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The effects of a standardized extract of Ginkgo biloba L. leaves (EGb) and its terpene constituents, bilobalide and ginkgolides, on the activities of detoxification enzymes, i.e., glutathione S-transferases (GSTs) and DT-diaphorase, and glutathione contents, were investigated in the mouse liver. Oral treatment with EGb (100-1,000 mg/kg) and bilobalide (10-30 mg/kg) once a day for 4 days caused a dose-dependent elevation in GST activity. Ginkgolide A (30 mg/kg, for 4 days) also significantly elevated GST activity, whereas ginkgolide B and ginkgolide C at the same dose had no effects. EGb significantly increased the protein level of GST pi, and bilobalide significantly increased those of GST alpha and GST mu Moreover, EGb-treatment and bilobalide-treatment caused significant elevations in DT-diaphorase activity and in hepatic glutathione contents.  相似文献   

3.
Asbestos and its carcinogenic properties have been extensively documented. Asbestos exposure induces diverse cellular events associated with lung injury. Previously, we have shown that treatment with chrysotile shows significant alteration in phase I and phase II drug metabolizing enzyme system. In this study we have examined some potential mechanisms by which garlic treatment attenuates chrysotile-mediated pulmonary toxicity in rat. Female Wistar rats received an intratracheal instillation of 5 mg chrysotile (0.5 mL saline) as well as intragastric garlic treatment (1% body weight (v/w); 6 days per week). Effect of garlic treatment was evaluated after 1, 15, 30, 90, and 180 days by assaying aryl hydrocarbon hydroxylase (AHH), glutathione (GSH), glutathione S-transferase (GST), and production of thiobarbituric acid reactive substances (TBARS) in rat lung microsome. The results showed that AHH and TBARS formation were significantly reduced at day 90 and day 180 in chrysotile treated garlic cofed rats; GSH recovered 15 days later to the near normal level and GST elevated significantly after treatment of garlic as compared to chrysotile alone treated rat lung microsome. The data obtained shows that inhibition of AHH activity and induction of GST activity could be contributing factor in chrysotile-mediated pulmonary toxicity in garlic cofed rats. However, recovery of GSH and inhibition of TBARS formation by garlic and its constituent(s) showed that garlic may give protection by altering the drug metabolizing enzyme system.  相似文献   

4.
The effects of Maneb on antioxidant potentials and carbon assimilation were studied in leaves sorghum (Sorghum bicolor L.) plants (C4 species). The plants were sprayed by three doses; recommended dose (2.5 g/L), twice and three times higher at 25, 40 and 55 days after planting (DAP). The leaves were harvested at 5, 10 and 15 days after treatment (DAT) and proteins content, activities of antioxidative enzymes catalase (CAT), guaiacol peroxidase (POD), glutathione reductase (GR), glutathione-S-transferases (GST) and glyoxalase I (GlyI) as well as activity of key enzyme in primary fixation of atmospheric CO2 phosphoenolpyruvate carboxylase (PEPC) and chlorophyll content were estimated. The protein content was found increased under Maneb treatment. While the POD and GR activities appear unaffected, CAT activity increased at 10 and 15 DAT. Whereas the GST activity increased significantly in plants treated with 5 g/L at 5 DAT and in plant exposed to 2.5 g/L at 10 DAT. The activity and proteins levels of GlyI were increased progressively with increasing fungicide treatment. This increase was more pronounced at 5 DAT; being 1.7 and 1.5 fold for 5 and 7.5 g/L, respectively. However, both PEPC activity and chlorophyll content seem unchanged in presence of fungicide even at high concentration. These results indicate that sorghum leaves have a well-developed systems of protection from carbonyl stress.  相似文献   

