Isolation of major compounds from the bioactive fraction as well as their anti-inflammatory activities

Abstract

Magdi Boutros, Ahmed Ghali and Farid Fattah

A bio-guided fractionation of the defatted ethanolic extract (DEE) of the aerial parts of Trachelospermum jasminoides and its fractions: ethyl acetate fraction (EAF), chloroform fraction (CF) and n-butanol fraction (BF) were carried out, using carragenan induced rat paw edema method, to evaluate the in vivo acute anti-inflammatory potential at a given dose of 100 mg/kg body weight compared to indomethacin (20 mg/kg body weight). The EAF revealed the highest anti-inflammatory activity (76.92%) relative to the DEE and the CF (63.82 and 48.75%, respectively) at the same tested dose, while the BF was significantly inactive. The EAF and its major isolated compounds were investigated to determine the level of proinflammatory cytokines using enzyme-linked immunosorbant assay (ELISA). Seven major compounds were isolated from the EAF, identified as: trachelogenin, nor-trachelogenin and tracheloside, in addition to apigenin, luteolin, quercetin and luteolin-7-O-β-D-glucopyranoside. Identification of the isolated compounds was achieved by their physico-chemical properties and spectral analysis (1D and 2D NMR). The EAF and the isolated compounds inhibited the excessive production of tumor necrosis factor-alpha (TNF-α) and interleukin (IL)-1β. Furthermore, the liquid chromatography/electrospray ionization-tandem mass spectrometry (LC/ESI-MS) for the bioactive EAF was carried out to complete the phytochemical picture. The results of this study verified that the EAF and the major compounds exert their action through inhibition of TNF-α and IL-1 β.