Antifungal Activity Test of Ethanol Extract of Manukan Leaves (Rhinacanthus nasutus (L.) Kurz) Against Malassezia furfur Growth

Abstract

Medicinal plants are increasingly being explored as potential sources of natural antifungal agents to address the rising incidence of skin infections in tropical regions. Manukan leaves (Rhinacanthus nasutus (L.) Kurz) contain various secondary metabolites with potential antifungal, antibacterial, anti-inflammatory, antiviral, and anticancer activities. Although previous research has reported the antifungal activity of manukan leaves against Candida albicans, their activity against Malassezia furfur, a causative agent of tinea versicolor, has not yet been specifically investigated. In Waeperang Village, Buru Island, Maluku, manukan leaves have traditionally been used to treat skin infections; however, this empirical use has not been adequately supported by scientific evidence. This study aimed to evaluate the antifungal activity of the ethanol extract of manukan leaves against Malassezia furfur and to identify the groups of secondary metabolites potentially associated with this activity. Manukan leaves were extracted by maceration using ethanol. Antifungal activity was evaluated using the agar diffusion method, while the active compound groups were identified using thin-layer chromatography (TLC) combined with bioautography. The novelty of this study lies in the evaluation of manukan leaf extract against Malassezia furfur and the use of TLC-bioautography to identify compound groups potentially associated with its antifungal activity. The ethanol extract contained flavonoids, alkaloids, tannins, steroids, and terpenoids. The extract exhibited antifungal activity against Malassezia furfur at concentrations of 5%, 15%, 30%, and 60%, with the highest inhibition zone observed at 60% concentration (14.4 mm). TLC-bioautography indicated that tannins (Rf 0.63) and steroids (Rf 0.68) were suspected to contribute to the antifungal activity against Malassezia furfur.