福辛普利联合非诺贝特对糖尿病小鼠视网膜病变干预作用的研究

目的 研究福辛普利（Fosinopril）联合非诺贝特（Fenofibrate）对糖尿病小鼠视网膜细胞凋亡的影响及相关基因的表达和视网膜组织中血管内皮生长因子（vascular endothelial growth factor,VEGF）、氧化相关物质的影响,以明确其抑制糖尿病视网膜病变（diabetic retinopathy,DR）的作用机制。方法 选取清洁级性成熟ICR小鼠150只,随机分为5组（每组30只）：A组（假造模组,普通饲料喂养并给予相同体积的生理盐水）、B组（模型组,高脂饲料喂养4 w后给予腹腔注射链脲佐菌素（streptozotocin,STZ）,给予相同体积生理盐水灌胃8 w）、C组（福辛普利对抗组,高脂饲料喂养4 w后给予腹腔注射链脲佐菌素,给予福辛普利干预8 w）、D组（非诺贝特对抗组,高脂饲料喂养4 w后给予腹腔注射链脲佐菌素,给予非诺贝特干预8 w）、E组（福辛普利+非诺贝特联合对抗组,高脂饲料喂养4 w后给予腹腔注射链脲佐菌素,给予福辛普利+非诺贝特干预8 w）,0w和8w时测血糖BG,处死小鼠取眼球制备视网膜组织匀浆取上清检测谷光甘肽过氧化物酶（Glutathione peroxidase,GSH-PX）、超氧化物歧化酶（Superioxide dismutase,SOD）、活性氧类物质（Reactive oxygen species,ROS）、丙二醛（Malondialdehyde,MDA）、VEGF浓度,用RT-PCR法检测视网膜Bax与Bcl-2基因mRNA水平的表达,并用Tunel染色法检测视网膜细胞凋亡情况。结果B、C、D、E组小鼠用药前后血糖无差别(p>0.05); 均较A组明显升高(p<0.05);A组小鼠视网膜组织GSH-PX、SOD活性值及Bcl-2基因mRNA水平表达均高于其他四组（P＜0.05）,而ROS、MDA、VEGF、Bax基因mRNA水平表达与Tunel指数均低于B、C、D组（P＜0.05）;B组小鼠GSH-PX、SOD活性值及Bcl-2基因mRNA水平表达均低于其他四组（P＜0.05）,而ROS、MDA、VEGF、Bax基因mRNA水平表达与Tunel指数均高于其他四组（P＜0.05）;E组小鼠GSH-PX、SOD活性值及Bcl-2基因mRNA水平表达均高于C、D组（P＜0.05）,而ROS、MDA、VEGF、Bax基因mRNA水平表达与Tunel指数均低于C、D组（P＜0.05）;D组小鼠GSH-PX、SOD活性及Bcl-2基因mRNA水平表达均高于C组（P＜0.05）,而ROS、MDA、Bax基因mRNA水平表达与Tunel指数均低于C组（P＜0.05）;C组小鼠VEGF浓度值低于D组（P＜0.05）。结论 福辛普利及非诺贝特均能改善DR,通过抑制凋亡与抗氧化对视网膜起到一定的保护作用,但两药联合应用效果更佳。     

