Etude phytochimique, effet anticoccidien et évaluation biologique de Punica granatum L. et Olea europaea L.

Abstract

The objective of this research is to valorize the Punica granatum L. peels and Olea europaea L. leaves by measuring the phenolic compound concentrations and evaluating the biological activities of the crude extracts (P and O) and their fractions : diethyl ether (DP and DO), ethyl acetate (AP and AO), and butanolic (BP and BO). The results of the quantitative phytochemical analysis revealed a high concentration of polyphenols, flavonoids, flavonols, and tannins, with extracts from P. granatum being richer than those from O. europaea. The antioxidant potential was assessed using five in vitro tests. The the P. granatum fractions demonstrated greater antioxidant power than the standards used. The (DP) was the most potent in the DPPH and phenanthroline assays (3.36±0.11 and 1.04±0.10 μg/mL, respectively), whereas (AP) showed the highest activity in the ABTS, CUPRAC, and reducing power assays (1.26±0.04, 2.59±0.20 and 3.41±0.09 μg/mL, respectively). For O. europaea, the strongest activity was exerted by (DO) in the DPPH, ABTS, and CUPRAC assays (9.31±0.44, 6.89±0.39, 8.97±0.62 μg/mL, respectively) and by (AO) in the phenanthroline and reducing power assays (9.29±1.07 and 16.22±1.88 μg/mL, respectively). The results of the anti-Alzheimer activity revealed that the peel fractions showed good anti-cholinesterase activity, while only the extract (DO) exhibited anti-butyrylcholinesterase activity (85.92±7.80 μg/mL). The antibacterial activity was evaluated against two Gram-negative and two Gram-positive bacteria. Among the Gram-negative bacteria, P. aeruginosa was shown to be sensitive only to (BP), while all extracts showed significant activity against Gram-positive bacteria. Moreover, the determination of the minimum inhibitory concentration and minimum bactericidal concentration of the two plants showed that the best inhibitory concentration was observed against B. cereus with extracts (AP) and (BO) (0.39 and 12.50 mg/mL, respectively). The strongest bactericidal effect was exerted by (DP) against S. aureus (1.56 mg/mL) and by (DO) against both B. cereus and S. aureus (50 mg/mL). The anticoccidial potential of the crude extract from each plant (at 400 and 800 mg/kg of feed) and their powders (at 4 g/kg of feed) was conducted on Cobb 500 broiler chicks from day 14 to day 35 of age. The results demonstrated promising anticoccidial activity, with a significant reduction in the number of E. tenella oocysts per gram of feces in the treated groups. In addition, the incorporation of the hydro-ethanolic extract of P. granatum peels and O. europaea leaves into the poultry diet at concentrations of 800 and 400 mg/kg, respectively, helped to improve the broilers' zootechnical performances. The results showed that the studied extracts possess strong antioxidant, anticholinesterase, antibacterial, and anticoccidial properties, attributable to the quality and quantity of their phytochemical components, particularly their polyphenolic compounds. These plants represent a potential source of valuable substances that can replace chemical compounds used in the fields of pharmacology and nutrition.