The Effects of Tormentic Acid and Extracts from Callistemon citrinus on Candida albicans and Candida tropicalis Growth and Inhibition of Ergosterol Biosynthesis in Candida albicans .

Autor: Bvumbi C; Department of Biochemistry, Faculty of Science, University of Zimbabwe, Harare, Zimbabwe., Chi GF; Department of Organic Chemistry, University of Yaounde 1, P.O. Box 812, Yaoundé, Cameroon., Stevens MY; Department of Medicinal Chemistry, Uppsala Biomedical Center, Uppsala University, P.O. Box 574, SE-751 23 Uppsala, Sweden., Mombeshora M; Department of Biochemistry, Faculty of Science, University of Zimbabwe, Harare, Zimbabwe., Mukanganyama S; Department of Biochemistry, Faculty of Science, University of Zimbabwe, Harare, Zimbabwe.
Jazyk: angličtina
Zdroj: TheScientificWorldJournal [ScientificWorldJournal] 2021 Sep 21; Vol. 2021, pp. 8856147. Date of Electronic Publication: 2021 Sep 21 (Print Publication: 2021).
DOI: 10.1155/2021/8856147
Abstrakt: Candida albicans and Candida tropicalis are the leading causes of human fungal infections worldwide. There is an increase in resistance of Candida pathogens to existing antifungal drugs leading to a need to find new sources of antifungal agents. Tormentic acid has been isolated from different plants including Callistemon citrinus and has been found to possess antimicrobial properties, including antifungal activity. The study aimed to determine the effects of tormentic and extracts from C. citrinus on C. albicans and C . tropicalis and a possible mode of action. The extracts and tormentic acid were screened for antifungal activity using the broth microdilution method. The growth of both species was inhibited by the extracts, and C. albicans was more susceptible to the extract compared to C . tropicalis . The growth of C . albicans was inhibited by 80% at 100  μ g/ml of both the DCM: methanol extract and the ethanol: water extract. Tormentic acid reduced the growth of C. albicans by 72% at 100  μ g/ml. The effects of the extracts and tormentic acid on ergosterol content in C. albicans were determined using a UV/Vis scanning spectrophotometer. At concentrations of tormentic acid of 25  μ g/ml, 50  μ g/ml, 100  μ g/ml, and 200  μ g/ml, the content of ergosterol was decreased by 22%, 36%, 48%, and 78%, respectively. Similarly, the DCM: methanol extract at 100  μ g/ml and 200  μ g/ml decreased the content by 78% and 88%, respectively. A dose-dependent decrease in ergosterol content was observed in cells exposed to miconazole with a 25  μ g/ml concentration causing a 100% decrease in ergosterol content. Therefore, tormentic acid inhibits the synthesis of ergosterol in C. albicans . Modifications of the structure of tormentic acid to increase its antifungal potency may be explored in further studies.
Competing Interests: The authors declare that there are no conflicts of interest regarding the publication of this paper.
(Copyright © 2021 Chido Bvumbi et al.)
Databáze: MEDLINE
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