Assessment of lipid peroxidation and antioxidant capacity in non-alcoholic fatty liver disease.

BACKGROUND/AIMS: Lipid peroxidation/oxidative stress and/or endotoxin-induced cytokine release are implicated in the non-alcoholic fatty liver disease pathogenesis. Studies in the literature are experimental in nature and are based on histopathological evaluation and peripheral blood findings. In this study, we aimed to investigate the relationships between lipid peroxidation and antioxidant capacity in non-alcoholic fatty liver disease. METHODS: Twenty-six patients with an ethanol consumption of less than 20 g/day who were diagnosed ultrasonographically and histopathologically as non-alcoholic fatty liver disease and 16 healthy control subjects with normal ultrasonographical findings were included in the study. All viral and autoimmune markers in patient and control groups included in the study were negative. Non-alcoholic steatohepatitis samples obtained by fine needle aspiration were evaluated according to Brunt et al. The levels of glutathione, catalase, superoxide dismutase, and malonyldialdehyde in peripheral blood and liver biopsy samples were measured. RESULTS: Of patients with non-alcoholic fatty liver disease, 17 (65%) were detected to have mild, 7 (27%) moderate and 2 (8%) severe steatosis; portal inflammation was found in 17 patients (65%) and stage I fibrosis in 21 patients (80%). Minimal lobular inflammation was observed in all patients. In the patient group, the levels of erythrocytic glutathione, catalase, and superoxide dismutase were significantly lower but malonyldialdehyde levels were higher compared to the control group. It was revealed that hepatocytic reduced glutathione, catalase, and malonyldialdehyde levels were not correlated with peripheral blood levels, but there was a positive correlation between liver malonyldialdehyde level and liver reduced glutathione level. Plasma malonyldialdehyde level and liver glutathione had a negative correlation. CONCLUSIONS: It was discovered that lipid peroxidation and antioxidant capacity suppression due to its overuse were important in the non-alcoholic fatty liver disease pathogenesis, but antioxidant capacity was maintained well at tissue level in the early stages of the disease. Furthermore, it was identified that tissue lipid peroxidation and changes in antioxidant capacity were not reflected in the peripheral blood to the same extent.     

Lack of evidence for increased lipid peroxidation in ethanol-induced centrilobular necrosis of rat liver

The pathogenetic role of lipid peroxidation in ethanol-induced liver injury was previously supported by demonstration of increased formation of diene conjugates and decreased hepatic levels of reduced glutathione in ethanol-fed animals and alcoholic patients with liver injury. The present study was carried out to investigate whether these findings can be extended to a rat model that was shown to produce a spontaneous ethanol-induced liver injury progressing from steatosis to necrosis and fibrosis (Hepatology 6: 814, 1986). Despite the histological evidence of progression from hepatic steatosis to centrilobular necrosis in these animals, diene conjugate formation in mitochondrial and microsomal lipids was not enhanced when compared to pair-fed controls. In addition, hepatic levels of neither methionine nor glutathione were decreased in the ethanol-fed animals. The fatty acid composition of mitochondrial phospholipids from these animals was similar to that in the controls. However, in the microsomal phospholipids, the level of arachidonate (20:4) was depressed by about 50% as compared to the controls. These results demonstrate the lack of evidence for a pathogenetic relationship between lipid peroxidation and ethanol-induced liver injury progressing to centrilobular necrosis. They further suggest that the decreased levels of 20:4 commonly seen after chronic ethanol intake may not be due to a peroxidative loss.     

