Biological response of hepatomas to an extract of Fagopyrum esculentum M. (buckwheat) is not mediated by inositols or rutin

Cell culture models for assessing the effects of bioactive compounds in common buckwheat (Fagopyrum esculentum): a systematic review

Common buckwheat (CBW) is grown and consumed worldwide. In addition to its already established reputation as an excellent source of nutrients, CBW is gaining popularity as a possible component of functional foods. Whereas human studies remain the gold standard for evaluating the relationship between nutrition and health, the development of reliable in vitro or ex vivo models has made it possible to investigate the cellular and molecular mechanisms of CBW effects on human health. Herein is a systematic review of studies on the biological effect of CBW supplementation, as assessed on various types of cellular models. Although the studies reported here have been conducted in very different experimental conditions, the overall effects of CBW supplementation were found to involve a decrease in cytokine secretion and oxidation products, related mainly to CBW polyphenols and protein or peptide fractions. These chemical species also appeared to be involved in the modulation of cell signaling and hormone secretion. Although further studies are undoubtedly necessary, as is their extension to in vivo systems, these reports suggest that CBW-based foods could be relevant to maintaining and/or improving human health and the quality of life.

Buckwheat phenolic metabolites in health and disease

Buckwheat (Fagopyrum esculentum Moench, F. tataricum Gaertner) groats and flour have been established globally as nutritional foods because of their high levels of proteins, polyphenols and minerals. In some regions, buckwheat herb is used as a functional food. In the present study, reports of in vitro studies, preclinical and clinical trials dealing with the effect of buckwheat and its metabolites were reviewed. There are numerous reports of potential health benefits of consuming buckwheat, which may be in the form of food, dietary supplements, home remedies or possibly pharmaceutical drugs; however, adverse effects, including those resulting from contamination, must be considered. There are reports of antioxidative activity of buckwheat, which contains high levels of rutin and quercetin. On the other hand, both cytotoxic and antigenotoxic effects have been shown. Reduction of hyperlipidaemia, reduction of blood pressure and improved weight regulation have been suggested. Consuming buckwheat may have a beneficial effect on diabetes, since lower postprandial blood glucose and insulin response have been reported. In addition, buckwheat metabolites, such as rutin, may have intrinsic protective effects in preserving insulin signalling. Rutin has also been suggested to have potential therapeutic applications for the treatment of Alzheimer’s disease. The literature indicates that buckwheat is safe to consume and may have various beneficial effects on human health.

The "Other" Inositols and Their Phosphates: Synthesis, Biology, and Medicine (with Recent Advances in myo-Inositol Chemistry)

Cell signaling via inositol phosphates, in particular via the second messenger myo-inositol 1,4,5-trisphosphate, and phosphoinositides comprises a huge field of biology. Of the nine 1,2,3,4,5,6-cyclohexanehexol isomers, myo-inositol is pre-eminent, with "other" inositols (cis-, epi-, allo-, muco-, neo-, L-chiro-, D-chiro-, and scyllo-) and derivatives rarer or thought not to exist in nature. However, neo- and d-chiro-inositol hexakisphosphates were recently revealed in both terrestrial and aquatic ecosystems, thus highlighting the paucity of knowledge of the origins and potential biological functions of such stereoisomers, a prevalent group of environmental organic phosphates, and their parent inositols. Some "other" inositols are medically relevant, for example, scyllo-inositol (neurodegenerative diseases) and d-chiro-inositol (diabetes). It is timely to consider exploration of the roles and applications of the "other" isomers and their derivatives, likely by exploiting techniques now well developed for the myo series.

Glucose transporters: cellular links to hyperglycemia in insulin resistance and diabetes

Abnormal expression and/or function of mammalian hexose transporters contribute to the hallmark hyperglycemia of diabetes. Due to different roles in glucose handling, various organ systems possess specific transporters that may be affected during the diabetic state. Diabetes has been associated with higher rates of intestinal glucose transport, paralleled by increased expression of both active and facilitative transporters and a shift in the location of transporters within the enterocyte, events that occur independent of intestinal hyperplasia and hyperglycemia. Peripheral tissues also exhibit deregulated glucose transport in the diabetic state, most notably defective translocation of transporters to the plasma membrane and reduced capacity to clear glucose from the bloodstream. Expression of renal active and facilitative glucose transporters increases as a result of diabetes, leading to elevated rates of glucose reabsorption. However, this may be a natural response designed to combat elevated blood glucose concentrations and not necessarily a direct effect of insulin deficiency. Functional foods and nutraceuticals, by modulation of glucose transporter activity, represent a potential dietary tool to aid in the management of hyperglycemia and diabetes.

Buckwheat as a Functional Food and Its Effects on Health

Buckwheat (BW) is a gluten-free pseudocereal that belongs to the Polygonaceae family. BW grain is a highly nutritional food component that has been shown to provide a wide range of beneficial effects. Health benefits attributed to BW include plasma cholesterol level reduction, neuroprotection, anticancer, anti-inflammatory, antidiabetic effects, and improvement of hypertension conditions. In addition, BW has been reported to possess prebiotic and antioxidant activities. In vitro and animal studies suggest that BW's bioactive compounds, such as D-chiro-inositol (DCI), BW proteins (BWP), and BW flavonoids (mainly rutin and quercetin) may be partially responsible for the observed effects. The purpose of this paper is to review the recent research regarding the health benefits of BW, in vitro and in vivo, focusing on the specific role of its bioactive compounds and on the mechanisms by which these effects are exerted.

Consumption of buckwheat modulates the post-prandial response of selected gastrointestinal satiety hormones in individuals with type 2 diabetes mellitus

PURPOSE

In healthy participants and those with diet-controlled type 2 diabetes (T2DM), to (1) compare the acute 3-hour post-prandial response of glucose, insulin and other gastrointestinal hormones known to influence food intake and glucose metabolism after consumption of a food product made from whole grain buckwheat flour versus rice flour; (2) determine the effect of daily consumption of a food product made from whole grain buckwheat flour on fasting glucose, lipids and apolipoproteins.

METHODS

Healthy participants or those with T2DM consumed either buckwheat or rice crackers. Blood samples were collected at baseline and 15, 30, 45, 60, 120 and 180minutes after consumption. In a second phase of the study, participants consumed one serving of buckwheat crackers daily for 1week; fasting blood samples from day 1 and day 7 were analyzed.

RESULTS

Post-prandial plasma glucagon-like peptide-1, glucose-dependent insulinotropic peptide and pancreatic polypeptide were altered after consuming buckwheat versus rice crackers. Interestingly, changes in these hormones did not lead to changes in post-prandial glucose, insulin or C-peptide concentrations. Significant correlations were observed between both fasting concentrations and post-prandial responses of several of the hormones examined. Interestingly, certain correlations were present only in the healthy participant group or the T2DM group. There was no effect of consuming buckwheat for one week on fasting glucose, lipids or apolipoproteins in either the healthy participants or those with T2DM.

CONCLUSIONS

Although the buckwheat cracker did not modify acute glycemia or insulinemia, it was sufficient to modulate gastrointestinal satiety hormones.