The effects of water─soluble components isolated from Salvia miltiorrhiza on oxygen free radical prodction and lipid peroxidation were estimated. Five components(10 μmol/L)were shown to inhibit superoxide anion gen...The effects of water─soluble components isolated from Salvia miltiorrhiza on oxygen free radical prodction and lipid peroxidation were estimated. Five components(10 μmol/L)were shown to inhibit superoxide anion generation by xanthine─xanthine oxidase system. It was also demonstrated that six components( 100 μmol/L) prevented H_2O_2─induced hemolysis and MDA fonnation in mouse erythrocytes.The effects of Sal A, Sal B, Sal C and Ros A were dose dependent. In Langendorff rat heart, pretreatment with Sal A 20μmol/L significantly prevented MDA production induced by 30 min reoxygenation after 45 min anoxia.The results indicated that there were also other potent antioxidant componentts in Salvia milliorrhiza besides Dphl and Pal. The protection of Sal A against myocardial anoxiareoxygenation inury may be mainly ascribed to its oxygen free radical scavenging activity.展开更多
[Objective] Effects of different concentrations of nitric oxide on membrane lipid peroxidation of wheat induced by enhanced UV-B radiation were researched,sodium nitroprusside (SNP) was selected as an exogenous nitr...[Objective] Effects of different concentrations of nitric oxide on membrane lipid peroxidation of wheat induced by enhanced UV-B radiation were researched,sodium nitroprusside (SNP) was selected as an exogenous nitric oxide(NO)donor.[Method] There are 3 groups including CK,UV treatment group (B),B+SNP treatment group,0,1,2,3,4 d sampling after treatment respectively,and physiological and biochemical indexes of MDA content and CAT,POD,SOD and so on were determined,repeated 3 times,and statistical analyzed.[Result] The results showed that,after the enhanced UV-B radiation,activity of the catalase (CAT),superoxide dismutase (SOD) and of the guaiacol peroxidase (POD) all reduced apparently,and the concentration of malondialdehyde (MDA) increased obviously,leading to oxidative damage in wheat seedlings.Impose different concentrations of SNP after UV-B radiation,may mitigate oxidative damage of wheat seedling from different degrees,which was in agreement with the effect of making the concentration of MDA decrease and the activity of the CAT,SOD and POD all increased.The mitigation role of 0.01 mol/L SNP was more obvious for roots' oxidative damage,while 0.1 mmol/L SNP is more effective for oxidative damage of leaves.[Conclusion] Exogenous NO donor SNP had obvious relieve effects on oxidative damage of wheat seedlings caused by UV-B radiation,which can enhance adaptive capacity of plants to adversity stress.展开更多
The main purpose of this study was to investigate the protective actions of captopril and cicaprost on changes of membrane fluidity of cultured neonatal rat myocardial cells exposed to anoxia and sugar deprivation.Lip...The main purpose of this study was to investigate the protective actions of captopril and cicaprost on changes of membrane fluidity of cultured neonatal rat myocardial cells exposed to anoxia and sugar deprivation.Lipid peroxidation level estimated by determining the thiobarbituric acid reactive substance(TBARS)content and lactate dehydrogenase(LDH)released in culture medium was also observed in order to examine other membrane-related changes due to anoxia.Membrane fluidity was monitored by measuring changes in the steady state fluorescence anisotropy(r_s)by fluorescence spectroscopy.The r_s value,TBARS level and LDH release were significantly increased after 3 h anoxia.Captopril(180 μmol/L),cicaprost(30 nmol/L)and indomethacin(1μmol/L)did not alter r_s, TBARS level and LDH activity of normal cultured neonatal rat myocardial cells.However,both captopril and cicaprost significantly prevented the increases of r_s,TBARS content and LDH release in those cells exposed to anoxia and sugar deprivation.lndomethacin abolished the actions of captopril on TBARS production and LDH release,but maintained its membrane fluidity protection.These results indicate that captopril and cicaprost protect membrane fluidity and lipid peroxidation changes in anoxia- injured myocardial cells.The action mechanism of captopril may be due,in part,to stimulation of prostacyclin synthesis and/or release.展开更多
The mechanisms by which breviscapine (Bre) inhibits the lipid preoxidation in rat brain mitochondria were investigated. The mitochondrial lipid peroxidation of rat brain induced by oxygen free radical was measured by ...The mechanisms by which breviscapine (Bre) inhibits the lipid preoxidation in rat brain mitochondria were investigated. The mitochondrial lipid peroxidation of rat brain induced by oxygen free radical was measured by thiobarbituric acid spectrophotometry. The chelating activities of Bre for Fe 2+ were tested by differential spectrum. Superoxide anion (O 2)from xanthine xanthine oxidase (Xan XO) system and hydroxyl radical (·OH) from FeSO 4 H 2O 2 system were determined with spectrophotometry. It was found that Bre could effectively inhibit the lipid peroxidation of brain mitochondria induced by free radicals driven from Xan XO and FeSO 4 H 2O 2 system. The IC 50 of Bre were 93 01 μmol·L -1 for Xan XO system and 62 18 μmol·L -1 for FeSO 4 H 2O 2 system. Bre also scavenged O 2 and ·OH produced by Xan XO and FeSO 4 H 2O 2 systems. The IC 50 of Bre were 32 63 μmol·L -1 for O - 2 and 20 22 μmol·L -1 for ·OH. Furthermore, the chelating Fe 2+ activity of Bre was shown. It may be concluded that Bre inhibited lipid peroxidation at different stages of the reaction of oxygen free redial with the mitochondria membrane: (1) the formation of ·OH; (2) the initiation of the lipid peroxidation, by chelating Fe 2+ and scavenging O 2 as well as ·OH. The scavenging oxygen free radicals and chelating iron are the mechanisms of inhibitory effect of Bre on lipid peroxidation.展开更多
Aim: To examine the effects of melatonin treatment on lipid peroxidation (LPO) and the activities of antioxidant enzymes in the testicular tissue of streptozotocin (STZ)-induced diabetic rats. Methods: Twenty-si...Aim: To examine the effects of melatonin treatment on lipid peroxidation (LPO) and the activities of antioxidant enzymes in the testicular tissue of streptozotocin (STZ)-induced diabetic rats. Methods: Twenty-six male rats were randomly divided into three groups as follows: group Ⅰ, control, non-diabetic rats (n = 9); group Ⅱ, STZ-induced, untreated diabetic rats (n = 8); group Ⅲ, STZ-induced, melatonin-treated (dose of 10 mg/kg·day) diabetic rats (n = 9). Following 8-week melatonin treatment, all rats were anaesthetized and then were killed to remove testes from the scrotum. Results: As compared to group Ⅰ, in rat testicular tissues of grouap Ⅱ, increased levels of malondialdehyde (MDA) (P 〈 0.01) and superoxide dismutase (SOD) (P 〈 0.01) as well as, decreased levels of catalase (CAT) (P 〈 0.01) and glutathione peroxidase (GSH-Px) (P 〉 0.05) were found. In contrast, as compared to group Ⅱ, in rat testicular tissues of group Ⅲ, levels of MDA decreased (but this decrease was not significant, P 〉 0.05) and SOD (P 〈 0.01) as well as CAT (P 〈 0.05) increased. GSH-Px was not influenced by any of the treatment. Melatonin did not significantly affect the elevated glucose concentration of diabetic group. At the end of the study, there was no significant difference between the melatonin-treated group and the untreated group by means of body and testicular weight. Conclusion: Diabetes mellitus increases oxidative stress and melatonin inhibits lipid peroxidation and might regulate the activities of antioxidant enzymes of diabetic rat testes.展开更多
