Plumbagin (5-hydroxy-2-methyl-1,4-naphthoquinone), the major active constituent of Plumbago indica L., has been shown to be effective against a wide range of infectious microbes. In this study, plumbagin has been evaluated in vitro for its antifungal combinatory effect with amphotericin B against Candida albicans (C. albicans) clinical isolates and anti-hepatitis C virus (HCV) activity. Antifungal activity was determined by broth microdilution method, and combinatory effect was evaluated by checkerboard assay according to ΣFIC indices, while cytotoxicity was determined by MTT assay. Anti-HCV activity was determined in infected Huh7.5 cells using quantitative real-time reverse transcription PCR, and cytotoxicity was evaluated by MTT assay. Plumbagin exerted inhibitory effect against all C. albicans strains with minimum inhibitory concentration values ranging from 7.41 to 11.24 µg/mL. The additive effect of plumbagin when combined with amphotericin B at concentrations of (0.12, 0.13 and 0.19, 1.81 µg/mL, respectively) was obtained against five of seven strains tested with ΣFIC ranging from 0.62 to 0.91. In addition, plumbagin was found to be used safely for topical application when combined with amphotericin B at concentrations corresponding to the additive effect. Plumbagin exerted anti-HCV activity compared with that of telaprevir with IC50 values of 0.57 and 0.01 μM/L, respectively, and selectivity indices SI = 53.7 and SI = 2127, respectively. Our results present plumbagin as a potential therapeutic agent in the treatment of C. albicans and HCV infections. Copyright © 2016 John Wiley & Sons, Ltd.

Department of Applied Ecology Faculty of Environmental Sciences Czech University of Life Sciences Prague Kamýcká 129 165 21 Praha 6 Suchdol Prague Czech Republic

Department of Natural Drugs Faculty of Pharmacy University of Veterinary and Pharmaceutical Sciences Brno Palackého tř 1946 1 612 42 Brno Czech Republic

References provided by Crossref.org

A Microbiological, Toxicological, and Biochemical Study of the Effects of Fucoxanthin, a Marine Carotenoid, on Mycobacterium tuberculosis and the Enzymes Implicated in Its Cell Wall: A Link Between Mycobacterial Infection and Autoimmune Diseases

A Multi-Biochemical and In Silico Study on Anti-Enzymatic Actions of Pyroglutamic Acid against PDE-5, ACE, and Urease Using Various Analytical Techniques: Unexplored Pharmacological Properties and Cytotoxicity Evaluation