Anti-inflammatory activity of Corylopsis coreana uyeki extracts and isolated compounds by inhibiting nitric oxide and cytokine production

Abstract

Context: Corylopsis coreana Uyeki (Korean winter hazel) belongs to the Hamamelidaceae family. It is cultivated as an ornamental plant in South Korea. In traditional folk medicine, C. coreana has been used to treat irritated skin and inflammatory diseases. Aims: To study the anti-inflammatory effects of C. coreana Uyeki leaf and bark extracts as well as their major active compounds, we evaluated in vitro levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and nitric oxide (NO) using RAW 264.7 macrophages. Materials and Methods: Production of TNF-α and IL-6 cytokines was measured by ELISA assay, and NO inhibitory activity was tested by Griess assay. Results: Extracts of leaves and barks, as well as isolated compounds from these extracts, showed remarkable anti-inflammatory activities by inhibiting NO, TNF-α, and IL-6 cytokine production. In particular, the leaf extract showed more potent inhibitory activities than that of barks. Conclusions: Ellagitannins and flavonoids were probably related to the anti-inflammatory activity of CL (leaves) extract, providing evidence of the anti-inflammatory property of CL. Abbreviations used: TNF-α: Tumor necrosis factor-α; IL-6: Interleukin-6; CL: Corylopsis coreana; NO: Nitric oxide; LPS: Lipopolysaccharide; Tel 1: Tellimagrandin I; Tel 2: Tellimagrandin II; Cas: Casuarinin; Quer: Quercetin; EGCG: Epigallocatechin gallate.