Cytotoxic and antimicrobial effect induced by ethyl acetate extracts of Malaysian endophytic fungi (MBL, MPRT 3.2, SM 1.3 & SW 4) / Syaidatul Farhana Shamsul Bahrin

Colorectal cancer and infectious diseases are major problems of public health, with most of the burden falling upon developing countries. Unfortunately, current anticancer and antimicrobial chemotherapy are often compromised by side effects and drug resistance. This has led to active drug discovery from natural sources like the endophytes. Capitalising on the abundance of unexplored Malaysian endophytes that reside in marine plants, the present study aimed to assess cytotoxic and antimicrobial profiles of ethyl acetate extracts of endophytic fungi originated from Avicennia sp and Sonneratia sp. Another two extracts of marine fungi, SM l.3 and SW 4, were also included for comparison purposes. Briefly, the fungi were grown on PDA at 28°C for 14 days before being subjected to extraction. The resultant extracts (0.01 - 100µg/mL) were screened for their cytotoxicity against HCT 116 (colorectal cancer cell line) and antimicrobial properties against Staphylococcus aureus and Pseudomonas aureginosa. For cytotoxicity, SRB assay was performed after 72 h treatment. Data generated was used to determine the IC50 ( concentration of an inhibitor where the response is reduced by half). For antimicrobial assay, minimum inhibitory concentration (MIC) was determined. The present findings revealed the endophytic fungi derived MBL, as the most potent endophytic fungal extracts against HCT 116 with IC50 observed at 7.16µg/mL. Its IC50 falls within the NCI cut off concentration (IC50 < 20 µg/mL) for a crude extract to be considered as cytotoxic. Its potency was approximately 15.6-fold lower than that of 5- FU, the positive control. The cytotoxicity of the two marine fungal extracts appeared to be modest.