Antihepatotoxic Effects of chlorogenic acid from Anthocephalus cadamba

In the present study, chlorogenic acid (CGA) isolated from Anthocephalus cadamba was screened for hepatoprotective activity by in vitro and in vivo assay methods using carbon tetrachloride (CCl₄) as a model of liver injury. Intraperitoneal administration of CGA to mice at a dose of 100 mg/kg body weight for 8 days caused significant reversal in lipid peroxidation, enzymatic leakage, cytochrome P450 (Cyt P450) inactivation and produced enhancement of cellular antioxidant defence in CCl₄-intoxicated mice, revealing that the antioxidative action of CGA is responsible for its liver protective activity. CGA exhibited a better therapeutic protective action than silymarin (SM), in CCl₄-administered mice.     

水飞蓟宾胶囊对异烟肼和利福平肝损害小鼠的保护作用

目的：观察水飞蓟宾胶囊(SC)对异烟肼(INH)与利相干(RFP)合用致肝损伤小鼠的保护作用。方法：测定肝损伤小鼠在给予SC后肝指数、血清谷丙转氨酶(ALT)的活性，肝匀浆中谷胱甘肽(GSH)及丙二醛(MDA)的含量，肝微粒体中细胞色素P450含量及其亚型2E1的活性。结果：SC可对抗INH和RFP合用引起的肝指数、血清ALT水平、肝匀浆中的MDS含量及P450、4502E1活性的升高，增加GSH含量；病理学检查SC能明显减轻肝细胞的变性和坏死。结论：SC对INH和RFP肝毒性的保护作用与其稳定肝细胞膜、抑制脂质过氧化反应、清除自由基、抑制药物代谢酶有关。     

Antiobesity,hypolipidemic, antioxidant and hepatoprotective effects of Achyranthes aspera seed saponins in high cholesterol fed albino rats

Introduction

Numerous herbal medicines have been recommended for the treatment of different diseases. Achyranthes aspera, Linn. (Family: Amaranthaceae), popularly known as Charchitta or Pitpapra, is commonly used by traditional healers for the treatment of fever, malaria, dysentery, asthma, arterial hypertension, pneumonia, and diabetes. The root extract is well reputed for its insect molting hormonal activity. This investigation was conducted to evaluate the effects of saponins from Achyranthes aspera seeds on the serum lipid profile of albino rats fed a high cholesterol diet.

Material and methods

Hypolipidemic, antioxidant and hepatoprotective activities of these saponins were tested as described previously. To determine the mechanism underlying the observed effects, serum antioxidant status was assessed according to ABTS (2,2’-azino-bis-3-ethylbenzo-thiazoline-6-sulfonic acid), superoxide dismutase and ferric ion reducing antioxidant power (FRAP) assays in saponin-treated hyperlipidemic animals. Liver enzyme levels were determined to reveal any possible hepatotoxicity.

Results

Four-week oral administration of A. aspera seed saponins produced a significant (p < 0.05) decrease of total cholesterol, total triglycerides and LDL-C and a significant increase of HDL-C level in hyperlipidemic rats. Treatment with A. aspera seed saponins also showed a significant (p < 0.01) improvement of serum antioxidant status in tested animals. No significant hepatotoxicity was produced by such treatment as the serum liver enzyme activity remained unaltered.

Conclusions

Saponins from A. aspera seeds possess antihyperlipidemic and antioxidant properties which might lead to improvement of serum lipid profile and blood antioxidant status. Our findings support the folkloric use of this indigenous plant in the treatment of hyperlipidemia. However, its exact mechanism of action remains to be elucidated.     