竹节参总皂苷对异烟肼和利福平致小鼠肝损伤的保护作用

目的：研究竹节参总皂苷对异烟肼和利福平合用致小鼠肝损伤的保护作用。方法：灌胃异烟肼（75mg／kg）、利福平（100mg／kg）7d以复制小鼠肝损伤模型。40只雄性Bab1c小鼠随机分为正常对照（等容生理盐水）组、模型（等容生理盐水）组、水飞蓟宾（50mg／kg）组与竹节参总皂苷高、低剂量（100、50mg／kg）组,复制模型的同时灌胃给予相应药物,每天1次,连续7d。测定小鼠肝脏指数、血清丙氨酸氨基转移酶（ALT）和天冬氨酸氨基转移酶（AST）活性、肝匀浆中丙二醛（MDA）含量、超氧化物歧化酶（SOD）和谷胱甘肽过氧化物酶（GSH．Px）活性及mRNA的表达情况,并作小鼠一般情况与肝组织病理学观察。结果：与正常对照组比较,模型组小鼠肝脏指数显著升高,肝组织ALT、AST活性显著增强,sOD、GSH．Px活性显著减弱,MDA含量显著增加,GSH—Px和SOD。mRNA表达显著减弱（尸〈0．01或P〈0．05）。与模型组比较,竹节参总皂苷高、低剂量组小鼠肝脏指数显著降低,肝组织ALT、AST活性显著减弱,SOD：、GSH．Px活性显著增强,MDA含量显著减少,GSH—PX和SOD：mRNA表达显著增强（P〈0．01或P〈0．05）。正常对照组小鼠肝脏外观正常,肝小叶结构清楚,肝细胞索排列整齐,肝细胞轻微水肿,核结构清晰,肝窦正常;模型组小鼠肝脏明显肿大,质脆,边缘钝而厚,表面呈黄褐色颗粒状,肝细胞弥漫性水肿,胞浆疏松化,胞质色淡,肝细胞点状坏死,散在有炎性细胞浸润;竹节参总皂苷高、低剂量组小鼠肝大体与肝组织病理学均明显改善。结论：竹节参总皂苷对异烟肼和利福平合用致小鼠肝损伤具有明显的保护作用,其机制可能与其抗脂质过氧化有关。     

抑制NF-κB信号通路对顺铂致肺癌大鼠肾损伤的保护作用及其分子机制研究

摘要：目的:探索抑制核转录因子（NF）-κB信号通路对顺铂致肺癌大鼠肾损伤的保护作用及其分子机制研究。方法:将50只大鼠随机分为5组:正常对照组、肺癌组（Lewis细胞）、顺铂组(Lewis细胞+腹腔注射顺铂溶液5 mg·kg-1)、吡咯烷二硫代氨基甲酸盐（PDTC）组(Lewis细胞+腹腔注射PDTC 25 mg·kg-1)、PDTC+顺铂组（Lewis细胞+腹腔注射顺铂和PDTC）,每组10只。末次给药后,生化分析仪检测血清肌酐（SCr）、尿素氮（BUN）、胱抑素C（Cys C）、尿液肾损伤分子-1（Kim-1）水平,ELISA法测定肾组织中超氧化物歧化酶（SOD）和丙二醛（MDA）水平,RT-PCR检测肾组织肿瘤坏死因子-α（TNF-α）、白细胞介素（IL）-1β、IL-6水平,Western Blotting检测核因子2相关因子2（Nrf2）、血红素氧合酶-1（HO-1）、NF-κB p65、p-IκBα/IκBα的表达,HE染色检测肾组织损伤。结果:与肺癌组相比,顺铂组大鼠血SCr、BUN、Cys C、尿Kim-1水平及肾组织MDA、TNF-α、IL-1β、IL-6 mRNA、Nrf2、HO-1、NF-κB p65和p-IκBα/IκBα的表达明显升高（P<0.05）,肾组织SOD活性和GSH-Px活性明显降低（P<0.05）;与顺铂组相比,PDTC+顺铂组大鼠血SCr、BUN、Cys C、尿Kim-1水平及肾组织MDA、TNF-α、IL-1β、IL-6 mRNA、NF-κB p65和p-IκBα/IκBα的表达明显明显降低（P<0.05）,肾组织SOD、GSH-Px、Nrf2和HO-1的表达明显升高（P<0.05）。结论:抑制NF-κB信号通路可以降低炎症因子水平,还可以激活Nrf2的表达,降低氧化应激水平,保护顺铂致肺癌大鼠的肾组织损伤。     

