Total phenolics, flavonoids and antioxidant activity of fresh water macroalgae from Ubon Ratchathani, Thailand

Abstract

α, α-diphenyl-β-picrylhydrazyl (DPPH) free radical scavenging activity, antioxidant capacity, total phenolics and flavonoids contents of the extracts of fresh water macroalgae were studied. Three types of macroalgal ; 1) Spirogyra sp., 2) Cladophora glomerata and Microspora sp. and 3) Nostoc commune, were harvested from Ubon Ratchathani, Thailand. The macroalgaes were extracted with 95% ethanol. The ethanolic extracts showed high the DPPH free radical scavenging activity and antioxidant capacity. The percentage of DPPH free radical scavenging activity of the ethanolic extracts of type 1 (Spirogyra sp.) was 52.33 while type 2 (Cladophora glomerata and Microspora sp.) and type 3 (Nostoc commune) were lower. The antioxidant capacities of ethanolic extract of type 1, 2 and 3 algae were 178.89, 150.67 and 173.28 mg AE/g of extract, respectively. Total phenolic contents of ethanolic extract of type 1, 2 and 3 algae were 155.82, 12.12 and 18.22 mg GAE/g of extract, respectively. The total flavonoid contents of ethanolic extract of type 1, 2 and 3 algae were 2.64, 3.83 and 0.52 mg QE/g of extract, respectively. The Spirogyra sp. extract showed the highest in total phenolic contents, total flavonoid contents, antioxidant capacity and DPPH free radical scavenging activity. They are appropriate for applying to produce anti-aging cosmetics.