Résumé:
The aim of this study is to determine chemical composition, myeloperoxydase (MPO) and lipid peroxidation inhibition and the antimicrobial activity of propolis harvested in different areas in Algeria (Tigzirt, Ouled Ali, Ain-El-Arba, Yennarou, Ain Ouassara and Ksar El Hirane). Propolis ethyl acetate extract exibit the best biological properties in vitro (antioxidant activity, inhibition of MPO and LDL oxidation) and was investigated in vitro for that purpose. Thirty male rats were subjected to oxidative stress using aluminium chloride (34 mg AlCl3/kg during 45 days) and 45 days treated with ethyl acetate extracts of Tigzirt propolis (EAP1) in order to restore the oxidative damage of homeostasis and organs such as liver, kidney and lung. The obtained results have shown that EAP1 extract of propolis exibit the highest myeloperoxidase inhibition. The 50% inhibition of the enzyme activity (IC50) was obtained with a EAP1 concentration of 6.95 μg/mL. Propolis ethyl acetate HPLC fractionation and LC/MS analysis of the different fractions revealed the presence of phenolic compounds, oleic acid, cinnamic acid ant its derivatives, tyrosol, and a numerous flavonoïds such as chrysin, galangine, pinocembrin, quercetin, genistein and tectochrysin. Effect of propolis extracts on the AlC3 induced oxidative stress in rats treated with 50 mg propolis/ kg is brought out by a significant (P<0.05) decrease of cholesterolemia and triglyceridemia to about to 1.38 and 0.37 g/L, respectively. All the homeostasis troubles generated by the oxidative stress (increase of cholesterolemia, triglyceridemia, LDL, transaminases TGO and TGP, creatinine and urea levels) and liver, kidney and lung damages were restored with propolis extract. The antimicrobial effect of the different propolis extracts is illustrated by the minimal inhibitory concentrations (MIC) ranging from 0.35 to 4.25 mg of dry propolis extract/mL with an exception of the E. coli MIC which is up 5mg/mL. The more resistant strains to the inhibitory effects of propolis extract were the beneficial bacteria. These results have shown that propolis contains antimicrobial substances which possibly could be used as antimicrobial agents in many fields.
