槲皮素对大剂量X线暴露所致PC12细胞氧化性损伤的保护作用

目的探讨槲皮素对PC12细胞的毒性及其对大剂量X线诱导PC12细胞氧化性损伤的保护作用。方法槲皮素6.25,12.5,25,50和100μmol·L-1分别作用于PC12细胞,于24,48和72 h后采用MTT法检测PC12细胞增殖。槲皮素12.5,25和50μmol·L-1分别与PC12细胞预孵育2 h,随后采用4 GyX线辐照PC12细胞,于24 h后,采用MTT法检测PC12细胞增殖反应,黄嘌呤氧化酶法检测细胞内超氧化物歧化酶(SOD)活性,硫代巴比妥法检测丙二醛(MDA)含量,菲啉络合法检测总抗氧化能力(T-AOC),DCFH-DA探针法检测活性氧(ROS)含量。结果槲皮素6.25～100μmol·L-1与PC12细胞作用24 h(r=0.887,P<0.01)和48 h(r=0.872,P<0.01)具有促细胞增殖作用,作用72 h表现出明显的细胞毒性,且随浓度增加毒性增大(r=0.942,P<0.01)。与正常对照组比较,PC12细胞受辐射后细胞增殖反应、SOD活性和T-AOC降低(P<0.01),MDA和ROS含量增加(P<0.01)。与辐照对照组比较,槲皮素12.5,25和50μmol·L-1防护组PC12细胞增殖反应(r=0.751,P<0.01),SOD活性(r=0.837,P<0.01)和T-AOC(r=0.940,P<0.01)随槲皮素浓度增大而增高,MDA含量(r=0.845,P<0.01)和ROS含量(r=0.930,P<0.01)随槲皮素浓度的增高而降低。结论槲皮素对大剂量X线诱导PC12细胞氧化性损伤具有一定的防护作用,在12.5～50μmol·L-1浓度范围内其防辐射作用与浓度呈较好的相关性。     

Quercetin protects human peripheral blood mononuclear cells from OTA‐induced oxidative stress,genotoxicity, and inflammation

Ochratoxin A (OTA) is one of the most abundant food‐contaminating mycotoxins world wide, and is detrimental to human and animal health. This study evaluated the protective effect of quercetin against OTA‐induced cytotoxicity, genotoxicity, and inflammatory response in lymphocytes. Cytotoxicity determined by MTT assay revealed IC₂₀ value of OTA to be 20 µM, which was restored to near control values by pretreatment with quercetin. Oxidative stress parameters such as antioxidant enzymes, LPO and PCC levels indicated that quercetin exerted a protective effect on OTA‐induced oxidative stress. Quercetin exerted an antigenotoxic effect on OTA‐induced genotoxicity, by significantly reducing the number of structural aberrations in chromosomes and comet parameters like, % olive tail moment from 2.76 ± 0.02 to 0.56 ± 0.02 and % tail DNA from 56.23 ± 2.56 to 12.36 ± 0.56 as determined by comet assay. OTA‐induced NO, TNF‐α, IL‐6, and IL‐8 were significantly reduced in the quercetin pretreated samples indicating its anti‐inflammatory role. Our results demonstrate for the first time that quercetin exerts a cytoprotective effect against OTA‐induced oxidative stress, genotoxicity, and inflammation in lymphocytes. © 2014 Wiley Periodicals, Inc. Environ Toxicol 31: 855–865, 2016.     

