in their tipper systemic leaves, indicating that JA and phenylpropanoid pathways were activated, and the defense response was stimulated systemically. The increase in LOX and PAL activities in neighboring intact poplar cuttings sug- gested that there exists the interplant communication between poplar plants mediated by the herbivore-induced volatiles. Methyl jasmonate （MeJA） was also proved to be an airborne signal to induce defense response in P simonii × P pyramidalis ＇Opera 8277＇ cuttings.展开更多
Lipoxygenase （LOX, EC1.13.11.12） is a key enzyme during the degradation of lipids in animals and even plants, and also the first key enzyme responsible for the biosynthesis of jasmonate. To purify and characterize t...Lipoxygenase （LOX, EC1.13.11.12） is a key enzyme during the degradation of lipids in animals and even plants, and also the first key enzyme responsible for the biosynthesis of jasmonate. To purify and characterize the OsLOX1 gene from rice seeds, the entire coding region of the OsLOX1 gene was inserted into an expression vector pET30a（＋） and transformed into Escherichia coil BL21 （DE3）. Expression of the fusion protein was successfully induced by isopropyl-β-D- thiogalactopyranoside （IPTG） and the purified recombinant protein was obtained by His.Bind Kits. Further assay showed that the purified recombinant protein exhibited the LOX activity. The optimum pH was 4.8 （acetate buffer） and the optimum temperature was 30℃ for the above enzyme. Thus, the recombinant might confer an available usage for the synthesis of jasmonate in vitro, and also provides a possibility for elucidating the inter-relationship between the primary structure of the plant seed lipoxygenase protein and its physiological functions.展开更多
Background: Increased mitogen-activated protein kinase (MAPK) phosphorylation has been detected in peripheral nerve of human subjects and animal models with diabetes as well as high-glucose exposed human Schwann cells...Background: Increased mitogen-activated protein kinase (MAPK) phosphorylation has been detected in peripheral nerve of human subjects and animal models with diabetes as well as high-glucose exposed human Schwann cells, and have been implicated in diabetic peripheral neuropathy. In our recent studies, leukocytetype 12/15-lipoxygenase inhibition or gene deficiency alleviated large and small nerve fiber dysfunction, but not intraepidermal nerve fiber loss in streptozotocin-diabetic mice. Methods: To address a mechanism we evaluated the potential for pharmacological 12/15-lipoxygenase inhibition to counteract excessive MAPK phosphorylation in mouse and cell culture models of diabetic neuropathy. C57Bl6/J mice were made diabetic with streptozotocin and maintained with or without the 12/15-lipoxygenase inhibitor cinnamyl-3,4-dihydroxy-α-cyanocinnamate (CDC). Human Schwann cells were cultured in5.5 mMor30 mMglucose with or without CDC. Results: 12(S) HETE concentrations (ELISA), as well as 12/15-lipoxygenase expression and p38 MAPK, ERK, and SAPK/JNK phosphorylation (all by Western blot analysis) were increased in the peripheral nerve and spinal cord of diabetic mice as well as in high glucose-exposed human Schwann cells. CDC counteracted diabetes-induced increase in 12(S)HETE concentrations (a measure of 12/15-lipoxygenase activity), but not 12/15-lipoxygenase overexpression, in sciatic nerve and spinal cord. The inhibitor blunted excessive p38 MAPK and ERK, but not SAPK/ JNK, phosphorylation in sciatic nerve and high glucose exposed human Schwann cells, but did not affect MAPK, ERK, and SAPK/JNK phosphorylation in spinal cord. Conclusion: 12/15-lipoxygenase inhibition counteracts diabetes related MAPK phosphorylation in mouse and cell culture models of diabetic neuropathy and implies that 12/15-lipoxygenase inhibitors may be an effective treatment for diabetic peripheral neuropathy.展开更多
The flavor of the soymilk and soyflour obtained from the lipoxygenase mutant isolines was concentrated by simultaneous distillation and extraction (SDE), and its constituents were identified by gas chro-matography (GC...The flavor of the soymilk and soyflour obtained from the lipoxygenase mutant isolines was concentrated by simultaneous distillation and extraction (SDE), and its constituents were identified by gas chro-matography (GC) and gas chromatography-mass spectrometry. Results showed that the same 24 flavor constituents were isolated in both soymilk and soyflour, and most of them were aldehydes and alcohols. Lox2 was most responsible for the production of the volatile and beany-flavor components, and Lox1 less responsible. Lox3 was least responsible and can reduce the yield of hexanal. Either Lx1 or Lx2 could significantly reduce the volatile and beany-flavor, and Lx3 could significantly increase the yield of hexanal. Primary and secondary interactions existed among the null mutant genes, and the major effects and interactions could be affected by processing conditions. The isoline with triple lipoxygenase null genes yielded the least volatile and beany-flavor components, and the isoline without the lipoxygenase gene Lx3 produced the greatest amount of the volatile and beany-flavor components. The amounts of volatile and beany-flavor components produced by the other isolines were between that of the isoline with triple lipoxygenase null genes and the isoline without lipoxygenase gene Lx3. According to the correlation analysis, the hexanal amount could be used as an index in evaluating the importance of lipoxygenase isozymes in the yield of beany-flavor compounds, and the effects of the different types of lipoxygenase null mutants in controlling beany-flavor compounds. The cultivars with triple lipoxygenase null genes will be a quality raw material for soy food processing.展开更多
Fruit ripening is a complex process and is regulated by many factors. Ethylene and polygalacturonase （PG）, lipoxygenase （LOX）, expansin （EXP） are all critical regulating factors in fruit ripening and softening p...Fruit ripening is a complex process and is regulated by many factors. Ethylene and polygalacturonase （PG）, lipoxygenase （LOX）, expansin （EXP） are all critical regulating factors in fruit ripening and softening process. With antisense ACS tomato, Nr mutant tomato and cultivated tomato as materials, Northern blot hybridization showed that PG, LeEXP1 and LOXexpressed differently in different parts of cultivated tomato fruit during ripening, which was related to fruit ripening. The ripening process of columella and radial pericarp was faster than pericarp. In both Nr mutant and antisense ACS transgenic tomato fruit, expression levels ofPG, LeEXPI and LOXwere generally lower than those in cultivated fruit but still related to fruit ripening. The expression levels ofPG, LeEXP1 and LOX increased in the mature green tomato fruits after 0.5 h treatment with ethylene （100 μL/L）. These results indicate that gene expression ofPG, LeEXP1 and LOXwere positively regulated by ethylene. The time and cumulative effect of the concentration exists in the expression of PG regulated by ethylene. The regulation of LOX expression mainly depended on the fruit development after great amount of ethylene was produced. PG played a major role in ripening and softening of tomato fruit, and cooperated with the regulation of EXP and LOX.展开更多