A systematic study was conducted to determine the effects of water stress on the activities of protective enzymes and lipid peroxidation in maize. The results showed that, under water stress, the activities of superox...A systematic study was conducted to determine the effects of water stress on the activities of protective enzymes and lipid peroxidation in maize. The results showed that, under water stress, the activities of superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) in leaves and roots increased sharply at prophase and metaphase growth stages, such as, male tetrad stage, but then declined towards the physiological maturity. The protective enzyme activities in roots were lower than those in leaves. The content of malondialdehyde (MDA) increased according to the severity of water stress. The content of MDA in roots was lower than that in leaves. The activities of protective enzymes and lipid peroxidation in roots were positively related to that in leaves with most of the correlation coefficients being significant. The content of soluble proteins in roots and leaves decreased with increasing drought stress. The ear characteristics deteriorated and the economic yields of maize decreased significantly under water stress. The main factors that caused reduction of yields were the decrease in the number of ear kernels and 100-kernel weight.展开更多
Objective To investigate the effects of fluoride on lipid peroxidation, DNA damage and apoptosis in human embryo hepatocyte L-02 cells. Methods Lipid peroxide (LPO) level, reduced glutathione (GSH) content, DNA damage...Objective To investigate the effects of fluoride on lipid peroxidation, DNA damage and apoptosis in human embryo hepatocyte L-02 cells. Methods Lipid peroxide (LPO) level, reduced glutathione (GSH) content, DNA damage, apoptosis, and cell cycle analysis were measured after in vitro cultured L-02 cells were exposed to sodium fluoride at different doses (40 μg/mL, 80 μg/mL, and 160 μg/mL) for 24 hours. Results Fluoride caused an increase of LPO levels and a decrease of GSH content in L-02 cells. There appeared to be an obvious dose-effect relationship between the fluoride concentration and the observed changes. Fluoride also caused DNA damage and apoptosis and increased the cell number in S phase of cell cycle in the cells tested. There was a statistically significant difference in DNA damage and apoptosis when comparing the high dose of fluoride treated cells with the low dose of fluoride treated cells. Conclusion Fluoride can cause lipid peroxidation, DNA damage, and apoptosis in the L-02 cell experimental model and there is a significant positive correlation between fluoride concentration and these pathological changes.展开更多
In order to increase vegetable productivity by improving environmental conditions, this article investigates the effects of exogenous silicon on the activities of major antioxidant enzymes and on lipid peroxidation un...In order to increase vegetable productivity by improving environmental conditions, this article investigates the effects of exogenous silicon on the activities of major antioxidant enzymes and on lipid peroxidation under chilling stress, and it examines whether silicon-induced chilling tolerance is mediated by an increase in antioxidant activity. Cucumis sativus cv. Jinchun 4 was hydroponically cultivated to the two-leaf stage, at which point seedlings were watered with different concentrations of silicon (0, 0.1 and 1 mmol L^-1) and separately exposed to normal (25/18℃) or chilling (15/8℃) temperatures for six days under low light (100μmol m^-2 s^-9. Data were collected from the second leaves on the percentage of withering and the levels of endogenous silicon, malondialdehyde (MDA), hydrogen peroxide (H202), superoxide radical (O2^.-), superoxide dismutase (SOD, EC 1.15.1.1), glutathione peroxidase (GSH-Px, EC 1.11.1.9), ascorbate peroxidase (APX, EC 1.11.1.11), monodehydroascorbate reductase (MDHAR, EC 1.6.5.4), glutathione reductase (GR, EC 1.6.4.2), reduced glutathione (GSH) and ascorbate (AsA). Compared to normal temperatures, chilling resulted in partially withered leaves and increased MDA content. When 0.1 or 1 mmol L^-1 exogenous silicon was combined with chilling, the withering of the cucumber leaves was reduced relative to the original chilling treatment, while the endogenous silicon content was increased, antioxidants such as SOD, GSH-Px, APX, MDHAR, GR, GSH, and AsA were more active, and the levels of H2O2, O2^.-, and MDA were lower. We propose that exogenous silicon leads to greater deposition of endogenous silicon and thereby increases antioxidant activities and reduces lipid peroxidation induced by chilling.展开更多
On the basis of the phytotron, the effects of high temperature (daily average temperature 25, 30, 35 and 40℃, respectively) on antioxidant enzymes and lipid peroxidation in flag leaves of wheat at 50% relative air ...On the basis of the phytotron, the effects of high temperature (daily average temperature 25, 30, 35 and 40℃, respectively) on antioxidant enzymes and lipid peroxidation in flag leaves of wheat at 50% relative air moisture during grain fastest filling stage [19-21 days after anthesis (DAA)] were studied. The wheat cultivars tested were Yangmai 9 with weak-gluten and Yangmai 12 with medium-gluten. Compared with 25℃, the higher the temperature was, the higher was the MDA content in flag leaves, while lower were the SOD, POD, and CAT activities. SOD and CAT activities in Yangmai 12 appeared to be more sensitive to high temperature than that in Yangmai 9. But POD activity in Yangmai 12 was less sensitive to high temperature. MDA content in Yangmai 12 was higher than that in Yangmai 9. The 1000-grain weight declined with increase in temperature.展开更多
Water culture experiment was conducted to study the effects of selenium(Se) on glutathione peroxidase(GSH-Px) activity,reduced glutathione(GSH) concentration and the accumulation of malonaldehyde(MDA),the product of l...Water culture experiment was conducted to study the effects of selenium(Se) on glutathione peroxidase(GSH-Px) activity,reduced glutathione(GSH) concentration and the accumulation of malonaldehyde(MDA),the product of lipid peroxidation in rice seedling,as well as the effect of se on oxidizing ability of roots under ferrous stress.Results showed that appropriate amount of se significantly increased GSH-Px activity in rice leaves,F=5.5 *,enhanced the amount of GSH and oxidizing ability of roots and reduced the concentration of MDA,F=4.9 *.Compared with Se0+Fe treatment,Se treatments increased the dry matter weight of rice seedling from 10.06% to 10.43%,F=4.09 *.展开更多
