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

ArticleinJournal of Medicinal Food 10(2):266-75 · July 2007with163 Reads
DOI: 10.1089/jmf.2006.234 · Source: PubMed
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.
    • "Moreover, a balance on the extent of inhibition of α-amylase and αglucosidase has to be achieved to reduce diarrhea and flatulence linked to undigested starch in the intestines. It also serves as an effective medium for bacterial fermentation processes leading to an increase in production of gases and butyrate (Kwon et al., 2007). Based on these reports and our previous experience of anti-oxidant scavenging studies on digested microalgal pigments, we investigated their ability to inhibit these two enzymes in vitro. "
    [Show abstract] [Hide abstract] ABSTRACT: Traditional medicines for controlling postprandial hyperglycemia includes herbs and plant extracts as well as synthetic drugs like acarbose. Synthetic drug molecules frequently have side effects such as flatulence and diarrhea. Cyanobacterial pigments have excellent anti-oxidant and free radical scavenging properties. Thus, α-amylase and α-glucosidase inhibiting activities of purified pigments and crude extracts from three cyanobacterial species, Lyngbya, Microcoleus, and Synechocystis sp., were investigated. Lyngbya extract had the highest total anti-oxidant activity (TAC) before digestion (48.26 ± 0.04 μg AAE ml−1) while purified lycopene had the highest TAC after digestion (154.16 ± 0.96 μg AAE ml−1). The Microcoleus extract had the highest ABTS scavenging activity before digestion (98.23 ± 0.25%) while purified C-phycocyanin (C-PC) had the highest ABTS scavenging after digestion (99.69 ± 0.04%). None of the digested or undigested extracts performed better than acarbose in inhibiting α-amylase but the digested Microcoleus extract was able to inhibit its activity by ~35%. The purified pigments gave inhibitory activities ranging from ~8 to 16%. The Lyngbya extract had the highest inhibitory activity against α-glucosidase both before and after digestion (62.22 ± 0.02 and 97.82 ± 0.03%, respectively). Purified C-phycoerythrin (C-PE), C-PC, lycopene and myxoxanthophyll could inhibit α-glucosidase in a range of ~83–96%. Considering the potent inhibitory activities of purified pigments against both α-amylase and α-glucosidase, cyanobacterial pigments could be used as food additives for their dual advantage of anti-oxidant and anti-hyperglycemic activities.
    Full-text · Article · Jul 2016
    • "Our results demonstrate that the extracts of the pasta were good inhibitors of alfa-glucosidase, but weaker inhibitors of alfa-amylase. These results are in agreement with earlier reports which revealed that plant phytochemicals are mild inhibitors of alfa-amylase and strong inhibitors of alfa-glucosidase activity [51,52]. These properties could confer advantage over synthetic drugs such as Acarbose used by diabetics in the management of post-prandial blood glucose. "
    [Show abstract] [Hide abstract] ABSTRACT: Background: Legumes contain elevated levels of health functional components. The objective of the present paper was to evaluate the nutritional properties and the post-prandial glycaemic responses of pasta obtained using 35% Vicia Faba (VF) bean flour, which is an important source of fiber and phytochemical compounds. Results: Protein and fiber content were higher in VF pasta compared with durum wheat semolina (DWS) pasta. The total phenol content in VF pasta was about two fold higher compared to that of DWS pasta. A higher total flavonoid content, higher antioxidant activity against peroxyl radicals evaluated by oxygen radical absorbance capacity (ORAC) assay was also observed in VF pasta. The comparison of post-prandial increase of glucose after VF intake or DWS demonstrated significant differences and VF pasta exhibited a lower glycemic index value, a lower glycemic load and higher glycemic profile compared with DWS pasta. Conclusion: The results suggest that enrichment with 35% Vicia faba bean has potential health benefits and that VF flour can be used as an ingredient to prepare added-value products.
    Full-text · Article · May 2016 · Advances in Bioresearch
    • "This is because any drug which a strong inhibitor of α-glucosidase could serve as effective therapy for postprandial hyperglycemia. Thus, the strong inhibition of α-glucosidase by the ethyl acetate fraction would slow down the breakdown of disaccharides to liberate glucose, thereby reducing glucose absorption from the small intestine [24]. This observation might be connected to the high phenolic content recorded in the fraction, because polyphenolic fractions from plants have been shown to inhibit α-glucosidase activity, allowing for tighter control of blood glucose [25]. "
    [Show abstract] [Hide abstract] ABSTRACT: In West Africa, various preparations of extracts of Bridelia ferruginea Bth. stem bark are used for management of diabetes mellitus and other metabolic disorders.The present study evaluated the inhibitory effect of ethyl acetate fraction on the key enzymes linked to type-2 diabetes (α-glucosidase and α-amylase) activities. The stem bark of the plant was sequentially extracted with ethanol and ethyl acetate and the tested for their inhibitory effect on α-glucosidase and α- amylase activities as well as determination of mode of inhibition was performed. Our findings revealed that the total phenolic content of the extract yielded 3.66 ± 0.05 mg GAE/100g. Furthermore, the results revealed that ethyl acetate fraction of B. ferruginea had α-glucosidase and α-amylase inhibitory activities with IC50 values of 4.52 ± 0.50 mg/mL and 5.42 ± 1.10 mg/mL respectively. Enzymes kinetics studies indicated that the ethyl acetate fraction is a non-competitive inhibitor for α-glucosidase and a competitive inhibitor for α-amylase. GC-MS analysis also revealed that the ethyl acetate fraction contained 2, 2'-Oxydiphenol, p-hydroxyphenyl ether, di-1H-pyrrol-1-yl-isopropenylsilane and carbonic acid, phenyl undec-10-enyl ester. It can be inferred from this study that ethyl acetate fraction of B. ferruginea stem bark possessed α-glucosidase and α-amylase inhibitory activities which may be due to the presence of phytochemicals such as phenols. 2, 2' oxydiphenol, and p-hydroxyphenyl ether, could be the main bioactive compounds responsible for the observed activities.
    Article · May 2016
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