桑黄水煎液对D-半乳糖衰老模型小鼠的抗氧化作用

目的 观察桑黄水煎液对D-半乳糖诱导小鼠氧化损伤的保护作用,并探讨其保护作用的可能机制。方法 ①ICR小鼠分为正常对照组,桑黄水煎液低、中、高剂量（2,6,12 g·kg^-1）组,连续给药15 d。②ICR小鼠分为正常对照组、模型组、维生素E组（50 mg·kg^-1）,桑黄水煎液低、中、高剂量（2,6,12 g·kg^-1）组,小鼠颈背部皮下注射D-半乳糖（120 mg·kg^-1）造成亚急性衰老模型,按分组连续给药42 d。比色法测定小鼠肝脏及血清中丙二醛（MDA）含量和抗氧化酶活力,如超氧化合物歧化酶（SOD）、总抗氧化能力（T-AOC）、过氧化酶（POD）等。Western blot检测肝脏中核因子E2相关因子2（Nrf2）和血红素氧合酶1（HO-1）的表达。结果 桑黄水煎液对正常小鼠和D-半乳糖诱导小鼠体质量及脏器指数均无明显影响。桑黄水煎液可显著提高正常小鼠肝脏中T-AOC和SOD酶活力（P<0.01,P<0.05）。各剂量桑黄水煎液可显著提高衰老模型小鼠血清中T-AOC,降低MDA含量（P<0.01,P<0.05）,同时中剂量增强肝脏中SOD （P<0.05）和POD酶活力（P<0.01）,中、高剂量均上调肝脏中Nrf2和HO-1蛋白表达水平（P<0.01）。结论 桑黄水煎液具有提高正常小鼠抗氧化能力和改善D-半乳糖致小鼠氧化损伤作用,此作用可能是通过调节Nrf2/HO-1途径增加体内抗氧化酶的活性,减少过氧化脂质的生成,进而提高机体抗氧化能力。     

纳米铜对肾细胞的氧化损伤作用

目的研究氧化应激在纳米铜引起肾细胞毒性中的作用。方法通过检测细胞内活性氧生成、金属硫蛋白表达、谷胱甘肽和丙二醛含量来了解纳米铜对肾细胞的氧化损伤作用。结果纳米铜可以剂量依赖性方式诱导细胞内ROS含量升高。20 mg.L-1纳米铜与细胞作用24 h,细胞内MT表达均明显增强。将0～40 mg.L-1纳米铜与HK-2细胞作用24 h,可引起细胞内GSH,培养上清中的MDA水平均呈剂量依赖性升高,而细胞内MDA、CuZn-SOD水平升高不明显。结论纳米铜在一定剂量和暴露时间条件下破坏了肾细胞内活性氧与抗氧化物质的动态平衡,引起氧化应激,这是纳米铜引起毒性损伤的机制之一。     

Hepatic oxidative stress,DNA damage and apoptosis in adult zebrafish following sub‐chronic exposure to BDE‐47 and BDE‐153

Polybrominated diphenyl ethers (PBDEs) are ubiquitous and prolific contaminant in both the abiotic and biotic environment because of the wide industrial applications of these chemicals. In the present study, the effects of 2,2′,4,4′‐tetrabrominateddiphenyl ether (BDE‐47) and 2,2′,4,4′,5,5′‐hexabromodiphenyl ether (BDE‐153) exposure on the induction of hepatic oxidative stress, DNA damage, and the expression of apoptosis‐related genes in adult zebrafish were investigated. The activities of antioxidant enzymes, such as catalase and superoxide dimutase, significantly increased when adult zebrafish was exposed to various concentrations of BDE‐47 and BDE‐153 for 7 and 15 days. BDE‐47 and BDE‐153 elicited significant alterations in zebrafish 7‐Ethoxyresorufin‐O‐deethylase activity at 3, 7, or 15 days of exposure. In addition, the significant increase in comet assay parameters of zebrafish hepatocytes in a concentration‐dependent manner indicated BDE‐47 and BDE‐153 induced DNA damage, probably due to observed oxidative stress. Furthermore, a monotonically upregulation of p53 and Caspase3, which are apoptotic‐regulated genes, and decreased expression ratio of the anti‐apoptotic B‐cell lymphoma/leukaemia‐2 and Bcl2‐associated X protein genes for all BDE‐47 and BDE‐153 treatments at 7 and 15 days indicated apoptosis induction in zebrafish liver. Our findings help elucidate the mechanisms of BDE‐47‐ and BDE‐153‐induced toxicity in zebrafish hepatocytes.     

