Health Benefits of Traditional Corn, Beans and Pumpkin; In Vitro Studies for Hyperglycemia and Hypertension Management

Department of Food Science, University of Massachusetts, Amherst, Massachusetts 01003, USA.
Journal of Medicinal Food (Impact Factor: 1.63). 07/2007; 10(2):266-75. DOI: 10.1089/jmf.2006.234
Source: PubMed


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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    • "The currently available medication acts through the stimulation and enhancement of endogenous insulin secretion, and by inhibiting common dietary enzymes such as αamylase and α-glucosidase (Rang et al. 2003). Enzymes such as α-amylase and α-glucosidase act synergistically to digest starch in the human body through the breakdown of starch by pancreatic α-amylase and the absorption of glucose by intestinal α-glucosidase (Kwon et al. 2007). Pancreatic α-amylase is a key enzyme that determines the rate of starch digestion by the hydrolysis of inner α- 1,4-glucosidic linkages, and produces linear and branched malto-oligosaccharides (Hizukuri et al. 1996). "
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    ABSTRACT: Two edible seaweeds, Sargassum polycystum and Sargassum wightii, were investigated for their antidiabetic potential using in vitro enzyme inhibitory assays. Among the various extracts, petroleum ether and ethyl acetate extracts of S. wightii showed significant inhibitory effects against α-amylase (IC50 378.3 µg/ml) and α-glucosidase (IC50 314.8 µg/ml). Methanol extract of S. wightii showed the highest inhibition against dipeptidyl peptidase-IV (DPP-IV) (IC50 38.27 µg/ml) and moderate antioxidant activity was observed in acetone extract of S. wightii (44%). Similarly, ethyl acetate extract of S. polycystum showed the highest inhibition against α-amylase (IC50 438.5 µg/ml) and methanol extract of S. polycystum showed maximum inhibition against α-glucosidase (IC50 289.7 µg/ml) and DPP-IV (36.94 µg/ml). The antioxidant activity was poor (22%). The extracts were investigated for in vitro cytotoxicity, DNA fragmentation in macrophages and haemolytic activity against erythrocytes, but no notable toxicity was observed with any of the tested extracts. Gas chromatography–mass spectrometry revealed the presence of the antidiabetic compound fucosterol and other major bioactive compounds, giving an insight into the antidiabetic and antioxidant properties of these algae. This study reveals the possible mechanisms of antidiabetic action in vitro, and these two seaweeds may also have an antidiabetic action in vivo.
    No preview · Article · Feb 2015 · Frontiers in Life Science
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    • "Pumpkin (Cucurbita moschata) belongs to Cucurbitaceae family, is a very popul ar vegetable with high productivity and storability. Pumpkin has good nutritive benefits with balanced calori es and is a good source of carotenoids (Murkovic et al., 2002; Hidaka and Nakatsu, 1987; Kwon et al., 2007). Pumpkins are very versatile in their uses for cooking, can be stored for up to 6 months before being consumed and hence can play an important role in maintaining nutritional levels during long dry seasons (Mendlinger et al., 1991). "
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    ABSTRACT: An experiment was conducted at Horticultural farm, Sher-e-Bangla Agricultural University, Bangladesh during period from November 2013 to March 2014 to evaluate the performance of four pumpkin lines (L1 to L4). From the result of the current study maximum number of branches/plant (3.7), vine length (4.0 m), leaf area (946.6 cm2), single fruit weight (3.5 kg) and yield (26.5 kg/plant) was found from L2 but maximum number of fruit/plant was found from L4 (10.0). Early flowering (56.3 days) and maturity (93.7 days) was found from L2 while minimum sex ratio (male flower : female flower) from L4 (0.33).
    Full-text · Article · Nov 2014
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    • "Inhibition of α-glucosidase suppresses postprandial hyperglycemia by slowing down the catabolism of dietary carbohydrates [6, 10]. Recent studies showed that phenolic phytochemicals from botanical sources are natural inhibitors of α-amylase and α-glucosidase [11–14] and thus can be potentially used to manage pre-diabetes progression to type 2 diabetes. "
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    ABSTRACT: Background Type 2 diabetes is a serious problem for developed countries. Prevention of prediabetes progression to type 2 diabetes with the use of natural products appears to a cost-effective solution. Previously we showed that enzymatically digested low molecular weight chitosan-oligosaccharide with molecular weight (MW) below 1,000 Da (GO2KA1) has potential for hyperglycemia management. Methods In this study we evaluated the effect of long-term supplementation of GO2KA1 on hyperglycemia using a db/db mice model. Additionally, we evaluated the effect of GO2KA1 on sucrase and glucoamylase activities and expression, using the same db/db mice model. Results After 42 days we observed that GO2KA1 supplementation reduced both the blood glucose level and HbA1c in a similar manner with a known anti-diabetic drug, acarbose. When the sucrase and glucoamylase activities of GO2KA1 and control mice were evaluated using enzymatic assay, we observed that GO2KA1 significantly inhibited sucrase in all 3 parts of the intestine, while glucoamylase activity was significantly reduced only in the middle and lower part. When the sucrase-isomaltase (SI) complex expression on mRNA level was evaluated, we observed that GO2KA1 had minimal inhibitory effect on the upper part, more pronounced inhibitory effect on the middle part, while the highest inhibition was observed on the lower part. Our findings suggest that long-term GO2KA1 supplementation in db/db mice results to significant blood glucose and HbA1c reduction, to levels similar with those of acarbose. Furthermore, our findings confirm previous in vitro observations that GO2KA1 has inhibitory effect on carbohydrate hydrolysis enzymes, namely sucrase, maltase and SI complex. Conclusions Results from this study provide a strong rationale for the use of GO2KA1 for type 2 diabetes prevention, via inhibition of carbohydrate hydrolysis enzymes. Based on the findings of this animal trial, clinical trials will be designed and pursued.
    Full-text · Article · Jul 2014 · BMC Complementary and Alternative Medicine
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