Misoprostol protection against acetaminophen-induced hepatotoxicity in the rat

The hepatoprotective effects of misoprostol on acetaminophen (APAP)-induced toxicity were studied in the rat. Liver injury was evaluated at 36 hr after APAP administration by measuring serum ornithine carbamoyltransferase (OCT) and alanine aminotransferase (ALT) levels, by using tetranitroblue tetrazolium (TNBT) staining and by histological analysis. After APAP administration, peak serum levels of the drug were detected at 15 min. Liver GSH was depleted from control levels of 448±48 µg/g to 82±2 µg/g (P<0.01) within 3 hr. Serum ALT levels increased significantly after 16 hr and H&E staining revealed significant hepatic necrosis after 12 hr. Rats treated with misoprostol before and after APAP administration showed reduced OCT and ALT levels at 36 hr of overdose (454±446 IU/liter and 2571±2944 IU/liter, respectively) compared to those without misoprostol treatment (1348±480 IU/liter and 6077±3025 IU/liter, respectively,P<0.01). TNBT staining showed a reduced area of damage from 28.6±22.3% to 7.3±8.9% (P<0.01), and H&E staining also showed less extensive hepatic necrosis in rats treated with misoprostol before and after the overdose. In a time sequence study, misoprostol treatment starting within 10 hr of overdose showed the same protective effect as when it was given before and after APAP ingestion. No protection was detected when the treatment was started during the development of hepatic injury. However, misoprostol given when injury was established seemed to be protective. Our results show that misoprostol protects the liver against APAP-induced injury if given within 10 hr of overdose. Late administration of misoprostol may also be beneficial and thus may be considered in treating patients with APAP toxicity.This study is supported by the Australian National Health and Medical Research Council Grant 91/0662.     

蛹虫草液体发酵产物冻干粉的抗氧化活性及保肝作用

目的研究蛹虫草液体发酵产物冻干粉的抗氧化活性及保肝作用。方法采用真空冷冻干燥的方法将蛹虫草液体发酵产物制成干粉并对冻干粉主要成分进行分析测定,通过DPPH自由基清除实验和衰老小鼠模型验证蛹虫草发酵产物冻干粉的抗氧化活性,通过小鼠急性肝损伤实验研究冻干粉的保肝作用,采用急性毒性试验验证冻干粉的安全性。结果蛹虫草发酵产物冻干粉含丰富的粗纤维、粗多糖、粗三萜及黄酮类物质。蛹虫草发酵产物冻干粉对DPPH自由基的半数有效浓度（EC50）为8．12mg／mL,在16mg／mL时对DPPH自由基的清除率为61．56％,与0．02mg／mL的维生素C（Vc）清除能力相当;蛹虫草发酵产物能显著提高衰老模型小鼠血清和肝脏中的总超氧化物歧化酶（T-SOD）、谷胱甘肽过氧化物酶（GSH-px）活力水平,降低丙二醛（MDA）含量,高剂量组的抗衰老效果与阳性药Vc组的抗氧化能力相当。小鼠急性肝损伤试验结果显示,冻干粉能有效降低模型组小鼠血液中门冬氨酸氨基转移酶（AST）与丙氨酸氨基转移酶（ALT）水平（P〈0．05）。冻干粉的半数致死量（LD50）远大于国家无毒标准15g／kg,属于无毒级别。结论蛹虫草发酵产物具有良好的抗氧化活性和保肝作用,且安全无毒。     

绿豆癀对四氯化碳所致小鼠急性肝损伤的保护作用

目的：研究绿豆癀对四氯化碳（CCl4）所致小鼠急性肝损伤的保护作用。方法：用CCl4制作小鼠急性肝损伤模型,绿豆癀和绿豆粉干预,测定血清AST及ALT含量,并作肝组织病理学检测。结果：绿豆癀和绿豆粉能降低小鼠血清AST和ALT的含量（P〈0.01或P〈0.05）;减轻肝细胞变性、坏死程度,缓解肝组织的病理改变,绿豆癀比绿豆粉效果好（P〈0.05）。结论：绿豆癀对CCl4所致小鼠急性肝损伤有保护作用。     

Clofibrate-induced in vitro hepatoprotection against acetaminophen is not due to altered glutathione homeostasis.

Prior induction of peroxisome proliferation protects mice against the in vivo hepatotoxicity of acetaminophen and various other bioactivation-dependent toxicants. The mechanisms underlying such chemoresistance are poorly understood, although they have been suggested to involve alterations in glutathione homeostasis. To clarify the role of glutathione in this phenomenon, we isolated hepatocytes from mice in which hepatic peroxisome proliferation had been induced with clofibrate. The cells were incubated with a range of acetaminophen concentrations and the extent of cell killing after up to 8 h was assessed by measuring lactate dehydrogenase leakage from the cells. Hepatocytes from clofibrate-pretreated mice were much less susceptible to acetaminophen than cells from vehicle-treated controls. However, the extent of glutathione depletion during exposure to acetaminophen was similar in both cell types, as were rates of excretion of the product of glutathione-mediated detoxication of acetaminophen's quinoneimine metabolite, 3-glutathionyl-acetaminophen. The glutathione-replenishing ability of clofibrate-pretreated cells after a brief exposure to diethyl maleate also resembled that of control cells. More importantly, prior depletion of glutathione by diethyl maleate did not abolish the resistance of clofibrate-pretreated cells to acetaminophen. Taken together, these findings indicate that although glutathione-dependent pathways may contribute to hepatoprotection during peroxisome proliferation, the resistance phenomenon is not due exclusively to this mechanism.     

