Anti-dengue potential of bioactive protein from exophytic bacteria that are symbiotic with brown algae Sargassum sp.

Abstract

Symbiont bacteria of algae are bioactive metabolite sources with potential as medicinal raw materials. This study aims to find out the anti-dengue potential of a protein fraction isolated from Enterobacter agglomerans SB 5(1) as the symbiont of brown algae Sargassum binderi collected from Lae-Lae island, South Sulawesi. These extracellular and intracellular fractions were isolated by ammonium sulphate fractionation at saturation levels of 0-20 %, 20-40 %, 40-60 %, and 60-80 %. The protein was purified by dialysis method using cellophane bag. Toxicity was tested by BSLT method using shrimp larvae of Artemia salina, Leach. Cytotoxicity test against vero cells infected with dengue virus DEVN-2 was performed by MTT method. Study findings indicate that intracellular protein fraction from E. agglomerans SB 5(1), a symbiont of brown algae Sargassum binderi, showed the presence of bioactive protein having strong toxicity with LC50 of 48.67 µg/mL. Anti-dengue activity toward vero cells indicates inhibition percentage and CC50 value of 70% and 260.37 µg./mL, respectively, therefore it had no potential as anti-virus dengue agent. In future studies, it is recommended to perform hydrolysis of protein compound from symbiont bacteria of Sargassum sp. to explore other peptide compounds with more potential as anti-dengue agents.