BACKGROUND: Studies have reported the antioxidant effects of lead and cadmium in the central nervous system, but very few have addressed the combined toxicity of lead and cadmium. The mechanisms by which these combin...BACKGROUND: Studies have reported the antioxidant effects of lead and cadmium in the central nervous system, but very few have addressed the combined toxicity of lead and cadmium. The mechanisms by which these combined heavy metals are toxic, as well as how to protect cells from these agents, remains poorly understood. OBJECTIVE: Primary cultured rat cortical neurons were used to determine the effects of combined lead and cadmium on levels of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), catalase (CAT), and acetylcholinesterase (ACHE), as well as malondialdehyde (MDA), and to evaluate the neuroprotective effects of N-acetylcysteine (NAC). DESIGN, TIME AND SETTING An in vitro toxicological observation was performed at the Comparative Medicine Center of Yangzhou University from August 2007 to April 2008. MATERIALS: Lead acetate, cadmium acetate, and NAC were purchased from Sigma-Aldrich (St. Louis, USA). Commercial kits of GSH-Px, SOD, CAT, ACHE, and MDA were purchased from Nanjing Jiancheng Bioengineering Institute, Nanjing, China. METHODS: The cerebral cortical neurons were isolated from newborn Sprague dawley rats at 24 hours after birth and primary cultured for 6 days. Thereafter, the cells were treated with a range of cadmium doses (0, 5.0, and 10.0μmol/L), lead doses (0, 1.0, and 2.0 μmol/L), or a combination of the two for 12 hours at 37℃in a 5% CO2 incubator, respectively. In addition, the cells were incubated with different doses of cadmium and/or lead and (0 and 50 μmol/L) NAC for 12 hours to assess the protective effects on cell survival. MAIN OUTCOME MEASURES: The activity of SOD, GSH-Px, CAT, and ACHE, as well as MDA content, in the cell lysates was detected using commercial kits. RESULTS: At 12 hours after treatment, compared to the control group, activity of GSH-Px, SOD, and AChE in the lead, cadmium, or combined treated cells was significantly decreased with increasing doses of cadmium/or lead (P 〈 0.05), but CAT activity and MDA levels were significantly increased (P 〈 0.05). The combination of cadmium and lead led to higher levels of toxicity than individual exposure. CONCLUSION: The degree of oxidative damage increased when the two heavy metals were combined. NAC protected neonatal cortical neurons by increasing activity of anti-oxidative enzymes and reducing lipid peroxidation, but the reduction was not statistically significant.展开更多
The pregnant rats with cigarette smoking exposure were used as the animal model for studying the pathogenesis of IUGR. The mechanism of preventing intrauterine growth retardation with 'Foshousan' plus Danshen ...The pregnant rats with cigarette smoking exposure were used as the animal model for studying the pathogenesis of IUGR. The mechanism of preventing intrauterine growth retardation with 'Foshousan' plus Danshen by protecting erythrocytes against lipid peroxidation damage was also preliminarily discussed.The erythrocyte membrane lipid peroxide content, erythrocyte SOD activities were detected by ultraviolet split-beam spectrophotometry and chemiluminescence technique. The results showed that the erythrocyte MDA levels and ratio of abnormal erythrocyte in model group were significantly higher than those in control group and treated group, and the fetal mean birth weight, erythrocyte SOD levels were all statistically significantly lower than those in control group and treated group. The fetal birth weight showed a significant positive correlation with SOD levels and a significant negative correlation with MDA level. The results suggest 'Foshousan' plus Danshen can protect erythrocytes against lipid peroxidation damage, thus conserving the normal form, structure and function of erythrocytes, improving the uteroplacental blood flow and thereby increasing the fetal mean birth weight.展开更多
Experiments were conducted to study the effects of selenium (Se) on glutathione peroxidase(GSH-Px) activity and the accumulation of malonaldehyde(MDA),the product of lipid peroxidation in soybean seedling, as well as ...Experiments were conducted to study the effects of selenium (Se) on glutathione peroxidase(GSH-Px) activity and the accumulation of malonaldehyde(MDA),the product of lipid peroxidation in soybean seedling, as well as the effect of Se on cell ultra structure of soybean leaf and nascent root under salt stress. Results showed that appropriate amount of Se addition increased GSH-Px activity in soybean leaves from 0. 810 to 1. 421μmol·g-1 fresh weight·min-1 F = 9.12, and reduced the concentration of MDA from 20.17 to 16.16 μmol·g-1 fresh weight, F = 5.44. Under salt stress,no obvious damage on chloplast membrane was observed in Se treated seedlings,and the structures of chloplast and mitochondrion were integrate,whereas in control (no Se addition),the cell membrane was destroyed seriously,chloplast degraded and mitochondrion disappeared. Compared with control,Se addition increased the dry matter weight of seedling by 2.92% to 21.86%, F =5.97.展开更多
Reports the effects of selenium on lipid peroxidation of soybean under continuous cropping stress.Results of pot culture and plot experiment showed that appropriate amount of Se addition increased the activity of glut...Reports the effects of selenium on lipid peroxidation of soybean under continuous cropping stress.Results of pot culture and plot experiment showed that appropriate amount of Se addition increased the activity of glutathione peroxidase (GSH-Px) significantly,and cleared away the excessive free radicals existing in soybean plant under continuous cropping stress,decreased the concentration of malonaldehyde(MDA),which is the end product of lipid peroxidation,maintained the perfection of chloroplast and mitochondrion structure,enhanced the resistance of continuous cropped soybean,and therefore increased the dry weight of seedlong and yield.展开更多