5.
牟少飞  梁沛  高希武 《昆虫知识》2006,43(4):491-495
采用人工饲料添加法,研究植物防御性次生物质槲皮素对B型烟粉虱Bemisiatabaci(Gennadius)成虫主要解毒酶系羧酸酯酶(CarE)和谷胱甘肽S-转移酶(GSTs)影响的剂量效应和时间效应。用低剂量槲皮素(0.01%,wv)处理B型烟粉虱成虫24h后,其羧酸酯酶(CarE)和谷胱甘肽S-转移酶(GSTs)比活力分别为51.09mOD(min·头)和2.249OD(mgpro.min),是对照的1.233倍和2.20倍;而高剂量的槲皮素对2种解毒酶没有诱导增加作用,甚至还有抑制作用。低剂量的槲皮素短时间处理烟粉虱后,可诱导2种酶活性增加,谷胱甘肽S-转移酶(GSTs)在0.005%的槲皮素处理30min后,比活力值达到8.454OD(mgpro·min),为对照的8.30倍。  相似文献   

6.
Microsomal glutathione transferase 1 (MGST1) is an integral homo-trimeric membrane protein with transferase and peroxidase activities. With glutathione as a co-substrate, it scavenges toxic compounds and may exert anti-apoptotic effect. We examined the effect of suppression of plasma membrane Ca(2+)-ATPase isoforms--PMCA2 or PMCA3 on MGST1 in PC12 cells. GSH level was significantly higher in PMCA2-reduced line, but similar GSSG/GSH ratios in all cell lines suggested an efficient protection or absence of oxidative stress. The ATP concentration decreased in both modified lines, although in PMCA2-suppressed cells the decrease was higher. Total GSTs activity in postmitochondrial fraction increased by 30% in the cells with reduced PMCA3. After treatment with MGST1 activator N-ethylmaleimide (NEM), the activity increased in both transfected lines by 30-40%. Real-time PCR also showed a higher mRNA expression of MGST1 in these lines. Staining with antibody recognizing all cytosolic and membrane-bound GSTs revealed the difference in oligomeric forms of GSTs, and specific anti-MGST1 antibody showed the presence of MGST1 hexamers in the transfected cells. Formation of similar hexamers was detected in the control line after treatment with peroxynitrite. Modification of MGST1 under reduced PMCAs amount may represent an adaptive mechanism that offers protection against the cytotoxicity mediated by increased Ca2+.  相似文献   

7.
The effects of altered thyroid state on the antioxidant defense system in the liver of differently aged rats were examined. Male rats aged 15, 45 and 75 days were treated with L-thyroxine, T(4) (40 microg/100 g body mass, s.c., one dose per day) for 14 days (finally aged 30, 60 and 90 days, respectively). The following antioxidant defense enzymes were measured: superoxide dismutases (both copper zinc, CuZn-SOD and manganese containing, Mn-SOD), catalase (CAT), glutathione peroxidase (GSH-Px), glutathione-S-transferase (GST), glutathione reductase (GR), as well as the content of low molecular mass antioxidant glutathione (GSH). The effect of T(4) on antioxidant defense system in the liver differs with respect to age. T(4) treatment decreased CAT and GST activities, as well as the content of GSH in animals aged 60 and 90 days. The same treatment elevated GR activity in rats at 30 days of age, this phenomenon was not observed in older animals. The different response of immature rats to thyroxine compared to older animals could be attributed to the differences in thyroxine metabolism and the developmental pattern. Direct effect of T(4) on mature rats can be considered as a part of its overall catabolic action.  相似文献   

8.
In the present study, potential anticancer effect of eugenol on inhibition of cell proliferation and induction of apoptosis in human MCF-7 breast cancer cells was investigated. Induction of cell death by eugenol was evaluated following MTT assay and monitoring lactate dehydrogenase released into the culture medium for cell viability and cytotoxicity, giemsa staining for morphological alterations, fluorescence microscopy analysis of cells using ethidium bromide and acridine orange and quantitation of DNA fragments for induction of apoptosis. Effect of eugenol on intracellular redox status of the human breast cancer cells was assessed by determining the level of glutathione and lipid peroxidation products (TBARS). Eugenol treatment inhibited the growth and proliferation of human MCF-7 breast cancer cells through induction of cell death, which was dose and time dependent. Microscopic examination of eugenol treated cells showed cell shrinkage, membrane blebbing and apoptotic body formation. Further, eugenol treatment also depleted the level of intracellular glutathione and increased the level of lipid peroxidation. The dose dependent increase in the percentage of apoptotic cells and DNA fragments suggested that apoptosis was involved in eugenol induced cell death and apoptosis might have played a role in the chemopreventive action of eugenol.  相似文献   

