Effects of Flavonoid and Saponins on Protecting HaCaT Cells and Ameliorating Ultraviolet Radiation B/Ultraviolet Radiation A-Induced Skin Photoaging

The skin serves as a natural barrier in the human body, protecting against pathogenic microorganisms and ultraviolet radiation (UV). Skin photoaging is a physiological stress reaction characterized by skin relaxation, dryness, abnormal pigmentation, and increased wrinkles due to prolonged exposure to ultraviolet radiation. The search and development of natural products that can effectively prevent skin photoaging have gained significant attention. We established the photoaging model by subjecting HaCaT cells and ICR mice to UVB+UBA irradiation. We employed CCK8 to assess the impact of Totol Flavonoid of Lichi Seed (TFLS) and Lychee Seed Saponins (LSS) on cell viability. We evaluated the effects of TFLS and LSS on apoptosis using flow cytometry. We utilized SIRT-IN-1 inhibitor to suppress the activity of SIRT1 and examined the mechanism by which TFLS and LSS alleviate UV-induced photoaging damage in cells and mice. We assessed skin inflammation in photoaging ICR mice through HE staining. We evaluated changes in collagen fibers and glia in the skin of photoaging ICR mice using Masson staining. We employed TUNEL staining to evaluate the apoptosis of skin cells in photoaging ICR mice. We extracted nucleic acid using nano-magnetic beads and detected the expression of SIRT1, TGF-β1, and Smad3 in HaCaT cells and mouse skin tissues using qPCR and WB. The study results demonstrate the protective effect of TFLS and LSS against UV-induced photoaging in HaCaT cells and ICR mouse skin, mitigating the damage caused by UV exposure. The mechanism underlying the attenuation of UV-induced photoaging by TFLS and LSS may involve activation of the SIRT1-TGF-β1/Smad3 signaling pathway.