Concomitant Intake of Quercetin with a Grain-Based Diet Acutely Lowers Postprandial Plasma Glucose and Lipid Concentrations in Pigs

Abstract

Treatment goals of diabetes mellitus type 2 (DMT2) include glycemic control and reduction of nonglycemic risk factors, for example, dyslipidemia. Quercetin, a plant-derived polyphenol, often discussed for possible antidiabetic effects, was investigated for acute postprandial glucose- and lipid-lowering effects in healthy growing pigs. Male pigs (n = 16, body weight = BW 25–30 kg) were fed flavonoid-poor grain-based meals without (GBM) or with quercetin (GBMQ). In a first experiment, postprandial plasma concentrations of glucose, nonesterified fatty acids (NEFA), and triacylglycerols were analyzed in 8 pigs receiving 500 g of either GBM or GBMQ (10 mg/kg BW) in a cross-over design. Blood samples were collected before, and up to 5 h every 30 min, as well as 6 and 8 h after the feeding. In the second experiment, 2 h after ingestions of 1000 g of either GBM or GBMQ (50 mg/kg BW) animals were sacrificed; gastric content was collected and analyzed for dry matter content. Quercetin ingestion reduced postprandial glucose, NEFA, and TG concentration, but two hours after ingestion of the meal no effect on gastric emptying was observed. Our results point to inhibitory effects of quercetin on nutrient absorption, which appear not to be attributable to delayed gastric emptying.

Effects of a 6-wk intraduodenal supplementation with quercetin on energy metabolism and indicators of liver damage in periparturient dairy cows

“…In previous studies, Q lowered concentrations of plasma lipids (Hoek-van den Hil et al, 2013;Jung et al, 2013;Wein and Wolffram, 2014), which was explained by the upregulation of genes involved in β-and Ω-FA oxidation and by the downregulation of ketogenic genes (Kobayashi et al, 2010). However, in contrast to our hypothesis, the Q treatment did not improve metabolic status compared with that of the control cows.…”

“…Some flavonoids have hepatoprotective potential (Harborne and Williams, 2000), and quercetin (Q) is one of the most potent flavonoids (Ader et al, 2000). Several studies, primarily with rodents and pigs, found decreased plasma lipid levels (Hoek-van den Hil et al, 2013;Jung et al, 2013;Wein and Wolffram, 2014) and prevention or reduction of lipid accumulation in the liver after Q treatment (Aguirre et al, 2011;Beltrán-Debón et al, 2011;Joven et al, 2012). The underlying mechanisms of these effects included an improvement in the Ω-and β-oxidation of FA in the liver and an upregulation of the genes involved in lipid metabolism (Kobayashi et al, 2010;Jung et al, 2013;Hoek-van den Hil et al, 2013).…”

The Combination of Resveratrol and Quercetin Attenuates Metabolic Syndrome in Rats by Modifying the Serum Fatty Acid Composition and by Upregulating SIRT 1 and SIRT 2 Expression in White Adipose Tissue

“…Moreover, the decrease in fat accumulation was accompanied by a decrease in the concentration of free fatty acids with a concomitant decrease in triglyceride concentrations. Our results were consistent with other studies which indicated that RSV and QRC significantly suppressed the serum NEFA levels; however, in the present study we administer the combination of flavonoids and identified each NEFA, which had not been previously reported [ 19 , 30 , 31 ].…”

Complex Enzyme-Assisted Extraction Releases Antioxidative Phenolic Compositions from Guava Leaves

“…In addition, complex enzyme-assisted extraction is a higher-efficiency method to improve the release of the insoluble-bound phenolics and obtain the highest content of quercetin and kaempferol than a single enzyme-assisted extraction. As we all know, the absorption efficiency in human intestines and the bioactivities of quercetin were much higher than with its glycoside derivatives [ 21 , 22 , 23 ]. Treatment with β -glucosidase, cellulase, and complex enzymes caused the disruption of the bonds between the phenolics and the cell wall components of the GL matrix; thus, the insoluble-bound phenolics were released into soluble forms ( Table 2 ).…”