SOD类似物阻断百草枯诱导的N27细胞凋亡的作用

目的探讨在离体培养的细胞中,SOD类似物[manganese(Ⅲ)meso-tetrakis(N,N′-diethylimidazolium-2-yl)porphyrin,MnTDM]阻断百草枯诱导的N27细胞凋亡的作用。方法以N27细胞为多巴胺能神经元的细胞模型,检测不同浓度的MnTDM对百草枯诱导的N27细胞凋亡的保护作用,四甲基偶氮唑盐(MTT)法检测细胞活性及代谢状态;电镜观察凋亡形态;免疫细胞化学染色法观察凋亡相关蛋白Bax、Bcl-2蛋白的表达。结果经百草枯作用后N27细胞活性下降,且其下降程度与百草枯浓度的升高呈线性关系,MnTDM明显阻断百草枯诱导的细胞活性下降(P<0.05),且该阻断作用与MnTDM的浓度成正相关;MnTDM预处理后,电镜观察到细胞凋亡形态好转,凋亡相关蛋白Bcl-2表达升高,Bax表达降低,Bcl-2/Bax值升高。结论MnTDM对百草枯介导的凋亡有一定的保护作用,提示其可能对帕金森病患者的临床防治有一定作用。     

Melatonin reduces oxidative damage induced by aluminium in rat kidney

We evaluated the effect of melatonin (Mel), in male Wistar rats which received aluminium (Al) lactate for 12 weeks (0.57 mg Al/100 g body weight (b.w.), i.p. three times per week). Moreover rats received Mel (10 mg/kg b.w. i.p. 5 days/weeks) for 12 weeks. At the end of the treatment water and sodium balances were studied, and nephrogenic cyclic adenosine monophosphate (cAMP) was also measured. Urinary osmolality was measured after the administration of desmopressin (vasopressin agonist) to assess concentrating capacity. Oxidative stress in renal tissue and Na⁺–K⁺ATPase and gamma-glutamyl transferase (GGT) activities in whole plasma membrane were determined. Sodium and water balances were impaired by Al. We found decreased urinary concentrating ability and nephrogenic cAMP excretion. Al increased the Na⁺–K⁺ATPase activity, and serum aldosterone concentration. Mel normalized serum aldosterone level, the Na⁺–K⁺ATPase activity and potassium urinary without improving water and sodium excretion. Mel treatment did not improve the impaired urinary concentrating ability. Al reduced the GGT activity, an effect that persists in Al⁺ Mel. Al exposure promoted oxidative stress with an increase in lipid peroxidation (LPO), and a decrease in glutathione (GSH) and glutathione peroxidase (GSH-Px) and catalase (CAT) activities. Mel markedly attenuated oxidative stress produced by Al. This may result from the higher efficacy of melatonin in scavenging various free radicals and also because of its ability in stimulating the antioxidant enzymes. However, it only reduced some alterations in the renal functions particularly related to the water and sodium excretion, which would be independent of the increased production of reactive oxygen substances.     

Protective effect of quercetin on aroclor 1254-induced oxidative damage in cultured chicken spermatogonial cells.

Quercetin, a dietary-derived falvonol-type flavonoid, is ubiquitous in fruits and vegetables and plays important roles in human health by virtue of its antioxidant function. The present study was performed to investigate effects of quercetin on oxidative damage that was induced by an environmental endocrine disrupter, Aroclor 1254 (A1254), in cultured spermatogonial cells of embryonic chickens. Spermatogonial cells were dispersed from 18-day-old embryo and exposed to A1254 alone or in combination with quercetin. The oxidative damage was estimated by measuring contents of thiobarbituric acid-reactive substances (TBARS, an indicator of lipid peroxidation), activity of superoxide dismutase (SOD, a scavenger of superoxide), and activity of glutathione (GSH, an intracellular antioxidant). Results showed that quercetin had no deleterious effect on spermatogonial cells at 0.01 approximately 1 microg/ml. Exposure to A1254 (10 microg/ml) induced an increase of spermatogonial cell number, and membrane integrity was damaged by elevation of lactate dehydrogenase (LDH) leakage. Exposure to A1254 also induced an elevation in TBARS but a decrease in SOD activity and GSH content. However, compared with A1254 treatment alone, simultaneous supplementation with quercetin decreased LDH leakage to maintain the cell integrity, decreased the levels of TBARS to quench the free radicals, increased SOD activity and GSH content to restore the endogenous antioxidant defense system. Thus, quercetin displayed protective effects on spermatogonial cells from A1254-induced oxidative damage through increasing intracellular antioxidant levels and decreasing lipid peroxidation. Consequently, the antioxidant, such as quercetin, from food or feed consumed by human and animals may attenuate the negative effects of environmental endocrine disrupters.     

