Dracocephalum tanguticum Maxim Polysaccharide Ameliorate Autoimmune Hepatitis via Regulating TNF and IL-17 Signaling Pathways.

Dracocephalum tanguticum Maxim (DrT) is a well-known traditional medicinal and edible plant with hepatoprotective effects. In this study, crude polysaccharides of DrT (DrTPs) were obtained using the water extraction-ethanol precipitation method. Autoimmune hepatitis (AIH) models of both mice and ALM12 cells were produced by ConA. The serum liver function indexes (AST and ALT) were examined by ELISA, and liver tissue pathological changes were observed by HE staining. The hepatoprotective mechanism of DrTP80 was explored by RNA sequencing and verified by detecting the protein expressions using Western blot. As a result, DrTP80 could significantly reduce AST and ALT levels in the injured liver and ALM12 cells. DrTP80 also obviously improved the hepatopathological changes in liver tissue induced by ConA. Furthermore, RNA sequencing detected significant differences in gene expression, and the functions of differential genes were focused on TNF and IL-17 signaling pathways. Based on these two signaling pathways, 13 differentially expressed genes (Vcam1, Atf6b, Akt1, Irf1, Map2k3, Lcn2, Hsp90ab1, Anapc5, Traf4, Fosl1, Jun, Cxcl5, Nfκbia) among NC, CRC, and FP groups were screened and verified by Western blot. In conclusion, our results demonstrated that DrTP80 can alleviate immune liver damage induced by ConA, and its hepatoprotective mechanism may be related to regulating TNF and IL-17 signaling pathways. Our findings indicated that DrTP80 could be exploited as a healthy food supplement for the treatment of immune liver injury.