Previous studies have demonstrated that macroalgae is capable of producing secondary compounds
with good biological activities. Many active ingredients extracted from brown seaweed species have
been used in the production of cosmetics and medicines for human treatments. This study aims to assess
the bioactivity of Sargassum sp., which is distributed at Re Lon island of Binh An, Kien Luong district,
Kien Giang province. Ethanolic extract from Sargassum sp. is examined for antioxidant activity (in
vitro and in vivo) and antibacterial activity against pathogenic bacteria. The extract showed a
significant antioxidant activity using in vitro and in vivo method. Moreover, the ethanol extract from
Sargassum sp. also displayed antibacterial activity against Bacillus cereus, Bacillus subtilis and
Listeria innocua. Besides, the study also noted the presence of chemical components in Sargassum sp..
These findings indicated that Sargassum sp. is a potential herb containing of natural antioxidant and
antibacterial compounds. Further studies should be carried out for scientific identities and chemical
composition of this promising medicinal algae.