Abstract: The crude polyphenols extracted from Sargassum horneri were purified using macroporous adsorption resin, and the in vitro anti-inflammatory and hypoglycemic activities of the purified product were studied. Lipopolysaccharide (LPS) was used to induce RAW 264.7 macrophages to establish an in vitro inflammatory model. The optimal mass concentration of polyphenols from S. horneri was 40 μg/mL for reducing the NO content of inflammatory mediators. Compared with the model group, S. horneri polyphenols solution at 30 μg/mL significantly down-regulated the mRNA expression levels of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α) and IL-1β, and significantly inhibited the protein expression level of TNF-α, but had no significant inhibitory effect on the protein expression level of IL-1β; the inhibitory effect was positively correlated with the concentration of polyphenols. The half maximal inhibitory concentration (IC50) of S. horneri polyphenols on α-glucosidase was 5.96 μg/mL. According to the double reciprocal curve, the competitive inhibition constant (Kic) and noncompetitive inhibition constant (Kiu) were 0.06 and 6.68 μg/mL, respectively, indicating that the mode of inhibition was mixed-type with non-competitive being greater than competitive inhibition. Polyphenols from S. horneri have good anti-inflammatory and hypoglycemic activities, and can be used as a natural raw material in the fields of foods, health products and cosmetics.

Key words: Sargassum horneri polyphenols; anti-inflammatory activity; α-glucosidase activity; inhibition kinetics