维生素E、硒对非酒精性脂肪肝大鼠肝细胞色素P4501A1及脂质过氧化的干预作用

目的:研究维生素E、硒对非酒精性脂肪肝大鼠肝细胞色素P4501A1及脂质过氧化的干预作用.方法:♂SD大鼠,随机均分为5组:对照组(普通饲料)、模型组(高脂饲料)、VE干预组、Se干预组、VE Se干预组,建模5wk处死全部大鼠.生化方法检测血清及肝组织超氧化物歧化酶(SOD)和丙二醛(MDA)含量的变化,逆转录聚合酶链反应(RT-PCR)测定肝细胞色素P4501A1mRNA表达的变化,免疫组化方法测定肝组织中肿瘤坏死因子-α(TNF-α)、核因子-κB(NF-κB)表达的变化.结果:与对照组比较,模型组血清及肝组织中SOD显著降低(312.72±49.51kU/Lvs583.23±63.37kU/L;8.13±0.63U/mgprot.vs13.99±2.33U/mgprot.,P<0.01),MDA增高(13.40±4.24mmol/Lvs6.43±1.76mmol/L;9.79±0.94nmol/mgprot.vs6.80±0.97nmol/mgprot.P<0.01),细胞色素P4501A1mRNA表达水平,肝组织TNF-α、NF-κB蛋白表达明显增强(0.628±0.116vs0,0.230±0.013vs0.03±0.006,0.069±0.01vs0.003±0.001;P<0.05).与模型组比较VE组、Se组的血清及肝组织中SOD增高,MDA降低,细胞色素P4501A1mRNA表达水平略下降;肝组织TNF-α、NF-κB蛋白表达下降(P<0.05).VE Se组与模型组比较,血清SOD明显增高,其值接近对照组水平;细胞色素P4501A1mRNA表达水平显著下降(0.324±0.070vs0.628±0.116,P<0.05).结论:非酒精性脂肪肝的脂质过氧化损伤及相关因子的表达可能与肝细胞色素P4501A1表达上调有关.VitE和硒能提高机体的抗氧化能力,对非酒精性脂肪肝有保护作用,二者联合作用更明显.     

Inhibitory effect of melatonin on diquat-induced lipid peroxidation in vivo as assessed by the measurement of F2-isoprostanes

Melatonin is a powerful antioxidant and free radical scavenger. A large body of in vivo and in vitro evidence shows that melatonin effectively inhibits membrane lipid peroxidation; this damage was based on the measurement of malondialdehyde and/or 4-hydroxynonenal levels. In the current study, for the first time using a more sensitive and specific biomarker, i.e. F2-isoprostanes, we investigate the effect of melatonin on diquat-induced lipid peroxidation in Fischer 344 rats. When diquat (40 mg/kg body weight) was intraperitoneally injected into rats, the levels of liver F2-isoprostanes were significantly increased at 1, 3, and 6 hr while plasma free F2-isoprostanes concentrations were augmented at 3, 6, and 12 hr after administration of the toxin. In addition, the plasma alanine aminotransferase activity level was measured as a parameter of hepatoxicity; the activity of this enzyme was augmented at 3, 6, and 12 hr after diquat administration when compared with levels of this constituent in untreated control rats. Pretreatment with melatonin (20 mg/kg) 30 min before diquat administration resulted in a significant reduction in both tissue and plasma F2-isoprostanes levels, and plasma alanine aminotransferase activity. These findings, using a sensitive and specific index of lipid peroxidation, show that the hepatoxicity of diquat, at least partially, is a consequence of reactive oxygen species-induced lipid damage. Melatonin's protective effects likely relate to its direct free radical scavenging ability and/or due to other antioxidative processes induced by the indole.     

甜菜碱对酒精性肝损伤大鼠高同型半胱氨酸血症和肝脂质过氧化的影响

目的：观察甜菜碱对大鼠高同型半胱氨酸血症（hyperhomoeysteinemia，HHcy）和肝脏脂质过氧化的作用和影响。方法：将60只SD大鼠随机分为5组（每组12只）：正常对照组，模型组，甜菜碱低、高剂量组，腺苷蛋氨酸（S-adenosylmethionine，SAM）组。除对照组外，其余4组给予酒精、鱼油灌胃配合高脂饮食构建酒精性肝损伤大鼠模型，药物治疗于造模4周后开始，第8周处死全部大鼠，测定血浆总同型半胱氨酸（total plasma homoeysteine，tHcy）浓度、血清丙氨酸转氨酶（ALT）、天冬氨酸转氨酶（AST）、白蛋白（Alb）、白／球蛋白比值（A／G）、肝匀浆丙二醛（MDA）、超氧化物歧化酶（SOD）和还原型谷胱甘肽（GSH）含量，并进行肝脏病理组织学检查。结果：与对照组比较，模型组大鼠tHcy、ALT、AST、MDA含量均明显升高（P〈0．01），SOD、GSH水平明显降低（P〈0．01）。与模型组对比，甜菜碱低、高剂量组大鼠tHcy、ALT、AST、MDA均显著降低（P〈0．01），肝组织SOD含量明显上升（P〈0．01），GSH含量无显著变化（P〉0．05），甜菜碱低、高剂量组之间无明显差异（P〉0．05）；SAM组能显著增加肝组织GSH贮量（P〈0．01），但对血浆tHcy水平无显著影响（P〉0．05），余治疗作用均与甜菜碱治疗无显著差别（P〉0．05）。结论：甜菜碱可防治酒精性肝损伤，其机制可能为降低高同型半胱氨酸血症，改善肝组织脂质过氧化。本文结果显示，甜菜碱的作用优于腺苷蛋氨酸。     

