Etude phytochimique et évaluation biologique d’une plante endémique du genre Genista (Fabaceae)

Abstract

The present work concerns the phytochemical and biological study of an endemic species belonging to the Fabaceae family: Genista numidica Spach which has been collected from the region of Constantine. Our work on the extraction of the aerial parts of G. numidica followed by the chromatographic separation permitted the isolation of 14 secondary metabolites from the chloroformic and ethyl acetate extracts. The structures of 13 were identified and fully described, including a new triterpene. The molecular structures of isolated compounds were established mainly by the use of NMR 1D and 2D (1H, 13C, TOCSY-1D, COSY, HSQC and HMBC), high resolution mass spectrometry (HRESI-MS) and by comparison with the literature Data. The antioxidant activity of CHCl3, EtOAc and n-BuOH extracts of G.numidica has been investigated by DPPH test, the results showed that the ethyl acetate extract has a good scavenging effect in vitro against the DPPH radical (IC50 = 40.43 ±3.09 µg / ml). The antiproliferative activity of isolates ( lignans and saponins) was investigated on Jurkat, HeLa and MCF-7 cell lines. The most active component, the triterpene, 3-O- β-D-glucopyranosyl-olean-12-en-3β,27,28,29-tetraol, showed activity in all cell lines, an IC50 value of 37 ± 2.3 µM (Jurkat), 35 ± 1.7 µM (HeLa) and 50 ± 3.6 µM (MCF-7) respectively. The mechanism underlying its antiproliferative effect was investigated in HeLa cells. The results showed that this compound affect the cell cycle progression by inducing a robust G2/M bloc in HeLa cells.