表没食子儿茶素没食子酸酯对亚硫酸盐诱导的心肌细胞氧化损伤的抑制作用

<正>绿茶常被称为是天然的抗氧化剂,含有很多种酚类物质,其中以表没食子儿茶素没食子酸酯(EGCG)含量最高且生物活性最强。流行病学调查和实验室研究表明,EGCG具有清除自由基、抗氧化、抗癌、抗肿瘤等功效[1-2],如在日本     

MAPK pathway mediates epithelial‐mesenchymal transition induced by paraquat in alveolar epithelial cells

Epithelial‐mesenchymal transition (EMT) is believed to be involved in lung fibrosis process induced by paraquat (PQ); however, the molecular mechanism of this process has not been clearly established. The present study investigated the potential involvement of EMT after PQ poisoning. The expressions of EMT markers, such as E‐cadherin and α‐smooth muscle actin (α‐SMA), at multiple time points after exposure to different concentrations of PQ were evaluated by western blot analysis. Following PQ treatment, EMT induction was observed under microscopy. Related fibrosis genes, including Matrix metalloproteinase 2 (MMP‐2), Matrix metalloproteinase 9 (MMP‐9), collagens type I (COL I), and type III (COL III), were also evaluated by measuring their mRNA levels using RT‐PCR analysis. Signaling pathways were analyzed using selective pharmacological inhibitors for MAPK. Cell migration ability was evaluated by scratch wound and Transwell assays. The data showed that PQ‐induced epithelial RLE‐6NT cells to develop mesenchymal cell characteristics, as indicated by a significant decrease in the epithelial marker E‐cadherin and a significant increase in the extracellular matrix (ECM) marker α‐smooth muscle actin in a dose and time‐dependent manner. Moreover, PQ‐treated RLE‐6NT cells had an EMT‐like phenotype with elevated expression of MMP‐2, MMP‐9, and COL I and COL III and enhanced migration ability. Signal pathway analysis revealed that PQ‐induced EMT led to ERK‐1 and Smad2 phosphorylation through activation of the MAPK pathway. The results of the current study indicate that PQ‐induced pulmonary fibrosis occurs via EMT, which is mediated by the MAPK pathway. This implies that the MAPK pathway is a promising therapeutic target in alveolar epithelial cells. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1407–1414, 2016.     

Quercetin abrogates bisphenol A induced altered neurobehavioral response and oxidative stress in zebrafish by modulating brain antioxidant defence system

Bisphenol A (BPA), a well-recognized anthropogenic xenoestrogen, has been identified as a causative agent responsible for inducing carcinogenicity, cognitive impairment, neurotoxicity, oxidative stress, etc. However, BPA-induced neurotoxicity and its possible amelioration through natural compound intervention remain elusive. The current study was performed to elucidate the neurotoxic potential of BPA in zebrafish (Danio rerio) by waterborne exposure and its possible amelioration by quercetin co-supplementation. Protective effect of quercetin against BPA-induced altered neurobehavioral response, oxidative stress and neuromorphological changes were evaluated in zebrafish brain. The present findings reveal that BPA-induced altered neurobehavioral response was ameliorated by quercetin. Biochemical studies advocate the potential therapeutic efficacy of quercetin against BPA-induced oxidative stress in zebrafish brain. Quercetin also shows neuroprotection against BPA-induced augmented neuronal pyknosis in periventricular grey zone (PGZ) of zebrafish brain. These basic findings indicate that quercetin may act as an effective intervention against BPA-induced neurotoxicity in zebrafish through down-regulation of oxidative stress.     