依布硒啉对大鼠急性脊髓损伤后线粒体的保护作用

【摘要】目的 探讨依布硒啉对大鼠急性脊髓损伤后线粒体氧化损伤、细胞色素C释放及神经细胞凋亡的影响。方法 将60只健康SD大鼠随机分为5组,每组12只。采取用Allen’s法制脊髓损伤（SCI）模型,假手术组仅行椎板切除,SCI模型组行椎板切除+打击,甲基泼尼松龙组打击后给予甲基泼尼松龙腹腔注射处理（30 mg/kg）,依布硒啉组打击后给予依布硒啉腹腔注射处理（10 mg/kg）,生理盐水组打击后给予等体积0.1%二甲基亚砜的生理盐水溶液腹腔注射处理。术后24 h取受损脊髓,检测丙二醛（MDA）、谷胱甘肽（GSH）含量、细胞色素C表达及神经细胞凋亡情况。结果 依布硒啉组较SCI模型组脊髓组织线粒体中MDA含量明显降低,GSH明显增高,Western blot检测细胞色素C的释放量减少,TUNEL法检测神经细胞凋亡数目明显减少（均P<0.01）。结论 依布硒啉能够改善SCI后线粒体氧化损伤,减少线粒体细胞色素C释放,抑制神经细胞凋亡,对脊髓损伤起到保护作用。      

N-乙酰半胱氨酸对甲基汞致大鼠脑皮质氧化损伤和谷氨酸代谢障碍的影响

目的研究甲基汞致大鼠脑氧化损伤与谷氨酸代谢障碍的关系,探讨N-乙酰半胱氨酸(NAC)对甲基汞致大鼠神经毒性的防护作用。方法 40只Wistar大鼠按体重随机分成4组:对照组、4和12μmol/kg MeHg组及NAC预处理组。第1～3组皮下注射生理盐水,第4组皮下注射1 mmol/kg NAC;2 h后,第1组腹腔注射生理盐水,第2和3组分别腹腔注射4和12μmol/kg MeHg,第4组腹腔注射12μmol/kg MeHg,注射剂量均为5 ml/kg。干预隔日1次,染毒每日1次,连续干预与染毒4周。最后一次染毒24 h后,处死大鼠取其大脑皮质,测定汞、GSH、MDA、Glu、Gln、ROS含量,SOD、GSH-Px、PAG、GS活力,以及细胞凋亡率。结果随着染汞剂量的增大,脑皮质汞的含量也随之增大,GSH和Gln的含量降低,MDA、Glu和ROS的含量升高,SOD、GSH-Px和GS的活力降低,PAG的活力升高,细胞凋亡率增大;NAC预处理组与高剂量染汞组比较,上述指标均得到不同程度的拮抗。结论甲基汞可导致脑氧化损伤和谷氨酸代谢障碍,二者相互联系、相互促进;NAC对甲基汞所致氧化损伤和谷氨酸代谢障碍具有一定的防护作用。     

乌头提取物对心衰大鼠抗氧化能力的研究

目的：探讨乌头提取物对心衰大鼠抗氧化能力,并明确乌头提取物治疗心衰的作用。方法选取90只Wistar大鼠随机分为3组,空白组30只,对照组30只及实验组30只。实验组和对照组采用腹主动脉缩窄法制作慢性心衰大鼠模型。造模成功后对照组给予注射地高辛20 mg· kg－1,连续干预28 d;实验组在对照组的基础上加用乌头提取物,灌胃0．04 mg· kg－1,干预28 d,空白组以等体积生理盐水尾静脉注射0．04 g· kg－1。干预结束后,对大鼠采用腹腔注射麻醉方法,取腹主动脉血离心后取上层血清,按试剂盒方法测定超氧化物歧化酶（ SOD）、丙二醛（ MDA）、还原型谷胱甘肽（ GSH）。结果造模结束后,实验组与对照组SOD、MDA与GSH水平明显低于空白组,差异有统计学意义（ P＜0．05）。实验组与对照组SOD、MDA与GSH水平无明显差别,（ P＞0．05）;干预7 d及28 d后,与空白组相比,实验组与对照组SOD、MDA与GSH水平明显升高,差异有统计学意义（P＜0．05）,与对照组相比,实验组SOD、MDA与GSH水平明显升高,差异有统计学意义（P＜0．05）。结论向心衰大鼠体内注射乌头提取物,对提高心衰机体的抗氧化能力、改善心功能不全指导意义,值得临床推广。     

