02717nam a2200289Ia 4500 MX-MdCICY 20260521091754.0 CICY B-21120 Photochemoprotective effect of a fraction of a partially purified extract of Byrsonima crassifolia leaves against UVB-induced oxidative stress in fibroblasts and hairless mice Journal of PhotoChemistry and PhotoBiology B: Biology, 178, p.53-60, 2018 Ultraviolet B (UVB)irradiation increases the risk of various skin disorders, leading to inflammation and oxidative stress and thereby increasing the risk of skin photoaging and carcinogenesis. The use of photochemoprotectors such as natural products with antioxidant and anti-inflammatory properties represents a strategy for preventing UVB-induced skin damage. We investigated the photochemoprotective effect of a fraction of a partially purified extract of Byrsonima crassifolia leaves (BCF)on fibroblasts and hairless mice exposed to UVB radiation. The mixture of phenolic compounds in BCF prevented the decrease in reduced glutathione (GSH)levels in fibroblast cultures induced by UVB radiation more than some of their individual standards ((+)-catechin (CAT), epigallocatechin gallate and quercetin 3-O-?-d-glucopyranoside). Prepared gel formulations increased skin antioxidant activity, and BCF components and the CAT standard were retained in the HRS/J hairless mice epidermis 2h after application. Topical treatment with the BCF or CAT formulations (1 percent)significantly reduced the decrease in GSH levels and decreased myeloperoxidase activity and the secretion of pro-inflammatory cytokines IL-1? and IL-6 induced by UVB radiation (P<0.05), indicating that both BCF and CAT had anti-inflammatory effects. BCF inhibited UVB-induced metalloproteinase (MMP)-9 secretion/activity, whereas CAT had no effect on MMP-9 activity in the skin of treated animals. These results therefore suggest that BCF can be used as a photochemoprotective agent and antioxidant in the prevention/treatment of inflammation and oxidative stress of the skin induced by UVB radiation. ANTIOXIDANT ACTIVITY CATECHIN CYTOKINES METALLOPROTEINASE MYELOPEROXIDASE REDUCED GLUTATHIONE De Souza, R. O. Alves, G. D. A. D. Aguillera, A. L. S. Rogez, H. Fonseca, M. J. V. https://drive.google.com/open?id=1sS7Wx7zh1YRY6h11-TH77PFjYiJiKNrx&usp=drive_copy Para ver el documento ingresa a Google con tu cuenta: @cicy.edu.mx Loc REF1 250602s9999 xx |||||s2 |||| ||und|d 31136 31136 0 0 Loc 0 0 F1 CICY CICY RE 2025-06-25 0 B-21120 2025-06-25 16:25:01 2025-06-25 REF1