京尼平衍生物对硝普钠诱导的PC12细胞损伤的保护作用

目的探讨京尼平及其衍生物对硝普钠诱导的PC12细胞损伤的保护作用及其作用机制。方法通过62.5~1 000μmol/L硝普钠处理PC12细胞24 h建立细胞损伤模型,造模前2 h给予京尼平衍生物预处理,采用噻唑蓝比色法(MTT)考察京尼平衍生物对PC12细胞存活率的影响。Hoechst染色后观察细胞形态,以DCFH-DA探针和丙二醛(MDA)检测试剂盒分别检测PC12细胞内ROS、MDA水平,RT-PCR法检测PC12细胞抗氧化应激基因水平。结果与对照组比较,硝普钠能剂量相关性地降低PC12细胞的存活,在750μmol/L时具有统计学差异,而10μmol/L 1R-异丙基-6,7-二氢京尼平(化合物4)、1S-异丙基-6,7-二氢京尼平(化合物5)能够明显增加硝普钠诱导PC12细胞损伤后的细胞存活率(P0.05、0.01)。Hoechst染色形态学证实化合物4、5能够明显减少PC12细胞的凋亡。硝普钠诱导PC12细胞内氧化应激水平,化合物4、5能有效地降低ROS、MDA水平,并促进抗氧化酶基因GCLC、GPX、CAT m RNA表达,但对HO-1、Mn SOD基因表达水平无明显影响。结论京尼平衍生物可以抑制硝普钠诱导的PC12细胞损伤和细胞内氧化应激水平,其作用机制可能是通过影响抗氧化酶GCLC、CAT、GPX m RNA表达水平而实现。     

Furazolidone induced oxidative DNA damage via up-regulating ROS that caused cell cycle arrest in human hepatoma G2 cells

Furazolidone (FZD) is an antimicrobial agent that has been shown to have mutagenic, genotoxic and potentially carcinogenic properties when tested in a variety of systems in vitro and in vivo. In this study, we investigated FZD's DNA damaging effect in human hepatoma cells aiming at further defining the molecular mechanism of FZD's cytotoxicity. Addition of FZD resulted in cell growth suppression and cell cycle arrest in S phase accompanied by remarkable DNA strand breaks with increased levels of intracellular reactive oxygen species (ROS) and 8-hydroxydeoxyguanosine. Activities of antioxidases were down-regulated following FZD treatment and antioxidant agent catalase and superoxide dismutase ameliorated FZD's DNA damaging effects. Moreover, FZD caused much more extensive damage to mitochondrial DNA (mtDNA) than to nuclear DNA for which the decrease in mtDNA content correlated with FZD usage in a dose-dependent manner. However, there was no evidence of FZD induced mtDNA mutation in the mitochondrial DNA displacement loop. These results demonstrate that FZD up-regulates the production of intracellular ROS to cause oxidative DNA damage with mtDNA being the most vulnerable targets. Oxidative stress and the injury of mtDNA could be early indicators of FZD-induced cytotoxicity, with the resulting abnormal progression of the cell cycle.     

DNA damage and alterations in expression of DNA damage responsive genes induced by TiO2 nanoparticles in human hepatoma HepG2 cells

Abstract

We investigated the genotoxic responses to two types of TiO₂ nanoparticles (<25 nm anatase: TiO₂-An, and <100 nm rutile: TiO₂-Ru) in human hepatoma HepG2 cells. Under the applied exposure conditions the particles were agglomerated or aggregated with the size of agglomerates and aggregates in the micrometer range, and were not cytotoxic. TiO₂-An, but not TiO₂-Ru, caused a persistent increase in DNA strand breaks (comet assay) and oxidized purines (Fpg-comet). TiO₂-An was a stronger inducer of intracellular reactive oxygen species (ROS) than TiO₂-Ru. Both types of TiO₂ nanoparticles transiently upregulated mRNA expression of p53 and its downstream regulated DNA damage responsive genes (mdm2, gadd45α, p21), providing additional evidence that TiO₂ nanoparticles are genotoxic. The observed differences in responses of HepG2 cells to exposure to anatase and rutile TiO₂ nanoparticles support the evidence that the toxic potential of TiO₂ nanoparticles varies not only with particle size but also with crystalline structure.     

高良姜素对H_2O_2诱导A375细胞氧化损伤的保护作用

目的探讨高良姜素对人A375黑素瘤细胞氧化损伤的保护作用。方法以700μmol·L-1的H2O2处理人A375黑素瘤细胞,建立氧化损伤模型,并以1,5和10μg·mL-1的高良姜素拮抗其作用。用倒置显微镜观察细胞形态;采用MTT比色法检测细胞存活率;并检测各组细胞上清液中丙二醛(MDA)、总抗氧化能力(T-AOC)、过氧化氢酶(CAT)、一氧化氮合酶(NOS)、超氧化物歧化酶(SOD)和谷胱甘肽过氧化物酶(GSH-PX)。结果高良姜素能明显改善H2O2损伤后的A375细胞形态,显著提高人A375黑素瘤细胞的存活率。与模型组相比,高良姜素给药后均能提高A375细胞T-AOC、CAT、SOD和GSH-Px活力(P<0.05),而MDA和NOS明显降低(P<0.05)。结论高良姜素对H2O2诱导的A375细胞氧化损伤具有保护作用。     