异欧前胡素对四氯化碳致小鼠急性肝损伤的保护作用

目的：研究异欧前胡素对四氯化碳（CCl₄）诱导的小鼠急性肝损伤的保护作用。方法：60只昆明种小鼠随机分为正常对照（生理盐水）组、模型（生理盐水）组、水飞蓟宾（阳性对照,16 mg·kg^-1）组和异欧前胡素低、中、高剂量（8,16,32 mg·kg^-1）组,连续灌胃给药7 d,每天1次。末次给药1 h后,除正常对照组外其余各组小鼠腹腔注射0.1% CCl₄花生油溶液诱发小鼠急性肝损伤。16 h后摘眼球取血并处死小鼠,测定肝脏指数,检测血清中丙氨酸氨基转移酶（ALT）、天冬氨酸氨基转移酶（AST）及肝组织中丙二醛（MDA）、超氧化物歧化酶（SOD）及谷胱甘肽（GSH）水平;检测肝脏线粒体中MDA水平、ATP酶活性及线粒体膜电位。结果：CCl₄诱导小鼠肝脏指数及血清ALT和AST水平显著升高,肝细胞肿胀、变性、坏死,出现明显炎性损伤;使肝组织及肝线粒体中MDA水平显著升高,SOD与GSH水平显著降低;同时导致肝线粒体中ATP酶活性显著降低,线粒体膜电位下降。而水飞蓟宾及异欧前胡素均可显著逆转CCl₄引发的这些效应。结论：异欧前胡素对CCl₄诱导的小鼠急性肝损伤具有保护作用,其机制可能与清除氧化应激产物MDA,增加细胞内抗氧化酶SOD与GSH活性及改善线粒体功能有关。     

维生素C对顺铂所致大鼠肾损伤的保护作用

目的研究维生素C（Vit C）对顺铂所致肾损伤的保护作用,并探讨其可能的机制。方法将40只成年雌性SD大鼠按体重分成5组,分别为正常对照组（A组,生理盐水）、Vit C对照组（B组,500mg／kg）、顺铂化疗模型组（C组,6mg／kg）、顺铂（6mg／kg）＋Vit C（50mg／kg或500mg／kg）干预组（D1组及D2组）。腹腔注射Vit C进行前、中、后期全程保护,并于顺铂给药5d后采血处死动物,测定血清尿素氮（BUN）、肌酐（Cr）、肾皮质匀浆丙二醛（MDA）含量及谷胱甘肽过氧化物酶（GSH—Px）、超氧化物歧化酶（SOD）活力的变化。结果与C组相比,D1组及D2组的血清Cr及BUN、肾皮质匀浆MDA含量明显下降（P〈0．01或P〈0．05）,GSH—Px和SOD活力略有增加。结论Vit C可以减轻顺铂所致肾损伤,作用机制可能与其抗氧化作用和清除自由基活性密切相关。     

