Abstract
Natural products including alkaloids from algae may provide alternative source for new natural antioxidants due to their novel structure. In the present study the antioxidant properties of alkaloids extracted from Sargassum hornschuchii and Cystoseira compressa were assessed using various in vitro systems including 1,1-diphenyl-2-picrylhydrazyl (DPPH), superoxide, hydroxyl radicals, nitric oxide (NO) scavenging, phosphomolybdenum reduction and reducing power activity at different concentrations (6.25 to 100 mg/ml). The results showed that alkaloids rich extracts exhibit antiradical activity and reduction ability in concentration dependent. Extracts exhibit significant low scavenging activity on DPPH and nitric oxide radical activity Investigation … Rabia Alghazeer et al. compared to standard, ascorbic acid and butylated hydroxyanisole (BHA). Reducing power and total antioxidant of extracts showed less effect compared to standard, ascorbic acid and butylated hydroxyanisole (BHA). Superoxide, and hydroxyl radical assays showed a comparable scavenging activity compared to its standard. Therefore, new separation, purification techniques, and powerful identification methods are recommended to improve their antioxidant activity.