Ethyl acetate extract of Baccharis dracunculifolia DC inhibits TNF-α production in TNBS-induced colitis in rats

Baccharis dracunculifolia (BD) is the main botanical source of Brazilian green propolis, a natural product used to improve health. The ethyl acetate extract of this plant is rich in caffeic acid, p-coumaric acid, aromadendrin-4-O-methyl ether, 3-prenyl-p-coumaric acid, 3,5-diprenyl-p-coumaric acid and baccharin. This extract was effective scavenger of DPPH with the EC50 value of 63.53 vs. 1.89µg/ml of galic acid. Previous study in our research group showed that this extract presented improvement in experimental model of inflammatory bowel disease induced by trinitrobenzenesulfonic acid (TNBS) in rats. The aim of this study was to investigate by which means this extract acts. For this purpose, the rats were pre-treated for 5 days with 5 or 50mg/Kg by BD extract or azathioprine (2mg/Kg), the reference drug, before the colitis induction by TNBS. Macroscopic (score, extension of lesion, colonic weight/length) and biochemical parameters (gluthathione, myeloperoxidase, alkaline phosphatase, TNF-α and INF-γ) were evaluated. The doses of 5 and 50mg/Kg reduced the colon weight/length and the myeloperoxidase activity. Additionally, the dose of 50mg/Kg reduced colonic TNF-α levels. The reference drug only reduced the myeloperoxidase activity. The primary mechanism of BD anti-inflammatory actions appears to be immunomodulation via suppression of TNF-α production.