Phenolic Profile, Antioxidant and Antimicrobial Activities of Algerian Pistacia Lentiscus L. Leaf Extract

Abstract

     The objective of this study was to determine the composition of the phenolic extract from Pistacia lentiscus leaves (PLLPE) and to evaluate its antioxidant and antimicrobial activities.

The total polyphenol and flavonoid contents of P. lentiscus were determined using the Folin-Ciocalteu and AlCl3 methods, respectively. The total polyphenol content was determined to be 193.88 mg gallic acid equivalent, while flavonoids were determined to be 18.96 mg quercetin equivalent.

HPLC/MS revealed the presence of eight phenolic compounds, six flavonoids, and two phenolic acids. The most abundant compounds were kaempferol-3-O-glucoside (1.003 mg/mL) and quercetin-3-O-glucoside (0.865 mg/mL).

The extract showed significant antioxidant activity with a ability of PLLPE to scavenge DPPH (CI50 = 119.94 µg/mL) and reduce Fe2+ (CI50 = 2.18 mM Fe2+/mL) was concentration-dependent. The CI50 for β-carotene bleaching (298.07 µg/mL) was higher than that of the standards (i.e., ascorbic acid and quercetin). The FRAP assay showed that the antioxidant activity of PLLPE was lower than that of ascorbic acid but higher than that of quercetin.

The diameters of the inhibition zones generated by the antimicrobial activity of PLLPE against the different strains ranged from 5.13 mm (for the beneficial strain Lactobacillus rhamnosus) to 35.12 mm (for the pathogenic strain Staphylococcus aureus).