Antifungi of Euphorbia humifusa extract and its effect on ultrastructure of dermatophytes / 中草药

ABSTRACT

Objective By measuring the minimal inhibitory concentration(MIC) of Euphorbia humifusa extract in vitro to examine its antifungal effect and observe the effect of E.humifusa extract on the ultrastructure of dermatophytes,so as to explore the potential mechanism of its antifungal action.Methods Appling the standard approved by the National Committee for Clinical Laboratory Standards(NCCLS) Reference Method for Broth Dilution Antifungal Susceptibility Testing of Filamentous Fungi(M38-A) to investigating the MICs of E.humifusa extract against 60 strains of common clinical dermatophytes.Treated the sample with the routine method,the ultrastructure of dermatophytes was observed with scanning electron microscope(SEM) and transmission electron microscope(TEM).Results The mean MIC of E.humifusa extract against Trichophyton rubrum was 446 ?g/mL;The mean MIC of E.humifusa extract against Trichophyton mentagrophytes was 539 ?g/mL. After exposing to E.humifusa extract,cell surface wrinkled,and folds and cell breakage were observed under SEM.The cell wall was incomplete,the thickness of cell wall became uneven,the density of the cell wall decreased,and the cell membrane became discontinuous with TEM observation.The organelles such as mitochondria and endoplasmic reticulum were deeply damaged.The cytoplasma was aggregated and some high density electron light areas as well as vacuoles were formed.Conclusion E.humifusa extract has a strong antifungal effect which could obviously change the conformation and the ultrastructure of dermatophytes.