The antioxidants and antimicrobial properties of propolis collected from some localities in Western Algeria

Abstract

The chemical analysis , antibacterial and antioxidant activities of propolis collected from north Western parts of Algeria were investigated. Total polyphenols and flavonoids contents of extracts were measured. The UV absorption spectrum showed and confirmed their polyphenols constituents. The major constituents in EEP were identified by high-performance liquid chromatography (HPLC) analysis. All EEP samples were active against Gram positive (Staphylococcus aureus, Bacillus subtilis, Bacillus cereus,) but no activity against Gram-negative bacteria (Pseudomonas aeruginosa, Escherichia coli). The propolis extract obtained from Sidi bel Abbés (SFS-SBA) showed unique HPLC profile. The minimum inhibitory concentration (MIC) of EEPs ranged from 0.01 to 2.6 % v/v and the mean diameters of growth inhibition of the EEP ranged between 8.05 and 21.4 mm. The antioxidant activity was measured by using ferric reducing power (FRAP), 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical-scavenging and ESR methods. Propolis TIA-2 and MOH-MAS samples showed the highest antioxidative capacity, after 35 min. While, TIA-1, NED-TL and SFS-SBA samples showed the highest antioxidative potential of measured EEPs, after 3 min. TIA-2 sample showed the highest antibacterial, antioxidant activity and highest DPPH free radical scavenging activity as well as the highest polyphenols and flavonoids content, compared to other propolis samples. The FT-IR spectra of propolis samples confirmed the presence of polyphenolic constituents. The ESI-MS of samples showed major ions at m/z 206, 256 and 284 which correspond to sinapic acid, Pinocembrin and Galangin-5-ME. These data confirmed the presence of phenolics constituents. The thermal properties of extracts were measured by using DSC and TGA. These results, support the idea that propolis can be a promising naturally food preservative in food industry and alternative candidate for management of bacterial infections caused by drug-resistant microorganisms.