Antibacterial and cytotoxic cytochalasins from the endophytic fungus Phomopsis sp. harbored in Garcinia kola (Heckel) nut. Issue 1 (December 2016)

• Record Type: Journal Article
• Authors: Jouda, Jean-Bosco; Tamokou, Jean-de-Dieu; Mbazoa, Céline; Douala-Meli, Clovis; Sarkar, Prodipta; Bag, Prasanta; Wandji, Jean
• Is Part Of: BMC complementary and alternative medicine. Volume 16:Issue 1(2016)
• Page Start: 1
• Page End: 9
• Publication Date: 2016-12
• Subjects: Garcinia kola -- Endophytic fungi -- Phomopsis sp -- Metabolites -- Cytochalasins -- Antibacterial -- Cytotoxic; Alternative medicine -- Periodicals; Complementary Therapies -- Periodicals; 615.505
• DOI: 10.1186/s12906-016-1454-9
• Languages: English
• ISSNs: 1472-6882

Abstract

Abstract Background The continuous emergence of multidrug-resistant (MDR) bacteria drastically reduced the efficacy of our antibiotic armory and consequently, increased the frequency of therapeutic failure. The search for bioactive constituents from endophytic fungi against MDR bacteria became a necessity for alternative and promising strategies, and for the development of novel therapeutic solutions. We report here the isolation and structure elucidation of antibacterial and cytotoxic compounds fromPhomopsis sp., an endophytic fungus associated withGarcinia kola nuts. Methods The fungusPhomopsis sp. was isolated from the nut ofGarcinia kola. The crude extract was prepared from mycelium ofPhomopsis sp. by maceration in ethyl acetate and sequentially fractionated by column chromatography. The structures of isolated compounds were elucidated on the basis of spectral studies and comparison with published data. The isolated compounds were evaluated for their antibacterial and anticancer properties by broth microdilution and 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide methods respectively. The samples were also tested spectrophotometrically for their hemolytic properties against human red blood cells. Results The fractionation of the crude extract afforded three known cytochalasins including 18-metoxycytochalasin J (1), cytochalasins H (2) and J (3) together with alternariol (4). The cytochalasin compounds showed different degrees of antibacterial activities against the tested bacterial pathogens.Shigella flexneri was the most sensitive microorganism whileVibrio cholerae SG24 andVibrio cholerae PC2 were the most resistant. Ampicillin did not show any antibacterial activity againstVibrio cholerae NB2, Vibrio cholerae PC2 andShigella flexneri at concentrations up to 512 μg/mL, but interestingly, these multi-drug resistant bacterial strains were sensitive to the cytochalasin metabolites. These compounds also showed significant cytotoxic properties against human cancer cells (LC50 = 3.66–35.69 μg/mL) with low toxicity to normal non-cancer cells. Conclusion The three cytochalasin compounds isolated from thePhomopsis sp. crude extract could be a clinically useful alternative for the treatment of cervical cancer and severe infections caused by MDRShigella andVibrio cholerae.