Free Radical Scavenging and Hepatoprotective Constituents from the Leaves of Juglans sinensis

In the course of searching for hepatoprotective agents from natural products, six compounds were isolated from the MeOH extract of the leaves of Juglans sinensis, as guided by their DPPH free radical scavenging activity. The structures were determined as juglanoside B (1), quercetin 3-O-alpha-L-arabinofuranoside (avicularin, 2), quercetin 3-O-alpha-L-arabinopyranoside (guaijaverin, 3), quercetin 3-O-alpha-L-rhamnopyranoside (quercitrin, 4), (+)-catechin (5) and quercetin 3-O-beta-D-galactopyranoside (hyperin, 6). Compounds 2-6 showed significant DPPH free radical scavenging effects. An evaluation for the hepatoprotective activity of the isolated compounds on drug-induced cytotoxicity was conducted, and compounds 1, 2, and 5 showed protective effects against nitrofurantoin-induced cytotoxicity, and compound 5 also exhibited a moderate protective effect on amiodarone-induced cytotoxicity in Hep G2 cells.     

Hepatoprotective constituents ofcudrania tricuspidata

Phytochemical investigation of the MeOH extract of the root barks of Cudrania tricuspidata Bureau (Moraceae), as guided by hepatoprotective activity in vitro, furnished four isoprenylated xanthones, cudratricusxanthone A (1), cudraxanthone L (2), cudratricusxanthone E (3), and macluraxanthone B (4). All of these compounds showed the significant hepatoprotective effect on tacrine-induced cytotoxicity in human liver-derived Hep G2 cells. Compounds 1, 2, and 4 also exhibited the significant hepatoprotective effect on nitrofurantoin-induced cytotoxicity in human liver-derived Hep G2 cells.     

Protective effects of acetylbergenin against carbon tetrachloride-induced hepatotoxicity in rats

The present study was undertaken to investigate whether or not the hepatoprotective activity of acetylbergenin was superior to bergenin in carbon tetrachloride (CCl4)-intoxicated rat. Acetylbergenin was synthesized by acetylating bergenin, which was isolated from Mallotus japonicus. The hepatoprotective effects of acetylbergenin were examined against CCl4-induced liver damage in rats by means of serum and liver biochemical indices. Acetylbergenin was administered orally once daily for 7 successive days, then a 0.5 ml/kg mixture of CCl4 in olive oil (1:1) was intraperitoneally injected at 12 h and 36 h after the final administration of acetylbergenin. Pretreatment with acetylbergenin reduced the elevated serum enzymatic activities of alanine/aspartate aminotransferase, sorbitol dehydrogenase and gamma-glutamyltransferase in a dose dependent fashion. Acetylbergenin also prevented the elevation of hepatic malondialdehyde formation and depletion of glutathione content dose dependently in CCl4-intoxicated rats. In addition, the decreased activities of glutathione S-transferase and glutathione reductase were restored to almost normal levels. The results of this study strongly suggest that acetylbergenin has potent hepatoprotective activity against CCl4-induced hepatic damage in rats by glutathione-mediated detoxification as well as having free radical scavenging activity. In addition, acetylbergenin doses of 50 mg/kg showed almost the same levels of hepatoprotective activity as 100 mg/kg of bergenin, indicating that lipophilic acetylbergenin is more active against the antihepatotoxic effects of CCl4 than those of the much less lipophilic bergenin.     