Hormonal regulation of pro-inflammatory and lipid peroxidation processes in liver of old ovariectomized female rats

There is now a large body of evidence suggesting that the decline in ovarian function with menopause is associated with spontaneous increases in pro-inflammatory cytokines. On the other hand, oxidative stress has been implicated in the pathogenesis of several alterations due to menopause, and can arise through the increased production of lipid peroxides (LPO) and/or a deficiency of antioxidant defense. The aim of the present study was to investigate the effect of aging and ovariectomy on various physiological parameters related to inflammation and oxidative stress in livers obtained from old female rats and the influence of chronic exogenous administration of estrogens, phytoestrogens and growth hormone on these. Thirty-six female Wistar rats of 22 months of age were used in the present study. Twelve of them remained intact, and the other 24 had been ovariectomized at 12 months of age. Intact animals were divided into two groups and treated for 10 weeks with GH or saline, and ovariectomized animals were divided into four groups and treated for the same time with GH, estrogens, phytoestrogens or saline. A group of 2 month old intact female rats was used as young control. Protein expression of iNOS, HO-1, IL-6, TNFα, and IL-1β were determined by Western blot analysis. The levels of NO _x , LPO, TNFα, IL-1β, IL-6 and IL-10 were determined in different fractions of the liver. Levels of LPO in the liver homogenates as well as iNOS protein expression and NO _x levels were increased in old rats as compared to young animals; this effect was more evident in ovariectomized animals. Pro-inflammatory cytokines TNF-α, IL-1β and IL-6 were significantly increased and anti-inflammatory IL-10 decreased during ageing and after ovariectomy. Aging also significantly increased expression of HO-1 protein and ovariectomized rats showed an additional increase. Hormonal administration to the ovariectomized groups decreased NO _x , LPO levels and pro-inflammatory cytokines as compared with untreated rats. Significant rise in IL-10 and reductions in the iNOS, IL-6, TNFα and IL-1β proteins expression were also found. Oxidative stress and inflammation induced during aging in the liver are more marked in castrated than in intact old females. Administration of the different hormonal replacement therapies was able to inhibit the induction of pro-inflammatory cytokines and iNOS, decreased the levels of oxidative stress markers and had therapeutic potential in the prevention of liver injury.     

依达拉奉对实验性肝纤维化大鼠脂质过氧化的影响

目的探讨依达拉奉（EDA）对实验性肝纤维化大鼠脂质过氧化的影响。方法以四氯化碳诱导大鼠肝纤维化模型。30只Sprague—Dawley大鼠随机分为对照组（10只）、肝纤维化模型组（10只）和EDA防治组（10只）。检测各组大鼠血清谷丙转氨酶、谷草转氨酶水平及肝组织羟脯氨酸、丙二醛含量和超氧化物歧化酶活性。结果EDA防治大鼠血清谷丙转氨酶和谷草转氨酶水平分别为714．2±28．2U／L和766．0±11．0U／L,较模型组（1110．3±45．9U／L和1640．3±26．7U／L,P〈0．05和P〈0．01）明显降低;EDA组大鼠肝组织羟脯氨酸和丙二醛含量分别为0．4±0．1μg／mg和5．5±2．3nmol／gl,较模型组（0．8±0．1μg／mg和7．5±2．1nmol／gl,P均〈0．01）显著下降;EDA组大鼠超氧化物歧化酶活性为129．7±2．3u／g,较模型组（933±3．9u／g,P〈0．01）明显升高;EDA组和模型组大鼠肝组织纤维化评分分别为2．7±1．0和3．5±0．7,差异显著（P〈0．01）。结论EDA对大鼠肝纤维化有一定的防治作用,其机制很可能与抗脂质过氧化损伤有关。     

