Experimental Study Of "Wubai Powder" Dissolving Microneedle Patches In The Treatment Of Chloasma

Objective: The therapeutic effect of "Wubai Powder" dissolving microneedle patches on the melasma model guinea pigs and the related situation of melanin was observed as well as the activity of total superoxide dismutase(T-SOD)and the content changes of malondialdehyde(MDA)before and after treatment which can provide certain references for the external treatment of traditional Chinese medicine for melasma.Method: The clean grade tricolor guinea pigs were randomly divided into normal group,model group,acupoint application with dissolving microneedle group,traditional powder acupoint application group,pure microneedle matrix acupoint application group,and positive drug group.The other groups were given progesterone systemic attack and ultraviolet irradiation method to prepare the guinea pig melasma model except he normal group.After the model was introduced successfully,both normal and model groups were treated with pure hydrogel matrix acupoint application only,while the other groups were treated with corresponding patch/drug for acupoint application or smear intervention,which were carried out for 8 hours daily for 30 days.After treatment,the melanin of guinea pigs in each group was observed by immunohistochemical staining.The T-SOD activity of guinea pig skin homogenate was determined by hydroxylamine method and MDA content was determined by thiobarbituric acid method respectively.Results: In terms of positive cell ratio,positive cell density,average optical density value and H-Score,"Wubai powder" dissolving microneedle patch application group was lower than other groups in comparison with model group,blank microneedle patch application group and positive drug control group,respectively.The difference was statistically significant(P<0.01).The results of T-SOD activity determination showed that the activity of T-SOD in the group of "Wubai Powder" dissolving microneedle patch significantly increased(P<0.01)comparing with the model group,pure microneedle matrix acupoint application group and positive drug control group.The MDA content of "Wubai Powder" soluble microneedle patch application group significantly decreased comparing with the model group,pure microneedle matrix acupoint application group and positive drug control group,and the difference was statistically significant(P<0.01).Conclusion: "Wubai Powder" dissolving microneedle patch can reduce the melanin content,increase the activity of T-SOD and decrease the content of MDA in the skin tissue of the guinea pig model of chloasma.The therapeutic effect is better than those of blank microneedle patch and positive drug groups.