Moringa oleifera Lam prevents acetaminophen induced liver injury through restoration of glutathione level

Initiation of acetaminophen (APAP) toxicities is believed to be promoted by oxidative stress during the event of overdosage. The aim of the present study was to evaluate the hepatoprotective action of Moringa oleifera Lam (MO), an Asian plant of high medicinal value, against a single high dose of APAP. Groups of five male Sprague-Dawley rats were pre-administered with MO (200 and 800 mg/kg) prior to a single dose of APAP (3g/kg body weight; p.o). Silymarin was used as an established hepatoprotective drug against APAP induced liver injury. The hepatoprotective activity of MO extract was observed following significant histopathological analysis and reduction of the level of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP) in groups pretreated with MO compared to those treated with APAP alone. Meanwhile, the level of glutathione (GSH) was found to be restored in MO-treated animals compared to the groups treated with APAP alone. These observations were comparable to the group pretreated with silymarin prior to APAP administration. Group that was treated with APAP alone exhibited high level of transaminases and ALP activities besides reduction in the GSH level. The histological hepatocellular deterioration was also evidenced. The results from the present study suggested that the leaves of MO can prevent hepatic injuries from APAP induced through preventing the decline of glutathione level.     

Cubosomes as a Potential Oral Drug Delivery System for Enhancing the Hepatoprotective Effect of Coenzyme Q10

Coenzyme Q10 (CoQ10) acts as an antioxidant that protects the cells by preventing lipid peroxidation. Owing to its low solubility, CoQ10 has shown poor delivery properties and poor bioavailability. The aim of this study is to develop CoQ10 loaded cubosomes in order to enhance its oral delivery and hepatoprotective activity. Cubosomes are cubic nanostructured systems resulting from the colloidal dispersion of cubic liquid crystalline structure in water. CoQ10 loaded cubosomes were prepared using poloxamer 407 and glyceryl monooleate at three weight ratios (1:2.5, 1:5 and 1:7.5) and were further characterized. They were investigated for their hepatoprotective effect in thioacetamide (TAA) induced hepatotoxicity in Wistar rats. The developed CoQ10 cubosomes exhibited moderate to high entrapment efficiency percentages (44.69–75.96%), nanometric dimensions (132.4–223.2 nm), and negatively charged zeta potential values (<-21.3). In-vitro release profiles showed a sustained release of CoQ10 from the developed cubosomes up to 48 h. In-vivo study revealed an improved hepatoprotective effect of CoQ10 cubosomes via reducing liver enzymes, nitric oxide and malondialdehyde as well as elevating phosphoinositide 3-kinase, catalase and glutathione peroxidase, compared to plain drug. These results were in good agreement with histopathological investigations. Consequently, the developed cubosomes showed a potential effect in enhancing the hepatoprotective activity of CoQ10.     

火麻仁油对高脂血症大鼠血脂代谢及保肝作用研究

目的:探讨火麻仁油对高脂血症大鼠血脂代谢及肝脏的保护作用。方法:采用高脂饲料建立大鼠高脂血症模型,随机分为正常对照组、高脂模型组、火麻仁油高剂量组1.5 g·kg-1、中剂量组1.0 g·kg-1、低剂量组0.5 g·kg-1和血脂康阳性对照组(0.5 g·kg-1),连续给药35 d,观察不同剂量火麻仁油对高脂血症大鼠血清中总胆固醇(TC)、三酰甘油(TG)、高密度脂蛋白胆固醇(HDL-C)、低密度脂蛋白胆固醇(LDL-C)、超氧化物岐化酶(SOD)、丙二醛(MDA)、丙氨酸氨基转移酶(ALT)、门冬氨酸氨基转移酶(AST)及肝脏中超氧化物岐化酶(SOD)和丙二醛(MDA)等生化指标的影响。结果:与模型组比较,火麻仁油各剂量组均能明显降低高脂血症模型大鼠血清中TC、TG、ALT的含量以及动脉粥样硬化指数(P<0.05或P<0.01)、并显著提高血清和肝脏中SOD酶活性(P<0.01);中、高剂量可以显著性地降低高脂血症模型大鼠血清AST、MDA含量(P<0.01);高剂量可以显著降低血清LDL-C以及肝脏中MDA含量(P<0.01)。结论:火麻仁油对高脂血症大鼠具有良好的降血脂的作用,而且具有较好的肝脏保护作用,其作用机制可能与改善脂质代谢和增强机体抗氧化能力有关。     

