Anti-Neuroinflammatory Effects of Houttuynia cordata Extract on LPS-Stimulated BV-2 Microglia

Purpose: To evaluate the anti-neuroinflammatory effects of Houttuynia cordata extract (H. cordata) in lipopolysaccharide (LPS)-stimulated BV-2 microglial cells, and its anti-oxidant properties. Methods: Anti-oxidant properties were evaluated by 1, 1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging assay. Cell viability was assessed by 3-(4, 5-dimethylthiazol-2-yl)-2, 5diphenyl-tetrazolium bromide (MTT) assay. LPS was used to stimulate BV-2 cells. Nitric oxide (NO) levels were measured using Griess assay. Inducible NO synthase (iNOS) expression, interleukin (IL)-6 expressional level were determined by enzyme-linked immunosorbent assay (ELISA) and Western blot analysis. Results: Ethyl actetae (HC-EA) extract of H. cordata significantly scavenged DPPH free radicals in a concentration-dependent fashion. The increased levels of NO, iNOS and IL-6 in LPS-stimulated BV-2 microglial cells were also suppressed by HC-EA extract in a concentration-dependent manner. Conclusion:The result indicate that the HC-EA extract exhibited strong anti-oxidant properties and inhibited the excessive production of pro-inflammatory mediators, including NO, iNOS and IL-6, in LPSstimulated BV-2 cells. The anti-oxidant phenolic compounds present in HC-EA extract might play an important role in ameliorating neuroinflammatory processes in LPS-stimulated BV-2 microglial cells.