THE ACTIVITIES of the ergosterol biosynthetic enzymes, lanosterol 14α-demethylase and squalene epoxidase were assayed by measuring the ergosterol content of C. albicans cell membrane under different antifungal drug treatments as compared to control. The ergosterol was measured using the spectrophotometric sterol quantification method. Fluconazole (lanosterol 14 α-demethylase inhibitor) and terbinafine (squalene epoxidase inhibitor) inactivate both enzymes and stopped the ergosterol biosynthesis completely in susceptible isolates of C. albicans. Partial inhibition was observed in resistant isolates of C. albicans. Combined mixture of fluconazole (FLU) with terbinafine (TRB) acted synergistically on the ergosterol biosynthetic enzymes leasing to disappearance of the 4-peaked curve characteristic to ergosterol.
Keywords: Candida albicans, Lanosterol 14α-demethylase, Squalene epoxidase, Antifungal drugs, Ergosterol