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Highlights: [•] Isolation of new dimer and two natural monomers of phenolic acid amides from Limoniastrum guyonianum. [•] Determination of their structures structure and stereochemistry were determined by NMR. [•] Estimation of the antioxidant activities of these molecules. [ABSTRACT FROM AUTHOR]

Highlights: [•] Fractionation of the ethyl acetate partition of Limoniastrum guyonianum by CPC. [•] Assessment of phenolic contents of the 10 fractions. [•] Investigation of the antioxidant activities of Limoniastrum fractions. [•] Exploration of the anti-amyloidogenic and the antibacterial capacities of fractions. [•] Determination of phenolic composition by HPLC of the most active fractions. [ABSTRACT FROM AUTHOR]

Abstract: The antioxidant capacities of the crude extract, aqueous and ethyl acetate partitions of Limoniastrum guyonianum Boiss. (Zita) were investigated in this study. The ethyl acetate phase exhibited a significant antioxidant activity as judged by total antioxidant activity, DPPH test and reducing power. Fractionation of this extract by centrifugal partition chromatography (CPC) using quaternary Arizona solvent systems composed of n-heptane/ethyl acetate/methanol/water led to ten fractions. The antioxidant capacities of these fractions were assessed using the same previous tests. Fraction 8 showed the highest antioxidant capacity (1291.1mg GAE/g DR), the power ability to quench DPPH radical (IC50 =2μg/ml) and to reduce Fe3+ (EC50 =65μg/ml). From this fraction, three powerful flavonoids were isolated (1–3): gallocatechin (1), epigallocatechin (2) and epigallocatechin-3-O-gallate (3). These findings suggest that the antioxidative property of L. guynianum is may be related to the presence of these flavonoids, which can be used in various industrial fields. [Copyright &y& Elsevier]

Abstract: Suaeda fruticosa is an edible and medicinal halophyte known for its hypoglycaemic and hypolipidaemic activities. In this study, novel biological activities of the shoot extracts related to their phenolics were investigated. Results showed an appreciable total phenolic (31.8mgGAE/gDW) in shoot extracts. The estimation of antioxidant capacities using oxygen radical absorbance capacity (ORAC method) and a cell based-assay (WS1) of four extracts (hexane, dichloromethane, methanol and water) showed that shoot methanol extract exhibit the highest antioxidant activities. The same extract displayed the utmost anti-inflammatory activity, inhibiting nitric oxide (NO) release, by 66.4% at 160μg/ml in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. Besides, the dichloromethane extract showed the highest anticancer activity against human lung carcinoma (A-549) and colon adenocarcinoma cell lines (DLD-1, Caco-2 and HT-29) with specificity against DLD-1 (IC50 =10±1μg/ml). These findings demonstrate the remarkable potentiality of this edible halophyte as valuable source of antioxidants which exhibit original and interesting anti-inflammatory and anticancer capacities. [Copyright &y& Elsevier]

Abstract: Antioxidants are the chemical substances that reduce or prevent oxidation. The present study aimed to assess in vitro and ex vivo antioxidant activities of four acetonic extracts Tunisian halophytes (Suaeda fruticosa, Suaeda pruinosa, Suaeda mollis and Suaeda maritima). Various experimental models were used for characterization of antioxidant activities of shoot extracts. Eventually, the promising specie was subjected to phenolic identification using RP-HPLC. The analyzed shoot extracts exhibited that antioxidant activities varied considerably as function of species. The highest DPPHng ability was found in S. mollis with the lowest IC50 value (2.5μg/ml), followed by S. pruinosa, S. fruticosa and S. maritima. The same tendency was observed with ferric reducing power. Concerning β-carotene bleaching assays and total antioxidant activity, results showed that S. fruticosa exhibited the highest antioxidant ability against the inhibition of β-carotene bleaching, and a better total antioxidant capacity. Moreover antioxidant capacities using ORAC method and a cell based-assay showed that S. mollis, S. fruticosa, and S. pruinosa exhibit statistically similar antioxidant activity. The identification of phenolic compounds in S. mollis extract using RP-HPLC revealed that 2,5-dihydroxybenzoic acid and rutin hydrate were the major molecules. These results suggested that Suaeda species showed a variability of their antioxidant activities. [Copyright &y& Elsevier]