Pathogenesis of centrilobular necrosis following congestion of the liver

The exact pathogenesis of centrilobular necrosis following congestion of the liver is still unknown. We reviewed the clinical data related to systemic circulatory disturbance and histopathology of the liver and the gut in 320 autopsy subjects. Congestion of the liver alone was associated only with atrophy and loss of hepatocytes in centrilobular areas, but not with hepatocellular coagulative necrosis. In many patients with coagulative necrosis of centrilobular hepatocytes and congestion of the liver, fibrin thrombi and neutrophil infiltration in the sinusoids, which are the characteristic histopathological features of the liver in endotoxaemia, were found in and around the necrotic area. Congestion, erosion or haemorrhage of the intestinal mucosa, which may allow entrance of endotoxin into the liver through the portal vein, was seen in such patients. Prolonged hypotension or shock, which may lead to portal endotoxaemia, was present in half the patients with centrilobular necrosis and congestion of the liver. These results suggest that not only congestion of the liver but also portal endotoxaemia may be involved in the pathogenesis of centrilobular necrosis in patients with congestion of the liver.     

枳黄方对急性乙醇性肝损伤大鼠肝脂质过氧化水平的影响及机制

目的探讨枳棋子、大黄水提液（枳黄方）对急性乙醇性肝损伤大鼠（ALD）的保护作用。方法将30只大鼠随机分为A、B、C三组每组10只,其中A组予枳黄方6．0ml／kg灌胃,B、C组予6．0ml／kg生理盐水灌胃;间隔45min后A、B组予56。白酒14ml／kg灌胃,C组予50％葡萄糖14mL／kg灌胃,均为1次／d,连续10d。最后1次灌胃后禁食14h,以2％戊巴比妥钠40mg／kg腹腔注射麻醉大鼠,采集肝组织。羟胺法检测肝脏超氧化物歧化酶（SOD）活力,TBA法检测肝脏丙二醛（MDA）水平;采用RT—PCR技术检测肝脏NADPH氧化酶gp-91phox mRNA及p22phox mRNA表达。结果与B组比较,A组SOD活性显著升高,MDA水平及gp-91phox、p22phoxmRNA表达显著降低。结论枳黄方能对抗ALD大鼠肝脏脂质过氧化,可能机制为降低肝脏NADPH氧化酶gp-91phox mRNA及p22phox mRNA表达。     

正肝化瘀方对肝纤维化大鼠肝组织脂质过氧化的影响

[目的]观察正肝化瘀方对肝纤维化大鼠肝组织脂质过氧化的影响.[方法]36只SD大鼠随机分为正常组、模型组、治疗组,模型组、治疗组采用四氯化碳复合因素诱导大鼠肝纤维化模型.治疗组以正肝化瘀方灌胃,模型组、正常组同时以等量0.9％氯化钠灌胃.6周末,麻醉后开腹摘取肝、脾脏,天狼星红染色观察肝组织胶原沉积程度,比色法检测肝组织超氧化物歧化酶(SOD)、谷胱甘肽(GSH)活力和丙二醛(MDA)含量.[结果]模型组SOD、GSH活力明显下降,MDA含量明显增加;治疗组SOD、GSH活力较模型组有明显提高,MDA含量有所下降;2组比较,差异有显著性意义(P＜0.05).[结论]正肝化瘀方有抗脂质过氧化、减轻肝细胞损害及其脂肪变性的作用,其抗肝纤维化机制与通过脂质过氧化作用、促进自由基清除、减少胶原合成与沉积有关.     

The significance of lipid peroxidation in drug-induced liver damage

Using the primary hepatotoxin paracetamol (acetaminophen) as a model it is shown in vivo in the mouse that the phase I metabolism of this agent causes a dose-dependent lipid peroxidation. This finding is extended to other xenobiotics activated in phase I and becomes manifest only if the glutathione redox systems as an endogenous defense system is paralyzed. The concept of lipid peroxidation being an early causal event in hepatocellular destruction was experimentally examined: Animals with alimentary selenium deficiency lacking glutathione peroxidase activity were much more susceptible to drug overdosage. Animals pretreated with liposomally entrapped reduced glutathione were totally resistant. Using the isolated perfused liver it is demonstrated that lipid peroxidation precedes cell disintegration. These animal data are discussed with respect to the biochemical parameters available for man. The results suggest an involvement of lipid peroxidation in certain acute chemical lesions, but do not justify to derive a general pathogenic concept based on lipid peroxidation.     

