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 μg/ml (p < 0.01 at 10 μg/ml). The increased levels of NO (35.32 ± 3.62 μM) and protein expressions of iNOS were inhibited by HFE extract in LPS-stimulated BV-2 cells. Increased pro-inflammatory cytokines such as TNF-α and IL-6, were also significantly suppressed by HFE (p < 0.001 at 80 μg/ml). Further, HFE blocked the expression of NF-κB 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.

Keywords
Hizikia fusiforme; Antioxidant activity; Anti-neuroinflammation activity; Inducible nitric oxide synthase; Interleukin-6