Research Article: Effect of monsoon variations on the antioxidant contents and antioxidant activity of Sargassum ilicifolium

Algae has recently drawn attention due to its strong potential for biological activities as a promising natural antioxidant resource. In this regard, seasonal variations of Sargassum illicifolium antioxidant activities were evaluated in the present study. S. illicifolium was collected from three coastal sites of the Oman Sea from April to May (spring) 2020 and October to November (autumn) 2020, representing pre- and post-monsoon, respectively. The methanolic extract was used to evaluate its antioxidant activities and properties. Regarding antioxidant activity (DPPH), there is a significant difference for the ferric reducing antioxidant power (FRAP), total flavonoids, total anthocyanin, and β-carotene variables analyzed between different sites during pre- and post-monsoon (p 0.05). Meanwhile, IC50 in pre-monsoon was significantly higher than in post-monsoon (p 0.05). However, statistical analysis revealed a strong positive correlation between IC50 and FRAP content in pre-monsoon; total phenolic and anthocyanin contents positively correlated to β-carotene post-monsoon. This study revealed that the seasonal variations lead to alter the biological activities regarding antioxidant contents in S. illicifolium, which need to be considered when considering the seaweed as a commercial antioxidant resource.