Antioxidant and anti-inflammatory activity of Cotinus coggygria extracts

Abstract

Aim of this study was the investigation of antioxidant and anti-inflammatory activities of the smoke tree, Cotinus coggygria Scop., Anacardiaceae. Ground, dried young shoots were extracted with acetone and then fractionated with chloroform, ethyl-acetate and water (yield of extracts: 42.5%, 7.3%, 53.0% and 39.7%, respectively). Content of total phenolics and tannins was determined using Folin-Ciocalteu reagent and total flavonoids on basis of flavonoid-aluminium complex formation [1]. Antioxidant activity was evaluated with FRAP test [2], DPPH radical scavenging activity [3] and lipid peroxidation (LP) test [4]. The carrageenan-induced rat paw oedema test was used for investigation of anti-inflammatory activity [5]. Highest content of total phenolics (92.9%), tannins (83.4%) and flavonoids (3.5%) was determined in ethyl-acetate fraction. In this fraction gallic acid, apigenine, luteoline and their derivatives were detected by HPLC. All extracts showed antioxidant effects but the highest activity was obtained with the ethyl-acetate fraction. This fraction also exhibited significant ferric reducing ability (5.0 mmol Fe 2+/g extract), very high DPPH radical scavenging activity (SC50=1.7µg/ml) and high inhibition of LP on liposomes (IC50=41.8µg/ml). Furthermore, it reduced the carrageenan rat paw oedema in a dose-dependent manner; doses of 50mg/kg and 100mg/kg led to a 46.5% and 76.7% reduction of the oedema, being statistically very significant (p<0.01). At a dose of 100mg/kg the anti-inflammatory effect of the ethyl-acetate fraction was more pronounced than that of indomethacin (8mg/kg; p<0.01).