Efficacy and possible mechanisms of topical tranexamic acid in melasma = Efficacy and possible mechanisms of topical tranexamic acid in melasma

다국어 초록 (Multilingual Abstract)

Background: Tranexamic acid (TA) is suggested as an efficient treatment modality for melasma. Objectives: To investigate the effects and action mechanism of topical TA in the treatment of melasmaMethods: Twenty-three subjects with melasma applied a2% TA formulation on the whole face for 12 weeks. Clinical effects were evaluated using the modified melasma area and severity index (mMASI) and a chromameter. Skin biopsies were obtained from ten subjects to evaluate pigmentation, vascularity, and the expression levels of possible paracrine factors contributing to the effect of TA. Results: Most subjects had mild melasma with mMASI under 5. The mMASI scores significantly improved in 22 of 23 subjects after application. The L* values were increased and the a* values were decreased in both lesional and perilesional normal skin. Fontana-Masson staining showed a significant decrease in the melanin content in the epidermis. The number of CD31-positive vessels and the expression of the vascular endothelial growth factor both tended to decrease. Endothelin-1 (ET-1) was found to be downregulated with TA. Conclusion: Topical TA is effective for melasma. The immunohistochemical study found that the suppression of ET-1 may be one of the action mechanisms of TA on melasma.