Pharmaceutical delivery systems are developed to improve the physicochemical properties of therapeutic compounds. Emulsions are one of these drug delivering systems formulated using water, oils and lipids as main ingr...Pharmaceutical delivery systems are developed to improve the physicochemical properties of therapeutic compounds. Emulsions are one of these drug delivering systems formulated using water, oils and lipids as main ingredients. Extensive data are usually generated on the physical and chemical characteristics of these oil-in-water and lipid emulsions. However, the oxidative tendency of emulsions is often overlooked. Oxidation impacts the overall quality and safety of these pharmaceutical emulsions. Additionally, introducing oxidatively unstable emulsions into biological systems further promotes oxidation in situ. Products of these reactions then continue to pose serious harm to cells and fuel other physiological oxidation reactions. Consequently, the increase of oxidation products leads to oxidative damage to biological systems. Thus, emulsions with lower lipid peroxidation are more stable and will reduce the negative effects of oxidation in situ. Preventive measures during the formulation of emulsions are important. Many naturally occurring and cost effective substances possess low oxidation tendencies and confer oxidative protection when used in emulsions. Additionally,certain preparatory methods should be employed to reduce or better control lipid peroxidation.Finally, emulsions must be evaluated for their oxidation susceptibility using the various techniques available. Careful attention to the preparation of emulsions and assessment of their oxidative stability will help produce safer emulsions without compromising efficacy.展开更多
Leymus chinensis seedlings were treated with 0.05--10 mmol/L vitamin E under osmotic stress in the presence of polyethylene glycol(PEG) as the stress reagent. The effects of the different concentrations of exogenous...Leymus chinensis seedlings were treated with 0.05--10 mmol/L vitamin E under osmotic stress in the presence of polyethylene glycol(PEG) as the stress reagent. The effects of the different concentrations of exogenous vitamin E on the activities of SOD, POD and free proline, and the MDA contents under drought stress were examined so as to ascertain the mechanism of Leymus chinensis resistance to drought stress and explore the possible preventive measures. The results indicate that the activities of SOD and POD decreased but the free proline and MDA contents increased as drought stress was accentuated, showing an enhancement of oxidative stress that may cause a decline in membrane stabilization. However, the activities of SOD and POD and the free proline content increased, whereas the MDA content reduced in Leymus chinensis pretreated with vitamin E in comparison with that of the control. This indicates that exogenous vitamin E enhanced the antioxidation of Leymus chinensis seedlings. It suggests that cytomembrane can be protected from damage by increasing the free proline content and the activities of SOD and POD that result in enhancing the drought resistance of Leymus chinensis seedlings.展开更多
Lipid peroxidation plays a pivotal role in the pathogenicity and maintenance of hepatitis. Thus, substances protecting hepatocyte membranes from lipid peroxidation are of great importance in the management of hepatoto...Lipid peroxidation plays a pivotal role in the pathogenicity and maintenance of hepatitis. Thus, substances protecting hepatocyte membranes from lipid peroxidation are of great importance in the management of hepatotoxicity and hepatitis. The present work deals with the in vitro hepatoprotective activity of the methanol extract of Desmodium uncinatum, its sub-fractions, the major isolated compounds and some of their semi-synthetic derivatives in order to study structure activity relationships. Using hydrogen peroxide (H2O2)-induced lipid peroxidation of hepatocyte membranes as a model, the hepatoprotective-guided phytochemical survey of the methanol extract of aerial parts of D. uncinatum was carried out by successive column chromatography. One of the most active compounds (Isovitexin) was chemically transformed to yield new semi-synthetic. The identification of isolated and semi-synthetic compounds was performed using NMR techniques, mass spectrometry and by comparison of their data with those reported in the literature. The n-butanol fraction was the most effective (IC50: 22.9 μg/mL) compared to the crude methanol extract (IC50: 43.6 μg/mL) and other fractions. The n-butanol sub-fractions FA (containing non-phenolic compounds) and FB (mainly containing phenolic compounds) exhibited respective IC50 of 14.36 and 128.2 μg/ml. Purification of FA yielded 3-O-β-D-glucopyranosyl-β-sitosterol (1), 3-O-β-D- 2-acetyl-amino-2-deoxyglucopyranoxyloleanoic acid (2), (2S, 3S, 4R, 7R, 8Z)-1-O-β-D-glucopyranosyl-2-[(R)-2'-hydroxyarachidoylamino]-docosan-8-ene-3,4,7-triol (4), spiraeamide (5), mannitol (6), while FB afforded essentially three C-glycosylflavonoids namely isovitexin (7), vitexin (8) and vicenin-3 (9). Chemical transformations (methylation, allylation and prenylation) of isovitexin afforded five new semi-synthetic derivatives: 4',5,7-O- trimethyli-sovitexin (10), 4'-O-allylisovitexin (11), 4',7-O-diallylisovitexin (12), 4'-O-prenylisovitexin (13) and 8-C-prenyl-4',7-O-diprenylisovitexin (14). The screening of these derivatives revealed that allylation did not significantly affect the hepatoprotective activity while methylation, prenylation, number and position of sugar moieties on the A ring of flavonoids significantly reduced it. Results demonstrated that the n-butanol fraction obtained from the methanol extract of Desmdium uncinatum may possess hepatoprotective activity due to its content in C-glycosylflavonoids and cerebrosides. Hydroxyl groups in C-glycosylflavonoids are important for their lipid peroxidation inhibitory activity.展开更多
Membrane lipid peroxidation and protective enzyme activity in leaves of low-phosphorus-tolerant rice cultivars Dalidao and Liantangzao 3, and low-phosphorus-sensitive cultivars Huzhanqi and Xinsanbaili were studied un...Membrane lipid peroxidation and protective enzyme activity in leaves of low-phosphorus-tolerant rice cultivars Dalidao and Liantangzao 3, and low-phosphorus-sensitive cultivars Huzhanqi and Xinsanbaili were studied under low phosphorus stress with sandy culture. Results indicated that low-phosphorus stress aggravated the membrane lipid peroxidation in rice leaves, and it was more severe in low-phosphorus-sensitive cultivars than that in low-phosphorus-tolerant eultivars. During the period of low-phosphorus stress, the activities of SOD, CAT and POD maintained relatively stable in low-phosphorustolerant cultivars, whereas those increased obviously at early stage and subsequently decreased rapidly in the low-phosphorus-sensitive cultivars, suggesting that the absolute activities of protective enzymes had no relation with the low-phosphorus stress, while the changing trend was reverse.展开更多
