Pinexol inhibits in vitro inflammatory biomarkers by blocking NF-κB signaling pathway and protects mice from lethal endotoxemia

Abstract

Korean red pine (Pinus densiflora) bark extract is used for the treatment of chronic inflammatory-related ailments through as yet undefined mechanisms. The present study was conducted to explore the anti-inflammatory activities of Korean red pine bark extract (commercially called Pinexol in Korea) in murine RAW 264.7 macrophages and LPS-induced shock in mice. Here, we set out to determine whether the anti-inflammatory effects of Pinexol are mediated to suppress nuclear factor-κB (NF-κB) activation in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. We found that Pinexol significantly suppressed LPS-stimulated nitric oxide (NO) and IL-6 production without affecting cell viability. Pinexol inhibited the expression of LPS-induced inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) protein and their mRNA expression. As a result, Pinexol inhibited pro-inflammatory cytokines such as IL-6, which is hypothesized as being due to the suppression of LPS-induced NF-κB activation. Moreover, Pinexol improved the survival rate during lethal endotoxemia by inhibiting the production of TNF-α and IL-6 in an animal model and our GC-MS analysis using derivertization showed that four major components of Pinexol were cathechin, epi-catechin, and methylated catechins. Therefore, we demonstrate here the evidence that Korean red pine bark extract potentially inhibits the biomarkers related to inflammation in vitro and in vivo, and might be provided as a potential candidate for treatment of inflammatory diseases.