The Anti-Oxidative and Anti-Neuroinflammatory Effects of Sargassum horneri by Heme Oxygenase-1 Induction in BV2 and HT22 Cells

Sargassum horneri is used as a traditional medicinal agent and exhibits various pharmacological effects. In this study, we found that the 70% EtOH extract contained 34.37 ± 0.75 μg/mg fucosterol. We tested the antioxidant activities of the 70% EtOH extracts and their fractions. The CH2Cl2-soluble fraction showed the strongest DPPH and ABTS radical scavenging activities. Next, we evaluated the anti-neuroinflammatory effects of S. horneri on lipopolysaccharide (LPS)-stimulated BV2 cells. Pretreatment with the extract and fractions suppressed LPS-induced production of nitric oxide (NO) in BV2 cells. The 70% EtOH, CH2Cl2-soluble fraction, and water-soluble fraction inhibited the production of prostaglandin E2, interleukin-6, and tumor necrosis factor-α, as well as markedly blocking LPS-induced expression of inducible NO synthase and cyclooxygenase-2 via inactivation of the nuclear factor-kappa B pathway. In addition, the CH2Cl2-soluble fraction showed the most remarkable heme oxygenase (HO)-1 expression effects and increased nuclear erythroid 2-related factor translocation in the nucleus. In HT22 cells, the CH2Cl2-soluble fraction inhibited cell damage and ROS production caused by glutamate via the regulation of HO-1. Therefore, CH2Cl2-soluble fractions of S. horneri can attenuate oxidative action and neuroinflammatory responses via HO-1 induction, demonstrating their potential in the treatment of neuroinflammatory diseases.