Bear bile powder attenuates senecionine-induced hepatic sinusoidal obstruction syndrome in mice / 中国天然药物

Hepatic sinusoidal obstruction syndrome (HSOS) via exposure to pyrrolizidine alkaloids (PAs) is with high mortality and there is no effective treatment in clinics. Bear bile powder (BBP) is a famous traditional animal drug for curing a variety of hepatobiliary diseases such as cholestasis, inflammation, and fibrosis. Here, we aim to evaluate the protective effect of BBP against HSOS induced by senecionine, a highly hepatotoxic PA compound. Our results showed that BBP treatment protected mice from senecionine-induced HSOS dose-dependently, which was evident by improved liver histology including reduced infiltration of inflammatory cells and collagen positive cells, alleviated intrahepatic hemorrhage and hepatic sinusoidal endothelial cells, as well as decreased conventional serum liver function indicators. In addition, BBP treatment lowered matrix metalloproteinase 9 and pyrrole-protein adducts, two well-known markers positively associated with the severity of PA-induced HSOS. Further investigation showed that BBP treatment prevents the development of liver fibrosis by decreasing transforming growth factor beta and downstream fibrotic molecules. BBP treatment also alleviated senecionine-induced liver inflammation and lowered the pro-inflammatory cytokines, in which tauroursodeoxycholic acid played an important role. What's more, BBP treatment also decreased the accumulation of hydrophobic bile acids, such as cholic acid, taurocholic acid, glycocholic acid, as well. We concluded that BBP attenuates senecionine-induced HSOS in mice by repairing the bile acids homeostasis, preventing liver fibrosis, and alleviating liver inflammation. Our present study helps to pave the way to therapeutic approaches of the treatment of PA-induced liver injury in clinics.

The protective effect of schisandrol A against senecionine-induced hepatotoxicity in mice / 药学学报

Hepatotoxicity induced by herbal medicines such as Gynura japonica, which contains large amount of pyrrolizidine alkaloids (PAs) such as senecionine (SEN), is among the most serious problems of herbal drug-induced liver injury, yet there is no effective treatment in clinic. We have previously reported that ritonavir (the well-known CYP3A4 inhibitor) protected rats against Gynura japonica-induced liver injury in rats, which was closely related to the inhibition of the metabolic activation of PAs. A large number of lignans have been identified in Schisandrae Chinensis Fructis and are reported to attenuate drug-induced liver injuries by modulating the drug metabolism enzymes. Therefore, the present study investigated the protective effect and potential mechanism of schisandrol A (SoA, a representative lignan identified in Schisandrae Chinensis Fructis) against SEN-induced hepatotoxicity in mice. All experiments were approved by the Animal Research Committee of Shanghai University of Traditional Chinese Medicine (PZSHUTCM210604002). Animal welfare and the animal experimental protocols were strictly consistent with related ethics regulations of Shanghai University of Traditional Chinese Medicine. Liver injury was induced by a single gavage of SEN (150 μmol·kg-1); mice in the protection group were gavaged with SoA (116 μmol·kg-1) 7 days before SEN treatment. The results show that SoA dramatically alleviated SEN-induced liver injury in mice. Mice in the protection group showed decreased serum activities for alanine aminotransferase and aspartate aminotransferase; in addition, the hepatic necrosis and sinusoidal hemorrhage in SEN-treated mice were markedly attenuated in the protection group. The serum contents of SEN metabolites in mice were decreased. In vitro studies were performed by using human liver microsomes and proved that SoA inhibits CYP3A4 to decrease the metabolism of SEN. These studies indicate that SoA attenuated SEN-induced liver injury in mice, which was closely related to the inhibition of the metabolic activation of SEN. These results provide a better understanding of the relationship between CYP3A4 and PA-induced toxicity. This work also will be helpful in developing effective treatments for SEN-induced liver injury based on inhibition of its metabolic activation, and in making reasonable evaluations of the safety of herbal medicines containing PAs such as G. japonica.