Lipoxygenase(LOXs)is a kind of dioxygenase without heme and iron,which plays an important role in the development and adaptation of many plants to the environment.However,the study of strawberry LOX gene family has no...Lipoxygenase(LOXs)is a kind of dioxygenase without heme and iron,which plays an important role in the development and adaptation of many plants to the environment.However,the study of strawberry LOX gene family has not been reported.In this study,14 LOX genes were identified from the diploid woodland strawberry genome.The phylogenetic tree divides the FvLOX gene into two subfamilies:9-LOX and 13-LOX.Gene duplication event analysis showed that whole-genome duplication(WGD)/segmental duplication and dispersed duplication effectively promoted the expansion of strawberry LOX family.QRT-PCR analysis showed that FvLOX genes were expressed in different tissues.Expression profile analysis showed that FvLOX1 and FvLOX8 were up-regulated under low temperature stress,FvLOX3 and FvLOX7 were up-regulated under drought stress,FvLOX6 and FvLOX9 were up-regulated under salt stress,FvLOX2,FvLOX3 and FvLOX6 were up-regulated under salicylic acid(SA)treatment,FvLOX3,FvLOX11 and FvLOX14 were up-regulated under methyl jasmonate(MeJA)treatment,FvLOX4 and FvLOX14 were up-regulated under abscisic acid(ABA)treatment.Promoter analysis showed that FvLOX genes were involved in plant growth and development and stress response.We analyzed and identified the whole genome of strawberry FvLOX family and characterized a variety of FvLOX candidate genes involved in abiotic stress response.This study laid a theoretical and empirical foundation for the response mechanism of strawberry to abiotic stress.展开更多
The purification and characterization of lipoxygenase （LOX, EC 1.13.11.12） from the green algae Enteromorpha clathrata were studied. Two components marked LOX - 1 and LOX - 2 were purified and their molecular masses...The purification and characterization of lipoxygenase （LOX, EC 1.13.11.12） from the green algae Enteromorpha clathrata were studied. Two components marked LOX - 1 and LOX - 2 were purified and their molecular masses were estimated to be 102 and 79 ku by SDS - PAGE. Both LOX - 1 and LOX - 2 were stable over the pH wide range 6.0 - 10.0 and had the optimum pH of 10.0 and 8.6, at optimum temperature of 30 and 25℃, respectively. Substrate specificities of LOX - 1 and LOX - 2 were the greatest towards linoleic acid, followed by arachidonic acid and linolenic acid. The Michaelis constant values of LOX - 1 and LOX - 2 were 0.23 and O. 20 mmol/dm^3 with the substrate of linoleic acid. The LOX activities were stimulated greatly by Ca^2＋ but inhibited by Hg2 ~ and the antioxidants such as BHA, BHT and TBHQ. The hydroperoxide products of LOX were analysed by HPLC with the substrate of methyl linoleate, and the results showed that LOX - 1 formed mainly 9-hydroperoxides while LOX - 2 formed both 9- and 13-hydroperoxides at a ratio of 24： 76.展开更多
Beany flavor of soybean(Glycine max(L.)Merr.)is caused by oxidation of polyunsaturated fatty acids by the action of three lipoxygenases(LOX1,LOX2 and LOX3)present in mature seeds.The unpleasant flavor restricts human ...Beany flavor of soybean(Glycine max(L.)Merr.)is caused by oxidation of polyunsaturated fatty acids by the action of three lipoxygenases(LOX1,LOX2 and LOX3)present in mature seeds.The unpleasant flavor restricts human consumption of soybean products.This problem could be solved through genetic elimination of alleles that code these enzymes.Parental cultivars and two hybrid population were selected and analyzed using genetic markers for alleles locus,encoding L_(ox1),L_(ox2)and L_(ox3)free.The SSR marker Satt 212 confirmed the presence of the homozygous null-allele L_(x3)in the cultivar BRS 213,which were used for hybridization with BR 36.Heterozygote F1 hybrid plants and homozygous L_(x3)lines in F_(2)segregating populations were successfully identified.The SSR markers Sat090 and Sat417 were the most effective diagnostic markers among all SSR markers tested.Satt090 and Satt417 confirmed the presence of the homozygous L_(x2)null-allele in the parental cultivar BRS 213 by flanking L_(x2)loci at 3,00 and 2,77 cM,respectively.The presence of L_(x2)null allele in the F_(2)segregating populations between BRS 213 and BRS 155 was successfully identified with a selection efficiency of 98%and have great potential for further application in the Brazilian breeding program aimed at improving soybean seed quality.展开更多
This study was to investigate the responses of phospholipase D（PLD） and lipoxygenase（LOX） to mechanical wounding in postharvest cucumber（Cucumis sativus L.cv.Biyu-2） fruits.Membrane-associated Ca2＋ content,acti...This study was to investigate the responses of phospholipase D（PLD） and lipoxygenase（LOX） to mechanical wounding in postharvest cucumber（Cucumis sativus L.cv.Biyu-2） fruits.Membrane-associated Ca2＋ content,activities and gene expression of PLD and LOX,and contents of phosphatidylcholine（PC）,phosphatidylinositol（PI）,and phosphatidic acid（PA） were determined in cucumber fruits following mechanical wounding.Results show that PLD and LOX activities increased with the PLD and LOX mRNAs which are upregulated upon wounding,while membrane-associated Ca^2＋ content decreased.Accompanying with the increase of PLD and LOX activities,accumulation of PA and losses of PC and PI were observed in all fruits,but there were differences of degrees between wounded and control fruits.Results suggest that PLD and LOX might be the main hydrolytic enzymes of phospholipids in postharvest cucumber fruits participating in the mechanical wounding injury.The activation of PLD and LOX might be the result of gene expression,which could be This study was to investigate the responses of phospholipase D（PLD） and lipoxygenase（LOX） to mechanical wounding in postharvest cucumber（Cucumis sativus L.cv.Biyu-2） fruits.Membrane-associated Ca^2＋ content,activities and gene expression of PLD and LOX,and contents of phosphatidylcholine（PC）,phosphatidylinositol（PI）,and phosphatidic acid（PA） were determined in cucumber fruits following mechanical wounding.Results show that PLD and LOX activities increased with the PLD and LOX mRNAs which are upregulated upon wounding,while membrane-associated Ca2＋ content decreased.Accompanying with the increase of PLD and LOX activities,accumulation of PA and losses of PC and PI were observed in all fruits,but there were differences of degrees between wounded and control fruits.Results suggest that PLD and LOX might be the main hydrolytic enzymes of phospholipids in postharvest cucumber fruits participating in the mechanical wounding injury.The activation of PLD and LOX might be the result of gene expression,which could be stimulated by the Ca^2＋ flowing from the membrane to the cytoplasm upon receiving the wounding signals.展开更多
