Mechanism of action of tetrandrine, a natural inhibitor of Candida albicans drug efflux pumps.
Mechanism of action of tetrandrine, a natural inhibitor of Candida albicans drug efflux pumps.
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DOI：
10.1248/yakushi.129.623
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发表时间：
2009-05
期刊：
影响因子：
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通讯作者：
Hong Zhang;Aili Gao;Fengxia Li;Gehua Zhang;H. Ho;W. Liao
中科院分区：
文献类型：
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作者：
Hong Zhang;Aili Gao;Fengxia Li;Gehua Zhang;H. Ho;W. Liao
先前已经观察到天然化合物粉防己碱（泰特）与氟康唑（FLC）在体外和治疗白色念珠菌感染的小鼠中的协同作用。为了探讨这些协同作用的机制，16株C。采用流式细胞术和荧光分光光度法检测来自同一亲本但FLC敏感性不同的白念珠菌。罗丹明123（Rh 123）阳性细胞和细胞内Rh 123荧光强度测定的积累/流出实验涉及无或非细胞毒性剂量的泰特。从每个菌株中提取的总RNA用于比较泰特给药前和给药后24 h FLC敏感、敏感剂量依赖和耐药菌株中药物外排泵基因的表达。蓄积实验确定Rh 123阳性细胞的平均百分比为26.65%（无TET）和70.99%（泰特30 μ g/ml），细胞内Rh 123荧光强度的平均值分别为11.34和18.00。外排实验表明，Rh 123阳性细胞的百分比分别为1.79%（无泰特）和42.57%（泰特30 μ g/ml），各自的平均细胞内Rh 123荧光强度分别为0.74和2.19。在不存在泰特的情况下，FLC敏感株、敏感剂量依赖株和耐药株之间的MDR 1、FLU 1、CDR 1和CDR 2表达水平差异具有统计学显著性（p<0.05）。与无TET条件相比，24 h TET处理的菌株显示出具有统计学差异（p<0.05）的MDR 1（FLC耐药菌株）、FLU 1（FLC敏感剂量依赖性和耐药菌株）以及CDR 1和CDR 2（FLC敏感、敏感剂量依赖性和耐药菌株）表达。因此，泰特可抑制C.白念珠菌药物外排系统，减少药物外排。其作用机制与抑制药物外排泵基因MDR 1、FLU 1、CDR 1和CDR 2的表达有关。
Synergistic effects have previously been observed for a natural compound, tetrandrine (TET), with fluconazole (FLC) in vitro and in the treatment of Candida albicans-infected mice. To investigate the mechanisms of these synergistic effects, 16 strains of C. albicans from the same parent but with different FLC sensitivities were examined using flow cytometry and fluorescent spectrophotometry. Rhodamine 123 (Rh123)-positive cells and intracellular Rh123 fluorescence intensity were determined in accumulation/efflux experiments involving no or a noncytotoxic dose of TET. Total RNA extracted from each strain was used to compare the expressions of drug efflux pump genes in FLC-susceptible, -susceptible dose-dependent, and -resistant strains before and 24 h after TET administration. Accumulation experiments determined that mean percentages of Rh123-positive cells were 26.65% (TET-free) and 70.99% (TET 30 microg/ml), and mean respective intracellular Rh123 fluorescence intensities were 11.34 and 18.00. Efflux experiments showed that percentages of Rh123-positive cells were 1.79% (TET free) and 42.57% (TET 30 microg/ml), respectively, and respective mean intracellular Rh123 fluorescence intensities were 0.74 and 2.19. Differences in MDR1, FLU1, CDR1, and CDR2 expression levels in the absence of TET were statistically significant (p<0.05) between FLC-susceptible, -susceptible dose-dependent, and -resistant strains. Compared with TET-free conditions, 24 h TET-treated strains showed statistically different (p<0.05) expression of MDR1 (FLC-resistant strain), FLU1 (FLC-susceptible dose-dependent and -resistant strains), and CDR1 and CDR2 (FLC-susceptible, -susceptible dose-dependent, and -resistant strains). Thus TET can inhibit the C. albicans drug efflux system and reduce drug efflux. Its mechanism of action is related to the inhibition of expression of the drug efflux pump genes MDR1, FLU1, CDR1, and CDR2.