Mechanisms underlying the protection of berberine against liver injury induced by lipopolysaccharide in mice

AIM: To investigate the protective effects of berberine against liver injury induced by lipopolysaccharide in mice and the mechanisms underlying its protective effect.METHODS: The male mice were divided randomly into control,berberine group,LPS group and berberine treatment group.Mice were administered intragastrically with distilled water(0.01 mL/g) or(5 g/L) neutral sulfate berberine(0.01 mL/g) once a day for 5 days and injected intraperitoneally with normal saline or LPS(0.02(mL/g),28 mg/kg)at 1 h after gavage on day 5.Blood was collected for determining alanine aminotransferase(ALT) and aspartate aminotransferase(AST) activities,the content of tumor necrosis factors-α(TNF-α) at 10 h and 2 h after LPS or normal saline injection,respectively.Furthermore,the liver tissue was processed,and histological changes and ultrastructure in liver were observed with light and electron microscopy,malondialdehyde(MDA) content and superoxide dismutase(SOD) activity in liver were also detected.RESULTS: Both ALT and AST activities in serum in LPS group were higher than those in control and berberine treatment group.LPS increased the serum TNF-ɑ content at 2 h after injection,which was reversed by berberine pretreatment.The histological examination showed that LPS caused severe hepatic cell edema,degeneration,apoptosis and even necrosis,and ultrastructure observation demonstrated that LPS induced mitochondrial swelling,condensation and margination of chromatin,irregular nuclear envelope in hepatocytes.The above pathological changes produced by LPS were attenuated by berberine pretreatment.Moreover,MDA contents in liver tissue were higher in LPS group than control and berberine treatment group,but there were no significant difference in SOD activity between berberine treatment and LPS group.CONCLUSION: Berberine has a protective effect on LPS-induced liver injury in mice,the mechanisms may be related to its decreasing the production of TNF-α,inhibiting lipid peroxidation and protecting mitochondria.