Liuweiwuling tablets attenuate acetaminophen-induced acute liver injury and promote liver regeneration in mice

Abstract

Aim: To explore the mechanism of protection against acetaminophen-induced acute liver injury by Liuweiwuling tablets. Methods: Intraperitoneal injections of acetaminophen (250 mg/kg) were used to induce acute liver injury in male C57BL/6 mice. A total of 24 healthy mice were randomly assigned to two groups: an acute liver injury group (control group) and a Liuweiwuling tablet group. Mice were given Liuweiwuling tablets or a vehicle (PBS) orally prior to the administration of acetaminophen. Serum alanine aminotransferase (ALT) and aspartate aminotransaminase (AST) levels were measured at different time points within one week, and pathological examinations of liver tissues were performed 36 h after induction of acute liver injury. Serum inflammatory cytokines, such as high mobility group box protein B1 (HMGB1), tumor necrosis factor (TNF)-α and interleukin IL-1b, were detected using an ELISA method according to the manufacturer's instructions. Hepatic morphological changes at 36 h were assessed by hematoxylin and eosin staining. Expression of proliferating cell nuclear antigen (PCNA) in liver tissue was determined by Western blot analysis. The mRNA levels of hepatocyte proliferation markers (PCNA, CyclinD1 and p21) were detected by real-time quantitative reverse transcription-polymerase chain reaction. Results: The levels of ALT/AST in the Liuweiwuling tablet group were decreased significantly at 6, 12 and 24 h compared to that of the control group (654.38 120.87 vs 1566.17 421.64, 1154.18 477.72 vs 4654.84 913.71 and 935.13 252.34 vs 4553.75 727.37, P < 0.01). Serum HMGB1 levels at 6 and 12 h for the Liuweiwuling tablet group were significantly lower than those of the control group (23.49 3.89 vs 58.6 3.65, 61.62 13.07 vs 27.32 5.97, P < 0.01). Furthermore, serum TNF-α and IL-1b levels at 12 h in the Liuweiwuling tablet group were also significantly lower than those of the control group (299.35 50.61 vs 439.03 63.59, 57.42 12.98 vs 160.07 49.87, P < 0.01). Centrilobular necrosis was evident in liver tissue of mice with acetaminophen-induced acute liver injury, but was almost abolished in the Liuweiwuling tablet group. The expression levels of PCNA and CyclinD1 were up-regulated in liver tissue in the Liuweiwuling tablet group (321.08 32.87 vs 157.91 21.52, 196.37 25.39 vs 68.72 11.27, P < 0.01); however, expression of p21 in liver tissue was downregulated compared to that of the control group (40.26 9.97 vs 138.24 13.66, P < 0.01). Conclusion: Liuweiwuling tablets can attenuate acute liver injury by decreasing inflammatory cytokine (HMGB1, TNF-α and IL-1b) levels and promoting liver regeneration.