动物造模,大鼠皮肤光损伤 z-bio 2021-04-29 472

　　Purpose: To study the protective effects of various sunscreen standards on the photodamage of the skin of rats by ultraviolet rays, and to provide background data for evaluating sunscreen cosmetics.

　　Method: Use long-wave ultraviolet (UVA, 320-400nm, 4.5mJ·Cm-2·S-1) + medium-wave ultraviolet (UVB, 280-320nm, 0.036mJ·Cm-2·S-). It will be established. 1) A rat model of radiation-induced skin phototoxicity injury by irradiating twice a week for 4 consecutive weeks, with a cumulative irradiation time of 440 minutes. Sun protection standards are applied to each sun protection standard group (S1, S2, P2, P3, P7). 30 minutes before each irradiation. After the experiment, the skin was observed by histopathology, and the expression of the skin melanoma specific marker (HMB45) was detected by immunohistochemistry.

　　Result: The levels of epidermal hyperplasia, sebaceous gland hyperplasia, skin damage score and melanoma-specific markers (HMB45) in the S2 group were significantly lower than those in the model group (P\u003c0.05). Thickening of the epidermis was observed in the P3 and P2 groups. Compared with the model group, the ratio of skin damage score and HMB45 expression was significantly reduced; compared with the model group, the SI group [UVA protection (PFA) 4.5 for epidermal thickening and skin damage score] was significant. Compared with the model group, the thickness of the epidermis in the P7 group was significantly reduced. Generally speaking, the protective effect of standard products is consistent with PFA and sun protection factor (SPF) values.

　　Conclusion: The protective effect of sunscreen cosmetics on skin damage caused by ultraviolet rays is related to the PFA and SPF values.