枳黄方对急性酒精性肝损伤大鼠肝脂质过氧化水平的影响及其机制研究

目的:观察枳黄方对急性酒精性肝损伤大鼠肝脂质过氧化水平的影响,并探讨其机制。方法:通过酒精灌胃法制造急性酒精性肝损伤大鼠模型,采用HE染色观察肝病理变化;羟胺法检测肝脏SOD活力;TBA法检测肝脏MDA含量;采用RT-PCR技术检测肝脏NADPH氧化酶gp-91phox mRNA的表达量。结果:枳黄方能改善急性酒精性肝损伤之肝脏病理变化;下调肝脏NADPH氧化酶gp-91phox mRNA的表达;显著降低肝脏MDA含量(P<0.05);显著提高肝脏SOD活力(P<0.01)。结论:枳黄方能对抗酒精性肝损伤大鼠肝脏脂质过氧化,这可能与其能降低肝脏NADPH氧化酶gp-91phox mRNA的表达有关。     

Role of xanthine oxidase in ethanol-induced lipid peroxidation in rats

To investigate a possible role of free radical production by xanthine oxidase in the pathogenesis of ethanol-induced hepatic lipid peroxidation, chow-fed rats were given ethanol (5 g/kg) and placed at 32 degrees C for 6 h, which resulted in increased hepatic malondialdehyde levels. Pretreatment with allopurinol in amounts that effectively inhibited xanthine metabolism also significantly decreased ethanol-induced lipid peroxidation, suggesting participation of free radicals produced by xanthine oxidase in the peroxidative process. Both acetaldehyde and purine can serve as substrates for xanthine oxidase. Pretreatment with cyanamide increased hepatic acetaldehyde levels 5-fold, yet this was associated with a decrease in lipid peroxidation, indicating that acetaldehyde is not the xanthine oxidase substrate involved. By contrast, ethanol increased hepatic contents of hypoxanthine and xanthine and enhanced urinary output of allantoin (a final product of xanthine metabolism), incriminating increased metabolism of purines. Ethanol administration also enhanced hepatic nicotinamide adenine dinucleotide (reduced form). A corresponding rise of nicotinamide adenine dinucleotide (reduced form) in vitro inhibited xanthine dehydrogenase activity by 60%-76%. Increased purine degradation, possibly associated with a shift from the dehydrogenase to the xanthine oxidase pathway (secondary to nicotinamide adenine dinucleotide [reduced form]-mediated inhibition of xanthine dehydrogenase activity) is proposed as a possible mechanism for ethanol-stimulated free radical production. Because allopurinol attenuates the associated lipid peroxidation, this agent might be considered for possible therapeutic use in alcohol-induced liver damage.     

姜黄素对酒精诱导的大鼠脂质过氧化反应的影响

目的:观察姜黄素对酒精性肝病大鼠肝脏氧化应激指标SOD,MDA和NO及血清ALT,AST和ALP水平的影响,探讨姜黄素对酒精诱导的大鼠脂质过氧化反应的影响.方法:将40只SD大鼠随机分为对照组、模型组、姜黄素治疗Ⅰ组(40 mg/kg)、姜黄素治疗Ⅱ组(80 mg/kg)和姜黄素治疗Ⅲ组(160mg/kg),每组8只.除对照组用等量生理盐水灌胃外,其他组均采用56度白酒6.72 g/(kg·d)灌胃的方法制作酒精性肝病大鼠模型,6 wk后姜黄素治疗Ⅰ、Ⅱ、Ⅲ组分别加用姜黄素ig,至12 wk末,处死大鼠,抽取血标本测定血清ALT、AST及ALP水平;留取肝组织标本测定SOD活性、MDA及NO含量,常规HE染色观察肝脏病理变化.结果:与对照组相比,模型组大鼠血清ALT、AST及ALP水平显著升高(86.4±7.5 vs 33.5±10.3;201.0±16.8 vs 116.5±12.0;205.1±20.0 vs 104.6±9.4:均P<0.01);肝组织SOD活性明显下降(80.21±4.55 vs 180.24±27.53,P<0.01),MDA及NO含量显著升高(3.29±0.34vs 1.35±0.12;4.37±0.21 vs 2.72±0.13:均P<0.01).与模型组相比,各姜黄素治疗组血清ALT、AST及ALP水平(Ⅰ组:66.5±9.6,171.4±10.8,176.4±13.7:Ⅱ组:52.4±12.0,145.8±11.9,146.9±13.8:Ⅲ组:40.9±7.9,135.0±11.8,127.1±12.6)明显降低(P<0.05或P<0.01),肝组织MDA及NO含量(Ⅰ组:2.84±0.27,4.01±0.17;Ⅱ组:1.95±0.23,3.60±0.16;Ⅲ组:1.65±0.08,3.22±0.13)均显著降低(P<0.05或P<0.01),而SOD活性(92.36±6.47,117.69±21.96,146.70±27.361明显提高(P<0.05或P<0.01),其中以Ⅱ、Ⅲ治疗组较为显著.模型组大鼠肝细胞出现不同程度的脂肪变性,伴有点、灶状坏死,炎性细胞浸润,各姜黄素治疗组肝脏病理变化不同程度的轻于模型组.结论:姜黄素能抑制脂质过氧化,减轻或防治酒精诱导的肝损伤.     

