Anti-inflammatory effects of alkaloid enriched extract from roots of Eurycoma longifolia Jack

Objective:To examine the in vitro and in vivo anti-inflammatory effects of the alkaloid enriched extract (ELA) from the roots of Eurycoma longifolia.Methods:The in vitro anti-inflammatory effects of ELA were evaluated by examining its inhibitory activities against nitric oxide (NO) production and inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX-2) expressions in lipopolysaccharide (LPS)-stimulated RAW264.7 cells.The level of NO produced in the culture media was determined by Griess method.The iNOS and COX-2 protein expressions were analyzed by Western blot.The in vivo effect of ELA was evaluated on LPS-induced septic shock in mice model.Mice mortality was monitored for 5 days after injection of LPS.The chemical contents of the ELA were determined by using various chromatographic and spectroscopic techniques.Results:The ELA was found to exhibit a significant anti-inflammatory effect in both in vitro and in vio models.The results demonstrated that ELA dose-dependently inhibited LPS-induced NO production as well as the protein iNOS and COX-2 expressions.In the septic shock model,ELA dose-dependently protected mice from LPS-induced mortality.Further study on the isolated components of ELA indicated that 9,1 0-dimethoxycanthin-6-one may contribute significantly to the anti-inflammatory effects of the extract.Conclusions:These results suggest that ELA exhibits the anti-inflammatory activity via suppression of pro-inflammatory mediators such as NO, iNOS,and COX-2 and protects mice from LPS-induced mortality in septic shock model.