Anticancer and antibacterial secondary metabolites from the endophytic fungus  Penicillium sp. CAM64 against multi-drug resistant Gram-negative bacteria.

Jean-Bosco Jouda, Jean-de-Dieu Tamokou, Céline Djama Mbazoa, Prodipta Sarkar, Prasanta Kumar Bag, Jean Wandji
1. Department of Organic Chemistry, Faculty of Science, University of Yaoundé I, P.O Box 812, Yaoundé,
Cameroon
2. Department of Biochemistry, Faculty of Science, University of Dschang, P.O. Box 67 Dschang, Cameroon
3. Department of Biochemistry, University of Calcutta, 35 Ballygunge Circular Road, Kolkata-700 019, India

Abstract
Background: The emergence of multiple-drug resistance bacteria has become a major threat and thus calls for an urgent need  to search for new effective and safe anti-bacterial agents.

Objectives: This study aims to evaluate the anticancer and antibacterial activities of secondary metabolites from Penicillium sp.,
an endophytic fungus associated with leaves of Garcinia nobilis.

Methods:The culture filtrate from the fermentation of Penicillium sp.was extracted and analyzed by liquid chromatography– mass spectrometry, and the major metabolites were isolated and identified by spectroscopic analyses and by comparison with  published data. The antibacterial activity of the compounds was assessed by broth microdilution method while the anticancer  activity was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay.

Results:The fractionation of the crude extract afforded penialidin A-C (1-3), citromycetin (4), p-hydroxyphenylglyoxalaldoxime  (5) and brefelfin A (6). All of the compounds tested here showed antibacterial activity (MIC = 0.50 – 128 µg/mL) against Gramnegative multi-drug resistance bacteria, Vibrio cholerae (causative agent of dreadful disease cholera) and Shigella flexneri (causative  agent of shigellosis), as well as the significant anticancer activity (LC 50 = 0.88 – 9.21 µg/mL) against HeLa cells.

Conclusion:The results obtained indicate that compounds 1-6 showed good antibacterial and anticancer activities with no  toxicity to human red blood cells and normal Vero cells.

Keywords: Garcinia nobilis, endophytic fungi, secondary metabolites, antibacterial activity, anticancer activity.