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10.
目的: 分析镉(Cd)负荷不同时间对小鼠睾丸抗氧化酶的影响及维生素C(VC)的保护作用。方法: 清洁级雄性昆明小鼠72只分为4组(n=18):对照组、Cd组(CdCl2 3 mg/kg)、VC组(200 mg/kg)、VC(200 mg/kg)+ Cd(CdCl2 3 mg/kg)组,每日染毒1次,染毒1 d和3 d及同时补充VC保护,第1日和第3日染毒24 h后,每组取半数小鼠称重,取血清和睾丸组织;检测睾丸脏器系数,血清和睾丸组织丙二醛(MDA)、超氧化物歧化酶(SOD),及睾丸组织谷胱甘肽过氧化物酶(GSH-Px)、还原型谷胱甘肽(GSH)、氧化型谷胱甘肽(GSSG)及总谷胱甘肽(T-GSH)。结果: 与对照组比较,Cd组1 d和3 d小鼠体重和睾丸脏器系数下降;染毒3 d,Cd组小鼠血清SOD显著降低、MDA显著升高(P<0.05);Cd组1 d小鼠睾丸的SOD、GSH-Px、T-GSH及GSH/GSSG显著升高(P<0.05),而3 d的上述指标均显著降低(P<0.05),Cd组1 d和3 d MDA水平均显著升高(P<0.05);VC处理后减轻的程度有所降低。与Cd组比较,VC+ Cd组血清SOD和MDA水平在染毒3 d变化有显著性差异(P<0.05);VC+ Cd组在染毒1 d和3 d,小鼠睾丸的SOD、GSH-Px、T-GSH及GSH/GSSG水平变化有显著性差异(P<0.05),VC+ Cd组在染毒3 d睾丸的MDA水平显著降低(P<0.05)。与Cd组1 d比较,染毒3 d小鼠的血清SOD水平显著降低(P<0.05),睾丸指标变化也有显著性差异(P<0.05)。结论: VC处理可在一定程度上改善镉负荷小鼠的抗氧化功能,对睾丸氧化损伤具有保护作用。  相似文献   

11.
It is well known that the nervous system has increased susceptibility to methanol intoxication. The present study reveals the effect of methanol intoxication on antioxidant status, lipid peroxidation and DNA integrity in hypothalamic-pituitary-adrenal (HPA) axis organs and spleen. Non-specific and specific immune functions were analyzed. In addition, open field behavior, plasma corticosterone level and blood methanol level were estimated. Male Wistar albino rats were intoxicated with methanol (2.37 g/kg b.wt., i.p.) for 1 day, 15 and 30 days. Administration of methanol showed significant increase in enzymatic (superoxide dismutase, catalase, glutathione peroxidase), non-enzymatic (reduced glutathione and Vitamin C) antioxidants and lipid peroxidation (LPO) in hypothalamus and adrenal gland of day 1 group. However, decrease in enzymatic and non-enzymatic antioxidants with concomitant increase in LPO level were observed in 15 and 30 days groups. Plasma corticosterone level was significantly increased in day 1 and 15 days groups whereas, 30 days methanol intoxication group showed considerable decrease in corticosterone level compared with control animals. Cell-mediated immune response of footpad thickness was significantly decreased with an increased leukocyte migration inhibition. Humoral immune response of antibody titers was elevated in methanol-intoxicated groups. Neutrophil functions, adherence and phagocytic index (PI) were found to be significantly decreases. Furthermore, significant increase in the avidity index and nitro blue tetrozolium reduction was observed in the methanol exposed animals. Day 1 methanol exposed group showed increased PI compared to the control ones. Methanol exposure for 30 days showed an increased DNA fragmentation in the hypothalamus, adrenal glands, and spleen. In conclusion, exposure to methanol-induced oxidative stress disturbs the HPA-axis function altering the level of corticosterone, which lead to varied non-specific and specific immune response in experimental rats.  相似文献   

