Figure 7 Schematic diagram of the protective mechanism of icariin in renal tubulointerstitial fibrosis of CKD. Icariin may inhibit the process of Keap1-dependent Nrf2 degradation, allowing Nrf2 protein to accumulate and translocate to the nucleus. Once in the nucleus, Nrf2 binds to ARE sequence, activates downstream cytoprotective genes, and eventually mitigates tubulointerstitial fibrosis. DAMPs, damage-associated molecular patterns; ARE, antioxidant response element; NQO1, NAD(P)H quinone oxidoreductase-1; HO-1, heme oxygenase-1; GPx, glutathione peroxidase; SOD, superoxide dismutase.