Latifolin Inhibits Oxidative Stress-Induced Senescence via Upregulation of SIRT1 in Human Dermal Fibroblasts.

Latifolin, a natural flavonoid found in Dalbergia odorifera T. Chen, has been reported to exhibit anti-inflammatory and anticarcinogenic activities in vitro. However, the anti-aging effects of latifolin are unknown. In this study, we selected a model in vitro system, hydrogen peroxide (H ₂ O ₂ )-induced senescence in human dermal fibroblasts (HDFs), to examine the protective effects of latifolin against senescence and the detailed molecular mechanisms involved. Latifolin reversed the senescence-like phenotypes of the oxidant-challenged model, including senescence-associated β-galactosidase (SA-β-gal) staining, cell proliferation, and the expression of senescence-related proteins, such as caveolin-1, ac-p53, p21 ^Cip1/WAF1 , p16 ^Ink4α , pRb, and cyclinD1. We also found that latifolin induced the expression of silent information regulator 1 (SIRT1) in a concentration- and time-dependent manner, and the anti-senescence effect of latifolin was abrogated by SIRT1 inhibition. Latifolin also suppressed the activation of Akt and S6K1 and attenuated the increase in SA-β-gal activity after H ₂ O ₂ exposure. Our results indicate that latifolin exerts protective effects against senescence in HDFs and that induction of SIRT1 and inhibition of the mammalian target of rapamycin (mTOR) pathway are key mediators of its anti-aging effects.