Saponins isolated from the root of Platycodon grandiflorum protect against acute ethanol-induced hepatotoxicity in mice

The protective effects of saponins isolated from the root of Platycodon grandiflorum (Changkil saponins: CKS) against alcoholic steatosis in liver injury induced by acute ethanol administration were investigated. Pretreatment with CKS prior to ethanol administration significantly prevented the increases in serum alanine aminotransferase activity, hepatic TNF-α level, hepatic lipid peroxidation and hepatic triglyceride level. CKS prevented ethanol-induced steatosis and necrosis, as indicated by liver histopathological studies. Additionally, CKS protected against ethanol-induced depletion of hepatic glutathione levels. CYP2E1 has been suggested as a major contributor to ethanol-induced oxidative stress and liver injury. The concurrent administration of CKS efficaciously abrogated the CYP2E1 induction and CYP2E1-dependents hydroxylation of aniline as compared to the individual treatment at higher doses. These findings suggest that CKS may prevent ethanol-induced acute liver injury, possibly through its ability to block CYP2El-mediated ethanol bioactivation and its free radical scavenging effects.     

Protective effect of saponins derived from the roots of Platycodon grandiflorum against carbon tetrachloride induced hepatotoxicity in mice

The purpose of this study was to investigate the protective effects of the saponins isolated from the root of Platycodi Radix (Changkil saponins: CKS) on carbon tetrachloride (CCl(4))-induced hepatotoxicities in mice. Pretreatment with CKS prior to the administration of CCl(4) significantly prevented the increase in serum alanine aminotransferase and aspartate aminotransferase activities and hepatic lipid peroxidation formation. In addition, CKS prevented CCl(4)-induced apoptosis and necrosis, as indicated by a liver histopathologic study and DNA laddering. To determine whether Fas/Fas ligand (FasL) pathway involved in CCl(4)-induced acute liver injury, Fas and FasL proteins and caspase-3, -8 activities were tested by western blotting and ELISA. CKS markedly decreased CCl(4)-induced Fas/FasL protein expression levels and in turn attenuated CCl(4)-induced caspase-3, -8 activities in mouse livers. Additionally, CKS protected the CCl(4)-induced depletion of hepatic glutathione levels. The effect of CKS on CYP2E1, the major isozyme involved in CCl(4) bioactivation, was investigated. Treatment with CKS resulted in a significant decrease in the CYP2E1-dependent hydroxylation of aniline. In addition, CKS exhibited antioxidant effects on FeCl(2)-ascorbate induced lipid peroxidation in liver homogenates, and on superoxide radical scavenging activity. These findings suggest that the protective effects of CKS against CCl(4)-induced acute liver injury possibly involve mechanisms related to its ability to block CYP2El-mediated CCl(4) bioactivation and its free radical scavenging effects, and that is also protects against Fas/FasL pathway mediated apoptosis.     

Panax notoginseng saponins protect against chronic ethanol-induced hepatic steatosis

Chronic alcohol consumption induces hepatic steatosis, the early stage of alcoholic liver disease (ALD). The aim of present study is to investigate the protective effect of Panax notoginseng saponins (PNS) against chronic ethanol-induced hepatic steatosis in vivo. Mice were pair-fed a modified Lieber-DeCarli liquid diet containing alcohol or isocaloric maltose dextrin as control diet with or without PNS (200 mg/kg, BW) for 8 weeks. Animals supplemented with PNS were protected against hepatic lipid accumulation induced by chronic ethanol exposure. Accordingly, PNS could significantly decrease the elevation of plasma triglyceride, plasma enzyme activities, i.e. alanine aminotransferase (ALT) and aspartate aminotransferase (AST), and hepatic TNF-α and IL-6 levels which were induced by chronic alcohol exposure. In addition, PNS markedly reduced the lipolysis of white adipose tissue (WAT) that stimulated by alcohol feeding through the inhibiting protein expression of phosphorylation of hormone-sensitive lipase (p-HSL), rather than total HSL. Furthermore, alcohol exposure also enhanced fatty acid uptake capacity in liver by elevated hepatic CD36 expression, which could attenuated by PNS treatment. These results demonstrate that PNS supplementation protects against chronic ethanol-induced hepatic steatosis, which is associated with ameliorating dysfunctional lipid metabolism of WAT and the reduced inflammatory cytokines. Our findings suggested that PNS might be potential to be developed as an effective agent for the treatment of chronic alcoholic steatosis.     

