Abstract:To study the action mechanisms of total triterpenoids (TIO) in Inonotus obliquus on acetaminophen (APAP)-induced liver injury in mice, a total of 48 SPF-grade ICR male mice were divided into six groups with seven-day administration as follows: blank control; model; silymarin-treated (50 mg/kg); and TIO-treated low , medium, and high dose (15 mg/kg, 30 mg/kg, and 60 mg/kg, respectively). After the last administration, all groups, except the blank group, were subjected to a one-time abdominal injection of 300 mg/kg APAP to establish the liver injury models. Subsequently, the activities of alanine aminotransferase, aspartate aminotransferase, and superoxide dismutase were determined, and the contents of reduced glutathione and malondialdehyde were measured. Furthermore, the liver was processed for hematoxylin–eosin and Hoechst 33258 staining to observe pathological changes. The high dose of TIO reduced the aspartate aminotransferase and alanine aminotransferase contents to 8.38 U/L and 11.13 U/L, respectively, and that of malondialdehyde to 20.71 pmol/(mg pro). The superoxide dismutase and reduced glutathione levels were increased to 628.39 U/(mg pro) and 126.28 U/(mg pro), respectively Hematoxylin-eosin staining revealed the structure of the liver lobules in the TIO-treated medium- and high-dose and the silymarin-treated groups to be complete and clear, and the liver cell injury to be effectively repaired. Hoechst 33258 staining showed that the numbers of apoptotic liver cells in the TIO-treated groups were significantly reduced, and the fluorophore color was weakened. The above results indicate that the total triterpenoids in Inonotus obliquus provide marked protection against APAP-induced liver injury in mice. The mechanism may be related to reduction in oxidative stress and inhibition of apoptosis.