The changes of malondialdehyde (MDA), H2O2, and O2^7 content, or the activities of superoxide dismutase (SOD), catalase (CAT), ascrobate peroxidase (APX), peroxidase (POD), phenylalanine ammonia lyase (PAL...The changes of malondialdehyde (MDA), H2O2, and O2^7 content, or the activities of superoxide dismutase (SOD), catalase (CAT), ascrobate peroxidase (APX), peroxidase (POD), phenylalanine ammonia lyase (PAL), and polyphenol oxidase (PPO) in pea seedlings (Pisum sativum L.) under wounding and treatment of exogenous jasmonic acid (JA) were investigated. The results showed that the activities of both phenylalanine ammonia lyase (PAL) and polyphenol oxidase (PPO) were significantly increased by wounding and application of JA. The metabolism of reaction oxidative species (ROS) was enhanced, especially O2^7 and H2O2 appeared to rapidly increase. The activities of antioxidant enzymes such as SOD, CAT, APX and POD were also increased. Treatment of JA of 1 or 10 μmol L^-1 could effectively induce plant defense response, and thus decrease the peroxidation of cell membrane lipid. However, high concentration of JA (100 μmol L^-1) resulted in unbalance of metabolism of ROS and promoted the peroxidation of cell membrane lipid. We thus suggested that JA, under the suitable concentration, could induce defense response of pea seedlings to wounding.展开更多
The role of salvia miltiorrhiza bunge (SMB) In protection of lipid peroxidation induced by CCl4 was studied in primary cultured human fetal hepatocytes. The results showed that SMB had significant effect inhibiting li...The role of salvia miltiorrhiza bunge (SMB) In protection of lipid peroxidation induced by CCl4 was studied in primary cultured human fetal hepatocytes. The results showed that SMB had significant effect inhibiting lipid peroxidation of the hepatocytes when exposed to CCl4 as compared with the non-protective co4trol. SMB could decrease the production of malondialdehyde (MDA) and the release of ALT, and increase the synthesis of albumin (ALB) and the activity of Se-dependent glutothione peroxidase (Se-GSH-Px). These results suggest that the suppression of lipid peroxidation may be largely due to the increased activity of Se-GSH-Px.展开更多
文摘The effects of water─soluble components isolated from Salvia miltiorrhiza on oxygen free radical prodction and lipid peroxidation were estimated. Five components(10 μmol/L)were shown to inhibit superoxide anion generation by xanthine─xanthine oxidase system. It was also demonstrated that six components( 100 μmol/L) prevented H_2O_2─induced hemolysis and MDA fonnation in mouse erythrocytes.The effects of Sal A, Sal B, Sal C and Ros A were dose dependent. In Langendorff rat heart, pretreatment with Sal A 20μmol/L significantly prevented MDA production induced by 30 min reoxygenation after 45 min anoxia.The results indicated that there were also other potent antioxidant componentts in Salvia milliorrhiza besides Dphl and Pal. The protection of Sal A against myocardial anoxiareoxygenation inury may be mainly ascribed to its oxygen free radical scavenging activity.
基金Supported by National Natural Science Foundation of China(No.30671061)Natural Science Foundation of Shanxi Province(No.2008011059-1 and No.20041101)~~
文摘[Objective] Effects of different concentrations of nitric oxide on membrane lipid peroxidation of wheat induced by enhanced UV-B radiation were researched,sodium nitroprusside (SNP) was selected as an exogenous nitric oxide(NO)donor.[Method] There are 3 groups including CK,UV treatment group (B),B+SNP treatment group,0,1,2,3,4 d sampling after treatment respectively,and physiological and biochemical indexes of MDA content and CAT,POD,SOD and so on were determined,repeated 3 times,and statistical analyzed.[Result] The results showed that,after the enhanced UV-B radiation,activity of the catalase (CAT),superoxide dismutase (SOD) and of the guaiacol peroxidase (POD) all reduced apparently,and the concentration of malondialdehyde (MDA) increased obviously,leading to oxidative damage in wheat seedlings.Impose different concentrations of SNP after UV-B radiation,may mitigate oxidative damage of wheat seedling from different degrees,which was in agreement with the effect of making the concentration of MDA decrease and the activity of the CAT,SOD and POD all increased.The mitigation role of 0.01 mol/L SNP was more obvious for roots' oxidative damage,while 0.1 mmol/L SNP is more effective for oxidative damage of leaves.[Conclusion] Exogenous NO donor SNP had obvious relieve effects on oxidative damage of wheat seedlings caused by UV-B radiation,which can enhance adaptive capacity of plants to adversity stress.
基金Supported by a grant for young researcher from Ministry of Public Health of P.R.C.
文摘The main purpose of this study was to investigate the protective actions of captopril and cicaprost on changes of membrane fluidity of cultured neonatal rat myocardial cells exposed to anoxia and sugar deprivation.Lipid peroxidation level estimated by determining the thiobarbituric acid reactive substance(TBARS)content and lactate dehydrogenase(LDH)released in culture medium was also observed in order to examine other membrane-related changes due to anoxia.Membrane fluidity was monitored by measuring changes in the steady state fluorescence anisotropy(r_s)by fluorescence spectroscopy.The r_s value,TBARS level and LDH release were significantly increased after 3 h anoxia.Captopril(180 μmol/L),cicaprost(30 nmol/L)and indomethacin(1μmol/L)did not alter r_s, TBARS level and LDH activity of normal cultured neonatal rat myocardial cells.However,both captopril and cicaprost significantly prevented the increases of r_s,TBARS content and LDH release in those cells exposed to anoxia and sugar deprivation.lndomethacin abolished the actions of captopril on TBARS production and LDH release,but maintained its membrane fluidity protection.These results indicate that captopril and cicaprost protect membrane fluidity and lipid peroxidation changes in anoxia- injured myocardial cells.The action mechanism of captopril may be due,in part,to stimulation of prostacyclin synthesis and/or release.
文摘The mechanisms by which breviscapine (Bre) inhibits the lipid preoxidation in rat brain mitochondria were investigated. The mitochondrial lipid peroxidation of rat brain induced by oxygen free radical was measured by thiobarbituric acid spectrophotometry. The chelating activities of Bre for Fe 2+ were tested by differential spectrum. Superoxide anion (O 2)from xanthine xanthine oxidase (Xan XO) system and hydroxyl radical (·OH) from FeSO 4 H 2O 2 system were determined with spectrophotometry. It was found that Bre could effectively inhibit the lipid peroxidation of brain mitochondria induced by free radicals driven from Xan XO and FeSO 4 H 2O 2 system. The IC 50 of Bre were 93 01 μmol·L -1 for Xan XO system and 62 18 μmol·L -1 for FeSO 4 H 2O 2 system. Bre also scavenged O 2 and ·OH produced by Xan XO and FeSO 4 H 2O 2 systems. The IC 50 of Bre were 32 63 μmol·L -1 for O - 2 and 20 22 μmol·L -1 for ·OH. Furthermore, the chelating Fe 2+ activity of Bre was shown. It may be concluded that Bre inhibited lipid peroxidation at different stages of the reaction of oxygen free redial with the mitochondria membrane: (1) the formation of ·OH; (2) the initiation of the lipid peroxidation, by chelating Fe 2+ and scavenging O 2 as well as ·OH. The scavenging oxygen free radicals and chelating iron are the mechanisms of inhibitory effect of Bre on lipid peroxidation.
