HMOX1 and renal fibrosis: Extant studies have found that AS-IV has protective effects on the kidneys and improves renal fibrosis by enhancing the expression of phosphorylated (p-) Smad3 C/p21 and nuclear factor (erythroid-derived 2)-like 2(Nrf2)/Heme oxygenase-1(HO-1), thereby inhibiting p-Smad 3L/plasminogen activator inhibitor (PAI)-1 and reducing ROS and α-SMA levels (Qin et al., 2023).