Polyphenolic composition of Lantana camara and Lippia chevalieri, and their Antioxidant and Antimicrobial Activities

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Résumé

In the present study, the antioxidant and antibacterial activities of methanolic extracts of two Verbenaceae ( Lantana camara L. and Lippia chevalieri Moldenke: aerial part) were investigated. Their polyphenolic composition in the ethyl acetate and aqueous fractions were characterized by HPLC-DAD. The antioxidant capability of the methanolic extracts was assessed by the Ferric Reducing Antioxidant Power (FRAP) and the scavenging activity of the free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH). The Minimum Inhibitory Concentrations (MIC) of the methanolic extracts (25 µg mL -1 ), and the minimum bactericidal concentrations (MBC) (12.5 µg mL -1 ) against 13 pathogenic bacteria and four serotyped bacteria from the American Type Culture Collection (ATCC) were also determined by the agar-well diffusion method. The results indicated that the L. chevalieri extracts are rich in phenolic compounds (among the 27 polyphenolic compounds detected, 20 belong to L. chevalieri ) and showed the highest antioxidant activities, simultaneously on iron (III) to iron (II)-reducing activity and the radical scavenging activity. However, L. camara displayed the best and the broadest antimicrobial spectrum, especially on Shigella flexneri and Pantoea sp. (two Gram-negative strains of bacteria). The nature of polyphenolics compounds detected (phenol acid and flavone) in the L. camara can justify this activity. Key words : Verbenaceae, HPLC-DAD, antioxidant activity, antimicrobial activity, polyphenolic compounds

Mots-clés

Lantana camara, Polyphenol, DPPH, Chemistry, Antimicrobial, Lippia, Verbenaceae, Food science, Antioxidant, Antibacterial activity, Traditional medicine, Botany, Bacteria, Biochemistry, Biology, Organic chemistry, Essential oil