Phenolic profile, antibacterial and cytotoxic properties of second grade date extract from Tunisian cultivars (Phoenix dactylifera L.)

The present study aimed to investigate the phenolic profile of second grade date extracts and evaluate their antimicrobial and cytotoxic activities with regard to some pathogenic microorganisms. Phenolic content was analyzed by HPLC. Antimicrobial activity was evaluated by the agar disk diffusion method, and in vitro cytotoxic activity was examined by cell proliferation assay. The results revealed that second grade dates presented three benzoic acids, five cinnamic acids and two flavonoids, with the predominance of ρ-coumaric acid (1998.80μg/100g). The antimicrobial activities showed that the date extracts were active against Gram (+) and Gram (-) bacteria, showing marked activity against Escherichia coli with an inhibition zone of 25mm. Cytotoxicity assays showed that the date extracts were able to inhibit the proliferation of HeLa cell lines. The results confirmed that the date extracts were rich in biologically active compounds that are highly valued in the functional food and nutraceutical industries.