Identification of Antioxidant Activity by Different Methods of a Freshwater Alga (Microspora sp.) Collected From a High Mountain Lake

Abstract

Algae contain a large amount of biological active compounds functioning as antioxidant, antimicrobial and anti-tumour. In the present research, antioxidant activity of freshwater alga Microspora sp. (Chlorophyta) extract prepared in different solvents (methanol, acetonitrile, ethanol, acetone and ethyl acetate) was determined with three different methods; 2,2-diphenyl-1-picrylhydrazyl (DPPH•), Iron (III) Reduction / Antioxidant Power (FRAP) Assay and Copper (II) Reductive Antioxidant Activity (CUPRAC). The alga samples collected from the high mountain lake (2733 m above sea level) localized in Gümüşhane province of Turkey. The algal extracts prepared in different solvents showed antioxidant activity. The values of DPPH• varied from 8.97% (in acetonitrile extract) to 31.15% (in methanol extract). As in the DPPH• method, the lowest and highest values in the FRAP method were measured based on ?M TEAC (Trolox Equivalent Antioxidant Capacity) in methanol and acetonitrile extracts as 60.303 ?M and 359.394 ?M respectively. While the lowest value of CUPRAC test was determined in acetonitrile extract (0.041 ?M TEAC ) as in the other tests, highest value was measured in ethanol extract (0.101 ?M TEAC ). The values of highest antioxidant activity in both DPPH• and FRAP methods was measured in the methanol solvent whilst was determined in the ethanol solvent for CUPRAC.