灵五颗粒对四氯化碳致小鼠肝损伤的保护作用

目的观察灵五颗粒对四氯化碳致小鼠急性肝损伤的保护作用。方法 108只小鼠随机分为正常组、四氯化碳模型组、灵五颗粒低、中、高(2.5、5.0、10 g/kg)剂量组和阳性药联苯双酯(0.15 g/kg)组。除正常组、四氯化碳模型组给予生理氯化钠溶液外,给药各组均分别给药7 d,于末次给药1 h后,各组小鼠(正常组除外)分别腹腔注射0.12%四氯化碳橄榄油溶液,造成急性肝损伤,在中毒后16 h取血和肝脏,分别检测各组动物肝功能等指标,并做肝脏病理组织学检查。结果四氯化碳模型组小鼠肝功能明显异常,谷丙转氨酶、谷草转氨酶显著升高,病理性观察肝组织变性、坏死严重;肝、脾肿大明显。灵五颗粒中、高剂量组小鼠血清中谷丙转氨酶的水平均非常显著低于模型组,并呈良好的剂量依赖性。高剂量组小鼠血清中谷草转氨酶的水平显著低于模型组,并显著降低肝损伤小鼠血清丙二醛的含量,显著升高超氧化物歧化酶活力和谷胱甘肽含量。结论灵五颗粒对四氯化碳致小鼠急性肝损伤有明显的保护作用,其作用机制可能与清除过氧化产物丙二醛,升高超氧化物歧化酶活力有关。     

Hepatoprotective activity of Hypericum perforatum L. alcoholic extract in rodents

In recent years, interest in the hepatoprotective plants and plant based chemicals is increasing. In Turkish folk medicine, Hypericum perforatum L. has been used for various purposes including liver protection. The hepatoprotective effect of H. perforatum was investigated in vivo by cannulating the rat bile duct for choleretic activity and by barbiturate sleeping time following CCI₄-induced hepatic injury. The increase in the bile secretion following intraduodenal injection of H. perforatum extract, and the appearance of its constituents in the bile were observed by its colour change and this observation was confirmed by thin layer chromatographic analysis suggesting the excretion of hypericin into the bile as well. It was observed that the extract shortens the barbiturate sleeping time of CCI₄-treated mice suggesting hepatoprotection.     

苦菊提取物对HepG2细胞的抗氧化作用及其机制研究

目的：考察苦菊提取物（CEE）对H₂O₂致HepG2细胞氧化应激损伤的保护作用,并探讨苦菊提取物在HepG2细胞中抗氧化作用机制。方法：通过MTT法和DCFH-DA荧光染色,检测H₂O₂处理HepG2细胞的活性和胞内ROS水平;在抗氧化反应元件（ARE）报告基因转染稳定的HepG2细胞内检测ARE-Luciferase活性;并通过荧光定量RT-PCR测定HepG2细胞内含有ARE序列相关基因的mRNA表达水平。结果：H₂O₂处理HepG2细胞后,细胞存活率下降,胞内ROS水平上升,而加入不同浓度的CEE则可明显改善上述结果。不同浓度的CEE处理转染ARE报告基因的HepG2细胞,可使细胞内的ARE活性呈浓度依赖性增强。此外,CEE可使HepG2细胞中含ARE序列的调控基因GCLC,GCLM和HMOX-1的mRNA表达水平上调,并呈浓度依赖性。结论：CEE通过降低ROS水平,抑制H₂O₂诱导的HepG2细胞损伤,而CEE对HepG2细胞的抗氧化保护作用机制可能与其激活HepG2细胞内Nrf2-ARE通路相关的抗氧化防御系统密切相关。