Anti-inflammatory activity of the active compounds of sanguisorbae radix in macrophages and in vivo toxicity evaluation in Zebrafish

Abstract

Sanguisorbae Radix (SR) is the root of the Sanguisorba officinalis L., a plant native to Asian countries and used in traditional medicine. We isolated the active components of SR and investigated their anti-inflammatory potential. Quercetin (QC), (+)-catechin (CC), and gallic acid (GA) were isolated from acetone extracts of SR. To elucidate the molecular mechanism by which these compounds suppress inflammation, we analyzed the transcriptional up-regulation of inflammatory mediators, such as nuclear factor-kappa B (NF-kB) and its target genes, inducible NOS (iNOS), and cyclooxygenase (COX)-2, in lipopolysaccharide (LPS)-stimulated macrophage RAW264.7 cells. Notably, QC, CC, and GA were found to inhibit the production of nitric oxide, tumor necrosis factor-alpha, and prostaglandin in a dose-dependent manner. Western blot results indicate that the compounds decreased the expression of iNOS and COX-2 proteins. Furthermore, the compounds decreased phosphorylation of IKK, IkB, ERK, p-38, and JNK proteins in LPS-induced cells. The results support the notion that QC, CC, and GA can potently inhibit the inflammatory response, with QC showing the highest anti-inflammatory activity. In in vivo toxicity studies in zebrafish (Danio rerio), QC showed no toxicity up to 25 μg/mL. Therefore, QC has non-toxic potential as a skin anti-inflammatory biomaterial.