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Cucurbitaceae are one of most widely used plant species for human food but lesser known members have not been examined for bioactive components. The purpose of this study was to evaluate the antioxidant and genoprotective activities from three cucurbitaceae seeds extracts and to identify phenolic components by LC-ESIMS/MS analysis. From the results, the yield of seeds extract was 20-41% (w/w) and samples had 16-40% total phenols as gallic acid equivalents (GAE). Compared with methanol solvent, using acidified methanol led to increased extraction yield by 1.4 to 10-fold, higher phenolic content (149.5 ± 1.2 to 396.4 ± 1.9 mg GAE/g), higher DPPH radical quenching and enhanced genoprotective activity using the pBR322 plasmid assay. LC-ESI-MS/MS analysis led to identification of 14-17 components, based on authentic standards and comparison with literature reports, as mainly phenolic acids and esters, flavonol glycosides. This may be the first mass spectrometric profiling of polyphenol components from cucurbitaceae seeds., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

The present work explores antimutagenic and antioxidant potential as well as total phenolics of aqueous and acidified methanol extractable components from clove (Syzygium aromaticum L.) seed. The magnitude of antimutagenic activity of clove seed extracts (CSE) against two mutant bacterial strains: S. typhimurium TA98 and S. typhimurium TA100 (Ames bacterial test) ranged from 34.11-79.74%. Antioxidant activity in terms of measurement of DPPH radical scavenging capacity and inhibition of linoleic acid peroxidation was noted to be 71.16-94.58% and 54.96-86.89%, respectively. CSE also exhibited an appreciable amount of total phenolics with contribution between 22.80 and 115.33 GAE mg/100g. A strong correlation between total phenolics and tested biological activities were recorded. The results of this study advocate that clove seed can be explored as a viable source of bioactives for the development of chemotherapeutic drugs against cancer in addition to acting as nutraceutical and functional food ingredient.

Theeffects of four extracting solvents [absolute ethanol, absolute methanol, aqueous ethanol (ethanol: water, 80:20 v/v) and aqueous methanol (methanol: water, 80:20 v/v)] and two extraction techniques (shaking and reflux) on the antioxidant activity of extracts of barks of Azadirachta indica, Acacia nilotica, Eugenia jambolana, Terminalia arjuna, leaves and roots of Moringa oleifera, fruit of Ficus religiosa,and leaves of Aloe barbadensis were investigated. The tested plant materials contained appreciable amounts of total phenolic contents (0.31-16.5 g GAE /100g DW), total flavonoid (2.63-8.66 g CE/100g DW); reducing power at 10 mg/mL extract concentration (1.36-2.91), DPPH(.) scavenging capacity (37.2-86.6%), and percent inhibition of linoleic acid (66.0-90.6%). Generally higher extract yields, phenolic contents and plant material antioxidant activity were obtained using aqueous organic solvents, as compared to the respective absolute organic solvents. Although higher extract yields were obtained by the refluxing extraction technique, in general higher amounts of total phenolic contents and better antioxidant activity were found in the extracts prepared using a shaker.

Medicinal plants namely P. guajava, F. benghalensis, C. paradisi, G. radicans, F. religiosa, V. vinifera, P. granatum, M. alba and Z. jujuba leaves were assessed for their total phenolics (TP), total flavonoids (TF) and antioxidant potential. The selected plant leaves were extracted in 80% methanol. The TP and TF contents found to be in the range of 24.0 to 47.6 mg GAE/g DW and 14.9-114.9 mg CE/g DW, respectively. Major phenolics, i.e. gallic acid, chlorogenic acid, caffeic acid, p-coumaric acid, m-coumaric acid, 4-hydroxy,3-methoxy benzoic acid, ferulic acid, syringic acid and vanillic acid were detected by reverse phase high-performance liquid chromatography (RP-HPLC). Among all plant leaves, P. granatum exhibited maximum amount of phenolic acids followed by M. alba. The DPPH radical scavenging activity was 29.11-83.20%, whereas reducing potential of 2.5 to 10 mg/ml was recorded to be 0.47-1.41. A positive relationship between total phenolics, total flavonoids and antioxidant capacity was found in selected medicinal plant leaves and results revealed that plant under investigation could be potential source of natural antioxidants. [ABSTRACT FROM AUTHOR]

This work explores underutilized Lemon (Citrus limon) and Galgal (Citrus pseudolimon) residues for their phenolic contents and in-vitro antioxidant activities. Methanolic extracts from different parts of these two Citrus species were tested for total phenolic contents (TPC), total flavonoid contents (TFC), DPPH radical scavenging activity, % inhibition of linoleic acid peroxidation and reducing power by using respective in-vitro antioxidant model assays. The percentage yield of extracts, total phenolic and flavonoid contents among parts tested varied from 6.13 - 24.20 g/100g, 98.20 - 199.18 (mg gallic acid equivalent/g of extract) and 19.95 - 39.60 (mg catechin equivalent/g of extract), respectively. Percent inhibition of linoleic acid peroxidation and DPPH radical scavenging capacity for the tested extracts ranged between 31- 60 and 40-62%, respectively. The overall order of antioxidant potential among parts of Citrus species was established to be: C. pseudolimon leave > C. limon leave > C. pseudolimon peel > C. limon peel > C. pseudolimon seed ≈ C. limon seed. It could be concluded that extracts of Citrus fruit residues, especially, leaves can be explored as an economically viable source of natural antioxidants and nutraceuticals. [ABSTRACT FROM AUTHOR]