In this study, the antioxidant activity of methanol extracts of five plants from the genus Phyllanthus was evaluated by various antioxidant assays, including total antioxidant, free radical scavenging, superoxide anion radical scavenging, hydrogen peroxide scavenging, nitric oxide scavenging, reducing power and metal ion chelating activities. The various antioxidant activities were compared to standard antioxidants such as butylated hydroxytoluene and ascorbic acid. All the extracts showed strong antioxidant activity in all the tested methods. Among the five plants Phyllanthus debilis has been found to possess the highest activity in all tested models, the activity decreased in the order Phyllanthus debilis>Phyllanthus urinaria>Phyllanthus virgatus>Phyllanthus maderaspatensis>Phyllanthus amarus. In addition to the antioxidant activity of these plants, the total phenolic compounds, flavonoids and flavonols were measured in the extracts. A correlation between the antioxidant activity and total phenolic content was observed.

In vitro antioxidant activities of methanol extracts of five Phyllanthus species from India

The objective of this study was to investigate how 6 commonly used solvent systems affected the yields of phenolic substances and the antioxidant capacity of extracts from 8 major classes of food legumes. Several antioxidant-related phytochemical compositions, namely, total phenolic content (TPC), total flavonoids content (TFC), and condensed tannins content (CTC), were investigated. In addition, antioxidant activities were tested using 2,2-diphenyl-1-picryhydrazyl (DPPH) free radical scavenging, ferric-reducing antioxidant power (FRAP), and the oxygen radical absorbance capacity (ORAC). The results showed that the 50% acetone extracts exhibited the highest TPC for yellow pea, green pea, chickpea, and yellow soybean. Acidic 70% acetone (+0.5% acetic acid) extracts exhibited the highest TPC, TFC, and FRAP values for black bean, lentil, black soybean, and red kidney bean. The 80% acetone extracts exhibited the highest TFC, CTC, and DPPH-free radical scavenging activity for yellow pea, green pea, chickpea, and yellow soybean. The 70% ethanol extracts exhibited the greatest ORAC value for all selected legumes. These results indicated that solvents with different polarity had significant effects on total phenolic contents, extracted components, and antioxidant activities. High correlations between phenolic compositions and antioxidant activities of legume extracts were observed. The information is of interest to the nutraceutical food/ingredient industries since legumes are a rich source of antioxidants.

A Comparative Study on Phenolic Profiles and Antioxidant Activities of Legumes as Affected by Extraction Solvents

Whole grain phytochemicals and health

Epidemiological studies have clearly shown that whole-grain cereals can protect against obesity, diabetes, CVD and cancers. The specific effects of food structure (increased satiety, reduced transit time and glycaemic response), fibre (improved faecal bulking and satiety, viscosity and SCFA production, and/or reduced glycaemic response) and Mg (better glycaemic homeostasis through increased insulin secretion), together with the antioxidant and anti-carcinogenic properties of numerous bioactive compounds, especially those in the bran and germ (minerals, trace elements, vitamins, carotenoids, polyphenols and alkylresorcinols), are today well-recognised mechanisms in this protection. Recent findings, the exhaustive listing of bioactive compounds found in whole-grain wheat, their content in whole-grain, bran and germ fractions and their estimated bioavailability, have led to new hypotheses. The involvement of polyphenols in cell signalling and gene regulation, and of sulfur compounds, lignin and phytic acid should be considered in antioxidant protection. Whole-grain wheat is also a rich source of methyl donors and lipotropes (methionine, betaine, choline, inositol and folates) that may be involved in cardiovascular and/or hepatic protection, lipid metabolism and DNA methylation. Potential protective effects of bound phenolic acids within the colon, of the B-complex vitamins on the nervous system and mental health, of oligosaccharides as prebiotics, of compounds associated with skeleton health, and of other compounds such as alpha-linolenic acid, policosanol, melatonin, phytosterols and para-aminobenzoic acid also deserve to be studied in more depth. Finally, benefits of nutrigenomics to study complex physiological effects of the 'whole-grain package', and the most promising ways for improving the nutritional quality of cereal products are discussed.

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New hypotheses for the health-protective mechanisms of whole-grain cereals: what is beyond fibre?

Three hard winter wheat varieties (Akron, Trego, and Platte) were examined and compared for their free radical scavenging properties and total phenolic contents (TPC) Free radical scavenging properties of wheat grain extracts were evaluated by spectrophotometric and electron spin resonance (ESR) spectrometry methods against stable 2,2-diphenyl-1-picryhydrazyl radical (DPPH*) and radical cation ABTS*+ (2,2'-azino-di[3-ethylbenzthiazoline sulfonate]) The results showed that the three wheat extracts differed in their capacities to quench or inhibit DPPH* and ABTS*+ Akron showed the greatest activity to quench DPPH radicals, while Platte had the highest capacity against ABTS*+ The ED50 values of wheat extracts against DPPH radicals were 060 mg/mL for Akron, 71 mg/mL for Trego, and 095 mg/mL for Platte under the experimental conditions The trolox equivalents against ABTS*+ were 131 +/- 044, 108 +/- 005, and 191 +/- 006 micromol/g of grain for Akron, Trego, and Platte wheat, respectively ESR results confirmed that wheat extracts directly reacted with and quenched free radicals The TPC were 4879 +/- 9278 microg gallic acid equivalents/g of grain No correlation was observed between TPC and radical scavenging capacities for DPPH* and ABTS*+ (p = 015 and p > 05, respectively)

Free radical scavenging properties of wheat extracts.

