Investigate The Effect Of Puerarin On Melanogenesis In Melanocyres And Its Possible Action Mechanism

Objective To observe the curative effect and security of topical application of 1%,3%,5% puerarin for treating vitiligo. To investigate the effect of puerarin on melanogenesis in melanocyres and its possible action mechanism.Methods Clinical observation:124 localized vitiligo patients were randomly included in this study. One leukoplakia was topical application of puerarin and the leukoplakia on the other side was used pimecrolimus. Photographs, VASI, RMI were taken before treatment and at every subsequent evaluations. Experimental research:The cell proliferation was detected by MTT assay, the melanin content by NaOH assay, and the mRNA and western level of microphthalmia-associated transcription factor (MITF), tyrosinase (TYR), tyrosinase related protein-1 (TRP-1) by RT-PCR and Western blot.Results Clinical observation results:Good results were obtained in 5.65%(n=7) of cases in puerarin group,8.87%(n=11) in pimecrolimus; fair repigmentation were achieved in 24.19% in puerarin group and 28.23% in the latter. The effective rate of pimecrolimus was 37.10% higher than puerarin group(29.84%), but no statistically significant difference could be detected between two groups(P=0.460). The effective rate of sixty-eight patients in puerarin group whose age were less than 16 years was 38.2%, and fifty-six patients whose age were more than 16 years was 17.8%. There was statistically significant difference between them. The effective rate of patients(n=72) in puerarin group whose lesions were in face and neck was 40.3%, and whose lesions were in trunk(n=52) was 17.8%. There was statistically significant difference between them. The effective rate of 58 patients in puerarin group whose duration were less than 12 months was 31.0%, and 52 patients whose duration were more than 12 months was 15.4%. There was no statistically significant difference. Topical application of puerarin in treating vitiligo and the efficiency rate were 22.7%,31.6%,35.7%, respectively. But there was no significant difference in three different concentration. Experimental research results:The strongest melanin synthesis was observed in melanocytes treated with puerarin of 40μmol/L(P<0.05); moreover, the mRNA and protein level of MITF, TYR, TRP-1 all increased in melanocytes treated with puerarin at 40μmol/L(P<0.05). compared with those in the cells without any treatment,40μmol/L puerarin can increased the protein expression of MITF, TYR and TRP-1 by 8.69%,10.28%,10.58%, respectively (P<0.05); moreover, MITF, TRP and TRP-1 mRNA levels in the puerarin treated cells increased by 2.48,1.91 and 1.63 times, respectively (P<0.05).Conclusion The effect of puerarin cream on vitiligo in children younger than 16 years old is better, and it has better effect on face and neck area. A considerable effect of puerarin cream and pimecrolimus in the treatment of vitiligo, and the security is good. Puerarin can promote melanogenesis and affect the mRNA and protein level of MITF, TYR, TRP-1 in melanocyres, this can provide the theoretical basis for topical puerarin for treating vitiligo.