钝化NF-κB的活化对酒精性肝损伤大鼠CYP3A的影响

目的研究核转录因子-κB(nuclear fastor kappa B,NF-κB)在酒精性肝损伤大鼠模型中的作用及对细胞色素P4503A(cytochrome P450 3A,CYP3A)代谢活力的影响。方法采用白酒灌胃法复制大鼠酒精性肝损伤模型,肝脏组织HE染色和血清中ALT和AST水平测定观测大鼠肝损伤情况,采用免疫组化法检测肝脏NF-κB的蛋白表达,通过HPLC法检测CYP3A的探针药物咪哒唑仑的血浆药物浓度,采用热板法观察大鼠舔足反应来体现咪哒唑仑的代谢情况,从而反映咪哒唑仑特异性代谢酶CYP3A的代谢活力。结果酒精性肝损伤模型组表现为轻度脂肪变性和炎症坏死,NF-κB明显活化,CYP3A代谢活力增强(P<0.05);钝化NF-κB的活化后,肝脏脂肪变性程度明显减轻,CYP3A代谢活力下调(P<0.05)。结论钝化NF-κB活化,可以减轻酒精性肝损伤的程度,并下调酒精性肝损伤导致的CYP3A代谢活性的增强。     

Altered activity of cytochrome P450 in alcoholic fatty liver exposed to ischemia/reperfusion

Ischemia/reperfusion (I/R) injury is a major cause of morbidity and mortality in liver surgery and transplantation, and fatty livers are susceptible to greater I/R injury and a higher incidence of primary graft nonfunction after transplantation. Because alcohol intake and obesity are major causes of fatty liver, this study was initiated to investigate the effect of chronic ethanol consumption on hepatic microsomal cytochrome P450 (CYP) activity after I/R. Rats were fed an alcohol liquid diet or a control isocaloric diet for 4 weeks, and then subjected to 60 min of hepatic ischemia and 5 h of reperfusion. It was found that, chronic ethanol consumption significantly increased liver weight, serum triglyceride (TG), liver TG, and serum aminotransferase activities. Moreover, alcoholic fatty livers exposed to I/R showed significantly higher levels of aminotransferase activities than the controls. No significant differences in microsomal CYP content or CYP1A1 activity were found between I/R treated animals fed a control diet (the CD + I/R group) and I/R treated animals fed an ethanol containing diet (the ED + I/R group). Moreover, whereas CYP1A2 activity was decreased in the ED + I/R group versus the CD + I/R group, CYP2E1 activity was elevated. Additionally, chronic alcohol consumption up-regulated TNF-alpha and IL-6 mRNA levels immediately after I/R. In conclusion, chronic ethanol consumption was found to potentiate hepatocellular damage as indicated by abnormalities in microsomal drug metabolizing function during I/R.     

Protective effect of saponins derived from roots of Platycodon grandiflorum on tert-butyl hydroperoxide-induced oxidative hepatotoxicity

There is increasing evidence that oxidative stress is implicated in the pathogenesis of various diseases, including alcoholic liver injury. In the present work, we investigate the protective effects of the saponins isolated from the roots of Platycodon grandiflorum A. DC (Campanulaceae), Changkil saponins (CKS), on the tert-butyl hydroperoxide (t-BHP)-induced oxidative injury (hepatotoxicity) in cultured rat primary hepatocytes and in rat livers. CKS significantly reduced t-BHP-induced oxidative injuries in cultured rat hepatocytes, as determined by cell cytotoxicity, intracellular glutathione (GSH) content and lipid peroxidation in a dose-dependent manner. CKS provided good protection from the t-BHP-induced production of intracellular reactive oxygen species and DNA damage. In addition, CKS was able to quench 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radicals and the superoxide radical. The in vivo study showed that the pretreatment with CKS prior to the administration of t-BHP significantly prevented the increase in the serum levels of hepatic enzyme markers (alanine aminotransferase and aspartate aminotransferase) and reduced oxidative stress, such as GSH content and lipid peroxidation, in the liver in a dose-dependent manner. These results support the anti-oxidative role of CKS, and demonstrate that CKS can scavenge oxygen free radicals and protect cells from oxidative stress.     

