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Poster communications
Galangin inhibits glucose-induced insulin secretion through the alteration of mitochondrial oxidative phosphorylation
Abstract : Background
Glucose stimulates insulin secretion through a complex metabolic sequence that includes mitochondrial respiration, ATP synthesis and L-type calcium channel (Cav) activation. We and others previously reported that flavonoids regulate glucose-induced insulin secretion by targeting key signaling proteins and cellular processes. Here, we examined the pharmacological behavior of the flavonoid galangin on insulin secretion and we investigated its mechanism by focusing on mitochondrial function.
Methods
Insulin secretion experiments were performed in INS-1 β-cell line and rat isolated pancreatic islets. Insulin release was quantified by the homogeneous time-resolved fluorescence (HTRF) method (Cisbio). INS-1 cells oxygen consumption was measured using the high-resolution Oxygraph-2k (OROBOROS Instruments).
Results
Galangin inhibits glucose-induced insulin secretion both in INS-1 cells and in rat isolated pancreatic islets. This flavonoid also inhibits insulin secretion induced by two substrates of mitochondrial metabolism namely leucine and methylsuccinate. In contrast, galangin has no effect on insulin secretion induced by the KATP inhibitor glibenclamide. In line with these findings, we observed that galangin behaves like the mitochondrial oxidative phosphorylation uncoupler CCCP which reduces insulin secretion and increases mitochondrial oxygen consumption rate.
Conclusion
Our work suggests that galangin inhibits glucose-induced insulin secretion by altering mitochondrial respiration. Therefore, we are currently investigating whether galangin impairs mitochondrial glucose-stimulated ATP synthesis.
https://hal.inrae.fr/hal-02941399
Contributor : Christelle Raynaud <>
Submitted on : Thursday, September 17, 2020 - 9:11:05 AM
Last modification on : Friday, March 19, 2021 - 11:34:05 AM
Long-term archiving on: : Thursday, December 3, 2020 - 8:59:46 AM
Contributor : Christelle Raynaud <>
Submitted on : Thursday, September 17, 2020 - 9:11:05 AM
Last modification on : Friday, March 19, 2021 - 11:34:05 AM
Long-term archiving on: : Thursday, December 3, 2020 - 8:59:46 AM
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