Numerous studies have revealed that TGF-β/SMAD2/3 signaling pathway is closely related to HSCs activation and fibrogenesis, for example, piperine inhibited HSCs activation and mitigated hepatic fibrosis via activating Nrf2 which sequentially repressed TGF-β/SMAD2/3 signaling pathway [38]. Here, SMAD2 is linked to Hepatic fibrosis.