美他多辛对酒精性脂肪肝大鼠CYP2E1表达的影响及其预防作用

目的探讨美他多辛对酒精性脂肪肝大鼠肝组织中CYP2E1表达的影响及其治疗酒精性脂肪肝的机制。方法 30只清洁级Wistar大鼠随机分为3组:正常组、模型组和预防组。采用乙醇(8g·kg~(-1)·d~(-1))灌胃,每日2次,间隔8h,持续8wk,建立酒精性脂肪肝动物模型。正常组:不灌服乙醇,给予等体积生理盐水;模型组:在每次灌服乙醇1h后,给予等体积灭菌注射用水;预防组:在每次灌服乙醇1h后给予美他多辛(300mg·kg~(-1)·d~(-1))。8 wk灌胃结束后,B超、HE染色和油红O染色观察脂肪肝形态变化,采用自动生化仪检测血清丙氨酸转氨酶(ALT)、天冬氨酸转氨酶(AST)、三酰甘油(TG)、总胆固醇(TC)含量,免疫组化和蛋白印迹法检测大鼠肝组织中CYP2E1的表达。结果模型组ALT、AST、TG、TC含量明显升高,与正常组和预防组比较有显著差异(P<0.01,P<0.05),预防组明显降低CYP2E1表达与模型组比较有显著差异(P<0.01)。结论美他多辛通过抑制CYP2E1表达的上调,有效预防酒精性脂肪肝的发展。     

大黄素对酒精和高脂饲养诱导的大鼠脂肪肝的影响

目的:观察大黄素对酒精和高脂饲养诱导的大鼠脂肪肝的防治作用.方法:采用高浓度酒精灌胃合并高脂饮食饲养制备大鼠脂肪肝模型,同时给予大黄素治疗.通过检测血清肝酶活性、肝组织匀浆脂质含量(TG)和肝脏组织学变化,观察不同剂量大黄素对脂肪肝的防治作用,并与正常组和二甲双胍组作对照.结果:模型组大鼠肝脏出现明显的脂肪变性,肝酶活性、血脂和肝组织TG含量明显升高;大黄素治疗组肝细胞脂肪变性显著减轻,肝碱性磷酸酶和g-谷氨酰基转移酶活性、血脂和肝组织TG含量较模型组显著下降,二甲双胍组较模型组差异无显著性.结论:大黄素对脂肪肝有一定的防治作用.     

赶黄草提取物对大鼠酒精性脂肪肝的保护作用研究

目的:研究赶黄草提取物对酒精性脂肪肝的保护作用。方法:以1.5%的硫酸亚铁饲料进行饲养,应用灌胃乙醇法复制酒精性脂肪肝大鼠模型,复制模型6周后停止灌胃乙醇。实验分为7组,即正常对照,模型,槲皮素高、低剂量(50、25mg·kg-1),硫普罗宁(50mg·kg-1)和赶黄草提取物高、低剂量(4000、2000mg·kg-1)组。灌胃给药,每天1次,连续6周。计算肝脏系数;对大鼠肝脏行油红O染色,进行病理学检查;检测大鼠血清中丙氨酸氨基转移酶(ALT)、天冬氨酸氨基转移酶(AST)、总胆固醇(TC)、甘油三酯(TG)的含量。结果:灌胃酒精6周后大鼠形成酒精性脂肪肝。与模型组比较,赶黄草提取物高、低剂量组大鼠肝脏脂肪变明显改善,大鼠血清中ALT、AST、TC、TG均显著降低(P<0.01或P<0.05)。结论:赶黄草对大鼠酒精性脂肪肝具有保护作用。     

