The emergence of tolerant Cryptococcus neoformans strains to antifungals has been described. It has directed researchers to screen for new antimicrobial compounds. In this context, several plant-derived compounds, such as anthraquinones (aloe emodin, barbaloin, and chrysophanol), have been investigated for their antimicrobial properties. This study aimed to evaluate the in vitro effect of aloe emodin, barbaloin and chrysophanol on C. neoformans in vitro growth. In addition, the interaction between these anthraquinones and amphotericin B and itraconazole was evaluated. Initially, the minimum inhibitory concentrations (MIC) of these compounds were determined against 17 strains of C. neoformans by the broth microdilution method and then pharmacological interaction assays were performed with 15 strains by the checkerboard method. Aloe emodin, barbaloin, and chrysophanol showed minimum inhibitory concentrations of 236.82–473.65 μM (64–128 μg/mL), 153–306 μM (64–128 μg/ml) and ≥1007 μM (≥256 μg/ml), respectively. Furthermore, aloe emodin (11/15), barbaloin (13/15), and chrysophanol (12/15) showed pharmacological synergism (FICI < 0.5) with amphotericin B at subinhibitory concentrations (MIC/4). The itraconazole-aloe emodin interaction was additive (1/15) (0.5 < FICI < 1.0). The itraconazole-barbaloin interaction were synergistic (2/15) and additive (5/15); whereas itraconazole-chrysophanol interactions were additive (2/15). Anthraquinones, especially aloe emodin and barbaloin, present in vitro antifungal activity against C. neoformans and potentiate the antifungal activity of amphotericin B.

中文翻译：

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蒽醌类化合物对新型隐球菌的抗真菌作用：检测与两性霉素 B 的协同作用。


已经描述了抗真菌药物耐受的新型隐球菌菌株的出现。它指导研究人员筛选新的抗菌化合物。在此背景下，人们对蒽醌（芦荟大黄素、芦荟甙和大黄酚）等多种植物源化合物的抗菌特性进行了研究。本研究旨在评价芦荟大黄素、芦荟甙和大黄酚对新型隐球菌体外生长的影响。此外，还评估了这些蒽醌类与两性霉素B和伊曲康唑之间的相互作用。最初，通过肉汤微量稀释法测定了这些化合物对 17 株新型隐球菌的最低抑菌浓度 (MIC)，然后通过棋盘法对 15 株菌株进行药理相互作用测定。芦荟大黄素、芦荟苷和大黄酚的最低抑制浓度分别为 236.82–473.65 μM (64–128 μg/mL)、153–306 μM (64–128 μg/ml) 和 ≥1007 μM (≥256 μg/ml) 。此外，芦荟大黄素 (11/15)、芦荟大黄素 (13/15) 和大黄酚 (12/15) 在亚抑制浓度 (MIC/4) 下与两性霉素 B 表现出药理学协同作用 (FICI < 0.5)。伊曲康唑-芦荟大黄素相互作用是相加的 (1/15) (0.5 < FICI < 1.0)。伊曲康唑-巴巴洛因相互作用具有协同作用（2/15）和相加作用（5/15）；而伊曲康唑-大黄酚的相互作用是相加的 (2/15)。蒽醌类化合物，尤其是芦荟大黄素和芦荟甙，对新型隐球菌具有体外抗真菌活性，并增强两性霉素 B 的抗真菌活性。