Gene expression profiling of A549 cells exposed to Milan PM2.5

Background

Particulate matter (PM) has been associated to adverse health effects in exposed population and DNA damage has been extensively reported in in vitro systems exposed to fine PM (PM2.5). The ability to induce gene expression profile modulation, production of reactive oxygen species (ROS) and strand breaks to DNA molecules has been investigated in A549 cells exposed to winter and summer Milan PM2.5.

Results

A549 cells, exposed to 10 μg/cm² of both winter and summer PM2.5, showed increased cytotoxicity at 24 h and a significant increase of ROS at 3 h of treatment. Despite these similar effects winter PM induced a higher number of gene modulation in comparison with summer PM. Both PMs modulated genes related to the response to xenobiotic stimuli (CYP1A1, CYP1B1, TIPARP, ALDH1A3, AHRR) and to the cell-cell signalling (GREM1) pathways with winter PM2.5 inducing higher fold increases. Moreover the winter fraction modulated also JUN (cell-cell signalling), GDF15, SIPA1L2 (signal transduction), and HMOX1 (oxidative stress). Two genes, epiregulin (EREG) and FOS-like antigen1 (FOSL1), were significantly up-regulated by summer PM2.5. The results obtained with the microarray approach have been confirmed by qPCR and by the analysis of CYP1B1 expression. Comet assay evidenced that winter PM2.5 induced more DNA strand breaks than the summer one.

Conclusion

Winter PM2.5 is able to induce gene expression alteration, ROS production and DNA damage. These effects are likely to be related to the CYP enzyme activation in response to the polycyclic aromatic hydrocarbons (PAHs) adsorbed on particle surface.     

盐酸戊乙奎醚对肺泡Ⅱ型上皮细胞氧化损伤的影响

目的 探讨盐酸戊乙奎醚对肺泡Ⅱ型上皮细胞氧化损伤的保护作用。方法 用过氧化氢（H2O2）加入A549 细胞培养液中制成 A549 细胞氧化损伤模型, 实验分为空白对照组（C 组）、 H2O2处理组（H 组）和盐酸戊乙奎醚-过氧化氢处理组 （P 组）。用 MTT 方法测 A549 细胞存活率, 用 TUNEL 方法测定细胞凋亡指数, 并测定细胞内的丙二醛（MDA）、 超氧化物歧化酶（SOD）、 还原型谷胱甘肽（GSH）、 烟酰胺腺嘌呤二核苷磷酸（NADPH）含量。结果 与 C 组比较, H 组的细胞存活率下降, 凋亡指数增加, MDA 含量上升, SOD、 GSH、 NADPH 的含量下降 （P＜0.05）。与H 组比较, P 组的细胞存活率增加, 凋亡指数下降, MDA 含量下降, SOD、 GSH、 NADPH 的含量增加（P＜0.05）。结论 盐酸戊乙奎醚对A549 细胞过氧化损伤具有保护作用。     

Ameliorative effect of polyphenols from Padina boergesenii against ferric nitrilotriacetate induced renal oxidative damage: With inhibition of oxidative hemolysis and in vitro free radicals

The aim of this study was to evaluate the antioxidant activities of diethyl ether (DEE) and methanol (M) extracts from brown alga Padina boergesenii using in vitro and in vivo antioxidant assay, which may help to relate the antioxidant properties with the possible outline of its ameliorative effect. M extract showed higher radical scavenging activity through ferric reducing antioxidant power 139.11 µmol tannic acid equivalent/g; DPPH 71.32 ± 0.56%; deoxyribose radical 88.31 ± 0.47%, and total antioxidant activity 0.47 ± 0.02 mg ascorbic acid equivalents/g. Oxidative red blood cell (RBC) hemolysis inhibition rate was significantly higher in M extract (150 mg/kg body weight) in reference to total phenolic content (r = 0.935). Rats administered with DEE and M extracts (150 mg/kg body weight) for seven days before the administration of ferric nitrilotriacetate (9 mg of Fe/mg/kg bodyweight). Rats pretreated with extracts significantly changed the level of renal microsomal lipid peroxidation, glutathione, and antioxidant enzymes in post‐mitochondrial supernatant (P < 0.05). Ameliorative effect of extracts against renal oxidative damage was evident in rat kidney through changes in necrotic and epithelial cells. HPTLC technique has identified the presence of rutin with reference to retardation factor (R_f) in both the extracts. These findings support the source of polyphenols (rutin) from P. boergesenii had potent antioxidant activity; further work on isolation of bioactive compounds can be channeled to develop as a natural antioxidant. © 2014 Wiley Periodicals, Inc. Environ Toxicol 30: 865–876, 2015.     

