RESUMEN
We aimed in the reported study to investigate the impact of using various solvents in the extraction of potentially active compounds from Algerian propolis. Phenolic and flavonoids contents in association with antioxidant activity of the tested extracts were evaluated. Moreover phenolic composition was determined using UFLC-MS/MS. The tested parameters varied according to the used solvent. Total phenolic and flavononid contents ranged from 0.81+/- 0.16 to 8.97+/- 0.25 EGA mg/g and from 0.57+/- 0.01 to 3.53+/- 0.84 EQ mg/g respectively. All the investigated extracts demonstrated notable antiradical and reducing activities. Ethyl acetate and n-butanol were found to contain the highest amounts of phenolic and flavonoid compounds and the strongest antioxidant properties. The antioxidant activity of propolis extracts appears to be largely influenced by total phenolic and flavonoid contents. Rutin, chlorogenic, ferulic, caffeic and gallic acids were found to be the main phenolic compounds in Algerian propolis. Our results suggest that Algerian propolis may be a poplar-type propolis
RESUMEN
Objective: To evaluate the essential oils (EO) composition, antimicrobial and antioxi-dant power of a local plant, Daucus gracilis (D. gracilis). Methods: The aerial parts of D. gracilis were subjected to hydro distillation by a Cle-venger apparatus type to obtain the EO which had been analyzed by gas chromatography and gas chromatography coupled with mass spectrometry, and screened for antimicrobial activity against five bacteria and three fungi by agar diffusion method. The mechanism of action of the EO was determined on the susceptible strains by both of time kill assay and lysis experience. The minimal inhibitory concentrations were determined by agar macro-dilution and micro-dilution methods. Anti-oxidative properties of the EO were also studied by free diphenyl-2-picrylhydrazyl radical scavenging and reducing power techniques. Results: The EO yielded 0.68 (v/w). The chemical analysis presented two dominant constituents which were the elemicin (35.3%) and the geranyl acetate (26.8%). D. gracilis EO inhibited the growth of Bacillus cereus and Proteus mirabilis significantly with minimal inhibitory concentrations of 17.15 mg/mL by the agar dilution method and 57.05 mg/mL and 114.1 mg/mL, respectively by liquid micro-dilution. A remarkable decrease in a survival rate as well as in the absorbance in 260 nm was recorded, which suggested that the cytoplasm membrane was one of the targets of the EO. The EO showed, also, important anti-oxidative effects with an IC50 of 0.002 mg/mL and a dose-dependent reducing power. Conclusions: D. gracilis EO showed potent antimicrobial and anti-oxidative activities and had acted on the cytoplasm membrane. These activities could be exploited in the food industry for food preservation.