Ergosterol, an essential constituent of membrane lipids of yeast, is distributed in both the cell membrane and the intracellular endomembrane system such as vacuoles. Honokiol, a major polyphenol isolated from Magnolia officinalis, has been shown to inhibit the growth of Candida albicans. Here, we assessed the effect of honokiol on ergosterol biosynthesis and vacuole function in C. albicans. Honokiol could decrease the ergosterol content and upregulate the expression of genes related with the ergosterol biosynthesis pathway. The exogenous supply of ergosterol attenuated the toxicity of honokiol against C. albicans. Honokiol treatment could induce cytosolic acidification by blocking the activity of the plasma membrane Pma1p H⁺-ATPase. Furthermore, honokiol caused the abnormal of vacuole morphology and function. Concomitant ergosterol feeding to some extent restored the vacuolar morphology and the function of acidification in cells treated by honokiol. Honokiol also disrupted the intracellular calcium homeostasis. Amiodarone attenuated the antifungal effects of honokiol against C. albicans, probably due to the activation of the calcineurin signalling pathway which is involved in honokiol tolerance.

中文翻译：

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和厚朴酚对白色念珠菌麦角甾醇生物合成和液泡功能的影响。

麦角甾醇是酵母膜脂的重要组成部分，分布于细胞膜和细胞内膜系统如液泡中。Honokiol 是一种从厚朴中分离出来的主要多酚，已被证明可以抑制白色念珠菌的生长。在这里，我们评估了和厚朴酚对白色念珠菌麦角甾醇生物合成和液泡功能的影响。和厚朴酚可降低麦角甾醇含量，上调麦角甾醇生物合成途径相关基因的表达。麦角固醇的外源供应减弱了和厚朴酚对白色念珠菌的毒性。和厚朴酚处理可通过阻断质膜 Pma1p H 的活性来诱导细胞溶质酸化⁺ -ATP酶。此外，和厚朴酚引起液泡形态和功能异常。伴随的麦角甾醇喂养在一定程度上恢复了和厚朴酚处理的细胞中的液泡形态和酸化功能。和厚朴酚还破坏细胞内钙稳态。胺碘酮减弱了和厚朴酚对白色念珠菌的抗真菌作用，这可能是由于与和厚朴酚耐受性有关的钙调磷酸酶信号通路的激活。