Department of Pharmacy, Jinan Military General Hospital, Jinan, China.
New Drug Research and Development Center, School of Pharmacy, Second Military Medical University, Shanghai, China.
Front Cell Infect Microbiol. 2017 Nov 29;7:491. doi: 10.3389/fcimb.2017.00491. eCollection 2017.
is one of the most common fungal pathogens. Our previous study demonstrated that concomitant use of berberine (BBR) and fluconazole (FLC) showed a synergistic action against FLC-resistant and BBR had a major antifungal effect in the synergism, while FLC played a role of increasing the intracellular BBR concentration. Since the antifungal activity of BBR alone is very weak (MIC > 128 μg/mL), it was assumed that FLC-resistant was naturally tolerant to BBR, and this tolerance could be reversed by FLC. The present study aimed to elucidate the mechanism underlying BBR tolerance in FLC-resistant and its disruption by FLC. The ergosterol quantitative analysis showed that the BBR monotreatment could increase the content of cellular ergosterol. Real-time RT-PCR revealed a global upregulation of ergosterol synthesis genes in response to BBR exposure. In addition, exogenous ergosterol could decrease intracellular BBR concentration and increase the expression of drug efflux pump genes, further reducing the susceptibility of to BBR. Similar to FLC, other antifungal agents acting on ergosterol were able to synergize with BBR against FLC-resistant . However, the antifungal agents not acting on ergosterol were not synergistic with BBR. These results suggested that ergosterol was required for BBR tolerance, and FLC could enhance the susceptibility of FLC-resistant to BBR by inhibiting ergosterol synthesis.
是最常见的真菌病原体之一。我们之前的研究表明，小檗碱（BBR）和氟康唑（FLC）的联合使用对氟康唑耐药株表现出协同作用，而 BBR 在协同作用中具有主要的抗真菌作用，而 FLC 则起到增加细胞内 BBR 浓度的作用。由于 BBR 单独的抗真菌活性非常弱（MIC>128μg/mL），因此假设氟康唑耐药株对 BBR 天然耐受，而 FLC 可以逆转这种耐受性。本研究旨在阐明氟康唑耐药株中 BBR 耐受的机制及其被 FLC 破坏的机制。麦角固醇定量分析表明，BBR 单药处理可增加细胞内麦角固醇含量。实时 RT-PCR 显示，BBR 暴露会导致麦角固醇合成基因的全局上调。此外，外源性麦角固醇可以降低细胞内 BBR 浓度并增加药物外排泵基因的表达，从而进一步降低 对 BBR 的敏感性。与 FLC 类似，其他作用于麦角固醇的抗真菌药物也能与 BBR 协同作用对抗氟康唑耐药株。然而，不作用于麦角固醇的抗真菌药物与 BBR 没有协同作用。这些结果表明，麦角固醇是 BBR 耐受所必需的，而 FLC 通过抑制麦角固醇合成增强氟康唑耐药株对 BBR 的敏感性。
