Phenolic antioxidants in beans and their effects on inhibition of radical-induced DNA damage

Characteristics of flavonol glycosides in bean (Phaseolus vulgaris L.) seed coats

Seed coats of coloured dry beans contain biologically active compounds. Flavonol glycosides were identified from acetone extracts of seed coats of black beans, pinto beans, and red kidney beans and evaluated for antioxidant activity. High Performance Liquid Chromatography - Mass Spectrometry/Mass Spectrometry (HPLC-MS/MS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging capacity were used to measure flavonols and antioxidant capacity, respectively. The main flavonol glycosides in black beans were the 3-O-glycosides of kaempferol, quercetin and myricetin; pinto beans contained kaempferol 3-O-glycosides, while red kidney beans contained quercetin 3-O-glycoside and quercetin 3-O-rutinoside (rutin). A flavonol triglycoside was identified in dark red kidney bean. Despite differences in total flavonol content, extracts from Eclipse, (black bean) and Windbreaker (pinto bean) had the significantly higher antioxidant activities than other bean seed coats. Results suggest seed coats of Windbreaker and Eclipse may have potential as functional food ingredients, though benefits may not be simply due to flavonols.

Sonchus oleraceus Residue Improves Nutritive and Health-Promoting Value of Common Bean ( Phaseolus vulgaris L.): A Metabolic Study

This study was conducted to evaluate the use of the phenolic-rich Sonchus oleraceus residue as an environmentally safe approach to induce the nutritive and health-promoting values of common bean ( Phaseolus vulgaris L. cv. Bronco). S. oleraceus shoot residue, at rates of 150 and 300 g m^-2, has improved soil fertility via accumulation of soil macronutrients, organic matter, organic carbon, and total phenolics. The growth and yield of bean were significantly increased. Moreover, chemical composition of the treated seeds was significantly altered, whereas higher levels of total antioxidant capacity, proteins, carbohydrates, and most of the individual phenolic acids, flavonoids, vitamins, essential amino acids, and unsaturated fatty acids were recorded. Interestingly, a concentration dependent effect was also observed, for instance, a lower saturated-to-unsaturated fatty acid ratio was only observed in the case of the lower residue rate. These findings recommend the use of S. oleraceus in organic farming of bean to enhance the health benefits of the produced seeds.

Comparison of pinoresinol diglucoside production by Phomopsis sp. XP-8 in different media and the characterisation and product profiles of the cultivation in mung bean

BACKGROUND

Phomopsis sp. XP-8 is an endophytic fungus with the ability to produce pinoresinol diglucoside (PDG) in vitro and thus has potential application in biosynthesis of PDG independent of plants. In order to enhance the production of PDG, 18 different natural materials were tested in solid-state cultivation of Phomopsis sp. XP-8.

RESULTS

Most of the tested natural materials promoted the production of PDG. A supplement derived from mung beans produced the highest PDG yield and better fungal growth than the other materials. Also, pinoresinol monoglucoside, pinoresinol and other substrates (phenylalanine, p-coumaric acid, cinnamic acid, caffeic acid, and ferulic acid) were obtained after fermentation on mung beans. Furthermore, PDG production was much higher when mung beans were incorporated into solid state agar versus a liquid medium. The highest pinoresinol diglucoside production (72.1 mg kg(-1) in fresh culture) was obtained in 9 days using a solid state culture of Phomopsis sp. XP-8 on a mung bean grain medium containing 100 g kg(-1) glucose. Mung bean water-soluble polysaccharide was identified as a major promoter of PDG production by Phomopsis sp. XP-8.

CONCLUSION

Mung bean, especially its water-soluble polysaccharide fraction, was an efficient natural material to promote PDG production by Phomopsis sp. XP-8. © 2015 Society of Chemical Industry.

Prowashonupana barley dietary fibre reduces body fat and increases insulin sensitivity in Caenorhabditis elegans model

Prowashonupana barley (PWB) is high in β-glucan with moderate content of resistant starch. PWB reduced intestinal fat deposition (IFD) in wild type Caenorhabditis elegans (C. elegans, N2), and in sir-2.1 or daf-16 null mutants, and sustained a surrogate marker of lifespan, pharyngeal pumping rate (PPR), in N2, sir-2.1, daf-16, or daf-16/daf-2 mutants. Hyperglycaemia (2% glucose) reversed or reduced the PWB effect on IFD in N2 or daf-16/daf-2 mutants with a sustained PPR. mRNA expression of cpt-1, cpt-2, ckr-1, and gcy-8 were dose-dependently reduced in N2 or daf-16 mutants, elevated in daf-16/daf-2 mutants with reduction in cpt-1, and unchanged in sir-2.1 mutants. mRNA expressions were increased by hyperglycaemia in N2 or daf-16/daf-2 mutants, while reduced in sir-2.1 or daf-16 mutants. The effects of PWB in the C. elegans model appeared to be primarily mediated via sir-2.1, daf-16, and daf-16/daf-2. These data suggest that PWB and β-glucans may benefit hyperglycaemia-impaired lipid metabolism.

