Antibacterial and cytotoxic activities assay from the extract of macroalga Halimeda cylindracea from Gulf of Boni, Indonesia

This study aimed to find out the antibacterial and cytotoxic activity of n-hexane, ethyl acetate, acetone, and ethanol extracts from macroalgae Halimeda cylindracea that was collected from Gulf of Boni. The antibacterial activity was evaluated against Stapilococcus aureus,Escherichia coli, and Salmonella typhi with the Kirby Bauer method. The cytotoxic activity was evaluated with a Brine Shrimp Lethality test. Extraction was performed successively with nhexane,ethyl acetate, acetone, and ethanol for 3 x 24 hours with maceration method and evaporated with a rotary evaporator to obtain dry extract. Antibacterial activity was evaluated by inhibition zone where the cytotoxic was observed by LC50 value of each tested extract. The result indicated that ethyl acetate extract showed active to all bacteria test which acetone extract was active against S. aureus and E. coli, n-hexane extract was active against S. aureus, and ethanol extract was not active to all bacteria test. N-hexane, ethyl acetate, acetone, and ethanol extracts of macroalgae H. cylindracea were toxic toward Arthemia salina Leach with moderate toxicity category with LC50 value 134.90, 281.84, 338.84 and 295.12 μg/mL respectively.