Harmine ameliorates CCl4-induced acute liver injury through suppression of autophagy and inflammation

CCl4-induced acute liver injury (ALI) is characterized by heightened autophagy, inflammation, and oxidative damage. Accumulating evidence suggests that harmine exerts beneficial effects in countering CCl4-induced ALI by mitigating inflammation and oxidative stress. However, the impact of autophagy on CCl4-induced ALI and the protective role of harmine remain unclear. This study aimed to investigate the potential protective effects of harmine against CCl4-induced ALI in mice by suppressing autophagy and inflammation. Male Kunming mice were orally administered harmine or bifendate for seven days. Subsequently, one hour after the final administration, the model group and treatment groups were intraperitoneally injected with CCl4 to induce ALI. The findings revealed that harmine significantly reduced the levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in serum, and ameliorated the liver histopathological changes induced by CCl4. Furthermore, harmine diminished the levels of TNF-α and IL-6, restored the levels of glutathione (GSH) and superoxide dismutase (SOD), and suppressed the production of nitric oxide (NO) and malondialdehyde (MDA) in the liver. Mechanistically, harmine down-regulated LC3B II/I, p38 MAPK, TLR4, and NF-κB levels, while upregulating p62, Bcl-2, Beclin1, ULK1, and p-mTOR expression. In conclusion, harmine mitigated CCl4-induced ALI by inhibiting autophagy and inflammation through the p38 MAPK/mTOR autophagy pathway, the Bcl-2/Beclin1 pathway, and the TLR4/NF-κB pathway.