牛磺酸和维生素C对锰致大鼠氧化损伤的拮抗作用

目的探讨牛磺酸(Tau)和维生素C(Vit-C)对锰致大鼠氧化损伤的影响,为阐明锰中毒的发病机制和防治提供依据。方法 Wistar大鼠32只,随机分为4组,分别为对照组、单纯染锰组、Tau和Vit-C干预组。对照组大鼠腹腔注射生理盐水,其余各组腹腔注射29.685 mg/kg Mn Cl2溶液。腹腔注射后2h,对照组和单纯染锰组大鼠隔日皮下注射生理盐水,Tau干预组隔日皮下注射125.15 mg/kg Tau,Vit-C干预组隔日皮下注射704.52 mg/kg Vit-C。每周染锰5次,1次/d,染毒4周。共计染锰20次,Tau和Vit-C干预各10次。测定肝、脑和肾组织还原型谷胱甘肽(GSH)、丙二醛(MDA)的含量和谷胱甘肽过氧化物酶(GSH-Px)、超氧化物歧化酶(SOD)的活力。结果与对照组比较,单纯染锰组大鼠肝脏、脑和肾组织MDA含量增加,肝肾组织GSH含量降低。脑组织GSH含量和GSH-Px活力有下降趋势,但统计学差异不明显。Tau干预组大鼠与单纯染锰组相比,肝脏、脑和肾组织MDA含量下降,GSH含量增加。脑和肾组织GSHPx活力增高,脑组织SOD活力增高。Vit-C干预组大鼠与单纯染锰组相比,大鼠肝脏MDA含量有下降趋势,脑和肾组织MDA含量明显下降。虽然大鼠肝脏、脑和肾组织GSH含量增加,但统计学差异不明显。仅肝组织GSH-Px活力明显增加。结论锰可使大鼠产生氧化损伤,Tau和Vit-C对锰致大鼠氧化损伤有一定的拮抗作用。     

大麻二酚通过激活PPAR-γ减轻四氯化碳所致小鼠急性肝损伤

目的探究大麻二酚(CBD)对四氯化碳(CCl4)诱导小鼠急性肝损伤的防治作用及机制。方法 42只6～8周龄C57BL/6J雄性小鼠随机分为对照组(9只)、模型组(9只)、CBD对照组(9只)、还原型谷胱甘肽(GSH)干预组(6只)、CBD干预组(9只),其中CBD对照组、GSH干预组、CBD干预组分别腹腔注射CBD 5 mg/kg、GSH 200 mg/kg、CBD5 mg/kg,对照组、模型组注射相同剂量的生理盐水。2 h后模型组、GSH干预组、CBD干预组分别腹腔注射含20%CCl4橄榄油5 m L/kg建立急性肝损伤模型,24 h后取血清检测丙氨酸转氨酶(ALT)、天冬氨酸转氨酶(AST)水平;HE染色观察小鼠肝组织病理变化;肝组织匀浆检测超氧化物歧化酶(SOD)、丙二醛(MDA)和GSH水平;Western blot检测肝组织过氧化物增殖物激活受体-γ(PPAR-γ)、环氧合酶-2(COX-2)蛋白的表达。结果与对照组比较,模型组细胞损伤坏死严重,ALT、AST、MDA水平及COX-2蛋白表达水平明显升高,SOD、GSH水平及PPAR-γ蛋白表达水平明显降低(均P<0.0...     

Role of receptor interacting protein (RIP)1 on apoptosis-inducing factor-mediated necroptosis during acetaminophen-evoked acute liver failure in mice

Acetaminophen (APAP) overdose induces apoptosis-inducing factor (AIF)-dependent necroptosis, but the mechanism remains obscure. The present study investigated the role of receptor interacting protein (RIP)1, a critical mediator of necroptosis, on AIF-dependent necroptosis during APAP-induced acute liver failure. Mice were intraperitoneally injected with APAP (300 mg/kg). As expected, hepatic RIP1 was activated as early as 1 h after APAP, which is earlier than APAP-induced hepatic RIP3 upregulation. APAP-evoked RIP1 activation is associated with hepatic glutathione (GSH) depletion. Either pretreatment or post-treatment with Nec-1, a selective inhibitor of RIP1, significantly alleviated APAP-induced acute liver failure. Moreover, Nec-1 improved the survival and prevented APAP-induced necroptosis, as determined by TdT-mediated dUTP-biotin nick end labeling (TUNEL) assay. Further analysis showed that Nec-1 significantly inhibited APAP-induced hepatic c-Jun N-terminal kinase (JNK) phosphorylation and mitochondrial Bax translocation. In addition, Nec-1 blocked APAP-induced translocation of AIF from the mitochondria to the nucleus. Of interest, no changes were induced by Nec-1 on hepatic CYP2E1 expression. In addition, Nec-1 had little effect on APAP-induced hepatic GSH depletion at early stage. Taken together, these results suggest that RIP1 is involved in APAP-induced necroptosis. Nec-1 is an effective antidote for APAP-induced acute liver failure.     

