Measurement of anthocyanin and antioxidant content of extracts of three important algal species on the northern shores of the Oman Sea

The presence of macroalgae, are important in aquatic habitats. Nowadays, this plants have been receiving increasing attention by many researchers as a promising natural rich sources of antioxidants. They have displayed numerous advantageous effects on biological activities, including antioxidants and cytotoxicity. In this regard, at the present study, the antioxidant properties of three species of native macroalgae to the northern coast of the Oman Sea (Sistan and Baluchestan province) were studied and compared. Sampling was carried out in autumn and winter of 2018 on the northern coast of the Oman Sea (Chabahar Gulf). The samples included one species of green (Ulva lactuca) and two brown (Sargassum illicifolium and Nizamuddinia zanardinii) algae. These species are predominantly found on the northern shores of the Oman Sea. After sampling, the algae were washed with sea water and tap water. The prepared samples were then dried and powdered with an electric mill. The extract was prepared in three steps. The first and second stages was carried out with distilled water and the third stage with methanol solvent. The total content of anthocyanin and flavonoid were measured by spectrophotometry method. Antioxidant properties were also measured by ferric reducing antioxidant power. Based on the results, a significant difference were observed in the studied indices between the studied species (p<0.05). Total anthocyanin contents in S. illicifolium, N. zanardinii and U. lactuca extracts was 8.31±1.14, 5.19±1.36 and 3.59±1.84 mg per 100 g dry weight, respectively (p<0.05). However, total flavonoid content between the studied extracts was 27.40±2.71, 21.12±1.14 and 0.39±0.12 mg per 100 g QE per 100 g dry weight and ferric reducing antioxidant power was 1.21±0.36, 0.67±0.10 and 0.60±0.12, respectively (p<0.05). In conclusion, the results of this study indicate that the total amount of anthocyanin and flavonoid contents as well as ferric reducing antioxidant power in S. illicifolium extract were significantly higher than U. lactuca and N. zanardinii extracts.