Abstract: Mesembryanthemum edule is used as a food ingredient and in traditional medicine. In this study, we investigated antioxidant activities of several extracts (methanol/acidified water, v/v: 20/80; 40/60 and 60/40) obtained from M. edule leaf, stem and root. Then, individual phenolics were characterised by reverse-phase HPLC coupled to electrospray ionisation mass spectrometry and multi-stage MS fragment analysis. Results showed that 40% methanol leaf extract, 40% methanol root extract and 20% methanol stem extract displayed the highest scavenging activity against DPPH and ABTS radicals. Regarding LC/ESI-MS/MS identification of active phenols, there were significant differences among the fractions of interest. In fact, 40% leaf extract mainly contained procyanidins, whereas propelargonidins were the major phenolics in 20% methanol stem extract, while, in 40% root extract, the active compounds remained unidentified. These results indicate that edible M. edule can be used as a nutraceutical in the pharmaceutical industry. [Copyright &y& Elsevier]

• Seed priming improved germination performance and seedling establishment under salt stress conditions. • Seed-priming conferred to cauliflower plants to better decipher subsequent salt stress. • H 2 O 2 as a pre-germination stimulus, helped cauliflower plants to prevent itself from subsequent oxidative injuries and so that better memory of subsequent salt stress. In the present study, we examined the impact of three seed priming agents; H 2 O 2 , GA 3 and NaCl on the oxidative stress status in primed seed germination dynamics and growth establishment of cauliflower seedlings subsequently grown under salt stress. Results showed beneficial effect of all priming agents in improving plant responses to salinity. However, specific differences, depending on development stage, organ and priming type were recorded. At the germination stage, GA 3 was the most advantageous agent to accelerate seedling emergence. At the seedling stage, seedlings obtained from redried H 2 O 2 -primed seeds showed the highest level of seed superoxide anion (5-fold) and H 2 O 2 (4-fold), resulting in higher MDA content (2.4-fold). At the same time, priming seeds with H 2 O 2 triggered the overall seedling antioxidant defense, including enzymatic (SOD, CAT, GPX and APX) and non-enzymatic systems (AsA, GSH and proline). Salinity restricted the growth of both leaves (43%) and roots (60%) of cauliflower seedlings issued from unprimed seeds. Under primed conditions, the relative contribution of GA 3 and NaCl was more associated with growth establishment and osmotic adjustment. However, H 2 O 2 role was greatly correlated with the antioxidant defense. Indeed, salt-treated seedlings issued from H 2 O 2 -primed seeds showed the lowest levels of superoxide anion, H 2 O 2 and MDA, resulting in the highest activities of the entire antioxidant systems. These findings support the hypothesis that cauliflower plants, when exposed to salt stress benefit from H 2 O 2 seed priming, as a pre-germination stimulus, to prevent itself from subsequent oxidative injuries, which supports the hypothesis of "stress memory" of subsequent salt stress. [ABSTRACT FROM AUTHOR]

Abstract: Diplotaxis species are edible and medicinal plants. This study investigates phenolic contents and biological activities in stems, leaves, and flowers of Diplotaxis harra and Diplotaxis simplex. Flowers exhibited the highest polyphenol content and D. harra was significantly more phenol-rich than D. simplex. Similarly, the highest antioxidant activities were found in D. harra flowers. Fractionation of D. harra extract revealed that 60% MeOH fraction showed the best antioxidant activities. Indeed, flower fractions were assayed for their activity against human pathogenic bacteria and the inhibitory percentages reached 100%. As regards fraction polarity, 60% and 80% MeOH fractions were the most active ones. Moreover, HPLC analysis showed that the main phenolic compound was cafeic acid for the two species, whereas p-Coumaric and 3,4-dimethoxybenzoic acids were identified only in D. simplex and sinapic acid was exclusive to D. harra. Overall, our findings indicate that Diplotaxis flowers could be used as a potent source of natural antioxidants and antibiotics. [Copyright &y& Elsevier]