五味子保肝作用的研究进展

五味子是常用的传统滋补类中药,具有宁心安神的功效,主治心神失养之虚烦心悸,失眠多梦等症状。近年来,国内外关于五味子在保肝方面的药理作用进行了大量的研究,本文对五味子在此方面的研究进行了总结阐述,为临床研究开发保肝新药提供了理论参考。     

口服齐墩果酸对D-氨基半乳糖致小鼠急性肝损伤的保护作用

目的 研究口服齐墩果酸(OA)对D-氨基半乳糖诱导小鼠急性肝损伤的保护作用.方法 将♂昆明种小鼠随机分为对照组、OA给药组、模型组、OA预处理组.采用ig给予OA给药组和OA预处理组小鼠200 μmol· kg-1 OA,ig给予对照组、模型组等体积菜籽油,每天2次,连续3d,末次给药1h后,ip给予对照组、OA给药组等体积生理盐水,ip给予模型组和OA预处理组800 mg· kg-1D-氨基半乳糖溶液造模,造模8h后,收集各组小鼠的血液和肝脏组织,测定小鼠血清中天冬氨酸氨基转移酶(AST)、丙氨酸氨基转移酶(ALT)和肝脏中丙二醛(MDA)的含量,观察肝组织病理学的改变,并应用实时定量RT-PCR检测肝毒性相关基因的表达水平.结果 OA预处理能降低D-氨基半乳糖所致小鼠血清中AST、ALT的活性及肝组织中MDA的含量,明显改善肝细胞坏死病变的程度,并逆转小鼠急性肝损伤所致的生长停滞及DNA损伤诱导基因153(Chop10)、生长停滞及DNA损伤诱导基因45、Egr1、mKC、TNF-α mRNA表达的增高.结论 OA对D-氨基半乳糖所致小鼠急性肝损伤具有保护作用,其机制可能与缓解急性内质网应激、减轻炎症和抗氧化有关.     

Eleusine indica L. possesses antioxidant activity and precludes carbon tetrachloride (CCl4)-mediated oxidative hepatic damage in rats

Objectives

The purpose of this study was to evaluate the ability of aqueous extract of Eleusineindica to protect against carbon tetrachloride (CCl₄)-induced hepatic injury in rats.

Methods

The antioxidant activity of E. indica was evaluated using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging assay. The total phenolic content of E. indica was also determined. Biochemical parameters [e.g. alanine aminotransferase (ALT), aspartate aminotransferase (AST), malondialdehyde (MDA), glutathione (GSH), catalase, glutathione peroxidase, glutathione reductase, glutathione S-transferase and quinone reductase] were used to evaluate hepatic damage in animals pretreated with E. indica and intoxicated with CCl₄. CCl₄-mediated hepatic damage was also evaluated by histopathologically.

Results

E. indica extract was able to reduce the stable DPPH level in a dose-dependent manner. The half maximal inhibitory concentration (IC₅₀) value was 2350 μg/ml. Total phenolic content was found to be 14.9 ± 0.002 mg/g total phenolic expressed as gallic acid equivalent per gram of extract. Groups pretreated with E. indica showed significantly increased activity of antioxidant enzymes compared to the CCl₄-intoxicated group (p < 0.05). The increased levels of serum ALT and AST were significantly prevented by E. indica pretreatment (p < 0.05). The extent of MDA formation due to lipid peroxidation was significantly reduced (p < 0.05), and reduced GSH was significantly increased in a dose-dependently manner (p < 0.05) in the E. indica-pretreated groups as compared to the CCl₄-intoxicated group. The protective effect of E. indica was further evident through decreased histopathological alterations in the liver.

Conclusion

The results of our study indicate that the hepatoprotective effects of E. indica might be ascribable to its antioxidant and free radical scavenging property.