Melatonin improves metabolic syndrome induced by high fructose intake in rats.
In this study, we examined whether melatonin improves metabolic syndrome induced by high fructose intake in male Wistar rats. Feeding of a diet containing 60% fructose (HFD) for 4 or 6 wk caused increased serum insulin, triglyceride, total cholesterol, free fatty acids, uric acid, leptin, and lipid peroxide concentrations as well as hepatic triglyceride and cholesterol concentrations, and relative intra-abdominal fat and liver weights. The 4- or 6-wk HFD feeding reduced serum high-density lipoprotein cholesterol and adiponectin concentrations. The 6-wk HFD feeding increased serum tumor necrosis factor-α concentration and hepatic lipid peroxide concentration and lowered hepatic reduced glutathione concentration. Daily intraperitoneal administration of melatonin (1 or 10mg/kg body weight), starting at 4-wk HFD feeding, attenuated these changes at 6-wk HFD feeding more effectively at its higher dose than at its lower dose. In an oral glucose tolerance test, rats with 4- or 6-wk HFD feeding showed higher serum insulin response curve and normal serum glucose response curve when compared with the corresponding animals that received the control diet. The 4- or 6-wk HFD feeding caused insulin resistance, judging from the scores of HOMR-IR and QUICKI, which are indices of insulin resistance. The daily administered melatonin (1 or 10mg/kg body weight) ameliorated the higher serum insulin response curve in the oral glucose tolerance test and insulin resistance at 6-wk HFD feeding more effectively at its higher dose than at its lower dose. These results indicate that melatonin improves metabolic syndrome induced by high fructose intake in rats.
Department of Nutrition, Faculty of Wellness, Shigakkan University, Ohbu, Japan.
Akira
A
Kitagawa
Yoshiji
Y
Ohta
Koji
K
Ohashi
D054392:Adipokines / Q000097:blood; D000704:Analysis of Variance; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D001786:Blood Glucose / Q000032:analysis / Q000187:drug effects; D001835:Body Weight / Q000187:drug effects; D002784:Cholesterol; D004032:Diet; D005632:Fructose / Q000008:administration & dosage* / Q000378:metabolism; D005951:Glucose Tolerance Test; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D008054:Lipid Peroxides; D008055:Lipids / Q000097:blood; D008099:Liver / Q000737:chemistry / Q000187:drug effects; D008297:Male; D008550:Melatonin / Q000494:pharmacology*; D024821:Metabolic Syndrome / Q000097:blood / Q000188:drug therapy* / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D014527:Uric Acid / Q000097:blood
D054392:Adipokines; D000975:Antioxidants; D001786:Blood Glucose; D007328:Insulin; D008054:Lipid Peroxides; D008055:Lipids; D014527:Uric Acid; D005632:Fructose; D002784:Cholesterol; D008550:Melatonin