Anti-Inflammatory Effects of 3-(4 '-Hydroxyl-3 ',5 '-Dimethoxyphenyl)Propionic Acid, an Active Component of Korean Cabbage Kimchi, in Lipopolysaccharide-Stimulated BV2 Microglia

Abstract

We investigated the protective ability of 3-(4 '-hydroxyl-3 ',5 '-dimethoxyphenyl)propionic acid (HDMPPA), an active principle in Korean cabbage kimchi, against the production of proinflammatory mediators and cytokines, and the mechanisms involved in lipopolysaccharide (LPS)-stimulated BV2 microglial cells. HDMPPA significantly suppressed the production of nitric oxide (NO) and prostaglandin E-2, along with the expression of inducible NO synthase and cyclooxygenase-2 in LPS-stimulated BV2 cells, at concentrations with no cytotoxicity. HDMPPA also attenuated the LPS-induced expression and secretion of proinflammatory cytokines, such as tumor necrosis factor-alpha and interleukin-1 beta. Furthermore, HDMPPA inhibited LPS-induced nuclear factor-kappa B (NF-kappa B) activation, which was associated with the abrogation of I kappa B-alpha degradation and phosphorylation, and subsequent decreases in NF-kappa B p65 levels. Moreover, the phosphorylation of mitogen-activated protein kinases (MAPKs) and Akt, a downstream molecule of phosphatidylinositol-3-kinase (PI3K), in LPS-stimulated BV2 cells was suppressed markedly by HDMPPA. This effect was associated with a significant reduction in the formation of intracellular reactive oxygen species. The findings in this study suggest that HDMPPA may exert anti-inflammatory responses by suppressing LPS-induced expression of proinflammatory mediators and cytokines through blockage of NF-kappa B, MAPKs, and PI3K/Akt signaling pathways and oxidative stress in microglia.