Health benefits of traditional corn, beans, and pumpkin: in vitro studies for hyperglycemia and hypertension management.
ABSTRACT Levels of obesity-linked non-insulin-dependent diabetes mellitus (NIDDM) and hypertension are highest among indigenous communities in North America. This is linked to changes in dietary pattern towards high calorie foods such as sugar, refined grain flour, and sweetened beverages. Therefore, a return to traditional dietary patterns may help to reduce these disease problems because of better balance of calories and beneficial nutrients. Further protective non-nutrient phenolic phytochemicals against NIDDM and hypertension are potentially high in these foods but less understood. In this study antidiabetic- and antihypertension-relevant potentials of phenolic phytochemicals were confirmed in select important traditional plant foods of indigenous communities such as pumpkin, beans, and maize using in vitro enzyme assays for -glucosidase, alpha-amylase, and angiotensin I-converting enzyme (ACE) inhibitory activities. In vitro inhibitory activities of these enzymes provide a strong biochemical rationale for further in vivo studies and dietary management strategy for NIDDM through the control of glucose absorption and reduction of associated hypertension. These enzyme inhibitory activities were further compared to total soluble phenolic content and antioxidant activity of the above-targeted plant foods. Pumpkin showed the best overall potential. Among the varieties of pumpkin extracts P5 (round orange) and P6 (spotted orange green) had high content of total phenolics and moderate antioxidant activity coupled to moderate to high alpha-glucosidase and ACE inhibitory activities. Therefore this phenolic antioxidant-enriched dietary strategy using specific traditional plant food combinations can generate a whole food profile that has the potential to reduce hyperglycemia-induced pathogenesis and also associated complications linked to cellular oxidation stress and hypertension.
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ABSTRACT: Cereals and legumes are key components of a healthy and balanced diet. Accordingly, many national nutritional guidelines emphasize their health promoting properties by placing them at the base of nutritional food pyramids. This concept is further validated by the observed correlation between a lower risk and occurrence of chronic diseases and the adherence to dietary patterns, like the Mediterranean diet, in which cereal grains, legumes and derived products represent a staple food. In the search for a dietary approach to control/prevent chronic degenerative diseases, protein derived bioactive peptides may represent one such source of health-enhancing components. These peptides may already be present in foods as natural components or may derive from hydrolysis by chemical or enzymatic treatments (digestion, hydrolysis or fermentation). Many reports are present in the literature regarding the bioactivity of peptides in vitro and a wide range of activities has been described, including antimicrobial properties, blood pressure-lowering (ACE inhibitory) effects, cholesterol-lowering ability, antithrombotic and antioxidant activities, enhancement of mineral absorption/bioavailability, cyto- or immunomodulatory effects, and opioid-like activities. However it is difficult to translate these observed effects to human. In fact, the active peptide may be degraded during digestion, or may not be absorbed or reach the target tissues at a concentration necessary to exert its function. This review will focus on bioactive peptides identified in cereals and legumes, from an agronomical and biochemical point of view, including considerations about requirements for the design of appropriate clinical trials necessary for the assessment of their nutraceutical effect in vivo.International Journal of Molecular Sciences 11/2014; 15:21120-21135. · 2.34 Impact Factor
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ABSTRACT: To investigate the inhibitory effect of phenolic-rich extracts from Cola nitida (C. nitida) seeds on key enzymes linked with type-2 diabetes and Fe(2+) induced oxidative stress in rat pancreas.Asian Pacific Journal of Tropical Biomedicine 05/2014; 4(Suppl 1):S405-12.
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ABSTRACT: Abstract This study evaluated the in vitro antioxidative activity of Khaya senegalensis extracts and inhibitory effects of some solvent fractions on α-glucosidase and α-amylase activities. The stem bark, root and leaf samples of the plant were sequentially extracted with ethyl acetate, ethanol and water and then tested for antioxidative activity. Our findings revealed that the ethanolic extract of the root had the highest antioxidative activity. Solvent-solvent fractionation of the root ethanolic extract yielded a butanol fraction that showed higher antioxidative activity than other fractions. Furthermore, the butanol fraction had significantly higher (p < 0.05) α-glucosidase and α-amylase inhibitory activities with IC50 values of 2.89 ± 0.46 and 97.51 ± 5.72 μg mL-1, respectively. Enzyme kinetic studies indicated that the butanol fraction is a non-competitive inhibitor for α-glucosidase with an inhibition binding constant Ki of 1.30 μg mL-1 and a competitive inhibitor of α-amylase with a Ki of 7.50 μg mL-1. GC-MS analysis revealed that the butanol fraction contained two chromones, p-anilinophenol and 3-ethyl-5-(3- ethyl-(3H)-benzothiazol-2-ylidene)-2-(p-tolylvinylamino)- 4-thiazolidinone. Data obtained in the study suggest that the butanol fraction derived from the ethanolic extract of K. senegalensis root possessed excellent antioxidative as well as α-glucosidase and a-amylase inhibitory activities while chromones and/or p-anilinophenol could be the main bioactive compounds responsible for the observed activities.Acta pharmaceutica (Zagreb, Croatia). 09/2014; 64(3):311-24.