The effects of growing conditions during the grain-filling period, including high temperature stress, total solar radiation, and average daily solar radiation, on the antioxidant properties of Trego wheat were evaluated. Bran extracts were prepared from Trego wheat, grown at four nonirrigated and one irrigated location in Colorado, and compared for their radical scavenging activities against ABTS*+ and DPPH*, Fe(2+) chelating capacities, and total phenolic contents. Significant differences in radical scavenging activities, chelating capacities, and total phenolic contents were detected among Trego bran samples grown at different locations, suggesting that growing conditions may influence the antioxidant properties of wheat. The bran sample obtained from Fort Collins had the strongest scavenging activity against either ABTS*+ or DPPH* radicals and the greatest chelating activity, whereas the highest total phenolic content was detected in bran samples from Walsh, indicating that each antioxidant activity may respond to the environmental changes differently. Positive correlations were detected between the DPPH* scavenging activity and either total solar radiation (r = 0.97, p = 0.03) or average daily solar radiation (r = 0.97, p = 0.03). In addition, HPLC analysis detected the presence of ferulic, syringic, vanillic, p-hydroxybenzoic, and coumaric acids in wheat bran. Additional research is needed to further investigate the effects of environmental conditions and the interactions between genotype and environmental factors on the antioxidant properties of wheat to promote the production of wheat with improved antioxidant properties by optimizing the growing conditions for a selected genotype.

Antioxidant properties of bran extracts from Trego wheat grown at different locations.

Water-soluble rosemary extracts were evaluated for their inhibitory effects on lipid oxidation and color change in cooked turkey products during storage. Changes were measured in thiobarbituric acid-reactive substances, hexanal production and color of the cooked turkey samples containing 0, 100, 250 and 500 ppm water-soluble resemary extracts, at storage day 0, 1, 2, 3, 5, 7, 10, and 13. The rosemary extracts showed significant protection of lipid oxidation and color change in cooked turkey. Higher levels of water-soluble rosemary extracts were more effective in delaying quality loss in cooked turkey at all tested storage times. Cette etude evalue le potentiel d'extraits de romarin hydrosolubles sur la stabilite et la qualite de produits a base de viande de dinde. Des echantillons de viandes de dinde contenant 0, 100, 250 et 500 ppm d'extraits de romarin sont entreposes pendant 0, 1, 2, 3, 5, 7, 10 et 13 jours a 4°C. Les resultats montrent que ces extraits inhibent l'oxydation lipidique et le changement de couleur dans la viande de dinde, et donc ameliorent la qualite et augmentent la duree de conservation du produit.

Rosemary Extracts as Inhibitors of Lipid Oxidation and Color Change in Cooked Turkey Products During Refrigerated Storage


Four commercial cereal products were examined and compared for their free radical scavenging properties, chelating capacity, and total phenolic contents. The Quaker Oat Bran™ ready-to-eat cold cereal showed the greatest activity to quench DPPH radicals, while the Quaker oatmeal had the highest capacity against ABTS+. Significant Fe2+ chelating activity was also detected in these cereal products with EDTA equivalents of 0.08 to 0.48 mg/g cereals. The total phenolic contents were 203 to 524 mg per gram of cereal products. These results indicate that readily available cereal products contain significant levels of antioxidants and may be an important source of dietary antioxidants.

Antioxidant Properties of Cereal Products

A dietary copper (Cu) deficiency is associated with a twofold increase in hepatic fatty acid biosynthesis. We hypothesized that the induction of hepatic lipogenesis associated with a dietary Cu deficiency reflected an enhanced expression of genes encoding lipogenic enzymes, i.e., fatty acid synthase (FAS). Male weanling rats were pair-meal fed for 42 days a high-sucrose diet that was Cu deficient (CuD; 0.7 microgram Cu/g) or Cu adequate (CuA; 5.0 micrograms Cu/g). The CuD diet increased FAS enzymatic activity twofold (P < 0.05). This rise in enzymatic activity was accompanied by a threefold increase in FAS mRNA and a 2.5-fold increase in FAS gene transcription (P < 0.05). Neither the mRNA abundance nor the rate of gene transcription for phosphoenolpyruvate carboxykinase or beta-actin was affected by the CuD diet. The induction of FAS gene transcription was associated with a 65-85% increase in hepatic reduced glutathione (GSH; P < 0.05). When hepatic GSH synthesis was suppressed by treating CuD rats with L-buthionine sulfoximine, the induction of FAS expression was completely prevented. Similarly, feeding N-acetylcysteine to CuA rats increased hepatic GSH levels 2.5-fold, and this was accompanied by a significant induction in FAS expression. These data indicate that the increase in hepatic lipogenesis associated with a Cu deficiency reflects an induction in hepatic lipogenic gene transcription (i.e., FAS) and that the rate of gene transcription may be dependent on hepatic thiol redox.

J. Wilson

Papers

Free radical scavenging properties of wheat extracts.

Antioxidant properties of bran extracts from Trego wheat grown at different locations.

Rosemary Extracts as Inhibitors of Lipid Oxidation and Color Change in Cooked Turkey Products During Refrigerated Storage

Antioxidant Properties of Cereal Products

Hepatic fatty acid synthase gene transcription is induced by a dietary copper deficiency