文摘Aim: To examine the effects of melatonin treatment on lipid peroxidation (LPO) and the activities of antioxidant enzymes in the testicular tissue of streptozotocin (STZ)-induced diabetic rats. Methods: Twenty-six male rats were randomly divided into three groups as follows: group Ⅰ, control, non-diabetic rats (n = 9); group Ⅱ, STZ-induced, untreated diabetic rats (n = 8); group Ⅲ, STZ-induced, melatonin-treated (dose of 10 mg/kg·day) diabetic rats (n = 9). Following 8-week melatonin treatment, all rats were anaesthetized and then were killed to remove testes from the scrotum. Results: As compared to group Ⅰ, in rat testicular tissues of grouap Ⅱ, increased levels of malondialdehyde (MDA) (P 〈 0.01) and superoxide dismutase (SOD) (P 〈 0.01) as well as, decreased levels of catalase (CAT) (P 〈 0.01) and glutathione peroxidase (GSH-Px) (P 〉 0.05) were found. In contrast, as compared to group Ⅱ, in rat testicular tissues of group Ⅲ, levels of MDA decreased (but this decrease was not significant, P 〉 0.05) and SOD (P 〈 0.01) as well as CAT (P 〈 0.05) increased. GSH-Px was not influenced by any of the treatment. Melatonin did not significantly affect the elevated glucose concentration of diabetic group. At the end of the study, there was no significant difference between the melatonin-treated group and the untreated group by means of body and testicular weight. Conclusion: Diabetes mellitus increases oxidative stress and melatonin inhibits lipid peroxidation and might regulate the activities of antioxidant enzymes of diabetic rat testes.
文摘A systematic study was conducted to determine the effects of water stress on the activities of protective enzymes and lipid peroxidation in maize. The results showed that, under water stress, the activities of superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) in leaves and roots increased sharply at prophase and metaphase growth stages, such as, male tetrad stage, but then declined towards the physiological maturity. The protective enzyme activities in roots were lower than those in leaves. The content of malondialdehyde (MDA) increased according to the severity of water stress. The content of MDA in roots was lower than that in leaves. The activities of protective enzymes and lipid peroxidation in roots were positively related to that in leaves with most of the correlation coefficients being significant. The content of soluble proteins in roots and leaves decreased with increasing drought stress. The ear characteristics deteriorated and the economic yields of maize decreased significantly under water stress. The main factors that caused reduction of yields were the decrease in the number of ear kernels and 100-kernel weight.
基金The work was supported by grants from the National Nature Science Foundation of China (No. 30271155) China national key basic research and development program (No. 2022CB512908).
文摘Objective To investigate the effects of fluoride on lipid peroxidation, DNA damage and apoptosis in human embryo hepatocyte L-02 cells. Methods Lipid peroxide (LPO) level, reduced glutathione (GSH) content, DNA damage, apoptosis, and cell cycle analysis were measured after in vitro cultured L-02 cells were exposed to sodium fluoride at different doses (40 μg/mL, 80 μg/mL, and 160 μg/mL) for 24 hours. Results Fluoride caused an increase of LPO levels and a decrease of GSH content in L-02 cells. There appeared to be an obvious dose-effect relationship between the fluoride concentration and the observed changes. Fluoride also caused DNA damage and apoptosis and increased the cell number in S phase of cell cycle in the cells tested. There was a statistically significant difference in DNA damage and apoptosis when comparing the high dose of fluoride treated cells with the low dose of fluoride treated cells. Conclusion Fluoride can cause lipid peroxidation, DNA damage, and apoptosis in the L-02 cell experimental model and there is a significant positive correlation between fluoride concentration and these pathological changes.
基金supported by the open fund of the State Key Laboratory of Crop Biology, China (200509).
文摘In order to increase vegetable productivity by improving environmental conditions, this article investigates the effects of exogenous silicon on the activities of major antioxidant enzymes and on lipid peroxidation under chilling stress, and it examines whether silicon-induced chilling tolerance is mediated by an increase in antioxidant activity. Cucumis sativus cv. Jinchun 4 was hydroponically cultivated to the two-leaf stage, at which point seedlings were watered with different concentrations of silicon (0, 0.1 and 1 mmol L^-1) and separately exposed to normal (25/18℃) or chilling (15/8℃) temperatures for six days under low light (100μmol m^-2 s^-9. Data were collected from the second leaves on the percentage of withering and the levels of endogenous silicon, malondialdehyde (MDA), hydrogen peroxide (H202), superoxide radical (O2^.-), superoxide dismutase (SOD, EC 1.15.1.1), glutathione peroxidase (GSH-Px, EC 1.11.1.9), ascorbate peroxidase (APX, EC 1.11.1.11), monodehydroascorbate reductase (MDHAR, EC 1.6.5.4), glutathione reductase (GR, EC 1.6.4.2), reduced glutathione (GSH) and ascorbate (AsA). Compared to normal temperatures, chilling resulted in partially withered leaves and increased MDA content. When 0.1 or 1 mmol L^-1 exogenous silicon was combined with chilling, the withering of the cucumber leaves was reduced relative to the original chilling treatment, while the endogenous silicon content was increased, antioxidants such as SOD, GSH-Px, APX, MDHAR, GR, GSH, and AsA were more active, and the levels of H2O2, O2^.-, and MDA were lower. We propose that exogenous silicon leads to greater deposition of endogenous silicon and thereby increases antioxidant activities and reduces lipid peroxidation induced by chilling.
基金This research work was financially supported by the National Natural Science Foundation of China(30571091,30170540).
文摘On the basis of the phytotron, the effects of high temperature (daily average temperature 25, 30, 35 and 40℃, respectively) on antioxidant enzymes and lipid peroxidation in flag leaves of wheat at 50% relative air moisture during grain fastest filling stage [19-21 days after anthesis (DAA)] were studied. The wheat cultivars tested were Yangmai 9 with weak-gluten and Yangmai 12 with medium-gluten. Compared with 25℃, the higher the temperature was, the higher was the MDA content in flag leaves, while lower were the SOD, POD, and CAT activities. SOD and CAT activities in Yangmai 12 appeared to be more sensitive to high temperature than that in Yangmai 9. But POD activity in Yangmai 12 was less sensitive to high temperature. MDA content in Yangmai 12 was higher than that in Yangmai 9. The 1000-grain weight declined with increase in temperature.