12.
The effect of magnesium deficiency on antioxidant defence system was studied in RBC of mice suffering from hypomagnesemia. The animals were kept for 8, 15 and 22 days on magnesium-deficient diet with consequent reduction of magnesium level in plasma by 38% at the first 8 days and by 64% after 22 days of experiment. The activities of the most important antioxidant enzymes, catalase, glutathione peroxidase, superoxide dismutase, glutathione reductase, glutahione S-transferase were assayed in hemolysates. The level of reduced glutathione in erythrocytes was measured as well. Apart from catalase, the activities of antioxidant enzymes were decreasing. The activity of superoxide dismutase decreased gradually during the experiment and on the 15th and 22nd day of experiment was significantly (P<0,05) lowered by 30 and 32% respectively. The catalase activity was increased on each point of the experiment with the peak value up to 149% on 15th day, and by 32% on 22nd day. Glutathione peroxidase activity was insignificantly reduced. The reduction of Glutatione reductase and Glutathione S-transferase activities by 24 and 21%, respectively, were observed after 8 days of the experiment with a further downward tendency. The reduced glutathione was significantly depleted after 8 days by 33% and was kept on that level in the course of the study. These findings support previous reports on the hypomagnesemia – induced alteration in endogenous enzyme antioxidant defences and glutathione redox cycle of mice.  相似文献   

13.
单宁酸对棉铃虫谷胱甘肽S转移酶的影响   总被引:12,自引:4,他引:8  
通过培养基混药法,研究了植物次生物质单宁酸对棉铃虫Helicoverpa armigera(Hübner)谷胱甘肽S-转移酶活性的影响。谷胱甘肽S-转移酶活性随棉铃虫发育期的进程而变化,在卵期最低,5龄、6龄幼虫和成虫期最高。用含0.005%单宁酸的饲料饲喂棉铃虫后,5龄和6龄幼虫的谷胱甘肽S-转移酶活性明显降低,分别为对照的59%和67%。单宁酸低剂量、短时间处理棉铃虫幼虫,可诱导中肠和脂肪体中的谷胱甘肽S-转移酶的活性增加,高剂量或低剂量长时间处理没有诱导增加作用,甚至还有抑制作用。单宁酸连续处理4代,对棉铃虫6龄幼虫中肠谷胱甘肽S 转移酶均有抑制作用,对脂肪体谷胱甘肽S-转移酶活性无明显影响或有抑制作用。单宁酸处理的第4代幼虫对溴氰菊酯的敏感度有增加的趋势,对甲基对硫磷的敏感度没有明显改变。  相似文献   

14.
Plaice were treated with an acute dose of a polyaromatic hydrocarbon (3-methylcholanthrene, 3-MC) or cadmium, or 3-MC and cadmium by i.p. injection. The effects on hepatic detoxication systems, cytochrome P-450 (ethoxyresorufin O-deethylase, EROD), UDP-glucuronyl transferase, glutathione S-transferase, glutathione peroxidase activities, total glutathione (GSH), metallothionein and Cd and Zn in the cytosol were studied over a 14 day period. 3-MC increased EROD (7-18-fold), glucuronyl transferase (40%) and GSH transferase (200%) activities, whereas GSH peroxidase activity decreased by 60%. Cd treatment inhibited EROD (90%), GSH transferase (90%) and GSH peroxidase (30%) activities and displaced Zn. Total GSH levels increased (200%) prior to onset of metallothionein synthesis (6 days). Cotreatment with 3-MC and Cd led to a marked increase in GSH levels (300%) but the onset of metallothionein synthesis was delayed by a week. Induction of enzyme activities was abolished, EROD activity was strongly inhibited and there was a transient 50-90% decrease in glucuronyl transferase, GSH transferase and GSH peroxidase activities on days 2 and 3 after treatment. The results indicate that a polyaromatic hydrocarbon could result in increased peroxidative damage, the heavy metal Cd can severely inhibit organic xeno- and endobiotic metabolism and that the effects of both agents may be synergistic.  相似文献   

15.