Oxidative stress potentiated by diallylsulfide, a selective CYP2E1 inhibitor, in isoniazid toxic effect on rat primary hepatocytes

Isoniazid (INH), one of the first-line antituberculosis drugs, has potential liver toxicity. Mechanisms reported by previous studies mainly focused on oxidative stress. In the present study, we investigated acute effects of diallylsulfide (DAS), a selective CYP2E1 inhibitor, on reduced glutathione (GSH) and reactive oxygen species (ROS) levels in rat primary hepatocytes treated with INH. In cultures treated with INH for 1, 4, 8h, significant loss of GSH content and decrease of ROS levels were observed. Moreover, when hepatocytes were co-treated with INH and 1mM DAS, accelerated GSH depletion and increased ROS production appeared. Further more, rat primary hepatocytes survival rates decreased significantly in cultures treated with INH together with DAS than in cultures treated with INH alone after 24h. In conclusion, DAS could potentiate INH toxic effect and this is the first study reporting the effect of DAS on oxidative stress in INH-induced hepatocytotoxicity.     

RIP1-mediated mitochondrial dysfunction and ROS production contributed to tumor necrosis factor alpha-induced L929 cell necroptosis and autophagy

Tumor necrosis factor alpha (TNFα) induces necroptosis and autophagy; however, the detailed molecular mechanism is not fully understood. In this study, we found that TNFα administration caused mitochondrial dysfunction and reactive oxygen species (ROS) production, which led to necroptosis and autophagy in murine fibrosarcoma L929 cells. Notably, the RIP1 (serine–threonine kinase receptor-interacting protein 1, a main adaptor protein of necroptosis) specific inhibitor necrostatin-1 (Nec-1) recovered mitochondrial dysfunction and ROS production due to TNFα administration. Moreover, pan-caspase inhibitor z-VAD-fmk (zVAD) increased RIP1 expression and exacerbated TNFα-induced mitochondrial dysfunction and ROS production, indicating that RIP1 led to mitochondrial dysfunction and ROS production. In addition, cytochrome c release from mitochondria was accompanied with TNFα administration, and Nec-1 blocked the release of cytochrome c upon TNFα administration, while zVAD enhanced the release. These further suggested that RIP1 induced mitochondrial dysfunction accompanied with cytochrome c release. Furthermore, autophagy inhibitor 3-methyladenine (3MA) did not affect RIP1 expression as well as mitochondrial dysfunction and ROS production. Together with our previous publication that autophagy was a downstream consequence of necroptosis, we concluded that TNFα induced mitochondrial dysfunction accompanied with ROS production and cytochrome c release via RIP1, leading to necroptosis and resulting autophagic cell death.     

Protective effects of echinacoside on carbon tetrachloride-induced hepatotoxicity in rats

