Effects of ascorbic acid on the antifungal action of amphotericin B.

Ascorbic acid enhanced the lethal but not the permeabilizing effects of amphotericin B on Candida albicans and Cryptococcus neoformans cells. Two other ene-diol acids, D-erythorbate and dihydroxyfumarate, also enhanced the lethal action of amphotericin B on Can. albicans. Maleic acid and gulanolactone, compounds structurally related to ascorbic acid but not containing the ene-diol group, had no such effect. It is assumed that ascorbic acid and the two other ene-diol acids acting as pro-oxidants augmented the oxidation-dependent killing of fungal cells induced by amphotericin B.