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 specie

Antioxidant and anti-inflammatory activities of Oroxylum indicum Kurz (L.) fruit extract in lipopolysaccharide-stimulated BV2 microglial cells

Purpose: To investigate the anti-inflammatory effects and antioxidant activity of Oroxylum indicum (L.) Kurz fruit extract in lipopolysaccharide (LPS)-stimulated BV2 microglia. Methods: BV2 cells were treated with LPS for 24 h in the presence or absence of O. indicum fruit extract. Then, nitric oxide (NO), reactive oxygen species (ROS) and interleukin 6 (IL-16) levels were measured using Griess reagent assay, CM-H2DCFDA and enzyme-linked immunosorbent (ELISA) assays, respectively. The in vitro antioxidant property of the extract was also investigated by 1,1- diphenyl-2-picrylhydrazyl (DPPH) and 2,2’-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) assays. Results: Levels of IL-6, NO, and ROS in LPS-treated BV2 cells were significantly higher than those in control (p < 0.01). However, exposure of LPS-treated BV2 cells to O. indicum extract led to a marked decrease in the levels of these parameters, when compared to the untreated cells (p < 0.01). Results from DPPH and ABTS assays showed that the O. indicum extract exhibited good antioxidant properties, with total flavonoid and total phenolic contents of 115.58 ± 1.09 and 131.04 ± 2.37 mg/g of dried extract, respectively. Conclusion: The results demonstrate that O. indicum fruit exerts anti-oxidant and anti-inflammatory effects in LPS-stimulated BV2 cells. Thus O. indicum fruit might be beneficial in the development of novel anti-oxidative and anti-neuroinflammatory herbal medicines. However, the mechanisms by which O. indium fruits reduces NO and IL-6 needs to be further investigated