Green tea leaf extract improves lipid and glucose homeostasis in a fructose-fed insulin-resistant hamster model.
The present study evaluated the effect of green tea (Camellia sinensis L.) leaf extract on triglyceride and glucose homeostasis in a fructose-fed hypertriglyceridemic, insulin-resistant hamster model. There was a significant decrease in plasma triglyceride levels following supplementation of the green tea epigallocatechin gallate-enriched extract (42% at 150 mg/(kg day) to 62% at 300 mg/(kg day) for 4 weeks). Compared to baseline, the fructose control group at the end of the study showed elevated serum insulin and apolipoprotein B levels, and decreased serum adiponectin levels. The fructose/green tea extract group showed a reversal in all of these metabolic defects, including an improvement in glucose levels during a glucose tolerance test. Triglyceride content was also examined in various tissues and compared to the control fructose group; supplementation of the green tea extract (300 mg/kg) reduced triglyceride content in liver and heart tissues. There was molecular evidence of improved lipid and glucose homeostasis based on peroxisome proliferator-activated receptor (PPAR) protein expression. Compared to the control fructose group, supplementation of the green tea extract (300 mg/kg) significantly increased PPARalpha and PPARgamma protein expression. In summary, the data suggest that intake of the green tea extract ameliorated the fructose-induced hypertriglyceridemia and the insulin-resistant state in part through PPAR.
Li
Rachel W
RW
Division of Medical Technology, John A. Burns School of Medicine, University of Hawaii at Manoa, Bio C-206, 1960 East-West Road, Honolulu, HI 96822, USA.
Douglas
Teresa D
TD
Maiyoh
Geoffrey K
GK
Adeli
Khosrow
K
Theriault
Andre G
AG
D000818:Animals; D001786:Blood Glucose / Q000187:drug effects* / Q000378:metabolism; D006224:Cricetinae; D004195:Disease Models, Animal; D005632:Fructose / Q000008:administration & dosage*; D006706:Homeostasis / Q000187:drug effects / Q000502:physiology; D007333:Insulin Resistance / Q000502:physiology*; D008055:Lipids / Q000097:blood*; D008297:Male; D008647:Mesocricetus; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology; D018515:Plant Leaves; D013662:Tea
D001786:Blood Glucose; D008055:Lipids; D010936:Plant Extracts; D013662:Tea; D005632:Fructose