Cytotoxic and antimicrobial effects induced by ethyl acetate extracts of Malaysian endophytic fungi (MKS 3.1 and MBFT TIP 2.1) / Nurfazura Mohd tahir

Drug resistance has always been the major obstacle of current treatment against infectious diseases and cancers. This has led to constant need for new drugs. Capitalizing on the abundance of unexplored Malaysian endophytes that reside in marine plants without causing significant harm, the present study was undertaken to assess the cytotoxic and antimicrobial profiles of ethyl acetate extracts of endophytic fungi originated from Terminalia and Avicennia plants. Another two marine fungal extracts, SM 2.2 and SW 2.3 Plate 2 originated from sea mud and sea water, were also included for comparison purposes. Basically, the extracts were prepared by soaking the fungi in ethyl acetate overnight before being extracted using a rotary evaporator. For cytotoxic assay, HCT 116 (human colorectal carcinoma cells) were seeded at 2,500 cells/ 200µL and incubated overnight to allow attachment. The cells were then treated with the extracts (0.01 - lOOµg/mL) for 72h. SRB assay was performed to generate data from which the ICso (inhibitory concentration of HCT 116 cells at 50%) was determined. The antimicrobial assay involved addition of pathogenic bacteria (Gram­ positive and negative) into extracts (0.01 - lOOµg/mL) prior to determination of the minimal inhibitory concentration (MIC). The present study found MKS 3.1 to be the most potent ethyl acetate extracts against HCT 116 (ICso = 1.18 ± 0.63). Its ICso, however, was approximately 2.6 fold higher than that of 5-FU, the positive control. In general, the endophytic fungal extracts elicited weak antimicrobial activity against both Gram-positive and negative bacteria (MIC = lmg/mL). The present study has uncovered the potential anticancer and antimicrobial effects of local endophytic fungi isolated from marine plants. The use of other organic solvents for extractions could perhaps harness other bioactive compounds produced by these endophytes.