Objectives： This study aimed to evaluate the in vitro antioxidant capacity, to determine the anti-inflammatory effect due to lipoxygenase inhibition and to test the antimicrobial activity of ethanolic extracts from l...Objectives： This study aimed to evaluate the in vitro antioxidant capacity, to determine the anti-inflammatory effect due to lipoxygenase inhibition and to test the antimicrobial activity of ethanolic extracts from leaves of seven climbing species belonging to the Bignoniaceae family. These species are Adenocalyrnrna rnarginatum （Cham.） DC., Amphilophium vauthieri DC., Cuspidaria convoluta （VEIL） A. H. Gentry, Dolichandra dentata （K. Schum.） L. G. Lohmann, Fridericia caudigera （S. Moore） L. G. Lohmann, Fridericia chica （Bonpl.） L. G. Lohmann and Tanaecium selloi （Spreng.） L. G. Lohmann. Methods： The antioxidant activity was evaluated using three methods, 2,2＇-azino-bis（3-ethylbenzothiazo line-6-sulfonic acid） （ABTS）, 2,2-diphenyl-l-picrylhydrazyl （DPPH）, and ferric reducing antioxidant power. Lipoxygenase-inhibiting activity was assayed spectrophotometrically; the result was expressed as percent inhibition. The antimicrobial activity was assessed using the agar disk diffusion method. Minimal inhibitory concentration （MIC） and minimal bactericidal]fungicidal concentration were also determined for each extract against 12 pathogenic bacterial strains of Staphylococcus aureus and seven fungal strains of the Candida genus. The identification of the major compounds present in the most promising extract was established by high-performance liquid chromatography-tandem mass spectrometry. Results： C convoluta, F. caudigera, and F. chica exhibited the best antioxidant activity by scavenging DPPH and ABTS~ radicals and reducing Fe3＋ ion. These extracts showed a notable inhibition of lipnxygenase. F. caudigera was found to have the lower MIC value against S. aureus strains and six Candida species. The extracts of F. caudigera and C. convoluta were active even against methicillin-resistant S. aureus. C convoluta had higher total phenol content, better antioxidant activity and superior anti- inflammatory and antimicrobial activity. The main phenolic compounds found in this extract were coumaric and hydroxybenzoic acid derivatives and glycosylated and nonglycosylated flavones. Conclusion： Most of the extracts exhibited antioxidant activity as well as in vitro inhibition of lipoxygenase, The excellent antimicrobial activity ofT. selloi and F. chica supports their use in traditional medicine as antiseptic agents, The extracts ofF. caudigera and C. convoluta, both with notable biological activities in this study, could be used as herbal remedies for skin care. In addition, this study provides, for the first time, information about phenolic compounds present in C convoluta.展开更多
Osmotic stress caused by low-temperature,drought and salinity was a prevalent abiotic stress in plant that severely inhibited plant development and agricultural yield,particularly in tea plant.Jasmonic acid(JA)is an i...Osmotic stress caused by low-temperature,drought and salinity was a prevalent abiotic stress in plant that severely inhibited plant development and agricultural yield,particularly in tea plant.Jasmonic acid(JA)is an important phytohormone involving in plant stress.However,underlying molecular mechanisms of JA modulated osmotic stress response remains unclear.In this study,high concentration of mannitol induced JA accumulation and increase of peroxidase activity in tea plant.Integrated transcriptome mined a JA signaling master,MYC2 transcription factor is shown as a hub regulator that induced by mannitol,expression of which positively correlated with JA biosynthetic genes(LOX and AOS)and peroxidase genes(PER).CsMYC2 was determined as a nuclei-localized transcription activator,furthermore,ProteinDNA interaction analysis indicated that CsMYC2 was positive regulator that activated the transcription of CsLOX7,CsAOS2,CsPER1 and CsPER3via bound with their promoters,respectively.Suppression of CsMYC2 expression resulted in a reduced JA content and peroxidase activity and osmotic stress tolerance of tea plant.Overexpression of CsMYC2 in Arabidopsis improved JA content,peroxidase activity and plants tolerance against mannitol stress.Together,we proposed a positive feedback loop mediated by CsMYC2,CsLOX7 and CsAOS2 which constituted to increase the tolerance of osmotic stress through fine-tuning the accumulation of JA levels and increase of POD activity in tea plant.展开更多
Kiwifruit (Actinidia deliciosa (A. Chev.) C. F. Liang et A. R. Ferguson cv. Bruno) was used toinvestigate the effects of acetylsalicylic acid (ASA, 1.0 mmol/L, pH 3.5) and ethylene (100 mL/L) treat-ments on changes at...Kiwifruit (Actinidia deliciosa (A. Chev.) C. F. Liang et A. R. Ferguson cv. Bruno) was used toinvestigate the effects of acetylsalicylic acid (ASA, 1.0 mmol/L, pH 3.5) and ethylene (100 mL/L) treat-ments on changes at endogenous salicylic acid (SA) levels and other senescence-related factors duringfruit ripening and softening at 20 ℃. The level of endogenous SA in ripening fruits declined and a closerelationship was observed between the change at endogenous SA level and the rate of fruit ripening andsoftening. ASA treatment elevated SA level in the fruit, slowed down the increases in lipoxygenase (LOX)and allene oxide synthase (AOS) activities, decreased the O22-. production in the preclimacteric phase andthe early phase of ethylene climacteric rise, maintained the stability of cell membrane, inhibited ethylenebiosynthesis, postponed the onset of the ethylene climacteric, and delayed the process of fruit ripeningand softening. On the contrary, application of ethylene to ripening kiwifruit resulted at a lower SA level, anaccelerated increases in the activities of LOX and AOS and the rate of O22-. production, an elevated relativeelectric conductivity and an advanced onset of ethylene climacteric, and a quicker fruit ripening andsoftening. It is suggested that the effects of ASA on ripening kiwifruit can be attributed to its ability toscavenge O22-. and/or to maintain stability of cell membrane.展开更多
Enzymatic metabolism of the 20 C polyunsaturated fatty acid(PUFA) arachidonic acid(AA) occurs via the cyclooxygenase(COX) and lipoxygenase(LOX) pathways, and leads to the production of various bioactive lipids termed ...Enzymatic metabolism of the 20 C polyunsaturated fatty acid(PUFA) arachidonic acid(AA) occurs via the cyclooxygenase(COX) and lipoxygenase(LOX) pathways, and leads to the production of various bioactive lipids termed eicosanoids. These eicosanoids have a variety of functions, including stimulation of homeostatic responses in the cardiovascular system, induction and resolution of inflammation, and modulation of immune responses against diseases associated with chronic inflammation, such as cancer. Because chronic inflammation is essential for the development of colorectal cancer(CRC), it is not surprising that many eicosanoids are implicated in CRC. Oftentimes, these autacoids work in an antagonistic and highly temporal manner in inflammation; therefore, inhibition of the pro-inflammatory COX-2 or 5-LOX enzymes may subsequently inhibit the formation of their essential products, or shunt substrates from one pathway to another, leading to undesirable side-effects. A better understanding of these different enzymes and their products is essential not only for understanding the importance of eicosanoids, but also for designing more effective drugs that solely target the inflammatory molecules found in both chronic inflammation and cancer. In this review, we have evaluated the cancer promoting and anti-cancer roles of different eicosanoids in CRC, and highlighted the most recent literature which describes how those molecules affect not only tumor tissue, but also the tumor microenvironment. Additionally, we have attempted to delineate the roles that eicosanoids with opposing functions play in neoplastic transformation in CRC through their effects on proliferation, apoptosis, motility, metastasis, and angiogenesis.展开更多