褪黑素对四氯化碳小鼠肝损伤的保护作用

目的　探讨褪黑素对四氯化碳肝毒性的保护作用。方法　给予小鼠四氯化碳（５ ｍｌ·ｋｇ － １ ） ,继后每隔６ ｈ ｉｐ 褪黑素１０ ｍ ｇ·ｋｇ － １ 。用胶原酶消化法分离小鼠肝细胞后,依次加用褪黑素（１０ － ５ ～１０ － １ １ ｍｏｌ· Ｌ－ １ ） 和四氯化碳（２０ ｍ ｍ ｏｌ· Ｌ－ １ ） 。以测定丙氨酸氨基转换酶（ Ａ Ｌ Ｔ） ,丙二醛（ Ｍ Ｄ Ａ） 和谷胱甘肽过氧化物酶活力,作为四氯化碳肝损伤的指标。用 Ｍ Ｔ Ｔ 法检测肝细胞活力。结果　四氯化碳可使小鼠血液 Ａ Ｌ Ｔ 活性和肝 Ｍ Ｄ Ａ 含量明显上升。体内应用 Ｍ Ｔ １０ ｍ ｇ·ｋｇ － １ ,则明显降低肝匀浆 Ｍ Ｄ Ａ 含量（ Ｐ＜ ００１） , 对血浆 Ａ Ｌ Ｔ 活性无明显影响。体外应用 Ｍ Ｔ（１０ － ５ ～１０ － ７ ｍｏｌ· Ｌ－ １ ） 亦可使肝细胞 Ｍ Ｄ Ａ 含量下降（ Ｐ＜ ００５） ,同时还可使肝细胞 Ａ Ｌ Ｔ 释放率下降,细胞活力上升（ Ｐ＜ ００５） 。结论　 Ｍ Ｔ 拮抗 Ｃ Ｃｌ４ 肝毒性的作用可能与其抗氧化能力有关     

α-硫辛酸对百草枯中毒大鼠胸腺Bax、Bcl-2表达及SOD活力、MDA水平的影响

目的:研究α-硫辛酸(α-lipoic acid, LA)对百草枯(paraquat, PQ)中毒大鼠胸腺Bax、Bcl-2表达及SOD活力、MDA水平的影响。方法:SD雄性大鼠40只,随机分为4组,分为正常组、模型组、α-硫辛酸低剂量组和α-硫辛酸高剂量组。实验结束后,取大鼠胸腺组织进行HE染色,观察大鼠胸腺组织结构的变化。采用黄嘌呤氧化酶法(羟胺法)测定SOD活力、MDA水平,SABC免疫组化试剂盒检测胸腺组织Bcl-2相关X蛋白(Human Bcl-2 associated X protein, Bax)和重组人B细胞淋巴瘤因子2(B-Cell lymphoma-2, Bcl-2)的表达。结果:模型组胸腺皮质区淋巴细胞呈松散状分布,皮髓质分界较模糊。与正常组比较,模型组大鼠胸腺组织SOD活力显著下降(P<0.01),MDA水平显著升高(P<0.01); Bax和Bcl-2蛋白表达量有所增加(P<0.01)。与模型组比较,LA低剂量组和高剂量组大鼠胸腺组织SOD活力均明显升高(P<0.01),MDA水平明显下降(P<0.01);Bax和Bcl-2蛋白表达量明显减少,Bcl-2/Bax比值明显提高(P<0.01)。结论:LA可能通过增高Bcl-2/Bax比值而抑制胸腺淋巴细胞的凋亡,从而为LA抗氧化损伤治疗PQ中毒的实验方法提供依据。