In vitro investigations of the potential health benefits of Australian-grown faba beans (Vicia faba L.): chemopreventative capacity and inhibitory effects on the angiotensin-converting enzyme, α-glucosidase and lipase

The functional properties, including antioxidant and chemopreventative capacities as well as the inhibitory effects on angiotensin-converting enzyme (ACE), α-glucosidase and pancreatic lipase, of three Australian-grown faba bean genotypes (Nura, Rossa and TF(Ic*As)*483/13) were investigated using an array of in vitro assays. Chromatograms of on-line post column derivatisation assay coupled with HPLC revealed the existence of active phenolics (hump) in the coloured genotypes, which was lacking in the white-coloured breeding line, TF(Ic*As)*483/13. Roasting reduced the phenolic content, and diminished antioxidant activity by 10-40 % as measured by the reagent-based assays (diphenylpicrylhydrazyl, 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) and oxygen radical absorbance capacity) in all genotypes. Cell culture-based antioxidant activity assay (cellular antioxidant activity) showed an increase of activity in the coloured genotypes after roasting. Faba bean extracts demonstrated cellular protection ability against H₂O₂-induced DNA damage (assessed using RAW264.7 cells), and inhibited the proliferation of all human cancer cell lines (BL13, AGS, Hep G2 and HT-29) evaluated. However, the effect of faba bean extracts on the non-transformed human cells (CCD-18Co) was negligible. Flow cytometric analyses showed that faba bean extracts successfully induced apoptosis of HL-60 (acute promyelocytic leukaemia) cells. The faba bean extracts also exhibited ACE, α-glucosidase and pancreatic lipase inhibitory activities. Overall, extracts from Nura (buff-coloured) and Rossa (red-coloured) were comparable, while TF(Ic*As)*483/13 (white-coloured) contained the lowest phenolic content and exhibited the least antioxidant and enzyme inhibition activities. These results are important to promote the utilisation of faba beans in human diets for various health benefits.

Antioxidant and anti-inflammatory activities of bean ( Phaseolus vulgaris L.) hulls

Hulls obtained by mechanical abrasive dehulling from four bean cultivars were extracted with two solvents, aqueous (70%) acetone and water, and the extracts evaluated for antioxidant and anti-inflammatory activities in relation to their phenolic contents. Total phenolic content and antioxidant activity of bean hulls, measured using oxygen radical absorbance capacity (ORAC) values, were 6-8-fold those of corresponding whole beans. Aqueous acetone (70%) extracted over twice the amount of total phenolics from hulls that exhibited significantly higher antioxidant and stronger inhibitory effect on both cyclooxygenases, COX-1 and COX-2, than water. Acetone extract of black bean hull exhibited strong COX-1 (IC(50) = 1.2 microg/mL) and COX-2 (IC(50) = 38 microg/mL) inhibitory effects, even outperforming aspirin. Bean hull water extracts were stronger inhibitors of lipoxygenase, 15-LOX, than corresponding acetone extracts. Anti-inflammatory activity of bean hulls was dependent on their phenolic content and antioxidant activity that were significantly affected by cultivar and extracting solvent.

Antioxidant activity of a red lentil extract and its fractions

Phenolic compounds were extracted from red lentil seeds using 80% (v/v) aqueous acetone. The crude extract was applied to a Sephadex LH-20 column. Fraction 1, consisting of sugars and low-molecular-weight phenolics, was eluted from the column by ethanol. Fraction 2, consisting of tannins, was obtained using acetone-water (1:1; v/v) as the mobile phase. Phenolic compounds present in the crude extract and its fractions demonstrated antioxidant and antiradical activities as revealed from studies using a β-carotene-linoleate model system, the total antioxidant activity (TAA) method, the DPPH radical-scavenging activity assay, and a reducing power evaluation. Results of these assays showed the highest values when tannins (fraction 2) were tested. For instance, the TAA of the tannin fraction was 5.85 μmol Trolox^® eq./mg, whereas the crude extract and fraction 1 showed 0.68 and 0.33 μmol Trolox^® eq./mg, respectively. The content of total phenolics in fraction 2 was the highest (290 mg/g); the tannin content, determined using the vanillin method and expressed as absorbance units at 500 nm per 1 g, was 129. There were 24 compounds identified in the crude extract using an HPLC-ESI-MS method: quercetin diglycoside, catechin, digallate procyanidin, and p-hydroxybenzoic were the dominant phenolics in the extract.