Mechanism Of Synergy Of Tetrandrine On Fluconazole Against Hyphal Form Of Candida Albicans

ObjectiveTo investigate the synergistic effect of tetrandrine(Tet) on fluconazole against hyphal form of Candida albicans(C.albicans),provide idea and theory to find out and research synergist on antifungal agents.MethodsA series of 16 isolates of C.albicans which are different sensitive to fluconazole (susceptive isolates,dose-dependent isolates,and resistant isolates) have been investigated.These isolates were incubated into hyphal form.The maximum non-cytotoxicity concentration of Tet(MNCCT) on hyphal form of these isolates,and the MICs(minimum inhibitory concentration) of fluconazole alone and combinated with MNCCT on hyphal form of these isolates were determined according to CLSI proposed M27-A and M38-A methods.Compared the mRNA expression of MDR1, FLU1,CDR1,CDR2 and ERG11 between the treated group(incubated with MNCCT for 24 hours) and the control group(incubated without Tet) by RT-PCR(reverse transcription-polymerase chain reaction).ResultsThe MNCCT on hyphal form of these isolates is 2μg/mL.The MICs of fluconazole alone and combinated with MNCCT are 0.25～64μg/mL and 0.125～8μg/mL respectively,which have statistical significance(paired-sample t-test, P=0.000).The mRNA expression of MDR1 and CDR1 of the dose-dependent susceptive and resistant isolates are higher than the susceptive isolates among the control group(one-way ANOVA,P＜0.05).Among the control group,the mRNA expression of CDR2 of the resistant isolates,FLU1 of dose-dependent susceptive isolates and resistant isolates,and MDR1,CDR1 of susceptive,dose-dependent susceptive and resistant isolates are higher than the treated group(paired-sample t-test, P＜0.05).The mRNA expression of ERG11 of the dose-dependent susceptive isolates are higher than the susceptive isolates among the control group(Bonferroni,P=0.048). The mRNA expression of ERG11 of dose-dependent susceptive and resistance isolates in the control group are higher than the treated group(paired-sample t-test,P＜0.05).Conclusions1 Tetrandrine can inhance the antifungal effect of fluconazole on hyphal form of C. albicans in vitro.2 Tetrandrine can inbibit the mRNA expression level of efflux pumps gene:MDR1, FLU1,CDR1,CDR2 of hyphal form of C.albicans.3 Tetrandrine can inhibit the mRNA expression of the target enzyme gene of azoles: ERG11 of hyphal form of C.albicans.