Nitric oxide release and enhancement of lipid peroxidation in regenerating rat liver

BACKGROUND/AIMS: Clarification of the role of lipid peroxidation in the onset of liver proliferation has been hampered by the fact that both higher and lower lipid peroxidation have been reported after two-thirds partial hepatectomy. Recently, it has been shown that nitric oxide might be involved in the control of early responses after partial hepatectomy. We analysed the possible involvement of nitric oxide production in lipid peroxidation levels during liver regeneration. METHODS: Sham-operated, hepatectomised and sham and hepatectomised rats pretreated with two inhibitors of oxide nitric synthesis (aminoguanidine or N(G)-monomethyl-L-arginine) were used throughout. Animals were killed at 1, 3, 5 and 15 h after surgery. Cytosolic superoxide dismutase and microsomal-lysosomal catalase activities were measured. Lipid peroxidation levels were measured as thiobarbituric acid-reactive substances and conjugated dienes. Cytosolic nitrate (a stable metabolic product of nitric oxide) was enzymatically determined. Inducible-type nitric oxide synthase (iNOS) was analysed in hepatic cytosol by immunoblotting. DNA synthesis 24 and 48 h after surgery was assessed by [3H]thymidine incorporation. RESULTS: Increased lipid peroxidation was found in total homogenate, cytosol and microsomes. The hepatic cytosolic content of nitrates increased, reaching the highest values at 5 h posthepatectomy. Aminoguanidine or N(G)-monomethyl-L-arginine pretreatment blocked the rise of nitric oxide production and lipid peroxidation levels and decreased the DNA synthesis. The increase in hepatic iNOS protein expression at 5 h after partial hepatectomy disappeared with aminoguanidine pretreatment. CONCLUSIONS: Our experiments suggest that nitric oxide plays a role in the proliferation mechanism, although it is responsible, at least in part, for the enhanced lipid peroxidation.     

腺苷蛋氨酸对酒精性肝损伤大鼠甲硫氨酸代谢和脂质过氧化的影响

观察腺苷蛋氨酸（S-adenosylmethionine,SAM）对酒精性肝损伤大鼠的防治作用及机制。48只SD大鼠随机分为4组（每组12只）：正常对照组、模型组、腺苷蛋氨酸低及高剂量组。除对照组外,其余三组给予酒精、鱼油灌胃配合高脂饮食构建酒精性肝损伤大鼠模型,造模4周后腹腔注射SAM,第8周处死全部大鼠。测定血浆总同型半胱氨酸（total plasma homocysteine,tHcy）、血清丙氨酸转移酶（ALT）、甘油三酯（TC）、总胆固醇（TG）、肿瘤坏死因子-α（TNF-α）、转化生长因子（TGF-β）水平、肝匀浆丙二醛（MDA）和还原型谷胱甘肽（GSH）含量,及肝组织病理学检测。与对照组比较,模型组大鼠tHcy、ALT、TC、TG、TNF-α、TGF—β、MDA含量均明显升高（P〈0．01）;GSH水平降低（P〈0．01）。与模型组比较,SAM治疗组ALT、TC、TG、MDA（P〈0．01）和TNF-α、TGF—β明显降低（P〈0．05）,GSH含量升高（P〈0．01）,但血浆tHcy水平无显著变化（P〉0．05）。SAM低、高剂量组各项指标间比较无明显差别（P〉0．05）。SAM可明显改善大鼠酒精性肝损伤,其机制可能与其降低肝组织脂质过氧化、并与抗免疫炎性因子和抗增殖有关。