Abstract:Objective:To observe the effect of Compound Lycii Fructus Granules on the prevention and treatment of skin injury induced by ultraviolet B (UVB) in mice with melasma. Methods:A total of 40 female ICR mice were randomly divided into the normal group, the model group, the positive group and the Chinese medicine group,with 10 mice in each group. On the day before modeling,the positive group was given 100 mg/kg aqueous solution of vitamin C by gastric irrigation;the Chinese medicine group was given 9.3 g/kg aqueous solution of Compound Lycii Fructus Granules by gastric irrigation;the normal group and the model group were given an equivalent volume of 0.9% sodium chloride solution by gastric irrigation. The intervention lasted for 15 consecutive days. On the second day of drug intervention,except for the normal group,the other groups were irradiated with UVB for 14 consecutive days (twice a day,with one hour for each time) to induce melasma. The pathological changes in skin of mice were observed by HE staining;the expression of melanin in skin of mice was observed by immunohistochemistry; the expressions of tyrosinase,total antioxidant capacity (T- AOC),total superoxide dismutase (T- SOD),catalase (CAT) and malondialdehyde (MDA) in skin tissue of mice were detected by spectrophotometry. Results: Compared with the normal group,the skin of mice in the model group showed wrinkles and dullness;the epidermal epithelial cells,inflammatory cells and sebaceous glands appeared hyperplasia;and the levels of melanin, tyrosinase and MDA in skin tissue were increased (P<0.05);T-AOC,CAT and T-SOD showed a trend of decrease,but the difference showed no significant difference (P>0.05). Compared with that in the model group,skin injury of mice in the positive group and the Chinese medicine group was relieved;the levels of melanin and tyrosinase in skin tissue were decreased (P<0.05);the levels of T- AOC and T- SOD in skin tissue of mice in the positive group and the Chinese medicine group were increased (P<0.05,P<0.01); the MDA level in skin tissue of mice in the Chinese medicine group was decreased,the difference being significant (P<0.05). Conclusion: Compound Lycii Fructus Granules can effectively relieve skin injury induced by UVB in mice with melasma,and its mechanism is related to reducing the levels of tyrosinase and MDA in skin tissue.