Investigation of antifungal activity of ononis spinosa L ASH used for the therapy of skin infections as folk remedies

Abstract

Traditional folk remedies used for centuries come up focus of interest in recent years, due to the trend of use of herb-derived natural products. In addition, increasing morbidity and mortality rates of opportunistic fungal infections and accelerating antifungal resistance rates of fungi lead to the use of alternative therapies with herb-derived preparations as novel antifungals. Ononis spinosa L. (spiny restharrow), which is classified in Leguminosae family, is one of the plants used in herbal medicine as folk remedies for the treatment of skin lesions and/or infections as well as many other disorders. Antibacterial, antifungal, anti-inflammatory and analgesic effects of Ononis spinosa (OS) have already been supported by different studies. The roots and aerial sections of OS are the mainly employed parts for application, however local communities inhabiting at southeastern parts of Anatolia, Turkey, employ the ashes of OS widely to heal the skin infections. There have been no reports about the antifungal activity of OS ashes as far as the current literature is concerned. The aim of this study was to investigate the antifungal activity of ashes of OS, collected from a rural area located at Southeast Anatolia. Ashes of OS have been obtained by burning the plant samples at 400̈C, and extracted in sterile distilled water and ethanol. The efficacy of aqueous and ethanol extracts of OS ashes were tested against 10 fungi, of which one was a Candida albicans standard strain (ATCC 95071) and the others were clinical isolates (C.albicans, Candida glabrata, Candida tropicalis, Candida krusei, Candida guilliermondii, Candida parapsilosis, Candida pelliculosa, Trkhosporon asahii, Trichophyton rubrum). Antifungal susceptibility test was performed by disc diffusion (DD) method and the results were confirmed with minimum inhibitory concentration (MIC) and minimal fungicidal concentration (MFC) values determined by microdilution method. The results indicated that both aqueous and ethanol extracts of OS ash showed antifungal activity against C. albicans ATCC 95071 (DD inhibition zones were 16 and 15 mm, respectively; MIC= 1.25 ug/ml, MFC= 1.25 ug/ml), whereas against C.glabrata clinical isolate only ethanol extract exhibited antifungal activity (DD inhibition zone= 10 mm, MIC= 5.00 ug/ml, MFC= 40.00 ug/ml). No antifungal effect was detected against the other clinical Candida spp, T.asahii and T.rubrum isolates. In conclusion, since our results emphasize that extracts of OS ash that traditionally used for skin disorders, showed promising degrees of antifungal activity against some of Candida strains, these preliminary data should be supported by further large-scale studies.