Potentiation of antifungal effect of amphotericin B by squalene, an intermediate for sterol biosynthesis.

The antifungal effect of a polyene antibiotic amphotericin B (AMB) was almost completely abrogated by exogenous addition of 0.1 microgram/ml ergosterol in the medium. The cytocidal effect of AMB on Saccharomyces cerevisiae was synergistically enhanced when cultured for more than 4 hours with squalene, an obligatory intermediate molecule for sterol formation. However, we could not find significant increase in cellular level of ergosterol content in the yeast cells fed with squalene.