Biological and physiological responses of Candida albicans to some natural products and some heavy metals

Abstract

The factors responsible for Candida albicans pathogenesis are still not fully understood and increasing resistance to commonly used antifungal agents necessitates the search for new formulations. The effect of heavy metals on the growth of Candida albicans (ATCC 10231) was tested, where Se, CO and Zn caused 100%, 72.65 and 17.4% dry weight inhibition, respectively. The inhibitory effect of different natural extracts on Candida albicans such as ethanolic extract of propolis, methanolic extract of Miswak (Salvadora persica), methanolic extract of Black seed (Nigella sativa), Musk oil (Moschus moschiferus), essential oil of clove bud (Syzygium aromaticum and Peppermint oil (Mentha biperatta) on Candida albicans was evaluated. The antifungal agent fluconazole was used as a positive control. Combination between 50ppm of selenium and 50ppm of fluconazole increased the activity of fluconazole against Candida albicans. Moschus moschiferus showed more potent inhibitory effect on the growth of Candida albicans. Addition of 50ppm selenium to Moschus moschiferus, showed highly increase of its antifungal potency against Candida albicans. Total protein and lipid content of Candida albicans decreased greatly in presence Moschus moschiferus, selenium or both together in the growth media, while, carbohydrate content  increased slightly in the presence of selenium but sharply decreased in the presence of Moschus moschiferus alone and in the combination between Moschus moschiferus and selenium.100ppm of cobalt prevented formation of germ tube while equivalent 1ml of Moschus moschiferus 100ml media had seemed to destroy the cells of Candida albicans, which can make these formulations an effective and safe alternative source for elimination of Candida albicans.