Crude extracts of <i>Momordica cochinchinensis</i> (Lour.) Spreng exerts antioxidant and anti-neuroinflammatory properties in LPS-stimulated BV2 microglia

Abstract

Purpose: To evaluate the antioxidant and anti-neuroinflammatory properties of the leaves, seeds and pulp of Momordica cochinchinensis  Spreng (commonly known as Gac) in vitro and in lipopolysaccharide (LPS)-activated BV2 microglial cells. Methods: Lipopolysaccharide was applied to BV2 cells for 24 h in the presence or absence of Gac extracts. Then, levels of reactive oxygen  species (ROS) were assayed using CM-H2DCFDA method, while nitric oxide (NO) level was determined with Griess reagent. The levels of  TNF-α and IL-6 were  determined using ELISA. Three different assays were used for determination of in vitro antioxidant activities of the  extracts, namely, 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging; 2,2’-azinobis-3- ethylbenzthiazoline-6-sulfonic acid (ABTS) scavenging,  and ferric-reducing antioxidant power (FRAP). Total flavonoids content (TFC) and total phenolic content (TPC) were also determined.  Results: There were significantly higher levels of ROS, NO, TNF and IL-6 in LPS-treated BV2 cells than in control cells (p < 0.05). However,  exposure of LPS treated BV2 cells to the leaf, seed and pulp extracts of Gac led to marked decreases in levels of ROS and inflammatory  mediators, when compared with untreated cells, with the seed extract producing significantly larger decreases in levels of ROS and inflammatory mediators than the leaf and pulp extracts (p < 0.05). The DPPH and ABTS radical scavenging activities and total reducing  power activities of the seed extract were superior to those of the leaf and pulp extracts. Moreover, the seed extract showed higher  contents of TFC and TPC than the other two extracts. Conclusion: Gac extracts exert antioxidant and anti-neuroinflammatory effects on LPS-activated BV2 cells and in an in vitro model.  Therefore, Gac extracts, especially seed extract, may be beneficial in the preparation of innovative antioxidative and anti-neuroinflammatory herbal remedies, as well as dietary supplements.