Icariin modulates the sirtuin/NF­κB pathway and exerts anti­aging effects in human lung fibroblasts.

Icariin (ICA) has been used as a promising anti­aging drug; however, its underlying molecular mechanism is yet to be elucidated. The present study aimed to determine the anti­aging molecular mechanisms of ICA. D­galactose (D­gal) was used to generate a cell aging model. IMR­90 human lung fibroblasts were pretreated with different concentrations of ICA (1, 2, 4, 8 and 16 µmol/l) for 6 h and subsequently incubated with D­gal (200 mmol/l) at 37˚C for 72 h. Senescence of IMR­90 cells was assessed by senescence­associated­ß­galactosidase (SA­ß­Gal) staining assay. Cell viability, and the expression levels of p53/p21, sirtuin (SIRT) 1/6 and p50/p65 were determined via the MTT assay and western blotting respectively. The results demonstrated that D­gal notably increased the proportion of SA­ß­Gal­positive cells and decreased the viability of IMR­90 cells; however, pretreatment with ICA reversed the effects of D­gal on IMR­90 cells in a concentration­dependent manner. Furthermore, it was also demonstrated that the activation of p53/p21 and nuclear factor­κB (NF­κB) signaling, and downregulation of SIRT1/6 may be involved in IMR­90 cells, in D­gal­induced aging and ICA may effectively prevent IMR­90 cells from these changes induced by D­gal. Taken together, the results of the present study suggest that the anti­aging molecular mechanisms of ICA may be associated with the regulation of the SIRT1/NF­κB pathway.