Synergistic Action of Amphotericin B and Antioxidants Against Certain Opportunistic Yeast Pathogens

Abstract

Results of earlier turbidimetric growth experiments showed that certain antioxidants prolonged the antifungal activity of amphotericin B (AB) against Candida albicans , presumably by retarding autoxidative destruction of the drug. Viability studies were designed to examine this in more detail. Subinhibitory concentrations of either butylated hydroxyanisole, n -propyl gallate, or nordihydroguaiaretic acid in combination with fungistatic levels of AB exerted synergistic fungicidal activity against two strains of C. albicans and one of C. parapsilosis . Although synergism was not seen in tests with a strain of Torulopsis glabrata , antioxidants prolonged the inhibitory action of AB against this organism. On the basis of these findings and other considerations that are discussed, it is suggested that stabilization of AB and the ability to act synergistically with AB represent two distinctly different effects of the antioxidants.

In vitro antifungal activities of amphotericin B in combination with acteoside, a phenylethanoid glycoside from Colebrookea oppositifolia

“…The subinhibitory concentration of AmB probably enhanced the cellular uptake of acteoside and, once inside the cell, this compound may have inhibited one or more physiological or biochemical process. Similar observations were made by Andrews et al (1977) and Beggs et al (1978), who found a synergistic action of AmB and antioxidants. They also speculated that antioxidants protect AmB from autooxidation, thereby decreasing the rate of spontaneous inactivation and prolonging its biological activity.…”

Kinetics of growth and accumulation of aflatoxin B1 by Aspergillus parasiticus in the presence of butylated hydroxyanisole, isoprothiolane, and nystatin

“…Solvent DMSO is frequently used in biological systems and some reports indicate that it does not inhibit growth of cultures. 16 In our experiment, the concentration of DMSO in media was ca 3.370, which was higher than that reported in the previous study.I6 Average inhibition of mold growth because of the presence of DMSO in our experiment, as compared with DMSOfree controls ( C , , Cz, and C3), was 38.3%. Since all GC values of each additive were compared with its own control, and assuming that DMSO did not exert any appreciable synergistic effect on growth, the inhibition caused by DMSO does not invalidate the results.…”

Secondary Assays for Testing the Mode of Action of Natural Products with Bioactivity Against Fungi

“…Coville (Zygophyllaceae)], which has been used in traditional medicine against at least 50 ailments including kidney stones, diabetes, inflammation, and arthritis (Arteaga et al, 2005). Previous studies also confirmed NDGA as an antifungal against pathogenic fungi (Beggs et al, 1978;Martinez-Tellez et al, 2005) and that it has antioxidant activity in vitro and in vivo (Harper et al, 1999). We examined antioxidant activities of subinhibitory levels of NDGA using an oxidative stress assay with SOD1 , a superoxide dismutase knockout strain.…”

“…In addition, several antioxidants, such as NDGA, have been shown to have a synergistic effect when combined with an antifungal (Beggs et al, 1978). NDGA is the primary antioxidant found in the creosote bush [Larrea tridentate (Sessé & Moc.…”