Attenuation of lipopolysaccharide-induced neuroinflammatory events in BV-2 microglial cells by Moringa oleifera leaf extract

Objective: To determine the anti-neuroinflammatory activity of Moringa oleifera leaf extract (MLE) under lipopolysaccharide stimulation of mouse murine microglia BV2 cells in vitro. Methods: The cytotoxicity effect of MLE was investigated by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl-tetrazolium bromide assay. The inflammatory response of BV-2 cells were induced with lipopolysaccharide. The generation of nitric oxide levels was determined by using Griess assay and the level of pro-inflammatory cytokines (IL-1 beta, IL-6 and TNF-alpha) was evaluated by ELISA kit. The expression of iNOS, COX-2 as well as IB-a was carried out by immunoblot analysis. Results: MLE reduced the nitric oxide production in concentration-dependent manner, and maintained the viability of BV-2 microglial cells which indicated absence of toxicity. In addition, MLE repressed the activation of nuclear factor kappa B by arresting the deterioration of I kappa B-alpha, consequently resulted in suppression of cytokines expression such as COX-2 and iNOS. Conclusions: MLE inhibitory activities are associated with the inhibition of nuclear factor kappa B transcriptional activity in BV2 microglial cells. Thus MLE may offer a substantial treatment for neuroinflammatory diseases.