文摘Water culture experiment was conducted to study the effects of selenium(Se) on glutathione peroxidase(GSH-Px) activity,reduced glutathione(GSH) concentration and the accumulation of malonaldehyde(MDA),the product of lipid peroxidation in rice seedling,as well as the effect of se on oxidizing ability of roots under ferrous stress.Results showed that appropriate amount of se significantly increased GSH-Px activity in rice leaves,F=5.5 *,enhanced the amount of GSH and oxidizing ability of roots and reduced the concentration of MDA,F=4.9 *.Compared with Se0+Fe treatment,Se treatments increased the dry matter weight of rice seedling from 10.06% to 10.43%,F=4.09 *.
基金the National Natural Science Foundation of China,No.305713647Natural Science Foundation of Jiangsu Province,No. BK2008214
文摘BACKGROUND: Studies have reported the antioxidant effects of lead and cadmium in the central nervous system, but very few have addressed the combined toxicity of lead and cadmium. The mechanisms by which these combined heavy metals are toxic, as well as how to protect cells from these agents, remains poorly understood. OBJECTIVE: Primary cultured rat cortical neurons were used to determine the effects of combined lead and cadmium on levels of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), catalase (CAT), and acetylcholinesterase (ACHE), as well as malondialdehyde (MDA), and to evaluate the neuroprotective effects of N-acetylcysteine (NAC). DESIGN, TIME AND SETTING An in vitro toxicological observation was performed at the Comparative Medicine Center of Yangzhou University from August 2007 to April 2008. MATERIALS: Lead acetate, cadmium acetate, and NAC were purchased from Sigma-Aldrich (St. Louis, USA). Commercial kits of GSH-Px, SOD, CAT, ACHE, and MDA were purchased from Nanjing Jiancheng Bioengineering Institute, Nanjing, China. METHODS: The cerebral cortical neurons were isolated from newborn Sprague dawley rats at 24 hours after birth and primary cultured for 6 days. Thereafter, the cells were treated with a range of cadmium doses (0, 5.0, and 10.0μmol/L), lead doses (0, 1.0, and 2.0 μmol/L), or a combination of the two for 12 hours at 37℃in a 5% CO2 incubator, respectively. In addition, the cells were incubated with different doses of cadmium and/or lead and (0 and 50 μmol/L) NAC for 12 hours to assess the protective effects on cell survival. MAIN OUTCOME MEASURES: The activity of SOD, GSH-Px, CAT, and ACHE, as well as MDA content, in the cell lysates was detected using commercial kits. RESULTS: At 12 hours after treatment, compared to the control group, activity of GSH-Px, SOD, and AChE in the lead, cadmium, or combined treated cells was significantly decreased with increasing doses of cadmium/or lead (P 〈 0.05), but CAT activity and MDA levels were significantly increased (P 〈 0.05). The combination of cadmium and lead led to higher levels of toxicity than individual exposure. CONCLUSION: The degree of oxidative damage increased when the two heavy metals were combined. NAC protected neonatal cortical neurons by increasing activity of anti-oxidative enzymes and reducing lipid peroxidation, but the reduction was not statistically significant.
文摘The pregnant rats with cigarette smoking exposure were used as the animal model for studying the pathogenesis of IUGR. The mechanism of preventing intrauterine growth retardation with 'Foshousan' plus Danshen by protecting erythrocytes against lipid peroxidation damage was also preliminarily discussed.The erythrocyte membrane lipid peroxide content, erythrocyte SOD activities were detected by ultraviolet split-beam spectrophotometry and chemiluminescence technique. The results showed that the erythrocyte MDA levels and ratio of abnormal erythrocyte in model group were significantly higher than those in control group and treated group, and the fetal mean birth weight, erythrocyte SOD levels were all statistically significantly lower than those in control group and treated group. The fetal birth weight showed a significant positive correlation with SOD levels and a significant negative correlation with MDA level. The results suggest 'Foshousan' plus Danshen can protect erythrocytes against lipid peroxidation damage, thus conserving the normal form, structure and function of erythrocytes, improving the uteroplacental blood flow and thereby increasing the fetal mean birth weight.
文摘Experiments were conducted to study the effects of selenium (Se) on glutathione peroxidase(GSH-Px) activity and the accumulation of malonaldehyde(MDA),the product of lipid peroxidation in soybean seedling, as well as the effect of Se on cell ultra structure of soybean leaf and nascent root under salt stress. Results showed that appropriate amount of Se addition increased GSH-Px activity in soybean leaves from 0. 810 to 1. 421μmol·g-1 fresh weight·min-1 F = 9.12, and reduced the concentration of MDA from 20.17 to 16.16 μmol·g-1 fresh weight, F = 5.44. Under salt stress,no obvious damage on chloplast membrane was observed in Se treated seedlings,and the structures of chloplast and mitochondrion were integrate,whereas in control (no Se addition),the cell membrane was destroyed seriously,chloplast degraded and mitochondrion disappeared. Compared with control,Se addition increased the dry matter weight of seedling by 2.92% to 21.86%, F =5.97.
基金National Nature Science Foundation projectgrant No:39870 4 70 Natural Scieuce Foundation of Heilongjiang Province
文摘Reports the effects of selenium on lipid peroxidation of soybean under continuous cropping stress.Results of pot culture and plot experiment showed that appropriate amount of Se addition increased the activity of glutathione peroxidase (GSH-Px) significantly,and cleared away the excessive free radicals existing in soybean plant under continuous cropping stress,decreased the concentration of malonaldehyde(MDA),which is the end product of lipid peroxidation,maintained the perfection of chloroplast and mitochondrion structure,enhanced the resistance of continuous cropped soybean,and therefore increased the dry weight of seedlong and yield.
文摘Pharmaceutical delivery systems are developed to improve the physicochemical properties of therapeutic compounds. Emulsions are one of these drug delivering systems formulated using water, oils and lipids as main ingredients. Extensive data are usually generated on the physical and chemical characteristics of these oil-in-water and lipid emulsions. However, the oxidative tendency of emulsions is often overlooked. Oxidation impacts the overall quality and safety of these pharmaceutical emulsions. Additionally, introducing oxidatively unstable emulsions into biological systems further promotes oxidation in situ. Products of these reactions then continue to pose serious harm to cells and fuel other physiological oxidation reactions. Consequently, the increase of oxidation products leads to oxidative damage to biological systems. Thus, emulsions with lower lipid peroxidation are more stable and will reduce the negative effects of oxidation in situ. Preventive measures during the formulation of emulsions are important. Many naturally occurring and cost effective substances possess low oxidation tendencies and confer oxidative protection when used in emulsions. Additionally,certain preparatory methods should be employed to reduce or better control lipid peroxidation.Finally, emulsions must be evaluated for their oxidation susceptibility using the various techniques available. Careful attention to the preparation of emulsions and assessment of their oxidative stability will help produce safer emulsions without compromising efficacy.
