Crithmum maritimum L. Volatile Compound's Diversity Through Tunisian Populations: Use of a Plant Organ-Based Statistical Approach for Chemotype Identification.

This work aimed to investigate the variability of the chemical composition of the aromatic halophyte Crithmum maritimum L. essential oils according to the geographical origin and separated organs, using a statistical approach based on the multiple analysis of variance and the Principal Component Analyses. One hundred twenty samples were collected from three distinct bioclimatic regions (10 samples×3 provenances×4 organs). Hydrodistillation of separated organs (roots, stems, leaves and flowers) yielded 0.13 to 1.75 % of the dry matter. Chemical investigation of the volatile compounds by Gas chromatography-mass spectrometry showed that C. maritimum essential oils were dominated by monoterpenes hydrocarbons, oxygenated monoterpenes, and phenylpropanoids varying, respectively, from 33.3 to 66.9, from 7.8 to 46.6 and from 4.5 to 57.2 % according to organs and localities. Statistical analyses identified three different chemotypes depending on the geographic origin as follow: γ-Terpinene-Thymol methyl ether / Dillapiole / Thymol methyl ether-Dillapiole.

Bio-Guided Fractionation of Retama raetam (Forssk.) Webb & Berthel Polar Extracts.

The fractionation of the methanolic extract (MeOH-E) of Retama raetam (Forssk.) Webb & Berthel and further analysis by thin layer chromatography resulted in four fractions (F1, F2, F3 and F4) that, in parallel with the MeOH-E, were screened for antioxidant, cytotoxic, antidiabetic and antibacterial properties. In addition, chemical characterization of their bioactive molecules was performed using LC-DAD-ESI/MSn. The results indicated that F3 was the most promising regarding antioxidant and cytotoxicity abilities, possibly due to its richness in flavonoids class, particularly isoflavones. In turn, F1 was characterized by the presence of the most polar compounds from MeOH-E (organic acids and piscidic acid) and showed promising abilities to inhibit α-amylase, while F4, which contained prenylated flavonoids and furanoflavonoids, was the most active against the tested bacteria. The gathered results emphasize the distinct biological potentials of purified fractions of Retama raetam.

Variability of antioxidant and biological activities of Rhus tripartitum related to phenolic compounds.

Rhus species are known in traditional medicine for their therapeutic virtue and their extracts showed numerous important properties including antimalarial, antimicrobial, antiviral, and hypoglycemic and anticonvulsant activities. Rhus tripartitum (Ucria) is a medicinal plant widely used in Tunisia folk medicine against chronic diarrhea and gastric ulcer. This study was designed to examine in vitro and ex vivo antioxidant, anti-inflammatory and anticancer activities of four extracts of Rhus tripartitum root cortex with increasing solvent polarity (hexane, dichloromethane, methanol and water). HPLC was used to identify and quantify phenolic compounds in Rhus extract. Water extract showed the highest antioxidant activity using oxygen radical absorbance capacity (ORAC method) with 8.95 ± 0.47 µmol Trolox/mg and a cell based-assay with 0.28 ± 0.12 µmol Trolox/mg as compared to the other fractions. Moreover, methanol extract displayed the strongest anti-cancer activity against human lung carcinoma (A-549) and colon adenocarcinoma cell lines (DLD-1) with an IC50 value of 60.69 ± 2.58 and 39.83 ± 4.56 µg/ml (resazurin test) and 44.52 ± 5.96 and 55.65 ± 6.00 µg/ml (hoechst test), respectively. Besides, the highest anti-inflammatory activity, inhibiting nitric oxide (NO) release, was exhibited by dichloromethane extract with 31.5 % at 160 µg/ml in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. The HPLC analysis showed that catechol and kaempferol were the major phenolics. These data suggest the richness of all fractions of Ucria root on interesting bioactive molecules with different polarity and confirm the known traditional therapeutics virtues of this species for the treatment of dysentery, diarrhea and gastric ulcer.

Variability of antioxidant and antibacterial effects of essential oils and acetonic extracts of two edible halophytes: Crithmum maritimum L. and Inula crithmoїdes L.

This work aimed to assess the richness of the food halophytes Crithmum maritimum and Inula crithmoїdes on phenolics and essential oils (EOs) and to evaluate the antioxidant and antibacterial potential of these metabolites. Results displayed that extract of I. crithmoїdes possesses considerable contents of phenolic compounds (14.1mg GAE.g⁻¹ DW) related to important antioxidant activities (IC50 = 13 µg ml⁻¹ for the DPPH test) as compared to C. maritimum. C. maritimum EOs composition is dominated by oxygenated monoterpenes, while I. crithmoїdes one is mainly consisted by monoterpene hydrocarbons. EOs have low antioxidant activity as compared to acetone extracts; nevertheless, they show best antimicrobial activity. A significant variability is also depicted between the provenances of each species and depended on the chemical nature of antioxidant and antibacterial molecules as well as the used tests.

Medicinal halophytes: potent source of health promoting biomolecules with medical, nutraceutical and food applications.

Salt-tolerant plants grow in a wide variety of saline habitats, from coastal regions, salt marshes and mudflats to inland deserts, salt flats and steppes. Halophytes living in these extreme environments have to deal with frequent changes in salinity level. This can be done by developing adaptive responses including the synthesis of several bioactive molecules. Consequently, several salt marsh plants have traditionally been used for medical, nutritional, and even artisanal purposes. Currently, an increasing interest is granted to these species because of their high content in bioactive compounds (primary and secondary metabolites) such as polyunsaturated fatty acids, carotenoids, vitamins, sterols, essential oils (terpenes), polysaccharides, glycosides, and phenolic compounds. These bioactive substances display potent antioxidant, antimicrobial, anti-inflammatory, and anti-tumoral activities, and therefore represent key-compounds in preventing various diseases (e.g. cancer, chronic inflammation, atherosclerosis and cardiovascular disorder) and ageing processes. The ongoing research will lead to the utilisation of halophytes as a new source of healthy products as functional foods, nutraceuticals or active principles in several industries. This contribution focuses on the ethnopharmacological uses of halophytes in traditional medicine and reviews recent investigations on their biological activities and nutraceuticals. The work is distributed according to the different families of nutraceuticals (lipids, vitamins, proteins, glycosides, phenolic compounds, etc.) discussing the analytical techniques employed for their determination. Information about the claimed health promoting effects of the different families of nutraceuticals is also provided together with data on their application.