Physiological responses of native Tunisian grapevines and some rootstocks to direct iron deficiency

Research Not

Phytochemical composition and antioxidant activity of Lavandula dentate extracts

Le but de ce travail consiste à étudier la composition des huiles essentielles et des polyphénols des racines, des tiges et des feuilles de la Lavande dentée et d’évaluer leurs potentialités antioxydantes. L’analyse et la quantification des huiles essentielles a montré que les feuilles sont les plus riches en huiles essentielles (0.89 mg/g MS) suivies par les tiges (0.68 mg/g MS) et enfin les racines (0,23 mg/g MS). Le constituant majeur de l’HE des racines est: le β-ocimène. D’autre part, le limonène représente le composé majeur de l’HE des tiges. Quant à l’HE des feuilles, elle est dominée par le camphre. D’autre part, nos résultats ont montré que les organes de la lavande montrent des teneurs en polyphénols totaux élevées et variables selon l’organe étudié. En effet, les extraits des racines sont caractérisés par le contenu le plus élevé en polyphénols. D’autre part, l’étude de l’activité antioxydante des extraits des différents organes a indiqué que les extraits de la racine sont particulièrement les plus actifs et que leur analyse par RP-HPLC a montré que ces derniers sont riches essentiellement en acide rosmarinique. Finalement, les extraits de la Lavande dentée et particulièrement ceux de la racine peuvent être considérés comme des sources alternatives d’antioxydants naturels puissants qui peuvent être utilisés en industrie agroalimentaire et pharmaceutique.In this study, Lavandula dentata organs (roots, stems and leaves) were investigated for their essential oils, total phenolics, flavonoids contents and antioxidant activities. Essential oil yields were 0.22% in roots, 0.68 % in stems and 0.89 % in flowers. Major components of the oils were β-ocimene, limonene and 1,8 cineol in roots, stems and leaves and flowers, respectively. In all organs, total phenolics content ranged from 42.57 to 16.17 mg gallic acid equivalents per gram of dry weight (mg GAE/g DW).The antioxidant activities of Lavandula dentata extracts obtained from the three organs were assessed using two tests (DPPH and reducing power). The root extract was strongly effective as DPPH radical scavenger and reducing agent. Thus, the identification of individual target polyphenolic compounds of roots was performed by RP-HPLC. The major phenolic compound detected in roots was rosmarinic acid. This activity was high enough for the plant to be a new and natural source of strongly antioxidant substances for use as natural additives in food and pharmaceutical industry

Health promoting potential of herbal teas and tinctures from Artemisia campestris subsp maritima: from traditional remedies to prospective products

This work explored the biotechnological potential of the medicinal halophyte Artemisia campestris subsp. maritima (dune wormwood) as a source of health promoting commodities. For that purpose, infusions, decoctions and tinctures were prepared from roots and aerial-organs and evaluated for in vitro antioxidant, anti-diabetic and tyrosinase-inhibitory potential, and also for polyphenolic and mineral contents and toxicity. The dune wormwood extracts had high polyphenolic content and several phenolics were identified by ultra-high performance liquid chromatography-photodiode array-mass-spectrometry (UHPLC-PDA-MS). The main compounds were quinic, chlorogenic and caffeic acids, coumarin sulfates and dicaffeoylquinic acids; several of the identified phytoconstituents are here firstly reported in this A. campestris subspecies. Results obtained with this plant's extracts point to nutritional applications as mineral supplementary source, safe for human consumption, as suggested by the moderate to low toxicity of the extracts towards mammalian cell lines. The dune wormwood extracts had in general high antioxidant activity and also the capacity to inhibit a-glucosidase and tyrosinase. In summary, dune wormwood extracts are a significant source of polyphenolic and mineral constituents, antioxidants and a-glucosidase and tyrosinase inhibitors, and thus, relevant for different commercial segments like the pharmaceutical, cosmetic and/or food industries.FCT - Foundation for Science and Technology [CCMAR/Multi/04326/2013]; Portuguese National Budget; FCT [IF/00049/2012, SFRH/BD/94407/2013]; Research Foundation - Flanders (FWO) [12M8315N]info:eu-repo/semantics/publishedVersio

LC-MS PHENOLIC COMPOSITION CHANGES AND ANTIOXIDANT CAPACITIES OF THE SAHARAN TREE ARGANIA SPINOSA LEAVES UNDER SALNITY

Adaptation of many plant species to hostile environmental conditions suggest the presence of powerful antioxidative constituents in their tissues such as phenolic compounds. Many works on antioxidant activity of the Moroccan argan oil have been carried out. However, it is the first time that salt impact on Algerian arganleaves is assessed. The main objective of this work was to study the soil salinity impact on phenolic content and composition, and the antioxidant activities of the argan leaves collected from three point in the same site of Tindouf region (Algeria) characterized by a gradient of salt concentration (Lightly Salt Tindouf, Salt Tindouf and Very Salt Tindouf). Variability of phenolic contents, antioxidant and free radical-scavenging activities of the argan leaves as function of salt soil concentration were evaluated. Identification was done by LC-MS system. Regarding phenolic contents (total polyphenol, flavonoid and condensed tannin), the Salt Tindouf leaves displayed the highest amounts (total polyphenol = 77.28 mg GAE/g DW). Moreover, the same tendency was observed for antioxidant activities, for instance, total antioxidant activity of leaves from Salt Tindouf was the highest (83.6 mg GAE/g DW). In addition, leaves from Salt Tindouf displayed the highest scavenging activity against DPPH radical (IC50 = 6.5 μg/ml) as compared to the two others points. These results were also confirmed by LC-MS analyses. Leaves synthesize more compounds with very important biological activities under salinity which allow them to be valorized in different fields, such as pharmacology and agro-food industries

Profiling of antioxidant potential and phytoconstituents of Plantago coronopus

The halophyte species Plantago coronopus has several described ethnomedicinal uses, but few reported biological activities. This work carried out for the first time a comparative analysis of P. coronopus organs in terms of phenolic composition and antioxidant activity of organic and water extracts from roots, leaves and flowers. The leaves contents in selected nutrients, namely amino acids and minerals, are also described. Roots (ethyl acetate and methanol extracts) had the highest radical scavenging activity (RSA) towards 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radicals, while leaves (hexane extract) had higher RSA on nitric oxide radical and iron chelating ability. High performance liquid chromatography (HPLC) analysis identified eighteen phenolics from which salicylic acid and epicatechin are here firstly described in Plantago species. Leaves had mineral levels similar to those of most vegetables, proving to be a good source for elements like calcium, sodium, iron and magnesium, and also for several of the essential amino acids justifying it use as food. Our results, especially those regarding the phenolics composition, can explain the main traditional uses given to this plantain and, altogether, emphasize the potential of P. coronopus as a source of bioactive molecules particularly useful for the prevention of oxidative stress-related diseases