Antibacterial and Cytotoxic Activities of Sponges Collected off the Coast of Togean Islands, Indonesia

Context: Marine sponges (Porifera: Demospongia) have astonishing structural diversity and broad biological activities. Aims: To evaluate the antibacterial and cytotoxic activities of five sponges collected off the coast of Togean Islands, Indonesia, identified as Spheciospongia inconstan, Melophlus sarasironum, Oceanapia amboinensis, Biemna sp and Axinella sp. Methods and Material: All dried sponges materials were extracted by maceration method using methanol and then evaporated by the rotary evaporator to obtain viscous extracts. The determination of antibacterial activity was performed by well agar diffusion method against Staphylococcus aureus and Escherichia coli while the cytotoxic activity was determined by MTT methods on human breast adenocarcinoma (MCF-7) and human colon colorectal carcinoma (HCT-116), followed by determination of the apoptosis mechanism by Annexin V-FTIC assay. Results: M. sarasinorum and Axinella sp showed strong inhibition against S.aureus and E.coli with the diameter of inhibition of 14.21 ± 0.92 mm and 14.36 ± 0.92 mm, and 10.01 ± 2.65 mm and 12.07 ± 1.54 mm, respectively. Moreover, they also exhibited potent cytotoxicity on HCT-116 with IC₅₀ values of 0.002 and 8.518 μg/mL, respectively. Meanwhile, on MCF-7, only M. sarasinorum showed moderate inhibition with an IC₅₀ value of 87.35 μg/mL. Annexin V-FTIC assay clearly showed that the cytotoxic mechanism of M. sarasinorum and Axinella sp on HCT-116 and MCF-7 was via apoptosis induction. Conclusion: The sponges of M. Sarasinorum and Axinella sp are undergoing further analysis to identify the active constituents which could be developed as potential antibacterial and anticancer agents.