Anti-inflammatory activity of flavonoids from Cayaponia tayuya roots

Ethnopharmacological relevance: Taiuia or tayuya (Cayaponia tayuya, Cucurbitaceae) is a climbing, lignified plant with a large swollen root that has traditionally been used as an anti-inflammatory and anti-rheumatic agent in the folk medicine of Brazil, Peru, and Colombia. The aim of the study: We have assayed the pharmacological properties of a flavonoid fraction obtained from the butanol extract of Cayaponia tayuya roots using two models of topical mouse ear oedema, paying special attention to its influence on the induction on pro-inflammatory enzymes and peptidic mediators. Material and methods: The in vivo experiments involved both the acute oedema induced by a single application of TPA and the subchronic inflammation brought on by repeated applications of TPA. The effects on the induction of pro-inflammatory enzymes and peptidic mediators in RAW 264.7 macrophages were analyzed with the aid of Western blot analysis. Results: The extract was identified as a mixture of flavonoids in which vicenin-2, spinosin, isovitexin, and a mixture of swertisin and isoswertisin were found. In acute TPA-induced oedema in mouse ears, the flavonoid-enriched fraction (at a dose of 0.5 mg/ear) inhibited the oedema by 66% (4.2 +/- 0.6 mg vs. 12.3 +/- 1.4 mg, P<0.01)while in the subchronic model, the inhibition reached 37% at a dose of 0.5 mg/ear x 7 applications (7.5 +/- 0.6 mg vs. 11.9 +/- 1.3 mg, P<0.05). When assayed in vitro, the flavonoid showed no toxicity at 33.45 mu g/mL on RAW 264.7 macrophages. Although the nitric oxide production in these cells was moderately reduced (42%) at 33.45 mu g/mL, the flavonoid-enriched fraction had no effect on TNF-alpha production. In addition, at 22.30 mu g/mL, the test sample inhibited both NOS and COX-2 expression by 98% and 49%, respectively. Conclusion: These results indicate that the anti-inflammatory activity of flavonoids from tayuya roots most likely stems from their inhibition of the induction of the enzymes COX-2 and NOS. (C) 2008 Elsevier Ireland Ltd. All rights reserved.