Phytochemical Diversity and Related Bioactivity of Ethyl Acetate Fraction from Different Organs and Provenances of the Edible Halophyte Crithmum Maritimum L.

Abstract

Sea fennel (Crithmum maritimum L.) is a facultative halophyte from the Apiaceae family. The variation of phenolic compounds, the antioxidant and antibacterial activities of different extracts of different organs of sea fennel were investigated. The roots, stems, leaves and seeds were collected from three bioclimatic stages of Tunisia. Solvent fractionation method (using aqueous acetone, petroleum ether and ethyl acetate) was adopted to separate the extract ingredient and to concentrate phenolics. Total phenolics, total flavonoids, and condensed tannins significantly varied between organs and localities. In leaves, the highest level of phenols was detected in the upper and sub-humid zones. However, in stems the high amounts of phenols were observed in semiarid climate. The antioxidant activity was evaluated through four different methods and the antimicrobial activity was assessed against five human pathogenic bacteria and a fungal strain. Multivariate analysis showed significant effect of organ and locality on the antioxidant properties. Results of the antibacterial activities showed significant differences among extracts and was reflected by a large spectrum of activity ranging from totally not active (Zones of inhibition (zi) < 1 mm) to very high activity (zi >16 mm). Combined statistical results allowed to select the more potent fraction to be analyzed using reversed-phase HPLC (RP-HPLC). The flavanol epigallocatechin was identified as a major phenolic compound which contributed greatly to the antioxidant capacity. The results established in this study highlighted the importance of this halophyte cash crop in the human diet as natural source of active components.