硫普罗宁对酒精性脂肪肝大鼠肝组织细胞色素P_(450)2E1表达的影响

目的:探讨硫普罗宁对大鼠酒精性脂肪肝细胞色素P4502E1(CYP2E1)表达的影响。方法:取Wistar大鼠30只随机分为3组:A组(空白对照组)、B组(模型组)、C组(硫普罗宁组)。B组和C组大鼠均以50%乙醇灌胃进行酒精性脂肪肝的造模,C组大鼠在造模后1h灌胃给予硫普罗宁(0.15g.kg-1.d-1),连续5周后,处死所有大鼠,分别检测血清中天冬氨酸氨基转移酶(AST)、丙氨酸氨基转移酶(ALT)的含量;逆转录聚合酶链反应(RT-PCR)检测CYP2E1表达水平;观察肝组织病理。结果:与A组比较,B组AST、ALT、CYP2E1水平均明显升高(P<0.01);与B组比较,C组上述指标均明显降低(P<0.01或P<0.05);病理组织观察发现C组肝脏脂肪变性程度明显轻于B组。结论:硫普罗宁可能通过降低CYP2E1在肝脏中的表达而具有防治酒精性脂肪肝的作用。     

Mechanisms of PPARα, sterol regulatory element binding proteins and AMP-activated protein kinase in alcoholic fatty liver diseases: Review北大核心CSCD

Alcoholic fatty liver disease (AFLD) is the first step to wards alcoholic liver disease (ALD). A beffer knowledge of AFLD will contribute to the prevention and therapy of ALD. It has been found that the occurrence and development of AFLD mainly involve the pathways of cytochrome P450 (CYP2E1), peroxisome proliferator-activated receptor a (PPARa), sterol regulatory element-binding proteins (SREBPs), AMP-activated protein kinase (AMPK), sirtuin 1(SIRT1), adiponectin and insulin. This review focuses on the importance of PPARa, SREBPs and AMPK pathway in alcoholic steatosis. It's reported that alcohol and its metabolite acetaldehyde inhibit PPARa and AMPK, and activate SREBP protein directly or indirectly, leading to liver lipid metabolic disorders, reducing the ability of fatty acid oxidation, causing lipid accumulation, and eventually inducing AFLD. Additionally, this review outlines the prospect of a therapeutics of AFLD targeting PPARa, SREBPs and AMPK. © 2017 Chinese Journal of Pharmacology and Toxicology. All rights reserved.     

酒精性脂肪肝脂质代谢研究进展

酒精性脂肪肝(AFL)是长期大量饮用酒精引发的肝脏损害性病变,可逆转也可进一步发展为肝纤维化和肝硬化。众多的脂肪细胞因子如瘦素(Leptin)、抵抗素(Resistin)和肿瘤坏死因子-α(TNF-α)在脂肪肝的发病中起到一定的促进作用,脂联素(Adiponectin)能改善脂质代谢,延缓脂肪肝的发生;脂联素通过腺苷酸活化蛋白激酶(AMPK)调节糖脂代谢、改善胰岛素敏感性。脂联素/AMPK信号通路是酒精在肝脏的作用靶点、也是调节PPARγ作用的重要信号通路;脂肪分化相关蛋白(ADRP)调节脂质代谢、促进酒精性脂肪肝的形成;过氧化物酶增殖体激活受体γ(PPARγ)参与机体脂质稳态的调节,脂肪肝时PPARγ表达增高,肝纤维化时PPARγ表达减少。对酒精性脂肪肝脂质代谢的深入研究,有助于阐明酒精性脂肪肝发病机制并为临床防治ALD及脂质代谢相关疾病提供新策略。     

Diet and risk of ethanol-induced hepatotoxicity: carbohydrate-fat relationships in rats.