In order to explore the response dynamics of the activities of defense related enzymes in cotton leaves towards the interactive stress of Helicoverpa armigera herbivory and omethoate application, the activities of phe...In order to explore the response dynamics of the activities of defense related enzymes in cotton leaves towards the interactive stress of Helicoverpa armigera herbivory and omethoate application, the activities of phenylalanine ammonia-lyase（PAL）, lipoxygenase（LOX）, and polyphenol oxidase（PPO） were examined from 6 to 126 h after cotton leaves were treated 12 h of H. armigera herbivory, and then sprayed with 800 mg L–1 omethoate. The results showed that the changes in the activities of PAL, LOX and PPO that occured under the interactive stress of H. armigera herbivory and omethoate application reflected the interactive effects of the two stresses on cotton defense. The similarity between the response dynamics of PAL, LOX, and PPO activities in cotton leaves under the interactive stress and that under H. armigera herbivory treatment alone showed that the induction of H. armigera herbivory on the activities of PAL, LOX and PPO in cotton leaves played a leading role in the interactive effects, and the effect of omethoate application played only a minor role. A joint factor analysis was performed according to a method which has been used to analyze the joint toxicity of pesticides; this analysis sought to clarify if there was a synergistic, antagonistic, or additive effect on PAL, LOX, and PPO activity in cotton leaves resulting from the interactive H. armigera herbivory and omethoate treatment. In the interactive effect on the response of PAL activity in cotton leaves, antagonistic effects of the omethoate application towards H. armigera herbivory were observed at 6 and 12 h. Synergistic effects were then observed at 18 and 30 h. Antagonistic effects were observed from 54 to 78 h and synergistic effects were finally observed at 126 h. The correlation between H. armigera herbivory and omethoate application in the interactive effect on cotton defense responses of LOX activity also fluctuated from synergism to antagonism during the time course. In the interactive effect on PPO activity, only antagonism was observed between H. armigera herbivory and omethoate application. In the interactive stress of H. armigera herbivory and omethoate application on cotton defense responses, omethoate affected the defense responses of cotton to H. armigera herbivory by producing antagonistic and synergistic effects. These results will be useful to understand the relationship between host plant and herbivorous pest.展开更多
Objective:To evaluate the anti-oxidani and anti-inflammatory activity of leaf extracts and fractions of Mangifera indica in in vitro conditions.Methods:In vitro DPPH radical scavenging activity and lipoxygenase（LOX）...Objective:To evaluate the anti-oxidani and anti-inflammatory activity of leaf extracts and fractions of Mangifera indica in in vitro conditions.Methods:In vitro DPPH radical scavenging activity and lipoxygenase（LOX） inhibition assays were used to evaluate the anti-oxidant and anti-inflammatory activities respectively.Methanolic extract（MEMI）,successive water extract （SWMI） and ethyl acetate fraction（EMEMI）,n-butanol fraction（BMEMI） and water soluble fraction （WMEMI） of methanolic extract were evaluated along with respective reference standards. Results:In in ritro DPPH radical scavenging activity,the MEMI,EMEMI and BMEMI have offered significant antioxidant activity with IC<sub>50</sub> values of 13.37.3.55 and 14.19μig/mL respectively.Gallic acid,a reference standard showed significant antioxidant activity with IC? value of 1.88 and found to be more potent compared to all the extracts and fractions.In m vitro LOX inhibition assay,the MEMI,EMEMI and BMEMI have showed significant inhibition of LOX enzyme activity with IC<sub>50</sub> values of 96.71.63.21 and 107.44μg/mL respectively.While,reference drug Indometlhacin also offered significant inhibtion against LOX enzyme activity with IC<sub>50</sub> of 57.75.Furthermore,MEMI was found to more potent than SWMI and among the fractions EMEMI was found to possess more potent antioxidant and anti-inflammatory activity.Conclusions:These findings suggest that the MEMI and F.MEMT possess potent anti-oxidani and anti-inflammatory activities in in vitro conditions.展开更多
Lipoxygenase 3 (LOX3) is a major component of the LOX isozymes in mature rice seeds. To investigate the role of LOX3 gene under stresses, a plant expression vector containing antisense cDNA of LOX3 was constructed. Ri...Lipoxygenase 3 (LOX3) is a major component of the LOX isozymes in mature rice seeds. To investigate the role of LOX3 gene under stresses, a plant expression vector containing antisense cDNA of LOX3 was constructed. Rice varieties Wuyunjing 7 and Kasalath were transformed by the Agrobacterium-mediated method and transgenic rice plants were generated. PCR and Southern blot results showed that the antisense LOX3 gene was integrated into the rice genome. Analyses of embryo LOX3 deletion and semi-quantitative RT-PCR confirmed the antisense suppression of LOX3 gene in transgenic plants. The T2 antisense plants of LOX3 were sensitive to drought stress, rice blast and bacterial blight compared with non-transgenic plants. These results suggest that the LOX3 gene might function in response to stresses.展开更多
Lipid oxidation in salt-dried yellow croaker(Pseudosciaena polyactis) was evaluated during processing with commonly used analytical indices, such as the peroxide value(POV), the thiobarbituric acid reactive substances...Lipid oxidation in salt-dried yellow croaker(Pseudosciaena polyactis) was evaluated during processing with commonly used analytical indices, such as the peroxide value(POV), the thiobarbituric acid reactive substances(TBARS) value, and oxidative-relative lipoxygenase(LOX) activity. Additionally, fatty acids were analyzed using gas chromatography-mass spectrometry. Both POV and TBARS increased significantly(P < 0.05) at the rinsing stage. POV reached its peak value of 3.63 meq O_2 per kg sample at the drying stage, whereas TBARS constantly increased from 0.05 to 0.20 mg MDA per kg sample. Processing of salt-dried yellow croaker had an extremely significant(P < 0.01) effect on LOX activity. Twenty-six fatty acids were identified. Combined eicosapentaenoic acid(EPA; C20:5n3) and docosahexaenoic acid(DHA; C22:6n3) content varied between(19.20 ±0.37) mg g^(-1) and(23.45 ± 1.05) mg g^(-1). The polyunsaturated fatty acid/saturated fatty acid(PUFA/SFA) ratio in yellow croaker was 0.73–1.10, and the n-6/n-3 PUFA ratio was approximately 0.13–0.20. The contents of most fatty acids varied significantly(P <0.05) during the different processing stages, and these differences were caused by lipid oxidation. C18:0, C16:1n7, C19:0, and C22:6n3 showed clear changes in principle component one of a principle components analysis. These fatty acids are potential markers for evaluating lipid oxidation in fish muscle because there was a significant correlation between these markers and TBARS and LOX activity(P < 0.05) with Pearson's coefficients > 0.931.展开更多
基金Supported by Baise Science Research and Technology Development Plan Project(20232022)Cuangxi College Students’Innovation and Entrepreneurship Training Program(Recommend National Level2022210599040S).