Background  

Human hookworm infection is a major cause of anemia and malnutrition of adults and children in the developing world. As part of on-going efforts to control hookworm infection, The Human Hookworm Vaccine Initiative has identified candidate vaccine antigens from the infective L3 larval stages and adult stages of the parasite. Adult stage antigens include the cytosolic glutathione-S-transferases (GSTs). Nematode GSTs facilitate the inactivation and degradation of a variety of electrophilic substrates (drugs) via the nucleophilic addition of reduced glutathione. Parasite GSTs also play significant roles in multi-drug resistance and the modulation of host-immune defense mechanisms.  相似文献   

16.
Acute and sub-acute toxic effects of a novel phosphorothionate coded as RPR-II on testis of albino rats were studied. In acute study rats received a single dose of 12.3 mg/kg of RPR-II and sacrificed after 24 hr. For sub-acute study 0.58 mg/kg/day was administered orally to rats for 10 and 21 days. Acute exposure of rats to RPR-II brought no change either in the gonadosomatic index (GSI) or in the structure of testis or in the serum levels of testosterone. Testis glutathione (GSH) level and glutathione S-transferase (GST) activity was significantly decreased whereas, acid phosphatase (AcP) levels increased significantly at 24 hr post-treatment. On 7th day (withdrawal period) after the cessation of the treatment the GSH, GST, AcP, and AkP levels reached to near control. The sub-acute study revealed a significant decrease in GSI on 10th and 21st day of the treatment. In contrast, a time-dependent and significant increased in GSH level and GST activity was observed on 100th and 21st day of post-treatment, except GSH level on 10th day, which was declined. Due to RPR-II treatment the testis AcP and alkaline phosphatase (AkP) levels were significant at both 10th and 21st day of medication but AcP levels were increased whereas AkP levels decreased. The histopathological studies on day 10th showed considerable loss of spermatozoids in testis and at 21st day complete derangement of cellular organization was observed. Testosterone levels decreased significantly on 10th day and remained significantly low at 21st day. However, withdrawal studies showed a recovery in testis of rat treated with RPR-II. GST, GSH, GSI, AcP and AkP values recovered, testosterone levels were also well recovered but recovery in testis structure remained at a low profile. The present study suggests that RPR-II may cause testicular toxicity in rats affecting the normal functioning of testis and it also gave some new information in withdrawal studies.  相似文献   

17.
To study the effects of aluminium (Al) on glutathione (GSH) metabolism in the small intestine, adult male Wistar rats were orally treated with AlCl3.6H2O at doses of 30, 60, 120 and 200 mg/kg body weight (b.w.) per day, during seven days. Controls received deionized water. At doses above 120 mg/kg b.w., Al produced both a significant reduction of GSH content and an increase of oxidized/reduced glutathione ratio (P < 0.05). The index of oxidative stress of the intestine mucosa in terms of lipid peroxidation evaluated by thiobarbituric acid reactive substances was significantly increased (52%) at higher Al dose used. The duodenal expression of the multidrug resistance-associated protein 2 in brush border membranes, determined by Western blot technique, was increased 2.7-fold in rats treated with 200mg AlCl3/kg b.w (P < 0.01). Intestine activities of both GSH-synthase (from 60 mg/kg b.w.) and GSSG-reductase (from 120 mg/kg b.w.) were significantly reduced (26% and 31%, respectively) while glutathione-S-transferase showed to be slightly modified in the Al-treated groups. Conversely, gamma-glutamyltranspeptidase activity was significantly increased (P < 0.05) due to the Al treatment. Al reduced in vitro mucosa-to-lumen GSH efflux (P < 0.05). A positive linear correlation between the intestine GSH depletion and reduction of in situ 45Ca intestinal absorption, both produced by Al, was found (r = 0.923, P = 0.038). Taking as a whole, these results show that Al would alter GSH metabolism in small intestine by decreasing its turnover, leading to an unbalance of redox state in the epithelial cells, thus contributing to deteriorate GSH-dependent absorptive functions.  相似文献   

18.
An isoenzyme of glutathione S-transferase (adGST) was purified from liver intestine of the seashell (Asaphis dichotoma) by GST-Sepharose 4B affinity chromatography followed by reverse-phase HPLC. The enzyme has a pI value of 4.6 and is composed of two subunits each with a molecular weight of 23kDa. It exhibits different catalytic activities toward the substrates 1-chloro-2,4-dinitrobenzene, 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole, ethacrynic acid, and p-nitrophenyl acetate and, fascinatingly, shows high activity toward CDNB. The amino acid composition of adGST was determined and found to be very similar to the Sloane squid GSTs. N-terminal analysis of the first 15 residues of adGST revealed that it has 73% sequence identity with the pig roundworm GSTs. The adGST shows characteristics similar to those of class sigma GSTs, as was indicated by its substrate specificity, N-terminal amino acid sequence, and amino acid composition.  相似文献   

