The cytotoxic effect of red and brown Malaysian sea weeds against liver cancer cell line (HepG2) / Nur Fatihah Zainal Abdim

Marine macroalgae are important ecologically and commercially sources in many regions of the world especially Asian countries. The marine macroalgae especially seaweeds have been one of the richest and most promising sources of bioactive metabolites in pharmaceutical application. Due to the toxicity of existing chemotherapeutic drugs, there is an urge to find an alternative source of chemotherapeutic agents. In this study, three marine endophytic fungi isolated from selected seaweeds (Gracilaria arcuata Zanardini, Gracilaria coronapifolia J.Agard and Padina minor Yamada) were investigated. The marine endophytic fungi isolated from these selected seaweeds were grown on two types of media which PDA supplemented with 1 % and 3% artificial sea salt. The cytotoxicity of the marine endophytic fungi (MY, CN and PA7) was evaluated by using MTT assay on liver cancer cell line (HepG2). The lowest IC50 values were observed at 24 hours of incubation time. Three out of six extracts showed very active cytotoxic activity MY 3%; 0.10±0.00µgml⁻¹, CN 3%; 2.45±1.77µgmr1, CN 1 %; 4.00±2.83µgml⁻¹ and another three showed active cytotoxic activity MY 1%; 10.50±0.71µgml⁻¹, PA7 1%; 12.00±2.83µgml⁻¹, PA7 3%; 11.00±1.41µgml⁻¹. MV 3% (10.50±0.71µgml⁻¹) exhibited the most pronounced extract. Among the extracts, MV 3% showed significant difference with MV 1 %, PA1 1 % and PA1 3% (p<0.05). In facts, among six tested extracts, the IC50 obtained for MV 3% extract was lower as compared to the IC50 of 5-FU at different incubation time (48 hours; 0.38 µgml⁻¹, 72 hours; 0.25 µgml⁻¹ and 96 hours; 0.38µgml⁻¹). Among the extracts, significance difference were only observed between MV 1 % and MV 3% (p<0.05) extracts. In this present study, 1 % of artificial sea salt was sufficient to exhibit cytotoxic effect except for marine endophytic fungi extract (MV 3%). Therefore, these tested marine endophytic fungi extracts might have potential as an alternative source against HepG2 cells and worth to be further studied as anticancer agents.