Low glycemic index sweet potato starch improves the postprandial glycemic response of STZ/nicotinamide-induced hyperglycemic rats by upregulating the proteins involved in insulin signaling

Ya Yen Chen, Ming Hoang Lai, Tai Chen Yu, Jen Fang Liu

Research output: Contribution to journalArticle

3 Citations (Scopus)


This study was to evaluate the effects of lower-GI starch on the insulin signaling in STZ/nicotinamide-induced hyperglycemic rats. We divided 13 hyperglycemic rats and 6 normal rats randomly into two groups respectively and fed a diet containing 575 g/kg as either low-GI sweet potato starch (designed as "S") or high-GI potato starch (designed as "P"). We labeled these four groups as HG-P, HG-S (hyperglycemic rats), N-P and N-S (normal rats). After consuming the diets for 4 weeks, the skeletal muscle was collected to measure the protein expression of the insulin receptor (IR), IR substrate (IRS)-1, and glucose transporter (GLUT)4. Two intraperitoneal glucose tolerance tests (IPGTTs) were also performed at 0th and 4th week to evaluate the postprandial glycemic response. The results showed that the area under the curve (AUC) for blood glucose at 4th week was significantly lower than that at 0th week in the HG-S group. The protein expression of IRS-1 and GLUT4 in the skeletal muscle was significantly upregulated in the HG-S group compared to the HG-P group. We concluded that starch with lower-GI improved the postprandial glycemic response of hyperglycemic rats and may associate with the upregulating the proteins involved in insulin signaling.

Original languageEnglish
Pages (from-to)179-185
Number of pages7
JournalCurrent Topics in Nutraceutical Research
Issue number3-4
Publication statusPublished - Aug 2012



  • Glycemic index
  • Hyperglycemic rats
  • Insulin signaling
  • Starch

ASJC Scopus subject areas

  • Medicine (miscellaneous)
  • Nutrition and Dietetics

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