Abstract
Senescent cells accumulate with age and contribute to age-related diseases and organ dysfunctions. Early evidence suggests that removal of senescent cells using senolytic drugs improves the aging phenotype in mice and may improve the health of individuals with chronic diseases. Signs of skin aging, including wrinkles, and sagging, occur largely due to the accumulation of senescent fibroblasts within the dermis; However, there is currently no skin treatment that eliminates senescent cells. In this study, human fibroblasts subjected to replicative aging and ionizing radiation exposure are used to screen plant extracts for potential senescent cell-destructive and/or senescent cell-forming activities. Angelica acutiloba-a traditional Chinese herbal medicine-selectively kills senescent cells without affecting the proliferating cells. Among the major components of this herb, ligustilide shows promising senescent cell-destructive properties, and selectively eliminates senescent cells by inducing an apoptosis. Moreover, ligustilide markedly inhibits senescence-associated secretory phenotypes. Administration of ligustilide to mouse skin eliminates senescent cells and increases dermal collagen density and subcutaneous adipose tissue content; it selectively promotes death of senescent cells without affecting non-senescent cells. These results provide evidence that a natural compound-ligustilide-may exhibit therapeutic effects on the skin aging phenotype by specifically inducing apoptosis in senescent cells.