文摘Leymus chinensis seedlings were treated with 0.05--10 mmol/L vitamin E under osmotic stress in the presence of polyethylene glycol(PEG) as the stress reagent. The effects of the different concentrations of exogenous vitamin E on the activities of SOD, POD and free proline, and the MDA contents under drought stress were examined so as to ascertain the mechanism of Leymus chinensis resistance to drought stress and explore the possible preventive measures. The results indicate that the activities of SOD and POD decreased but the free proline and MDA contents increased as drought stress was accentuated, showing an enhancement of oxidative stress that may cause a decline in membrane stabilization. However, the activities of SOD and POD and the free proline content increased, whereas the MDA content reduced in Leymus chinensis pretreated with vitamin E in comparison with that of the control. This indicates that exogenous vitamin E enhanced the antioxidation of Leymus chinensis seedlings. It suggests that cytomembrane can be protected from damage by increasing the free proline content and the activities of SOD and POD that result in enhancing the drought resistance of Leymus chinensis seedlings.
文摘Lipid peroxidation plays a pivotal role in the pathogenicity and maintenance of hepatitis. Thus, substances protecting hepatocyte membranes from lipid peroxidation are of great importance in the management of hepatotoxicity and hepatitis. The present work deals with the in vitro hepatoprotective activity of the methanol extract of Desmodium uncinatum, its sub-fractions, the major isolated compounds and some of their semi-synthetic derivatives in order to study structure activity relationships. Using hydrogen peroxide (H2O2)-induced lipid peroxidation of hepatocyte membranes as a model, the hepatoprotective-guided phytochemical survey of the methanol extract of aerial parts of D. uncinatum was carried out by successive column chromatography. One of the most active compounds (Isovitexin) was chemically transformed to yield new semi-synthetic. The identification of isolated and semi-synthetic compounds was performed using NMR techniques, mass spectrometry and by comparison of their data with those reported in the literature. The n-butanol fraction was the most effective (IC50: 22.9 μg/mL) compared to the crude methanol extract (IC50: 43.6 μg/mL) and other fractions. The n-butanol sub-fractions FA (containing non-phenolic compounds) and FB (mainly containing phenolic compounds) exhibited respective IC50 of 14.36 and 128.2 μg/ml. Purification of FA yielded 3-O-β-D-glucopyranosyl-β-sitosterol (1), 3-O-β-D- 2-acetyl-amino-2-deoxyglucopyranoxyloleanoic acid (2), (2S, 3S, 4R, 7R, 8Z)-1-O-β-D-glucopyranosyl-2-[(R)-2'-hydroxyarachidoylamino]-docosan-8-ene-3,4,7-triol (4), spiraeamide (5), mannitol (6), while FB afforded essentially three C-glycosylflavonoids namely isovitexin (7), vitexin (8) and vicenin-3 (9). Chemical transformations (methylation, allylation and prenylation) of isovitexin afforded five new semi-synthetic derivatives: 4',5,7-O- trimethyli-sovitexin (10), 4'-O-allylisovitexin (11), 4',7-O-diallylisovitexin (12), 4'-O-prenylisovitexin (13) and 8-C-prenyl-4',7-O-diprenylisovitexin (14). The screening of these derivatives revealed that allylation did not significantly affect the hepatoprotective activity while methylation, prenylation, number and position of sugar moieties on the A ring of flavonoids significantly reduced it. Results demonstrated that the n-butanol fraction obtained from the methanol extract of Desmdium uncinatum may possess hepatoprotective activity due to its content in C-glycosylflavonoids and cerebrosides. Hydroxyl groups in C-glycosylflavonoids are important for their lipid peroxidation inhibitory activity.
文摘Membrane lipid peroxidation and protective enzyme activity in leaves of low-phosphorus-tolerant rice cultivars Dalidao and Liantangzao 3, and low-phosphorus-sensitive cultivars Huzhanqi and Xinsanbaili were studied under low phosphorus stress with sandy culture. Results indicated that low-phosphorus stress aggravated the membrane lipid peroxidation in rice leaves, and it was more severe in low-phosphorus-sensitive cultivars than that in low-phosphorus-tolerant eultivars. During the period of low-phosphorus stress, the activities of SOD, CAT and POD maintained relatively stable in low-phosphorustolerant cultivars, whereas those increased obviously at early stage and subsequently decreased rapidly in the low-phosphorus-sensitive cultivars, suggesting that the absolute activities of protective enzymes had no relation with the low-phosphorus stress, while the changing trend was reverse.
基金the National Natural Sci-ence Foundation of China(30270918) the National High Technology Research and Development Programof China(863 Program2003AA241170).
文摘The changes of malondialdehyde (MDA), H2O2, and O2^7 content, or the activities of superoxide dismutase (SOD), catalase (CAT), ascrobate peroxidase (APX), peroxidase (POD), phenylalanine ammonia lyase (PAL), and polyphenol oxidase (PPO) in pea seedlings (Pisum sativum L.) under wounding and treatment of exogenous jasmonic acid (JA) were investigated. The results showed that the activities of both phenylalanine ammonia lyase (PAL) and polyphenol oxidase (PPO) were significantly increased by wounding and application of JA. The metabolism of reaction oxidative species (ROS) was enhanced, especially O2^7 and H2O2 appeared to rapidly increase. The activities of antioxidant enzymes such as SOD, CAT, APX and POD were also increased. Treatment of JA of 1 or 10 μmol L^-1 could effectively induce plant defense response, and thus decrease the peroxidation of cell membrane lipid. However, high concentration of JA (100 μmol L^-1) resulted in unbalance of metabolism of ROS and promoted the peroxidation of cell membrane lipid. We thus suggested that JA, under the suitable concentration, could induce defense response of pea seedlings to wounding.
文摘The role of salvia miltiorrhiza bunge (SMB) In protection of lipid peroxidation induced by CCl4 was studied in primary cultured human fetal hepatocytes. The results showed that SMB had significant effect inhibiting lipid peroxidation of the hepatocytes when exposed to CCl4 as compared with the non-protective co4trol. SMB could decrease the production of malondialdehyde (MDA) and the release of ALT, and increase the synthesis of albumin (ALB) and the activity of Se-dependent glutothione peroxidase (Se-GSH-Px). These results suggest that the suppression of lipid peroxidation may be largely due to the increased activity of Se-GSH-Px.