Okra ( Abelmoschus esculentus   Linn) inhibits lipopolysaccharide-induced inflammatory mediators in BV2 microglial cells

Purpose: To investigate the inhibitory effects of okra (Abelmoschus esculentus Linn.) extract on the production of reactive oxygen species (ROS) and pro-inflammatory cytokines in lipopolysaccharide (LPS)-stimulated BV2 microglia.
Methods: Okra was extracted with ethanol by Soxhlet extraction. Non-cytotoxic doses of okra at concentrations of 50, 100 and 200 μg/mL were used in this study. BV2 cells were cultured and treated with LPS in the presence or absence of okra at the concentrations indicated above. ROS, nitric oxide (NO), tumor necrotic factor alpha (TNF-α), interleukin 1 beta (IL-1β), phosphorylation levels of nuclear factor-kappa B (NF-kB) p65 and Akt were determined.
Results: Treatment of BV2 cells with okra concentrations of 50, 100 and 200μg/mL significantly suppressed LPS-induced NO as well as ROS compared to untreated cells. There was also a significant decrease in the production of TNF-α and IL-1β in okra-treated BV2 microglia cells. The level of LPSinduced NF-kB p65 phosphorylation was significantly decreased by okra treatment. In addition, okra inhibited LPS-induced Akt phosphorylation, which is an upstream molecule of NF-kB.
Conclusion: Okra exerts anti-oxidative and anti-inflammatory effects in LPS-stimulated BV2 microglial cells by suppressing Akt-mediated NF-κB pathway. This suggests that okra might be a valuable agent for the treatment of anti-neuroinflammatory diseases mediated by microglial cells.

Keywords
Abelmoschus esculentus Linn; Inflammatory cytokines; Lipopolysaccharide; Neuroinflammation; Microglia; Reactive oxygen species