Bioactive compounds-producing endophytic fungi from kra thum na mitragyna javanica koord & val. leaves

Abstract

One hundred and six endophytic fungal isolates were isolated from Mitragyna javanica leaves plants growing in Ayutthaya, Prathumthani and Amnatchareon provinces. These endophytic fungi were identified as Colletotrichum spp., Fusarium spp., Phomopsis spp., Phoma sp. Alternaria spp., Phyllostica spp. Xylaria spp., Penicillium spp., a Cladosporium sp. and the majority were mycelia sterilia. Crude extracts with ethyl acetate were examined for antimicrobial and anticancer activities. The antimicrobial activities were tested using paper disc diffusion assay technique against six reference microorganisms including Bacillus subtilis ATCC633, Staphylococus aureus ATCC25923, Pseudomonas aeruginosa ATCC9027, Escherichia coli ATCC25922, Saccharomyces cerevisiae TISTR5169 and Candida albicans ATCC1023. Seventy six percent showed antimicrobial activities against at least one tested microorganism with inhibition zones ranging from 7-40 mm. Six percent displayed a broad antimicrobial spectrum and twenty two percent inhibited the pathogenic yeast C. albicans. Moreover, the endophytic fungus isolate PT11 exhibited the strongest antimicrobial activity against all test microorganisms. Anticancer activities were examined with six human cancer cell lines including A375 ATCC no. CRL-1619(malignant melanoma), KatoIII ATCC no. HTB-103(gastric cancer), SW620 ATCC no. CCL-227(colorectal cancer), HepG2 ATCC no.HTB-8065 (liver cancer), BT474 ATCC no. HTB-20 (breast cancer), and Jurkat ATCC no. CRL-2063 (T-cell leukemia)) by the MTT method. The crude extracts of the endophytic isolates exhibited 58.49%, 60.38%, 58.49%, 45.28%, 61.32% and 31.13% cytotoxicity (cell viability < 40%) against A375, Kato III, SW620, BT474, HepG2, and Jurkat, respectively. The endophytic isolate PT01 had the most specific activity against (0% cell viability) jurkat cells with potential induced 90.04% apoptosis cell death. The high potential endophytic fungus PT11 and PT01 were identified. Based on nucleotide sequencing of ITS region, they were closely related to 99% identity of Nodulisporium sp. and Phoma herbarum. The endophytic isolate PT11 showed strong antimicrobial and anticancer was chosen for further study of bioactive compounds. Isolation of culture both crude extract of the fungus isolate PT11 obtained pure compound 1 The compound 1 displayed apoptosis-inducing activities against the 66.35±1.46% Jurkat at with with IC50 37.5±0.76 µg/ml