Nutritional status is a primary factor in the effects of xenobiotics and may be an important consideration in development of safety standards and assessment of risk. One important xenobiotic consumed daily by millions of people worldwide is alcohol. Some adverse effects of ethanol, such as alcohol liver disease, have been linked to diet. For example, ethanol-induced hepatotoxicity in animal models requires diets that have a high percentage of the total calories as unsaturated fat. However, little attention has been given to the role of carbohydrates (or carbohydrate to fat ratio) in the effects of this important xenobiotic on liver injury. In the present study, adult male Sprague-Dawley rats (8-10/group) were infused (intragastrically) diets high in unsaturated fat (25 or 45% total calories), sufficient protein (16%) and ethanol (38%) in the presence or absence of adequate carbohydrate (21 or 2.5%) for 42-55 days (d). Animals infused ethanol-containing diets adequate in carbohydrate developed steatosis, but had no other signs of hepatic pathology. However, rats infused with the carbohydrate-deficient diet had a 4-fold increase in serum ALT levels (p < 0.05), an unexpectedly high (34-fold) induction of hepatic microsomal CYP2E1 apoprotein (p < 0.001), and focal necrosis. The strong positive association between low dietary carbohydrate, enhanced CYP2E1 induction and hepatic necrosis suggests that in the presence of low carbohydrate intake, ethanol induction of CYP2E1 is enhanced to levels sufficient to cause necrosis, possibly through reactive oxygen species and other free radicals generated by CYP2E1 metabolism of ethanol and unsaturated fatty acids.     

安络化纤丸对大鼠高脂性脂肪肝的治疗作用

目的探讨安络化纤丸对大鼠高脂性脂肪肝的治疗作用。方法以连续饲以高脂饲料(基础饲料加10%猪油、2%胆固醇、0.5%胆酸钠、5%蛋黄)1个月的方法建立高脂性大鼠脂肪肝模型,造模成功后给予安络化纤丸治疗4周,观察一般情况及测定血清丙氨酸氨基转换酶(ALT)、天门冬氨酸氨基转换酶(AST)、总胆固醇(TC)和甘油三酯(TG)水平,测定肝匀浆TG、丙二醛(MDA)及肝组织超氧化物歧化酶(SOD)水平,并对大鼠肝脏行病理学检查。结果安络化纤丸可明显降低高脂性脂肪肝大鼠血清ALT、AST、TC和TG水平,降低肝组织TG含量,提高肝组织SOD活性,并降低肝组织MDA水平。安络化纤丸可显著改善高脂性脂肪肝大鼠肝组织的病理损害。结论安络化纤丸对大鼠高脂性脂肪肝有明显的治疗作用,其作用可能与其抗氧化作用有关。     

安络化纤丸预防大鼠酒精性脂肪肝形成的作用

目的研究安络化纤丸对大鼠酒精性脂肪肝(AFLD)形成的预防作用。方法首先经灌胃给予大鼠安络化纤丸预防性治疗4周,后用连续灌服酒精加喂以特制饲料的方法制备大鼠AFLD模型,造模成功后观察一般情况及测定血清谷丙转氨酶(ALT)、谷草转氨酶(AST)、碱性磷酸酶(AKP)、甘油三酯(TG)水平,测定肝组织匀浆TG、丙二醛(MDA)及超氧化物歧化酶(SOD)水平,并对大鼠肝脏组织作病理学检查。结果安络化纤丸可明显降低AFLD大鼠血清ALT、AST、AKP、TG水平,降低肝组织TG含量,升高肝组织SOD活性,并降低肝组织MDA水平。肝组织病理学结果表明,安络化纤丸可显著改善AFLD大鼠肝组织的病理损害。结论安络化纤丸有预防大鼠AFLD形成的作用。     

Protective effects of gypenosides against fatty liver disease induced by high fat and cholesterol diet and alcohol in rats

