Evaluation of bioactivity of phenolic compounds from the brown seaweed of Sargassum fusiforme and development of their stable emulsion

This study investigated the antioxidant and anti-inflammatory activities of polyphenol compounds (PC) from Sargassum fusiforme. The PC were consequently applied as the functional ingredient in preparing facial cleaner emulsions. The effects of the ratio of cosolvent (glycerol and 1,2-propanediol) (R (Gl:PG)) and mixing speed (V (m)) on the droplet size and rheological behavior of the facial cleaner emulsions containing PC were also investigated. The PC of S. fusiforme showed a high total phlorotannin content (88.48 +/- 0.30 mg PGE (100 mg)(-1) extract), a high antioxidant activity (IC50 of 10.93 mu g mL(-1)), and a high anti-inflammatory activity in the model 2 (inflammation prevention model). The antioxidant activity was better than that of the commercial antioxidant Trolox and the anti-inflammatory activity was similar to that of the anti-inflammatory chemical Dexamethasone. The facial cleaner emulsion containing the ratio of cosolvent of 1:1 and mixing speed of 300 rpm was found to be most stable as confirmed by minimal changes of mean diameter and microstructure within the examined storage period. This emulsion showed relatively higher viscosity, lower phase angle, stronger thixotropy, and exhibited similar non-Newtonian pseudoplastic behavior and thixotropy, as compared to two commercially available emulsions. The PC of S. fusiforme exhibited strong antioxidant and anti-inflammatory activities which could be employed as active ingredients in cosmetics. The stable cosolvent emulsion system was successfully established, providing a practical approach for application of S. fusiforme PC in the cosmetic industry.