Fig. 6.

The possible mechanism of Sirt1/FXR activation by 18b-GA in an ANIT-induced cholestasis rat model. 18b-GA can activate Sirt1 and promote the binding of FXR and RXR, which promotes upregulation of canalicular efflux transporters and entry into the bile. On the other hand, activation of Sirt1 promotes the expression of Nrf2, leading to marked upregulation of the basolateral efflux transporters, thereby promoting bile into the blood. ARE: antioxidant response element, RXR: retinoid X receptor, FXRE: FXR-responsive element