Total phenolic content, antioxidant and antimicrobial activities of extracts from Pistacia lentiscus leaves

The purpose of the current study was to investigate total phenolic (TPC), total flavonoids (TF) and flavonols (FV) contents, as well as antioxidant and antimicrobial activities of different extracts of Pistacia lentiscus leaves. TP compounds were quantified by Folin-Ciocalteu, while antioxidant properties were evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH), radical scavenging assay (RSA), Ferric reducing activity power (FRAP) and β-carotene bleaching (βCB) assay. The antimicrobial activity was assessed against Gram-positive bacteria (Micrococcus luteus, Bacillus subtilis and Listeria innocua), Gram-negative bacteriaum (Escherichia coli) and fungi (Candida pelliculosa and Fusarium oxysporum albidinis). Overall, the ethanol fraction (EEPL) exhibited the highest TPC (70.4 ± 7.07 mg GAE g^-1 powder), TF (32.06 ± 1.68 mg QE g^-1 powder), FV (14.36 ± 1.68 mg QE g-1 powder) and RSA (IC50 = 5.34 ± 0.2 μg mL^-1). Whereas, methanol extract (EMPL) displayed the highest FRAP (1.20 ± 0.02) and dichloromethane extract (EDPL) showed a high βCB (90.32 ± 2.98%). Furthermore, the antioxidant activities of extracts exhibited strong positive correlation with TP, TF and flavonols. The extracts obtained showed good inhibitory effect against most of the bacterial and fungal strains tested, suggesting their possible use as antimicrobial agents in medical or agro-industry sectors.