文摘[Objectives]To explore the effects of chlorogenic acid from honeysuckle on the secretion enzymes,lipoxygenase A4(LXA4),and blood biochemical indicators in mice with aluminum induced Alzheimer's disease(AD).[Methods]Chlorogenic acid was extracted from hon-eysuckle by ultrasound assisted alcohol extraction method.Seventy mice were randomly divided into normal group,model group,and low,me-dium and high dose groups of honeysuckle chlorogenic acid.All the mice in each group except for the normal group were given maltol aluminum by intraperitoneal injection to establish models of aluminum induced AD,continuously injected for 5 d and stopped for 2 d,totally poisoned for 8 weeks.Starting from the 5^(th) week of poisoning,the low,medium and high dose groups of honeysuckle chlorogenic acid were given honeysuck-le chlorogenc acid solution 40,80 and 160 mg/kg by gavage,respectively,while the normal group and the model group were fed with an equal volume of distilled water,all once daily,continuously gavaged until the end of the 8^(th) week.At the end of the experiment,the learning memory ability of the mice was tested by Y-type waler maze,and the number of tests required to reach the learning standard,the number of memory er-rors in 20 tests and the error rate of the mice were recorded.The brains of mice were taken to determine the contents of β-secretase,α-secre-tase,γ-secretase,LXA4 and acetylcholinesterase(AchE)in the homogenates of brain tissues by ELISA,and their blood was taken to deter-mine the biochemical indexes.[Results]Compared with the normal group,the number of learning tests,number of memory errors,error rate and the contents of β-secretase,γ-secretase and AchE in brain tissue of the mice in the model group were all significantly increased(all P<0.05),the contents of LXA4 in brain tissue were significantly decreased(all P<0.05),and the contents of α-secretase did not change significantly(all P>0.05);compared with the model group,the number of learning tests,the number of memory errors,the error rate and the content of β-secretase,γ-secretase and AchE in brain tissue were all significantly reduced(all P<0.05),the content of LXA4 in brain tissue of the high dose group of honeysuckle chlorogenic acid was significantly increased(P<0.05),and there was no significant change in the content of α-secretase in brain tissue of all groups of honeysuckle chlorogenic acid(all P>0.05).Compared with the normal group,the levels of blood glucose,TC,TG,ALT,BUN,Cr and UA in the model group and the levels of TC,TG and BUN in the low-and medium-dose groups of honeysuckle chlorogenic acid were significantly increased(all P<0.05),and the level of HDL-C in the model group and the levels of UA in the medium-and high-dose groups of honeysuckle chlorogenic acid were significantly decreased(all P<0.05);compared with the model group,the levels of blood glucose,ALT,BUN,UA in each group of honeysuckle chlorogenic acid,the levels of TC and Cr in medium and high dose groups of honeysuckle chlorogenic acid,and the level of TG in the high dose group of honeysuckle chlorogenic acid were all signifi-cantly lower(all P<0.05),while the level of HDL-C in the medium and high dose groups of honeysuckle chlorogenic acid and the level of to-tal protein in the high dose group of honeysuckle chlorogenic acid were all significantly higher(all P<0.05).[Conclusions]Chlorogenic acid from honeysuckle may improve AD induced by aluminum exposure via regulating related secretory enzymes,LXA4,and various biochemi-cal indicators.
基金supported by the Pro-gramme for Changjiang Scholars and the Innovative Research Team in Universities of China (PCSIRT0607)by the National Natural Science Foundation of China (30871727+2 种基金 30872037)the National Key Project of Scientific and Technical Supporting Programmes Funded by the Ministry of Science & Technology of China (2006BAD01A15 2006BAD24B04)
文摘A study was conducted to explore the defense response in woody plants after insect herbivory. The activities of two enzymes, lipoxygenase （LOX）, a key enzyme ofjasmonate （JA） pathway, and phenylalanine ammonia lyase （PAL）, a rate-limiting enzyme of phenyl- propanoid pathway, were measured in the leaves of one-year-old poplar （Populus simonii × P. pyramidalis ＇Opera 8277＇） cuttings after Clostera anachoreta larvae attack. The results show that the increased activities of LOX and PAL were found not only in the leaves wounded by C. anachoreta larvae but also in their tipper systemic leaves, indicating that JA and phenylpropanoid pathways were activated, and the defense response was stimulated systemically. The increase in LOX and PAL activities in neighboring intact poplar cuttings sug- gested that there exists the interplant communication between poplar plants mediated by the herbivore-induced volatiles. Methyl jasmonate （MeJA） was also proved to be an airborne signal to induce defense response in P simonii × P pyramidalis ＇Opera 8277＇ cuttings.
基金grants from the National Basic Research Program of China (Grant No. 2004CB2117204)the National High-tech Research and Development Program of China (Grant No. 2006AA100101)+1 种基金the National Program of Science Technology and Tackle Key Problem of Chinathe Program for Changjiang Scholars and Innovative Research Team in University (PCSIRT) of China
文摘Lipoxygenase （LOX, EC1.13.11.12） is a key enzyme during the degradation of lipids in animals and even plants, and also the first key enzyme responsible for the biosynthesis of jasmonate. To purify and characterize the OsLOX1 gene from rice seeds, the entire coding region of the OsLOX1 gene was inserted into an expression vector pET30a（＋） and transformed into Escherichia coil BL21 （DE3）. Expression of the fusion protein was successfully induced by isopropyl-β-D- thiogalactopyranoside （IPTG） and the purified recombinant protein was obtained by His.Bind Kits. Further assay showed that the purified recombinant protein exhibited the LOX activity. The optimum pH was 4.8 （acetate buffer） and the optimum temperature was 30℃ for the above enzyme. Thus, the recombinant might confer an available usage for the synthesis of jasmonate in vitro, and also provides a possibility for elucidating the inter-relationship between the primary structure of the plant seed lipoxygenase protein and its physiological functions.
文摘Background: Increased mitogen-activated protein kinase (MAPK) phosphorylation has been detected in peripheral nerve of human subjects and animal models with diabetes as well as high-glucose exposed human Schwann cells, and have been implicated in diabetic peripheral neuropathy. In our recent studies, leukocytetype 12/15-lipoxygenase inhibition or gene deficiency alleviated large and small nerve fiber dysfunction, but not intraepidermal nerve fiber loss in streptozotocin-diabetic mice. Methods: To address a mechanism we evaluated the potential for pharmacological 12/15-lipoxygenase inhibition to counteract excessive MAPK phosphorylation in mouse and cell culture models of diabetic neuropathy. C57Bl6/J mice were made diabetic with streptozotocin and maintained with or without the 12/15-lipoxygenase inhibitor cinnamyl-3,4-dihydroxy-α-cyanocinnamate (CDC). Human Schwann cells were cultured in5.5 mMor30 mMglucose with or without CDC. Results: 12(S) HETE concentrations (ELISA), as well as 12/15-lipoxygenase expression and p38 MAPK, ERK, and SAPK/JNK phosphorylation (all by Western blot analysis) were increased in the peripheral nerve and spinal cord of diabetic mice as well as in high glucose-exposed human Schwann cells. CDC counteracted diabetes-induced increase in 12(S)HETE concentrations (a measure of 12/15-lipoxygenase activity), but not 12/15-lipoxygenase overexpression, in sciatic nerve and spinal cord. The inhibitor blunted excessive p38 MAPK and ERK, but not SAPK/ JNK, phosphorylation in sciatic nerve and high glucose exposed human Schwann cells, but did not affect MAPK, ERK, and SAPK/JNK phosphorylation in spinal cord. Conclusion: 12/15-lipoxygenase inhibition counteracts diabetes related MAPK phosphorylation in mouse and cell culture models of diabetic neuropathy and implies that 12/15-lipoxygenase inhibitors may be an effective treatment for diabetic peripheral neuropathy.
文摘The flavor of the soymilk and soyflour obtained from the lipoxygenase mutant isolines was concentrated by simultaneous distillation and extraction (SDE), and its constituents were identified by gas chro-matography (GC) and gas chromatography-mass spectrometry. Results showed that the same 24 flavor constituents were isolated in both soymilk and soyflour, and most of them were aldehydes and alcohols. Lox2 was most responsible for the production of the volatile and beany-flavor components, and Lox1 less responsible. Lox3 was least responsible and can reduce the yield of hexanal. Either Lx1 or Lx2 could significantly reduce the volatile and beany-flavor, and Lx3 could significantly increase the yield of hexanal. Primary and secondary interactions existed among the null mutant genes, and the major effects and interactions could be affected by processing conditions. The isoline with triple lipoxygenase null genes yielded the least volatile and beany-flavor components, and the isoline without the lipoxygenase gene Lx3 produced the greatest amount of the volatile and beany-flavor components. The amounts of volatile and beany-flavor components produced by the other isolines were between that of the isoline with triple lipoxygenase null genes and the isoline without lipoxygenase gene Lx3. According to the correlation analysis, the hexanal amount could be used as an index in evaluating the importance of lipoxygenase isozymes in the yield of beany-flavor compounds, and the effects of the different types of lipoxygenase null mutants in controlling beany-flavor compounds. The cultivars with triple lipoxygenase null genes will be a quality raw material for soy food processing.
