In vitro anti-Malassezia activity of xanthorrhizol isolated from Curcuma xanthorrhiza Roxb

AIMS: This study aimed at investigating the anti-Malassezia activity of xanthorrhizol (XTZ) isolated from Curcuma xanthorrhiza Roxb. against Malassezia furfur ATCC 14521 and Malassezia pachydermatis ATCC 14522. METHODS AND RESULTS: The in vitro susceptibility tests for XTZ were carried out in terms of minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC), using broth microdilution method with endpoint after 48 h. Time-kill curves were determined at concentrations ranging from 0 to 25 microg ml(-1). The MIC values of XTZ against M. furfur and M. pachydermatis were 1.25 and 0.25 mug ml(-1), respectively. The MFC of XTZ was 5 microg ml(-1) for M. furfur and 2.5 microg ml(-1) for M. pachydermatis. Time-kill curves demonstrated that treatment with 25 microg ml(-1) of XTZ for 5 h was able to kill 100% of M. furfur, while 20 microg ml(-1) of XTZ for 15 min killed M. pachydermatis completely. CONCLUSION: XTZ shows potential as an anti-Malassezia agent for inhibiting the growth of M. furfur ATCC 14521 and M. pachydermatis ATCC 14522 in vitro. SIGNIFICANCE AND IMPACT OF THE STUDY: XTZ may be a useful alternative for treating Malassezia-associated diseases.