The aim of this study was to investigate the possible protective effects of echinacoside, one of the phenylethanoids isolated from the stems of Cistanches salsa, a Chinese herbal medicine, on the free radical damage of liver caused by carbon tetrachloride in rats. Treatment of rats with carbon tetrachloride produced severe liver injury, as demonstrated by dramatic elevation of serum ALT, AST levels and typical histopathological changes including hepatocyte necrosis or apoptosis, haemorrhage, fatty degeneration, etc. In addition, carbon tetrachloride administration caused oxidative stress in rats, as evidenced by increased reactive oxygen species (ROS) production and MDA concentrations in the liver of rats, along with a remarkable reduction in hepatic SOD activity and GSH content. However, simultaneous treatment with echinacoside (50mg/kg, intraperitoneally) significantly attenuated carbon tetrachloride-induced hepatotoxicity. The results showed that serum ALT, AST levels and hepatic MDA content as well as ROS production were reduced dramatically, and hepatic SOD activity and GSH content were restored remarkably by echinacoside administration, as compared to the carbon tetrachloride-treated rats. Moreover, the histopathological damage of liver and the number of apoptotic hepatocytes were also significantly ameliorated by echinacoside treatment. It is therefore suggested that echinacoside can provide a definite protective effect against acute hepatic injury caused by CCl(4) in rats, which may mainly be associated with its antioxidative effect.     

Necroptosis contributes to the cyclosporin A-induced cytotoxicity in NRK-52E cells

Cyclosporin A (CsA) induces renal tubular epithelial cells apoptosis and necrosis following in vitro exposure. The mechanisms of CsA-induced apoptosis have been studied intensively, whereas the mechanisms of necrosis remain to be elucidated. Necroptosis has been described as programmed necrosis. This study investigated the ability of CsA to induce necroptosis in the rat tubular cell line NRK-52E. The NRK-52E cells were incubated with CsA for 24 hours with or without necrostatin-1 (Nec-1). The majority of the NRK-52E cells died of necrosis as indicated by LDH leakage, Hoechst 33342/PI staining, and flow cytometry analysis. Cell death was significantly reduced by Nec-1 pretreated before CsA exposure. CsA-induced apoptosis and necrosis were also compared in NRK-52E cells with or without knockdown of receptor interaction protein 3 (RIP3) expression using small interfering RNA. Moreover, the role of reactive oxygen species (ROS) in CsA-induced cell death was also attempted. The result suggests that necroptosis contributes to the CsA-induced cytotoxicity in NRK-52E cells. Meanwhile, RIP3 and ROS are involved in CsA-induced necroptosis. To our knowledge, this is the first report on necroptosis in CsA-induced renal tubular cell death pathways, which might offer a novel protective target for CsA nephrotoxicity.     

柳茶提取物对异烟肼引起的肝损伤小鼠CYP2E1酶活性及mRNA表达的影响

目的 研究柳茶提取物对异烟肼引起小鼠肝损伤的CYP2E1基因表达的影响。方法 60只小鼠随机分为正常对照组、模型对照组、阳性对照组(水飞蓟宾胶囊)和柳茶提取物低、中、高剂量组(1.0,1.5,2.0 g·kg^-1),分别灌胃给予相应的药物,连续10 d,检测各组血清(ALT、AST)及肝脏相关生化指标以及肝脏组织(MDA、SOD、GSH-PX）、病理学变化、CYP2E1酶活性及mRNA表达。结果 与模型组比较,柳茶提取物组血清及肝脏相关生化指标有显著改善(P<0.05或0.001),病理学研究进一步证明了其保护作用,CYP2E1的酶活性及mRNA表达均明显降低(P<0.05)。结论 柳茶提取物可能通过抑制CYP2E1的活性和表达来减少自由基的产生,从而达到减轻异烟肼引起的小鼠氧化性肝损伤作用。     

l-Theanine prevents alcoholic liver injury through enhancing the antioxidant capability of hepatocytes