19.
干旱胁迫下沙生灌木花棒的抗氧化保护响应研究   总被引:20,自引:5,他引:15  
韩刚  党青  赵忠 《西北植物学报》2008,28(5):1007-1013
采用盆栽试验,测定了在不同土壤水分胁迫程度和胁迫时间下花棒苗抗氧化保护酶(SOD、CAT、POD、APX)活性和抗氧化物(AsA、GSH、Car)含量,并用隶属函数值法综合评价了试验条件下花棒苗的抗氧化能力。结果显示:(1)与同期适宜水分处理相比,花棒苗的抗氧化保护酶活性在中度和重度干旱胁迫30d时均显著增加;胁迫60d时,POD活性均显著降低,而其余酶活性仍增加(重度胁迫)或显著增加(中度胁迫);胁迫90d时,中度胁迫处理除APX活性持平外,其余酶活性仍显著升高,而重度胁迫处理的SOD活性持平、POD活性显著增加、CAT和APX活性均显著降低。(2)相对于同期适宜水分处理,干旱胁迫30d时,中度胁迫处理的花棒苗AsA、Car、GSH含量分别显著增加、稍有增加和显著降低,而重度胁迫的AsA显著增加,Car和GSH含量均显著降低;胁迫60d时,中度胁迫处理的AsA、Car、GSH含量分别显著增加、稍有降低和稍有提高,而重度胁迫的AsA、Car、GSH含量分别显著增加、稍有增加和显著降低;胁迫90d时,中度胁迫处理的AsA含量显著增加,Car和GSH含量均稍有提高,而重度胁迫的AsA含量稍有下降,Car和GSH含量则持平。(3)花棒苗的MDA含量在干旱胁迫过程中均比适宜水分处理增加,且中后期达到显著水平。(4)花棒苗抗氧化能力在干旱胁迫30d表现为重度干旱>中度干旱>适宜水分,胁迫60d为中度干旱>重度干旱>适宜水分,胁迫90d时为中度干旱>适宜水分>重度干旱。研究表明,花棒苗在中度干旱胁迫下能调动自身抗氧化保护酶类与抗氧化物质并提高其抗氧化能力,消除或减轻干旱诱导的活性氧毒害;重度干旱胁迫下的花棒苗在胁迫前中期亦能增强自身的抗氧化能力,但在胁迫后期因部分活性氧清除机制受到破坏而使抗氧化能力降低。  相似文献   

20.
Thermal trauma can damage organs away from the skin burn site and lead to multiple organ dysfunction. Following thermal injury, all tissues are exposed to ischemia, and as a result, resuscitation and reperfusion occur during the burning shock. Burn damage starts systemic inflammatory reactions that produce toxins and reactive oxygen radicals that lead to peroxidation. This study aimed to investigate, for the first time, the possible antioxidant effects of Myrtus communis ethanol extract on burn-induced oxidative distant organ injury orally. The thermal trauma was generated under ether anesthesia by exposing the dorsum of rats to 90 °C water bath for 10 s. 100 mg/kg/day Mrytus communis ethanol extract was applied orally for two days. Malondialdehyde (MDA) and glutathione (GSH) levels, glutatinone-S-transferase (GST), superoxidedismutase (SOD) and catalase (CAT) activities were determined to detect the possible antioxidant effects of myrtle on small intestine and lung tissues. Burn damage significantly increased MDA levels in lung and small intestine tissues, and significantly decreased GSH levels, CAT and GST activities in the small intestine and lung tissues compared to control group. Mrytus communis ethanol extract decreased MDA level and increased GSH level, SOD, CAT and GST activities significantly in either small intestine or lung tissues. Mrytus communis extract may be an ideal candidate to be used as an antioxidant adjunct to improve oxidative distant organ damage to limit the systemic inflammatory response and decreasing the recovery time after thermal injury.  相似文献   

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