In the present study, the protective effects of gypenosides from Gynostemma pentaphyllum on fatty liver disease (FLD) were examined in rats treated with high fat and cholesterol diet and alcohol. Male SD rats were divided into seven groups: control, model, lovastatin, silymarin, gypenosides high-, medium- and low-treatment groups. The latter 6 groups were fed high-fat and cholesterol diet and administered alcohol intragastricly once a day. Body weight was measured every week for 10 weeks, and the hepatic index was measured after 10 weeks. Compared with model group, levels of serum triglyceride (TG), total cholesterol (TC), free fatty acid (FFA), and low density lipoprotein cholesterol (LDL-C) level, malondialdehyde (MDA), serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activity, and hepatocyte apoptosis were significantly decreased in gypenosides groups; while serum high density lipoprotein cholesterol (HDL-C), superoxide dismutase (SOD) activity in both serum and hepatic tissue and mRNA and protein level of peroxisome proliferator-activated receptor α (PPAR-α) were significantly increased. Moreover, hepatic steatosis and mitochondrial damage were improved. These results suggested that gypenosides could prevent liver fatty degeneration in fatty liver disease through modulating lipid metabolism, ameliorating liver dysfunction and reducing oxidative stress.     

Cassia tora (Leguminosae) seed extract alleviates high-fat diet-induced nonalcoholic fatty liver

The aim of this study was to examine the effects of Cassia tora seeds on high-fat diet (HFD)-induced hepatic steatosis, and elucidate the molecular mechanisms behind its effects. After being fed a HFD for two weeks, rats were orally dosed with Cassia seed ethanol extract (CSEE) (100, 200, or 300 mg/kg) once daily for 8 weeks. CSEE induced dose-dependent reductions in plasma lipid levels, as well as decreased the over hepatic lipid accumulation. Furthermore, CSEE treatment improved HFD-induced hepatic histological lesions. CSEE enhanced the phosphorylation of AMP-activated protein kinase (AMPK) and its primary downstream targeting enzyme, acetyl-CoA carboxylase, up-regulated the gene expression of carnitine palmitoyl transferase 1, and down-regulated sterol regulatory element binding protein 1 and fatty acid synthase protein levels in the livers of HFD-fed rats. AMPK inhibition by compound C retarded CSEE-induced reduction in triglyceride accumulation in HepG2 cells stimulated by insulin. Our findings suggest that CSEE may regulate hepatic lipid homeostasis related with an AMPK-dependent signaling pathway. Targeting AMPK activation with CSEE may represent a promising approach for the prevention and treatment of obesity-related non-alcoholic fatty liver disease.     

The pathogenesis of ethanol versus methionine and choline deficient diet-induced liver injury

The differences and similarities of the pathogenesis of alcoholic (ASH) and non-alcoholic steatohepatitis (NASH) were examined. Mice (six/group) received one of four Lieber-Decarli liquid diets for 6 weeks: (1) paired-fed control diet; (2) control diet with ethanol (ethanol); (3) paired-fed methionine/choline deficient (MCD) diet; and (4) MCD plus ethanol (combination). Hepatotoxicity, histology, and gene expression changes were examined. Both MCD and ethanol induced macrovesicular steatosis. However, the combination diet produced massive steatosis with minor necrosis and inflammation. MCD and combination diets, but not ethanol, induced serum ALT levels by 1.6- and 10-fold, respectively. MCD diet, but not ethanol, also induced serum alkaline phosphatase levels suggesting bile duct injury. Ethanol increased liver fatty acid binding protein (L-FABP) mRNA and protein levels. In contrast, the combination diet decreased L-FABP mRNA and protein levels and increased hepatic free fatty acid and lipid peroxide levels. Ethanol, but not MCD, reduced hepatic S-adenosylmethionine (SAM) and GSH levels. Hepatic TNFalpha protein levels were increased in all treatment groups, however, IL-6, a hepatoprotective cytokine which promotes liver regeneration was increased in ethanol-fed mice (2-fold), but decreased in the combination diet-treated mice. In addition, the combination diet reduced phosphorylated STAT3 and Bcl-2 levels. While MCD diet might cause bile duct injury and cholestasis, ethanol preferentially interferes with the SAM-GSH oxidative stress pathway. The exacerbated liver injury induced by the combination diet might be explained by reduced L-FABP, increased free fatty acids, oxidative stress, and decreased IL-6 protein levels. The combination diet is an efficient model of steatohepatitis.     

Thiazolidinediones improve hepatic fibrosis in rats with non‐alcoholic steatohepatitis by activating the adenosine monophosphate‐activated protein kinase signalling pathway

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