Evaluation of Antioxidant and Anti-neuroinflammatory Activities of Hizikia fusiformis (Harvey) Okamura Extract

Purpose: To evaluate the in vitro antioxidant and anti-neuroinflammatory activities of Hizikia fusiformis (Harvey) Okamura extract (HFE) in lipopolysaccharide (LPS)-stimulated murine BV-2 microglial cells. Methods: The antioxidant activity of HFE was evaluated by measuring 1, 1-diphenyl-2-picryl-hydrazyl (DPPH) radical-scavenging activity using an ESR spectrometer. Cell viability was estimated by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl-tetrazolium bromide (MTT) assay. LPS-stimulated BV-2 microglia were used to study the expression and production of inflammatory mediators such as nitric oxide (NO), inducible NO synthase (iNOS) and Interleukin 6 (IL-6). Results: Treatment with Hizikia fusiformis extract (HFE) significantly scavenged the DPPH radicals with half-maximal concentration of (IC50) of 9.64 +/- 0.78 mu g/ml (p < 0.01 at 10 mu g/ml). The increased levels of NO (35.32 +/- 3.62 mu M) and protein expressions of iNOS were inhibited by HFE extract in LPS-stimulated BV-2 cells. Increased pro-inflammatory cytokines such as TNF-alpha and IL-6, were also significantly suppressed by HFE (p < 0.001 at 80 mu g/ml). Further, HFE blocked the expression of NF-kappa B activation in LPS-stimulated BV-2 cells. Conclusion: HFE can be considered as a useful therapeutic and preventive approach for the treatment of neurodegenerative diseases and oxidative stress-related diseases.