基金Supported by National Project of Scientific and Technical Supporting Programs Funded by Ministry of Science and Technology of China (No.2006BAD22B01)National Natural Science Foundation of China (No.30800767)Postdoctoral Fund of China (No.20080430725)
文摘Fruit ripening is a complex process and is regulated by many factors. Ethylene and polygalacturonase （PG）, lipoxygenase （LOX）, expansin （EXP） are all critical regulating factors in fruit ripening and softening process. With antisense ACS tomato, Nr mutant tomato and cultivated tomato as materials, Northern blot hybridization showed that PG, LeEXP1 and LOXexpressed differently in different parts of cultivated tomato fruit during ripening, which was related to fruit ripening. The ripening process of columella and radial pericarp was faster than pericarp. In both Nr mutant and antisense ACS transgenic tomato fruit, expression levels ofPG, LeEXPI and LOXwere generally lower than those in cultivated fruit but still related to fruit ripening. The expression levels ofPG, LeEXP1 and LOX increased in the mature green tomato fruits after 0.5 h treatment with ethylene （100 μL/L）. These results indicate that gene expression ofPG, LeEXP1 and LOXwere positively regulated by ethylene. The time and cumulative effect of the concentration exists in the expression of PG regulated by ethylene. The regulation of LOX expression mainly depended on the fruit development after great amount of ethylene was produced. PG played a major role in ripening and softening of tomato fruit, and cooperated with the regulation of EXP and LOX.
基金supported by the Science and Technology Innovation Fund of Fujian Agriculture and Forestry University(KHF200005)。
文摘Lipoxygenase(LOXs)is a kind of dioxygenase without heme and iron,which plays an important role in the development and adaptation of many plants to the environment.However,the study of strawberry LOX gene family has not been reported.In this study,14 LOX genes were identified from the diploid woodland strawberry genome.The phylogenetic tree divides the FvLOX gene into two subfamilies:9-LOX and 13-LOX.Gene duplication event analysis showed that whole-genome duplication(WGD)/segmental duplication and dispersed duplication effectively promoted the expansion of strawberry LOX family.QRT-PCR analysis showed that FvLOX genes were expressed in different tissues.Expression profile analysis showed that FvLOX1 and FvLOX8 were up-regulated under low temperature stress,FvLOX3 and FvLOX7 were up-regulated under drought stress,FvLOX6 and FvLOX9 were up-regulated under salt stress,FvLOX2,FvLOX3 and FvLOX6 were up-regulated under salicylic acid(SA)treatment,FvLOX3,FvLOX11 and FvLOX14 were up-regulated under methyl jasmonate(MeJA)treatment,FvLOX4 and FvLOX14 were up-regulated under abscisic acid(ABA)treatment.Promoter analysis showed that FvLOX genes were involved in plant growth and development and stress response.We analyzed and identified the whole genome of strawberry FvLOX family and characterized a variety of FvLOX candidate genes involved in abiotic stress response.This study laid a theoretical and empirical foundation for the response mechanism of strawberry to abiotic stress.
基金The Technology Research and Development Program ("863"Program) of China under contract No.2003AA625030.
文摘The purification and characterization of lipoxygenase （LOX, EC 1.13.11.12） from the green algae Enteromorpha clathrata were studied. Two components marked LOX - 1 and LOX - 2 were purified and their molecular masses were estimated to be 102 and 79 ku by SDS - PAGE. Both LOX - 1 and LOX - 2 were stable over the pH wide range 6.0 - 10.0 and had the optimum pH of 10.0 and 8.6, at optimum temperature of 30 and 25℃, respectively. Substrate specificities of LOX - 1 and LOX - 2 were the greatest towards linoleic acid, followed by arachidonic acid and linolenic acid. The Michaelis constant values of LOX - 1 and LOX - 2 were 0.23 and O. 20 mmol/dm^3 with the substrate of linoleic acid. The LOX activities were stimulated greatly by Ca^2＋ but inhibited by Hg2 ~ and the antioxidants such as BHA, BHT and TBHQ. The hydroperoxide products of LOX were analysed by HPLC with the substrate of methyl linoleate, and the results showed that LOX - 1 formed mainly 9-hydroperoxides while LOX - 2 formed both 9- and 13-hydroperoxides at a ratio of 24： 76.
文摘Beany flavor of soybean(Glycine max(L.)Merr.)is caused by oxidation of polyunsaturated fatty acids by the action of three lipoxygenases(LOX1,LOX2 and LOX3)present in mature seeds.The unpleasant flavor restricts human consumption of soybean products.This problem could be solved through genetic elimination of alleles that code these enzymes.Parental cultivars and two hybrid population were selected and analyzed using genetic markers for alleles locus,encoding L_(ox1),L_(ox2)and L_(ox3)free.The SSR marker Satt 212 confirmed the presence of the homozygous null-allele L_(x3)in the cultivar BRS 213,which were used for hybridization with BR 36.Heterozygote F1 hybrid plants and homozygous L_(x3)lines in F_(2)segregating populations were successfully identified.The SSR markers Sat090 and Sat417 were the most effective diagnostic markers among all SSR markers tested.Satt090 and Satt417 confirmed the presence of the homozygous L_(x2)null-allele in the parental cultivar BRS 213 by flanking L_(x2)loci at 3,00 and 2,77 cM,respectively.The presence of L_(x2)null allele in the F_(2)segregating populations between BRS 213 and BRS 155 was successfully identified with a selection efficiency of 98%and have great potential for further application in the Brazilian breeding program aimed at improving soybean seed quality.
基金Project (No.30771513) supported by the National Natural Science Foundation of China
文摘This study was to investigate the responses of phospholipase D（PLD） and lipoxygenase（LOX） to mechanical wounding in postharvest cucumber（Cucumis sativus L.cv.Biyu-2） fruits.Membrane-associated Ca2＋ content,activities and gene expression of PLD and LOX,and contents of phosphatidylcholine（PC）,phosphatidylinositol（PI）,and phosphatidic acid（PA） were determined in cucumber fruits following mechanical wounding.Results show that PLD and LOX activities increased with the PLD and LOX mRNAs which are upregulated upon wounding,while membrane-associated Ca^2＋ content decreased.Accompanying with the increase of PLD and LOX activities,accumulation of PA and losses of PC and PI were observed in all fruits,but there were differences of degrees between wounded and control fruits.Results suggest that PLD and LOX might be the main hydrolytic enzymes of phospholipids in postharvest cucumber fruits participating in the mechanical wounding injury.The activation of PLD and LOX might be the result of gene expression,which could be This study was to investigate the responses of phospholipase D（PLD） and lipoxygenase（LOX） to mechanical wounding in postharvest cucumber（Cucumis sativus L.cv.Biyu-2） fruits.Membrane-associated Ca^2＋ content,activities and gene expression of PLD and LOX,and contents of phosphatidylcholine（PC）,phosphatidylinositol（PI）,and phosphatidic acid（PA） were determined in cucumber fruits following mechanical wounding.Results show that PLD and LOX activities increased with the PLD and LOX mRNAs which are upregulated upon wounding,while membrane-associated Ca2＋ content decreased.Accompanying with the increase of PLD and LOX activities,accumulation of PA and losses of PC and PI were observed in all fruits,but there were differences of degrees between wounded and control fruits.Results suggest that PLD and LOX might be the main hydrolytic enzymes of phospholipids in postharvest cucumber fruits participating in the mechanical wounding injury.The activation of PLD and LOX might be the result of gene expression,which could be stimulated by the Ca^2＋ flowing from the membrane to the cytoplasm upon receiving the wounding signals.
