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Aim: The aqueous methanolic extracts of two plants from Algeria, Helichrysum stoechas subsp. rupestre and Phagnalon saxatile subsp. saxatile, were investigated for their antioxidant activity., Method: Total phenolics, flavonoids, and tannins were determined by spectrophotometric techniques. In vitro antioxidant and radical scavenging profiling was determined by spectrophotometric methods, through: Total antioxidant capacity, and radical scavenging effects by the DPPH and ABTS methods, reducing and chelating power, and blanching inhibition of the β-carotene., Results: All of the extracts showed interesting antioxidant and radical scavenging activity. The highest contents in phenolics, tannins, and the highest total antioxidant capacity as gallic acid equivalents of 97.5 ± 0.33 mg GAE/g DW was obtained for the flowers of H. stoechas subsp. rupestre extract in the phosphomolybdenum assay. An extract of the leafy stems of P. saxatile subsp. saxatile revealed the highest content of flavonoids, and the highest antioxidant activity by the radical scavenging and β-carotene assays when compared with standards. The best activity was by the scavenging radical DPPH with an IC50 value of 5.65 ± 0.10 μg·mL(-1)., Conclusion: The studied medicinal plants could provide scientific evidence for some traditional uses in the treatment of diseases related to the production of reactive oxygen species (ROS) and oxidative stress., (Copyright © 2014 China Pharmaceutical University. Published by Elsevier B.V. All rights reserved.)

In this work, liquid chromatography coupled to electrospray time-of-flight mass spectrometry (LC-ESI-TOF-MS) has been applied to screen bioactive metabolites in shoot extract of the medicinal halophyte Zygophyllum album. Among 10 compounds identified (saponins, flavonoids and sterols) five were reported for the first time in Z. album. Furthermore, novel biological activities of hexane, dichloromethane and methanolic extracts were assessed. Results showed that methanolic extract exhibit the highest antioxidant activity using in vitro ORAC test and anti-inflammatory activity, inhibiting by 84.8% NO release in RAW264.7 macrophages. However, dichloromethane extract proved the utmost antioxidant activity in cell (WS1) based-assay (IC50=57 μg/ml) and interesting anticancer capacity against human lung carcinoma (A-549) and colon adenocarcinoma (DLD-1) cells (IC50=37 and 48 μg/ml, respectively). These findings can be attributed to the presence of triterpenes, flavonoids and sterols in Z. album, which are widely known as powerful antioxidants and used in various industrial fields., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Although the genus Limonium was widely used in traditional medicine, few studies have focused on the biological capacities of different species of this group. In this study, biological activities of hexanic, dichloromethane, ethanolic, and methanolic extracts, related to their phenolic contents, and HPLC phytochemical analysis of the halophyte Limonium densiflorum were investigated on human cell lines and murine macrophages. The evaluation of the antioxidant capacities using oxygen radical absorbance capacity (ORAC method), superoxide anion scavenging activity and a cell based-assay (WS-1), showed that shoot methanol extract exhibited the highest antioxidant activity. Moreover, this extract demonstrated the best anti-inflammatory activity, inhibiting NO release by 80% at 160 μg/ml in LPS-stimulated RAW 264.7. The dichloromethane extract displayed the highest anticancer activity against human lung carcinoma (A-549) and colon adenocarcinoma cell lines (DLD-1) with IC 50 values of 29 and 85 μg/mL, respectively. The estimation of phenolic content showed that methanolic and ethanolic extracts had the highest amounts (56.1 and 48.1 mg EGA/g DW, respectively). The identification of phenolic compounds in methanolic extract of the plant, using RP-HPLC, revealed that trans 3-hydroxycinnamic acid, myricetin and isorhamnetin were the major molecules present which may be responsible for the biological activities of the species. Results obtained indicated that L. densiflorum extracts can be used potentially as a readily accessible and valuable bioactive source of natural products. [ABSTRACT FROM AUTHOR]

Abstract: Mesembryanthemum edule L. (sourfig, Aizoaceae) has long been used as food and in traditional medicine. This study was intended to characterize the antioxidant properties and the phenolic compounds of M. edule leaf, stem and root. The approach consisted to evaluate these organs for their antioxidant activities through several in vitro tests, to determine tissue contents in total phenolics, flavonoids and proanthocyanidins and to establish the phenolic composition through RP-HPLC analysis. All studied organs showed a high antioxidant activity as compared to positive control BHT, with maximal efficiency for stems followed by leaves and roots. The highest polyphenolic levels were found in stems and leaves (86.5 and 68.7mg GAE g−1 DW, respectively), suggesting that their strong antioxidant activity could be attributed to these phytochemicals. The HPLC analysis revealed that the main phenolic compounds were quercitrin and avicularin (1.4 and 1.15mgg−1 DW, respectively) in the leaves, while catechin and procyanidin B2 (1.66 and 1.54mgg−1 DW, respectively) were the most abundant phenolics in the stems. Overall, the strong antioxidant activity and richness of M. edule aerial tissues suggest that it could be advantageously used as a functional or nutraceutical food, to prevent or moderate oxidative stress-related diseases. [Copyright &y& Elsevier]

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]