ABSTRACT
Buckwheat (Fagopyrum esculentum Moench) groats contain the iminosugar D-fagomine as a minor component that might contribute to the alleged health benefits of this pseudo-cereal. This study presents analysis of D-fagomine in buckwheat-based foodstuffs by liquid chromatography coupled to mass spectrometry and an estimation of its presence in the human diet based on a published population-based cross-sectional nutrition survey. D-fagomine is present in common buckwheat-based foodstuffs in amounts ranging from 1 to 25 mg/kg or mg/L, it is stable during boiling, baking, frying and fermentation, and it is biosynthesised upon sprouting. The estimated total intake of D-fagomine resulting from a diet that includes such foodstuffs would be between 3 and 17 mg per day (mean for both genders; range from P5 to P95). A diet rich in buckwheat products would provide a daily amount of D-fagomine that may in part explain the beneficial properties traditionally attributed to buckwheat consumption.
Subject(s)
Fagopyrum/chemistry , Imino Pyranoses/analysis , Adolescent , Adult , Aged , Aged, 80 and over , Child , Cross-Sectional Studies , Diet , Fagopyrum/metabolism , Female , Humans , Imino Pyranoses/metabolism , Male , Middle Aged , Nutritive Value , Young AdultABSTRACT
D-Fagomine is an iminosugar originally isolated from seeds of buckwheat (Fagopyrum sculentum Moench), present in the human diet and now available as a pure crystalline product. We tested D-fagomine for activities connected to a reduction in the risk of developing insulin resistance, becoming overweight and suffering from an excess of potentially pathogenic bacteria. The activities were: intestinal sucrase inhibition in vitro (rat mucosa and everted intestine sleeves), modulation of postprandial blood glucose in rats, bacterial agglutination and bacterial adhesion to pig intestinal mucosa. When ingested together with sucrose or starch, D-fagomine lowered blood glucose in a dose-dependent manner without stimulating insulin secretion. D-Fagomine reduced the area under the curve (0-120 min) by 20 % (P < 0·01) and shifted the time to maximum blood glucose concentration (Tmax) by 15 min at doses of 1-2 mg/kg body weight when administered together with 1 g sucrose/kg body weight. Moreover, D-fagomine (0·14 mm) agglutinated 60 % of Enterobacteriaceae (Escherichia coli, Salmonella enterica serovar Typhimurium) populations (P < 0·01), while it did not show this effect on Bifidobacterium spp. or Lactobacillus spp. At the same concentration, d-fagomine significantly (P < 0·001) inhibited the adhesion of Enterobacteriaceae (95-99 % cells in the supernatant) and promoted the adhesion of Lactobacillus acidophilus (56 % cells in the supernatant) to intestinal mucosa. D-Fagomine did not show any effect on bacterial cell viability. Based on all this evidence, D-fagomine may be used as a dietary ingredient or functional food component to reduce the health risks associated with an excessive intake of fast-digestible carbohydrates, or an excess of potentially pathogenic bacteria.
