富硒长双歧杆菌抑制乙醇诱导的小鼠肝损伤

Inhibition Effect of Selenium-Enriched Bifidobacterium longum on Alcohol-induced Liver Damage in Mice

目的研究富硒长双歧杆菌对乙醇引起肝损伤的抑制作用及其机制。方法用体积分数20%乙醇造成雌性C57/BL6小鼠酒精性肝损伤模型,分别口服50,100 mg·kg^-1富硒长双歧杆菌治疗42 d。检测肝脏损伤;测定小鼠血清中丙氨酸氨基转移酶(ALT),天门冬氨酸氨基转移酶(AST)和γ-谷氨酰转肽酶(GGT)和肿瘤坏死因子α(TNF-α)含量;检测肝脏中丙二醛(MDA)含量和超氧化物歧化酶(SOD)活性,以及SREBP-1c,AMPK和PPAR-α的mRNA水平。结果摄入100 mg·kg^-1富硒长双歧杆菌能明显抑制体积分数20%乙醇引起的小鼠肝脂肪变性,降低肝脏系数,减轻肝组织病理损伤,减少肝组织中炎症,抑制升高的血清ALT、AST、GGT以及TNF-α水平;降低肝组织中MDA含量,升高肝组织中SOD活性;抑制SREBP-1c的mRNA水平,升高AMPK和PPAR-α的mRNA水平。结论富硒长双歧杆菌能够抑制乙醇诱导的小鼠肝损伤,其机制可能与抗氧化应激、抑制炎症及恢复脂质代谢平衡有关。

OBJECTIVE To study the effect of selenium-enriched Bifidobacterium longum on alcoholic liver damage and its mechanism.METHODS Alcoholic liver damage of female C57/BL6 mice were induced with 20% alcohol for 42 d,at the same time 50 or 100 mg·kg^-1 selenium-enriched Bifidobacterium longum were administrated respectively.Mice livers were collected for calculating liver index,HE staining and measuring liver tissue malondialdehyde(MDA)and superoxide dismutase(SOD)level.Serum were collected for measurement of alanine transarninase(ALT),aspartate aminotransferase(AST),γ-glutamyltransferase(GGT)and tumor necrosis factorα(TNF-α)levels.The mRNA levels of liver SREBP-1 c,AMPK and PPAR-αwere measured with Real-time PCR.RESULTS Selenium-enriched Bifidobacterium longum inhibited the increase in liver index and inflammation index induced with alcohol.Selenium-enriched Bifidobacterium longum also inhibited alcohol induced ALT,AST,GGT and TNF-α levels increase;decreased liver MDA levels and increased liver SOD levels.Selenium-enriched Bifidobacterium longum down-regulated SREBP-1 c mRNA and upregulated AMPK and PPAR-αmRNA levels of mice liver.CONCLUSION Selenium-enriched Bifidobacterium longum protects mice from alcohol induced liver damage in a dose dependent manner.Its protective mechanism might be anti-oxidation,inflammation inhibition and improvement of lipid metabolism.