Abstract: To study the hepatoprotective effects of the total flavonoids extracted from the dried root of Cyclea hypoglauca(Schauer)Diels(TFC)on mice with acute liver injury induced by carbon tetrachloride(CCl₄),and explore the mechanism based on oxidative stress,inflammatory response and toll-like receptor-4(TLR-4)/nuclear factor-kappa B(NF-κB)pathway.60 mice were randomly divided into normal group,model group,silymarin group(150 mg/kg),and TFC-low,medium,high dose groups(100,200,400 mg/kg).All mice were administrated by gavage once a day for 10 d with distilled water or corresponding dose of drugs(10 mL/kg).After 2 h of the last administration,the mice were injected intraperitoneally with 0.1% CCl₄ peanut oil solution(10 mL/kg)to induce the acute liver injury except the normal group.16 h later,the eye balls of mice were removed to take blood,and all mice were sacrificed to collect the liver tissue.Liver index was calculated based on body weight and liver weight of mice.Biochemical methods were used to measure the serum contents of alanine aminotransferase(ALT),aspartate aminotransferase(AST),alkaline phosphatasetotal(ALP),total bilirubin(TBIL),γ-glutamyl transpeptidase(γ-GT),superoxide dismutase(T-SOD),malondialdehyde(MDA)and glutathione peroxidase(GSH-Px).The enzyme-linked immunosorbent assay(ELISA)was used to detect the hepatic levels of tumor necrosis factor-α(TNF-α),interleukin-1β(IL-1β)and interleukin-6(IL-6).The relative expressions of TLR-4 and NF-κB in liver tissue were detected by Western blot.HE staining was used to observe the histopathological changes of liver.The results showed that TFC could significantly improve the liver tissue lesion,decrease the liver index and serum contents of AST,ALT,ALP,TBIL,γ-GT and MDA(P<0.05),enhance the activity of T-SOD and GSH-Px(P<0.05),and inhibit the hepatic levels of TNF-α,IL-1β,IL-6,TLR-4 and NF-κB(P<0.05).In summary,TFC had a hepatoprotective effect on mice with acute liver injury induced by CCl₄,and its mechanism may be related to inhibiting the oxidative stress levels,inflammatory response and TLR-4/NF-κB pathway.

Key words: Cyclea hypoglauca(Schauer)Diels, total flavonoids, acute liver injury, oxidative stress, inflammatory response, toll-like receptor-4/nuclear factor-kappa B pathway