Enhanced glucose tolerance by intravascularly administered piceatannol in freely moving healthy rats

• Published in: Biochemical and biophysical research communications 2016-02, Vol.470 (3), p.753-758
• Main Authors: Oritani, Yukihiro, Okitsu, Teru, Nishimura, Eisaku, Sai, Masahiko, Ito, Tatsuhiko, Takeuchi, Shoji
• Format: Article
• Language: English
• Subjects: absorption; Administration, Oral; Animals; AUC; blood glucose; Blood Glucose - drug effects; Blood Glucose - metabolism; Dose-Response Relationship, Drug; fasting; Fasting - blood; Freely moving rat; glucose clamp technique; Glucose tolerance; Glucose Tolerance Test; glucose tolerance tests; glycemic effect; Hypoglycemic Agents - administration & dosage; Injections, Intra-Arterial; Injections, Intravenous; Insulin; insulin resistance; Insulin Resistance - physiology; insulin secretion; ISO; Male; metabolites; oral administration; passion fruits; PIC; Piceatannol; Rats; Rats, Sprague-Dawley; seeds; Stilbenes - administration & dosage; Treatment Outcome
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2016.01.018

Piceatannol is a phytochemical in the seeds of passion fruit that has a hypoglycemic effect when orally administered. To elucidate the contribution of intact and metabolites of piceatannol after gastro-intestinal absorption to hypoglycemic effect, we examined the influence of piceatannol and isorhapontigenin on blood glucose concentrations during fasting and glucose tolerance tests by administering them intravascularly to freely moving healthy rats. We found that intravascularly administered piceatannol reduced the blood glucose concentrations during both fasting and glucose tolerance tests, but isorhapontigenin did not during either of them. Furthermore, we found that piceatannol increased the insulinogenic index during glucose tolerance tests and that piceatannol had no influence on insulin sensitivity by performing hyperinsulinemic euglycemic clamping tests. These results suggest that piceatannol orally intaken may enhance glucose tolerance by the effect of intact piceatannol through enhanced early-phase secretion of insulin. Therefore, oral intake of piceatannol might contribute to proper control of postprandial glycemic excursions in healthy subjects. •Intravascularly administered piceatannol enhanced the glucose tolerance in freely moving healthy rats.•Piceatannol increased the insulinogenic index during glucose tolerance tests in healthy rats.•Piceatannol had no influence on insulin sensitivity in healthy rats.