Pericarp of colored-seeded common bean (Phaseolus vulgaris L.) varieties a potential source of polyphenolic compounds

ArticleBioactive substances produced by plants are defined as secondary metabolites causing different pharmacological effects in human organism. Various plant raw materials, some known as vegetables or spices, are their source. Pericarp of white-seeded common bean varieties is a pharmacopoeial product traditionally used as an antidiabetic agent. The object of this study was to evaluate the biological value of pericarp of colored beans (cultivars: ‘Małopolanka’, ‘Nida’, ‘Rawela’, ‘Tip Top’, and ‘Nigeria’) compared to the reference white-seeded cultivar (‘Laponia’). Bean pericarp was characterized by a high level of polyphenolic compounds and antioxidant activity. Its phenolic acid content (expressed as caffeic acid equivalents) was at a similar level, at least 0.1 mg g -1 (0.01%). The highest amount of flavonoids was accumulated by the cultivars with dark blue and black seeds, respectively 0.138 and 0.139 mg g -1 DW, as well as by the whiteseeded cultivar (0.132 mg g -1 DW). The highest antioxidant activity (AA) was found for bean extracts of the cultivars ‘Laponia’ and ‘Małopolanka’, respectively 12.35 and 12.10%. Phenolic acid content was significantly positively correlated with AA of the bean extracts tested. This study indicates that pericarp of the colored-seeded bean cultivars is characterized by high biological value and can be used as a source of polyphenolic compounds

Possibilities to improve soil physical properties in garlic cultivation with cover crops as living mulches

[EN] The cultivation system with cover crops as living mulches is growing in importance in the worldwide agriculture as it combines an economical effect with pro-ecological and soil protecting activities. The plant species tested in the research were not frost resistant: buckwheat, millet, white mustard and berseem clover. A control were the plots without cover crops. The intercrops were sown in the first decade of August, in autumn a grown biomass was a living mulch, and after being damaged by frost in spring, the mulch was covering ground surface. Winter garlic bulbs were planted in grown biomass of cover plants, in the first decade of September. In the first decade of November and in the first decade of April, the selected soil parameters were determined in the soil layer of 0¿10 cm: actual soil moisture (%), soil bulk density (Mg · m¿3), total porosity (%) and water stability of soil aggregates (%). The harvest of garlic was conducted in the first decade of July. Cover crops mulches had an influence on soil physical properties. In spring, the soil from plots with cover crops mulching characterized with the highest moisture, higher total porosity and soil aggregates stability as well as lower soil bulk density. In comparison to the control cultivation of winter garlic, without cover crops, the effect of plants used for mulching on marketable yield was not observed. Garlic plants intercropped with the white mustard mulch formed leaves and bulbs of higher weight in comparison to cultivation without cover crops.Research was financed by the Ministry of Science and Higher Education of the Republic of Poland as part of the statutory activities of the Department of Vegetable Crops and Medicinal Plants, University of Life Sciences in Lublin.Salata, A.; Moreno-Ramón, H.; Ibañez Asensio, S.; Buczkowska, H.; Nurzynska-Wierdak, R.; Witorozec, A.; Parzymies, M. (2017). Possibilities to improve soil physical properties in garlic cultivation with cover crops as living mulches. Acta Scientiarum Polonorum Hortorum Cultus. 16(6):157-166. https://doi.org/10.24326/asphc.2017.6.14S15716616

Dolichol: A Component of the Cellular Antioxidant Machinery

Dolichol, an end product of the mevalonate pathway, has been proposed a biomarker of aging, but its biological role, not to mention its catabolism, has not been fully understood. UV-B radiation was used to induce oxidative stress in isolated rat hepatocytes by the collagenase method. Effects on dolichol, phospholipids-bound polyunsaturated fatty acids (PL PUFA) and known lipid soluble antioxidants [coenzyme Q (CoQ) and α-tocopherol] were studied. The increase in oxidative stress was detected by a probe sensitive to reactive oxygen species (ROS). Peroxidation of lipids was assessed by measuring the release of thiobarbituric acid reactive substances (TBARS). Dolichol, CoQ and α-tocopherol were assessed by high-pressure liquid chromatography (HPLC), PL PUFA by gas-liquid chromatography (GC). UV-B radiation caused an immediate increase in ROS as well as lipid peroxidation and a simultaneous decrease in the levels of dolichol and lipid soluble antioxidants. Decrease in dolichol paralleled changes in CoQ levels and was smaller than that in α-tocopherol. The addition of mevinolin, a competitive inhibitor of the enzyme 3-hydroxy-3-methylglutaryl CoA reductase (HMG-CoAR), magnified the loss of dolichol and was associated with an increase in TBARS production. Changes in PL PUFA were minor. These findings highlight that oxidative stress has very early and similar effects on dolichol and lipid soluble antioxidants. Lower levels of dolichol are associated with enhanced peroxidation of lipids, which suggest that dolichol may have a protective role in the antioxidant machinery of cell membranes and perhaps be a key to understanding some adverse effects of statin therapy