基金the financial support from Secretaría de Ciencia y Técnica UNCAUSConsejo Nacional de Investigaciones Científicas y Técnicas(CONICET),Argentina and Hospital 4 de Junio from Presidencia Roque Sáenz Pena,Chaco,Argentina
文摘Objectives： This study aimed to evaluate the in vitro antioxidant capacity, to determine the anti-inflammatory effect due to lipoxygenase inhibition and to test the antimicrobial activity of ethanolic extracts from leaves of seven climbing species belonging to the Bignoniaceae family. These species are Adenocalyrnrna rnarginatum （Cham.） DC., Amphilophium vauthieri DC., Cuspidaria convoluta （VEIL） A. H. Gentry, Dolichandra dentata （K. Schum.） L. G. Lohmann, Fridericia caudigera （S. Moore） L. G. Lohmann, Fridericia chica （Bonpl.） L. G. Lohmann and Tanaecium selloi （Spreng.） L. G. Lohmann. Methods： The antioxidant activity was evaluated using three methods, 2,2＇-azino-bis（3-ethylbenzothiazo line-6-sulfonic acid） （ABTS）, 2,2-diphenyl-l-picrylhydrazyl （DPPH）, and ferric reducing antioxidant power. Lipoxygenase-inhibiting activity was assayed spectrophotometrically; the result was expressed as percent inhibition. The antimicrobial activity was assessed using the agar disk diffusion method. Minimal inhibitory concentration （MIC） and minimal bactericidal]fungicidal concentration were also determined for each extract against 12 pathogenic bacterial strains of Staphylococcus aureus and seven fungal strains of the Candida genus. The identification of the major compounds present in the most promising extract was established by high-performance liquid chromatography-tandem mass spectrometry. Results： C convoluta, F. caudigera, and F. chica exhibited the best antioxidant activity by scavenging DPPH and ABTS~ radicals and reducing Fe3＋ ion. These extracts showed a notable inhibition of lipnxygenase. F. caudigera was found to have the lower MIC value against S. aureus strains and six Candida species. The extracts of F. caudigera and C. convoluta were active even against methicillin-resistant S. aureus. C convoluta had higher total phenol content, better antioxidant activity and superior anti- inflammatory and antimicrobial activity. The main phenolic compounds found in this extract were coumaric and hydroxybenzoic acid derivatives and glycosylated and nonglycosylated flavones. Conclusion： Most of the extracts exhibited antioxidant activity as well as in vitro inhibition of lipoxygenase, The excellent antimicrobial activity ofT. selloi and F. chica supports their use in traditional medicine as antiseptic agents, The extracts ofF. caudigera and C. convoluta, both with notable biological activities in this study, could be used as herbal remedies for skin care. In addition, this study provides, for the first time, information about phenolic compounds present in C convoluta.
基金supported by the National Natural Science Foundation of China(Grant Nos.32202542 and U20A2045)the Project of Major Science and Technology in Anhui Province(Grant No.202003a06020021)+2 种基金the Project of Science and Technology of Yunnan Province(Grant No.202102AE090038)Anhui Provincial Natural Science Foundation(Grant No.2108085QC121)the Natural Science Projects for Colleges and Universities in the Anhui Province(Grant No.KJ2021A0145)。
文摘Osmotic stress caused by low-temperature,drought and salinity was a prevalent abiotic stress in plant that severely inhibited plant development and agricultural yield,particularly in tea plant.Jasmonic acid(JA)is an important phytohormone involving in plant stress.However,underlying molecular mechanisms of JA modulated osmotic stress response remains unclear.In this study,high concentration of mannitol induced JA accumulation and increase of peroxidase activity in tea plant.Integrated transcriptome mined a JA signaling master,MYC2 transcription factor is shown as a hub regulator that induced by mannitol,expression of which positively correlated with JA biosynthetic genes(LOX and AOS)and peroxidase genes(PER).CsMYC2 was determined as a nuclei-localized transcription activator,furthermore,ProteinDNA interaction analysis indicated that CsMYC2 was positive regulator that activated the transcription of CsLOX7,CsAOS2,CsPER1 and CsPER3via bound with their promoters,respectively.Suppression of CsMYC2 expression resulted in a reduced JA content and peroxidase activity and osmotic stress tolerance of tea plant.Overexpression of CsMYC2 in Arabidopsis improved JA content,peroxidase activity and plants tolerance against mannitol stress.Together,we proposed a positive feedback loop mediated by CsMYC2,CsLOX7 and CsAOS2 which constituted to increase the tolerance of osmotic stress through fine-tuning the accumulation of JA levels and increase of POD activity in tea plant.
文摘Kiwifruit (Actinidia deliciosa (A. Chev.) C. F. Liang et A. R. Ferguson cv. Bruno) was used toinvestigate the effects of acetylsalicylic acid (ASA, 1.0 mmol/L, pH 3.5) and ethylene (100 mL/L) treat-ments on changes at endogenous salicylic acid (SA) levels and other senescence-related factors duringfruit ripening and softening at 20 ℃. The level of endogenous SA in ripening fruits declined and a closerelationship was observed between the change at endogenous SA level and the rate of fruit ripening andsoftening. ASA treatment elevated SA level in the fruit, slowed down the increases in lipoxygenase (LOX)and allene oxide synthase (AOS) activities, decreased the O22-. production in the preclimacteric phase andthe early phase of ethylene climacteric rise, maintained the stability of cell membrane, inhibited ethylenebiosynthesis, postponed the onset of the ethylene climacteric, and delayed the process of fruit ripeningand softening. On the contrary, application of ethylene to ripening kiwifruit resulted at a lower SA level, anaccelerated increases in the activities of LOX and AOS and the rate of O22-. production, an elevated relativeelectric conductivity and an advanced onset of ethylene climacteric, and a quicker fruit ripening andsoftening. It is suggested that the effects of ASA on ripening kiwifruit can be attributed to its ability toscavenge O22-. and/or to maintain stability of cell membrane.
基金Supported by The TüBITAK project,No.113S935(to Banerjee S)
文摘Enzymatic metabolism of the 20 C polyunsaturated fatty acid(PUFA) arachidonic acid(AA) occurs via the cyclooxygenase(COX) and lipoxygenase(LOX) pathways, and leads to the production of various bioactive lipids termed eicosanoids. These eicosanoids have a variety of functions, including stimulation of homeostatic responses in the cardiovascular system, induction and resolution of inflammation, and modulation of immune responses against diseases associated with chronic inflammation, such as cancer. Because chronic inflammation is essential for the development of colorectal cancer(CRC), it is not surprising that many eicosanoids are implicated in CRC. Oftentimes, these autacoids work in an antagonistic and highly temporal manner in inflammation; therefore, inhibition of the pro-inflammatory COX-2 or 5-LOX enzymes may subsequently inhibit the formation of their essential products, or shunt substrates from one pathway to another, leading to undesirable side-effects. A better understanding of these different enzymes and their products is essential not only for understanding the importance of eicosanoids, but also for designing more effective drugs that solely target the inflammatory molecules found in both chronic inflammation and cancer. In this review, we have evaluated the cancer promoting and anti-cancer roles of different eicosanoids in CRC, and highlighted the most recent literature which describes how those molecules affect not only tumor tissue, but also the tumor microenvironment. Additionally, we have attempted to delineate the roles that eicosanoids with opposing functions play in neoplastic transformation in CRC through their effects on proliferation, apoptosis, motility, metastasis, and angiogenesis.