l-Theanine is a unique amino acid in green tea. We here evaluated the protective effects of l-theanine on ethanol-induced liver injury in vitro and in vivo. Our results revealed that l-theanine significantly protected hepatocytes against ethanol-induced cell cytotoxicity which displayed by decrease of viability and increase of LDH and AST. Furthermore, the experiments of DAPI staining, pro-caspase3 level and PARP cleavage determination indicated that l-theanine inhibited ethanol-induced L02 cell apoptosis. Mechanically, l-theanine inhibited loss of mitochondrial membrane potential and prevented cytochrome c release from mitochondria in ethanol-treated L02 cells. l-Theanine also prevented ethanol-triggered ROS and MDA generation in L02 cells. l-Theanine restored the antioxidant capability of hepatocytes including GSH content and SOD activity which were reduced by ethanol. In vivo experiments showed that l-theanine significantly inhibited ethanol-stimulated the increase of ALT, AST, TG and MDA in mice. Histopathological examination demonstrated that l-theanine pretreated to mice apparently diminished ethanol-induced fat droplets. In accordance with the in vitro study, l-theanine significantly inhibited ethanol-induced reduction of mouse antioxidant capability which included the activities of SOD, CAT and GR, and level of GSH. These results indicated that l-theanine prevented ethanol-induced liver injury through enhancing hepatocyte antioxidant abilities.     

莲心总碱对脂多糖和D-氨基半乳糖诱导小鼠急性肝衰竭肝脏的保护作用

目的：研究莲心总碱（TAENN）对脂多糖和D-氨基半乳糖（LPS/GalN）诱导小鼠急性肝衰竭肝脏的保护作用及可能作用机制。方法：昆明种雄性小鼠随机分为4组：正常对照组、模型组、TAENN高剂量组（100 mg·kg^-1）、TAENN低剂量组（30 mg·kg^-1）。腹腔注射LPS/GalN建立小鼠急性肝衰竭模型;通过生存曲线分析、HE组织化学染色、肝脏指数和血清转氨酶活性分析评价动物肝损伤程度;通过检测血清及肝脏内中SOD、GSH、MDA、ROS、CAT、GSH-Px水平评价小鼠整体和肝脏内氧化应激的状况。结果：口服TAENN能有效降低LPS/GalN诱导的小鼠死亡,HE染色观察显示TAENN能明显减轻LPS/GalN诱导的肝脏显微结构变化;此外,TAENN明显缓解了LPS/GalN诱导的肝脏肿大,降低了小鼠血清中ALT和AST活性水平（P<0.01）。进一步研究表明,TAENN明显降低了模型小鼠血清中MDA的含量,而血清GSH和SOD水平则明显增加（P<0.01）;经TAENN处理后,小鼠肝组织中ROS和MDA的相对含量降低,而肝脏GSH、SOD、CAT和GSH-Px水平则显著增加（P<0.01）。结论：TAENN能有效缓解LPS/GalN诱导的小鼠肝衰竭,且这种对肝脏的保护作用与其抑制LPS/GalN诱导的肝脏氧化应激相关。     

Effects of lanthanum, cerium, and neodymium on the nuclei and mitochondria of hepatocytes: accumulation and oxidative damage

The aim of this study was to investigate the contents of lanthanum (La), cerium (Ce), and neodymium (Nd) that accumulate in nuclei and mitochondria isolated from the liver and their corresponding potential oxidative damage effects on nuclei and mitochondria. Five-week-old male imprinting control region (ICR) mice were exposed to chlorides of La, Ce, or Nd by oral gavage with one of three doses: 10, 20, or 40 mg/kgBW/day for 6 weeks. The concentrations of administered elements in hepatocyte nuclei and mitochondria were determined with inductively coupled plasma-mass (ICP-MS) spectrometry. The accumulation of La, Ce, and Nd in hepatocyte nuclei and mitochondria gradually increased in a dose-dependent manner with exposure to the elements, although the concentrations of La, Ce, and Nd in hepatocyte mitochondria were lower than those in their counterpart nuclei. In hepatocyte nuclei, superoxide dismutase (SOD) and catalase (CAT) activities decreased, whereas glutathione peroxidase (GPx) activity, glutathione (GSH) and malondialdehyde (MDA) levels increased. In hepatocyte mitochondria, SOD, CAT, and GPx activities and GSH levels were significantly decreased, and MDA levels were significantly increased. These results suggest that La, Ce, and Nd presumably enter hepatocytes and mainly accumulate in the nuclei and induce oxidative damage in hepatic nuclei and mitochondria.