Etude de l’activité antioxydante et antimicrobienne des composés phénoliques d’extrait des écorces de Punica granatum (Grenade)

Abstract

Among the medicinal plants that make up the vegetation cover is the genus punica, which is widely distributed mainly in semi-arid regions. Many species of this type are used in traditional medicine because they contain several molecules with therapeutic activities, among the best known species being Punica granatum. The organic extracts of the latter were obtained by maceration using three solvents: ethanol, methanol and acetone. The respective yields are: 15,113%, 33,913% and 56,9%. The total content of phenolic compounds was determined using the Folin-Ciocalteu reagent, it was 200, 180 and 80 mg Eg AG / g (equivalent of gallic acid per gram of extract) in the three ethanol, acetone And methanol respectively. The flavonoids were evaluated using the AlCl3 method, their contents being 80, 70 and 60 mg EQ / g Q (quercetin equivalent per gram of extract) in the three extracts respectively. Tannins are estimated using the colorimetric method in the presence of sulfuric acid, their contents being 122, 137 and 222 mg EQ / g C (equivalent of catechin per gram of extract) in the three extracts respectively. The antioxidant activity evaluated using the free radical reduction technique DPPH is the highest in the ethanol extract, but it is low for the other two extracts. Antimicrobial activity was determined on 11 microbial strains (five Candida albicans, one Staphylococcus aureus, two Enterococcus faecalis, one Streptococcus mutans, one Streptococcus salivarius and one Streptococcus constellatus), according to the disk diffusion method. The results indicate that the three extracts possess antimicrobial activity on all the strains tested.