Crocetin prevents dexamethasone-induced insulin resistance in rats.
The main objective of the study was to examine whether crocetin, a natural product from Gardenia jaminoides Ellis, has beneficial effects on the state of insulin resistance induced by dexamethasone in a rat model. Measured using the oral glucose tolerance tests (OGTT), male Wistar rats treated with subcutaneous dexamethasone (0.08 mg/kg/d) for 6 weeks exhibited reduced insulin sensitivity at weeks 2 and 4 and impaired glucose tolerance at week 4. In the dexamethasone-treated group, serum insulin, free fatty acids (FFA), triglyceride (TG) and tumor necrosis factor (TNF)-alpha levels were significantly increased at the end of the study. In addition, the hepatic glycogen content was reduced as indicated by periodic acid-Schiff (PAS) staining, and pancreatic islet beta cells showed compensatory hyperactivity suggested by immunohistochemical (IHC) staining using an antibody against insulin. Treatment with crocetin (40 mg/kg/d) significantly attenuated all the described effects of dexamethasone. These results suggest that crocetin might prevent the development of dexamethasone-induced insulin resistance and related abnormalities in rats.
Xi
Liang
L
Department of Pharmacology, China Pharmaceutical University, 24 Tongjia Xiang, Nanjing 210009, People's Republic of China.
Qian
Zhiyu
Z
Shen
Xiangchun
X
Wen
Na
N
Zhang
Yabing
Y
D000284:Administration, Oral; D000818:Animals; D001786:Blood Glucose / Q000187:drug effects*; D002338:Carotenoids / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000494:pharmacology* / Q000627:therapeutic use; D003907:Dexamethasone; D004195:Disease Models, Animal; D005638:Fruit; D032062:Gardenia; D005951:Glucose Tolerance Test; D007004:Hypoglycemic Agents / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000494:pharmacology* / Q000627:therapeutic use; D007333:Insulin Resistance; D008297:Male; D008517:Phytotherapy; D010936:Plant Extracts / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000494:pharmacology / Q000627:therapeutic use; D051381:Rats; D017208:Rats, Wistar; D014801:Vitamin A / Q000031:analogs & derivatives
D001786:Blood Glucose; D007004:Hypoglycemic Agents; D010936:Plant Extracts; C487773:trans-sodium crocetinate; D014801:Vitamin A; D002338:Carotenoids; D003907:Dexamethasone