Abstract

A study was conducted for screening the antimicrobial and anticancer activities of endophytic fungi isolated from leaves of Mitragyna javanica Koord and Val. A total of 73 fungal endophytes were obtained. Fifty-five isolates (75.47%) showed antimicrobial activities against at least one tested microorganism by the paper disc diffusion method. Out of these isolates, 5.47% displayed a broad antimicrobial spectrum. The endophytic fungus Nodulisporium sp. PT11 exhibited the strongest antimicrobial activity against all test microorganisms. Anticancer activities were examined with six human cancer cell lines including A375, KatoIII, SW620, HepG2, BT474, and Jurkat by the MTT method. The crude extracts of the endophytic isolates exhibited 53.42, 60.27, 54.79, 54.79, 36.98 and 19.17% cytotoxicity (cell viability < 40%) against A375, Kato III, SW620, BT474, HepG2 and Jurkat, respectively. The crude extracts of Phoma sp. PT01 had the most specific activity against Jurkat by inducing DNA fragmentation and the characteristic morphological features of apoptosis toward the target cancer cells using Hoechst 33258 fluorescence stain. These results of antimicrobial and anticancer screening support the view that endophytic fungi from M. javanica are a potential source of bioactive compounds.

Key words: Nodulisporium, Mitrajyna javanica, Phoma, apoptosis.