大黄酸通过抑制p38 MAPK磷酸化减轻UVB诱导的皮肤光老化损伤OA北大核心CSTPCD

The study aimed to reveal the effect and mechanism of rhein on skin photoaging injury induced by ultraviolet B(UVB).Rats were divided into 6 groups:normal control group(NC),UVB group,low dose Rhein group(L-Rhein),medium dose Rhein group(M-Rhein),high dose Rhein group(H-Rhein)and high dose Rhein+p38 MAPK agonist Anisomycin group(H-Rhein+Anisomycin).Rats in the NC group were shaved without irradiation,while the other groups were irradiated with UVB.In this study,the administration route of rhein was oral administration.Rats were treated for 8 weeks.After treatment,the body weight,water content of epidermis and the levels of oxidative stress indexes(SOD,CAT,GSH-Px and MDA)in skin tissue were measured,and the skin tissue was stained with HE staining and Masson trichrome staining,and the volume fraction of collagen(CVF)was calculated.The levels of TNF-α,IL-1β,IL-6,MMP-1,MMP-3 and Collagen Ⅰ mRNA in skin tissue were detected by RT-qPCR.The protein levels of p-p38 MAPK and p38 MAPK in skin tissue were detected by Western blotting.The results show that compared with UVB group,the phosphorylation level of p38 MAPK in L-Rhein group,M-Rhein group and H-Rhein group decreases,the water content of epidermis increases,the skin injury is alleviated,CVF increases,the relative expression of MMP-1 and MMP-3 mRNA decreases,the relative expression of Collagen Ⅰ mRNA increases,the level of SOD,CAT and GSH-Px increassd,the level of MDA decreases,and the relative expression of TNF-α,IL-1β and IL-6 mRNA decreases in the skin(P<0.05).Anisomycin attenuates the skin protective effect of rhein(P<0.05).This study shows that rhein attenuates UVB-induced skin photoaging injury by inhibiting p38 MAPK phosphorylation.Therefore,Rhein may be a candidate natural drug for the prevention and treatment of skin photoaging.