Antioxidant properties of ethanol extract and its different solvent fractions from Sargassum henslowianum

In this research,antioxidant activitiy of different fractions from ethanol crude extracts of S. henslowianum was investigated in vitro. The total phenolic contents of the 95% ethanol crude extracts and their four solvent fractions( viz.,petroleum ether( PE),ethyl acetate( EA),n- butanol and aqueous) were determined by Folin-Ciocalteu,and their antioxidant properties were evaluated using three assays including 1,1- Diphenyl- 2-picrylhydrazyl radical 2,2- Diphenyl- 1-( 2,4,6- trinitrophenyl) hydrazyl( DPPH),2,2'- Azinobis-( 3-ethylbenzthiazoline-6- sulphonate( ABTS) radical scavenging and oxygen radical absorbance capacity.The results showed that EA fraction had the highest content of total phenolics( 12.71 ± 0.02 mg gallic acid equivalents / g). All five fractions from S. henslowianum exhibited the antioxidant activity. EA fraction exhibited strongest antioxidant activities among all the fractions,which the values of IC_(50) based on DPPH· and ABTS+·were( 0.89 ± 0.01) mg /m L and( 0.73 ± 0.03) mg / m L respectively,and the values of ORAC was( 1803.78 ± 81.37) μmol Trolox equivalents / g.