Study on the antifungal activity and mechanism of Huangqin decoction against Trichophyton mentagrophytes / 中国药房

ABSTRACT

OBJECTIVE To study the antifungal activity of Huangqin decoction （HQD） against Trichophyton mentagrophytes and explore its mechanism. METHODS Minimal inhibitory concentration （MIC）， minimal fungicidal concentration （MFC）， mycelial length， spore germination rate， biomass and mycelium ultrastructure observation were performed to evaluate the antifungal activity of HQD against T. mentagrophytes. The effects of HQD on the cell wall of T. mentagrophytes were detected through sorbitol protection experiment. By measuring the content of ergosterol and the activities of squalene epoxide （SE） and lanosterol 14α-demethylase （CYP51）， the activity of HQD on the cell membrane of T. mentagrophytes was investigated. The effects of HQD on T. mentagrophytes mitochondria were investigated by determining the activities of malate dehydrogenase （MDH）， succinate dehydrogenase （SDH）， and ATPases （including sodium potassium ATPase， calcium magnesium ATPase， and total ATPase）. RESULTS HQD exhibited significant antifungal activity against T. mentagrophytes with MIC of 3.13 mg/mL and MFC of 25 mg/mL. After intervention with HQD， the mycelial length of T. mentagrophytes was significantly shortened （P＜0.05）； spore germination rate， biomass， the content of ergosterol in the cell membrane， the activities of SE and CYP51 in the cell membrane and MDH， SDH and ATPase in mitochondria were all decreased significantly （P＜0.05）； cell structure had been ；damaged to a certain extent， but the integrity of the cell wall had not been affected. CONCLUSIONS HQD shows significant antifungal activity against T. mentagrophytes， the mechanism of which may be associated with reducing the 0791- content of ergosterol in the cell membrane and the activities of SE， CYP51， and mitochondria-related enzymes.