基金supported by the Application Techniques of Pesticides Efficiently and Safely Program of the Ministry of Agricultural, China (200903033-02)the Prevention and Control Technology Research for Major Fruit and Vegetable Pests and Diseases and Integration Demonstration Program of the Key Technologies R&D Program of China during the 12th Five-Year Plan period (2012BAD19B06)
文摘In order to explore the response dynamics of the activities of defense related enzymes in cotton leaves towards the interactive stress of Helicoverpa armigera herbivory and omethoate application, the activities of phenylalanine ammonia-lyase（PAL）, lipoxygenase（LOX）, and polyphenol oxidase（PPO） were examined from 6 to 126 h after cotton leaves were treated 12 h of H. armigera herbivory, and then sprayed with 800 mg L–1 omethoate. The results showed that the changes in the activities of PAL, LOX and PPO that occured under the interactive stress of H. armigera herbivory and omethoate application reflected the interactive effects of the two stresses on cotton defense. The similarity between the response dynamics of PAL, LOX, and PPO activities in cotton leaves under the interactive stress and that under H. armigera herbivory treatment alone showed that the induction of H. armigera herbivory on the activities of PAL, LOX and PPO in cotton leaves played a leading role in the interactive effects, and the effect of omethoate application played only a minor role. A joint factor analysis was performed according to a method which has been used to analyze the joint toxicity of pesticides; this analysis sought to clarify if there was a synergistic, antagonistic, or additive effect on PAL, LOX, and PPO activity in cotton leaves resulting from the interactive H. armigera herbivory and omethoate treatment. In the interactive effect on the response of PAL activity in cotton leaves, antagonistic effects of the omethoate application towards H. armigera herbivory were observed at 6 and 12 h. Synergistic effects were then observed at 18 and 30 h. Antagonistic effects were observed from 54 to 78 h and synergistic effects were finally observed at 126 h. The correlation between H. armigera herbivory and omethoate application in the interactive effect on cotton defense responses of LOX activity also fluctuated from synergism to antagonism during the time course. In the interactive effect on PPO activity, only antagonism was observed between H. armigera herbivory and omethoate application. In the interactive stress of H. armigera herbivory and omethoate application on cotton defense responses, omethoate affected the defense responses of cotton to H. armigera herbivory by producing antagonistic and synergistic effects. These results will be useful to understand the relationship between host plant and herbivorous pest.
文摘Objective:To evaluate the anti-oxidani and anti-inflammatory activity of leaf extracts and fractions of Mangifera indica in in vitro conditions.Methods:In vitro DPPH radical scavenging activity and lipoxygenase（LOX） inhibition assays were used to evaluate the anti-oxidant and anti-inflammatory activities respectively.Methanolic extract（MEMI）,successive water extract （SWMI） and ethyl acetate fraction（EMEMI）,n-butanol fraction（BMEMI） and water soluble fraction （WMEMI） of methanolic extract were evaluated along with respective reference standards. Results:In in ritro DPPH radical scavenging activity,the MEMI,EMEMI and BMEMI have offered significant antioxidant activity with IC<sub>50</sub> values of 13.37.3.55 and 14.19μig/mL respectively.Gallic acid,a reference standard showed significant antioxidant activity with IC? value of 1.88 and found to be more potent compared to all the extracts and fractions.In m vitro LOX inhibition assay,the MEMI,EMEMI and BMEMI have showed significant inhibition of LOX enzyme activity with IC<sub>50</sub> values of 96.71.63.21 and 107.44μg/mL respectively.While,reference drug Indometlhacin also offered significant inhibtion against LOX enzyme activity with IC<sub>50</sub> of 57.75.Furthermore,MEMI was found to more potent than SWMI and among the fractions EMEMI was found to possess more potent antioxidant and anti-inflammatory activity.Conclusions:These findings suggest that the MEMI and F.MEMT possess potent anti-oxidani and anti-inflammatory activities in in vitro conditions.
基金supported by the grants from the National Basic Research Program of China (Grant No. 2004CB117204 and No. 2006CB100200).
文摘Lipoxygenase 3 (LOX3) is a major component of the LOX isozymes in mature rice seeds. To investigate the role of LOX3 gene under stresses, a plant expression vector containing antisense cDNA of LOX3 was constructed. Rice varieties Wuyunjing 7 and Kasalath were transformed by the Agrobacterium-mediated method and transgenic rice plants were generated. PCR and Southern blot results showed that the antisense LOX3 gene was integrated into the rice genome. Analyses of embryo LOX3 deletion and semi-quantitative RT-PCR confirmed the antisense suppression of LOX3 gene in transgenic plants. The T2 antisense plants of LOX3 were sensitive to drought stress, rice blast and bacterial blight compared with non-transgenic plants. These results suggest that the LOX3 gene might function in response to stresses.
基金the National Natural Science Foundation of China (Nos. 31371800 and 31571869)Earmarked Fund for Modern Agro-Industry Technology Research System (No. CARS-49-G27)Special Promotion of Guangdong Marine Fishery Science and Technology (Nos. A201301C01 and A201503)
文摘Lipid oxidation in salt-dried yellow croaker(Pseudosciaena polyactis) was evaluated during processing with commonly used analytical indices, such as the peroxide value(POV), the thiobarbituric acid reactive substances(TBARS) value, and oxidative-relative lipoxygenase(LOX) activity. Additionally, fatty acids were analyzed using gas chromatography-mass spectrometry. Both POV and TBARS increased significantly(P < 0.05) at the rinsing stage. POV reached its peak value of 3.63 meq O_2 per kg sample at the drying stage, whereas TBARS constantly increased from 0.05 to 0.20 mg MDA per kg sample. Processing of salt-dried yellow croaker had an extremely significant(P < 0.01) effect on LOX activity. Twenty-six fatty acids were identified. Combined eicosapentaenoic acid(EPA; C20:5n3) and docosahexaenoic acid(DHA; C22:6n3) content varied between(19.20 ±0.37) mg g^(-1) and(23.45 ± 1.05) mg g^(-1). The polyunsaturated fatty acid/saturated fatty acid(PUFA/SFA) ratio in yellow croaker was 0.73–1.10, and the n-6/n-3 PUFA ratio was approximately 0.13–0.20. The contents of most fatty acids varied significantly(P <0.05) during the different processing stages, and these differences were caused by lipid oxidation. C18:0, C16:1n7, C19:0, and C22:6n3 showed clear changes in principle component one of a principle components analysis. These fatty acids are potential markers for evaluating lipid oxidation in fish muscle because there was a significant correlation between these markers and TBARS and LOX activity(P < 0.05) with Pearson's coefficients > 0.931.
