Department of Pharmacognosy and Herbal Medicine, School of Pharmacy, University of Health and Allied Sciences, Ho, Ghana.
Department of Basic Science, School of Basic and Biomedical Sciences, University of Health and Allied Sciences, Ho, Ghana.
PLoS One. 2021 Dec 28;16(12):e0260956. doi: 10.1371/journal.pone.0260956. eCollection 2021.
Vulvovaginal candidiasis (VVC) is the second most common vaginal infection that affects women of reproductive age. Its increased occurrence and associated treatment cost coupled to the rise in resistance of the causative pathogen to current antifungal therapies has necessitated the need for the discovery and development of novel effective antifungal agents for the treatment of the disease. We report in this study the anti-Candida albicans activity of Solanum torvum 70% ethanol fruit extract (STF), fractions and some isolated compounds against four (4) fluconazole-resistant strains of C. albicans. We further report on the effect of the isolated compounds on the antifungal activity of fluconazole and voriconazole in the resistant isolates as well as their inhibitory effect on C. albicans biofilm formation. STF was fractionated using n-hexane, chloroform (CHCl3) and ethyl acetate (EtOAc) to obtain four respective major fractions, which were then evaluated for anti-C. albicans activity using the microbroth dilution method. The whole extract and fractions recorded MICs that ranged from 0.25 to 16.00 mg/mL. From the most active fraction, STF- CHCl3 (MIC = 0.25-1.00 mg/mL), four (4) known compounds were isolated as Betulinic acid, 3-oxo-friedelan-20α-oic acid, Sitosterol-3-β-D-glucopyranoside and Oleanolic acid. The compounds demonstrated considerably higher antifungal activity (0.016 to 0.512 mg/mL) than the extract and fractions and caused a concentration-dependent anti-biofilm formation activity. They also increased the sensitivity of the C. albicans isolates to fluconazole. This is the first report of 3-oxo-friedelan-20α-oic acid in the plant as well as the first report of betulinic acid, sitosterol-3-β-D-glucopyranoside and oleanolic acid from the fruits of S. torvum. The present study has demonstrated the anti-C. albicans activity of the constituents of S. torvum ethanol fruit extract and also shown that the constituents possess anti-biofilm formation and resistance modulatory activities against fluconazole-resistant clinical C. albicans isolates.
外阴阴道念珠菌病（VVC）是影响育龄妇女的第二大常见阴道感染。其发病率的增加以及与当前抗真菌疗法相关的治疗费用的增加，加上致病病原体对现有抗真菌药物的耐药性的上升，都需要发现和开发新型有效的抗真菌药物来治疗这种疾病。我们在这项研究中报告了 Solanum torvum 70%乙醇果实提取物（STF）、馏分和一些分离化合物对四种（4）氟康唑耐药的白色念珠菌的抗白色念珠菌活性。我们还报告了分离化合物对耐药分离株中氟康唑和伏立康唑抗真菌活性的影响以及它们对白色念珠菌生物膜形成的抑制作用。使用正己烷、氯仿（CHCl3）和乙酸乙酯（EtOAc）对 STF 进行了馏分，得到了四个相应的主要馏分，然后使用微量肉汤稀释法评估它们对白色念珠菌的活性。整个提取物和馏分记录的 MIC 范围为 0.25 至 16.00 mg/mL。从最活跃的馏分中，STF-CHCl3（MIC=0.25-1.00 mg/mL）中分离出四个（4）种已知化合物，分别为白桦脂酸、3-氧代-friedelan-20α-酸、豆甾醇-3-β-D-吡喃葡萄糖苷和齐墩果酸。这些化合物表现出比提取物和馏分更高的抗真菌活性（0.016 至 0.512 mg/mL），并导致浓度依赖性抗生物膜形成活性。它们还增加了白色念珠菌分离株对氟康唑的敏感性。这是 3-氧代-friedelan-20α-酸在植物中的首次报道，也是白桦脂酸、豆甾醇-3-β-D-吡喃葡萄糖苷和齐墩果酸在 Solanum torvum 果实中的首次报道。本研究表明，Solanum torvum 乙醇果实提取物的成分具有抗白色念珠菌活性，并且还表明这些成分具有抗生物膜形成和对氟康唑耐药的临床白色念珠菌分离株的耐药性调节活性。
