The dietary flavonoids naringenin and quercetin acutely impair glucose metabolism in rodents possibly via inhibition of hypothalamic insulin signalling

@article{Koch2012TheDF,
  title={The dietary flavonoids naringenin and quercetin acutely impair glucose metabolism in rodents possibly via inhibition of hypothalamic insulin signalling},
  author={Christiane E. Koch and Goutham Kumar Ganjam and Juliane Steger and Karen Legler and Sigrid St{\"o}hr and Daniel Schumacher and Nigel Hoggard and Gerhard Heldmaier and Alexander Tups},
  journal={British Journal of Nutrition},
  year={2012},
  volume={109},
  pages={1040 - 1051}
}
Secondary metabolites of herbs and spices are widely used as an alternative strategy in the therapy of various diseases. The polyphenols naringenin, quercetin and curcumin have been characterised as anti-diabetic agents. Conversely, in vitro, naringenin and quercetin are described to inhibit phosphoinositide-3-kinase (PI3K), an enzyme that is essential for the neuronal control of whole body glucose homoeostasis. Using both in vitro and in vivo experiments, we tested whether the inhibitory… 
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References

SHOWING 1-10 OF 65 REFERENCES
Myricetin, quercetin and catechin-gallate inhibit glucose uptake in isolated rat adipocytes.
TLDR
Three flavonoids, quercetin, myricetin and catechin-gallate, inhibit the uptake of methylglucose by adipocytes over the concentration range of 10-100 microM, suggesting that GLUT transporters are involved in flavonoid incorporation into cells.
Naringenin enhances insulin-stimulated tyrosine phosphorylation and improves the cellular actions of insulin in a dietary model of metabolic syndrome
TLDR
Naringenin improves insulin signaling and sensitivity and thereby promotes the cellular actions of insulin in this model of insulin resistance, while it did not affect the parameters in control diet-fed rats.
Naringenin, a citrus flavonoid, increases muscle cell glucose uptake via AMPK.
Naringenin inhibits phosphoinositide 3-kinase activity and glucose uptake in 3T3-L1 adipocytes.
Inhibitory mechanisms of flavonoids on insulin-stimulated glucose uptake in MC3T3-G2/PA6 adipose cells.
TLDR
Although genistein, silybin, EGCG and theaflavins had no effect on the insulin-stimulated activation of Akt, they blocked insulin-dependent GLUT4 translocation and provided novel insights into the modulation by flavonoids of insulin's actions, including glucose uptake in adipocytes.
Dietary quercetin alleviates diabetic symptoms and reduces streptozotocin-induced disturbance of hepatic gene expression in mice.
TLDR
Dietary quercetin might improve liver and pancreas functions by enabling the recovery of cell proliferation through the inhibition of Cdkn1a expression, which has heat-shock element in the promoter region, in the liver.
Interaction between flavonoids and the blood–brain barrier: in vitro studies
TLDR
It is demonstrated that flavonoids and some metabolites are able to traverse the blood–brain barrier (BBB) and that the potential for permeation is consistent with compound lipophilicity.
Naringenin Prevents Dyslipidemia, Apolipoprotein B Overproduction, and Hyperinsulinemia in LDL Receptor–Null Mice With Diet-Induced Insulin Resistance
TLDR
Naringenin, through its correction of many of the metabolic disturbances linked to insulin resistance, represents a promising therapeutic approach for metabolic syndrome.
SIMULTANEOUS ACTION OF THE FLAVONOID QUERCETIN ON CYTOCHROME P450 (CYP) 1A2, CYP2A6, N‐ACETYLTRANSFERASE AND XANTHINE OXIDASE ACTIVITY IN HEALTHY VOLUNTEERS
TLDR
The results of the present study indicate that quercetin inhibits CYP1A2 function, but enhances CYP2A6, NAT2 and XO activity in vivo, and some pharmacokinetic parameters relating to 1,7‐dimethylxanthine were affected by quercETin.
Dietary flavonoids: bioavailability, metabolic effects, and safety.
TLDR
Investigation in the possible health benefits of flavonoids has increased owing to their potent antioxidant and free-radical scavenging activities observed in vitro, and there is growing evidence from human feeding studies that the absorption and bioavailability of specific flavonoid is much higher than originally believed.
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