Citrus unshiu peel extract ameliorates hyperglycemia and hepatic steatosis by altering inflammation and hepatic glucose- and lipid-regulating enzymes in db/db mice.
Insulin resistance in Type 2 diabetes leads to hepatic steatosis that can accompanied by progressive inflammation of the liver. Citrus unshiu peel is a rich source of citrus flavonoids that possess anti-inflammatory, anti-diabetic and lipid-lowering effects. However, the ability of citrus unshiu peel ethanol extract (CPE) to improve hyperglycemia, adiposity and hepatic steatosis in Type 2 diabetes is unknown. Thus, we evaluated the effects of CPE on markers for glucose, lipid metabolism and inflammation in Type 2 diabetic mice. Male C57BL/KsJ-db/db mice were fed a normal diet with CPE (2 g/100 g diet) or rosiglitazone (0.001 g/100 g diet) for 6 weeks. Mice supplemented with the CPE showed a significant decrease in body weight gain, body fat mass and blood glucose level. The antihyperglycemic effect of CPE appeared to be partially mediated through the inhibition of hepatic gluconeogenic phosphoenolpyruvate carboxykinase mRNA expression and its activity and through the induction of insulin/glucagon secretion. CPE also ameliorated hepatic steatosis and hypertriglyceridemia via the inhibition of gene expression and activities of the lipogenic enzymes and the activation of fatty acid oxidation in the liver. These beneficial effects of CPE may be related to increased levels of anti-inflammatory adiponectin and interleukin (IL)-10, and decreased levels of pro-inflammatory markers (IL-6, monocyte chemotactic protein-1, interferon-γ and tumor necrosis factor-α) in the plasma or liver. Taken together, we suggest that CPE has the potential to improve both hyperglycemia and hepatic steatosis in Type 2 diabetes.
Department of Food Science and Nutrition, Kyungpook National University, Daegu, Republic of Korea.
Hae-Jin
HJ
Park
Un Ju
UJ
Jung
Su-Jung
SJ
Cho
Hee-Kyung
HK
Jung
Sangphil
S
Shim
Myung-Sook
MS
Choi
D000273:Adipose Tissue / Q000187:drug effects; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D002957:Citrus / Q000737:chemistry*; D003921:Diabetes Mellitus, Experimental / Q000188:drug therapy / Q000378:metabolism; D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy / Q000378:metabolism; D004798:Enzymes / Q000235:genetics / Q000378:metabolism; D005234:Fatty Liver / Q000188:drug therapy* / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D006003:Glycogen / Q000378:metabolism; D006943:Hyperglycemia / Q000188:drug therapy* / Q000378:metabolism; D007249:Inflammation / Q000188:drug therapy / Q000378:metabolism; D050356:Lipid Metabolism / Q000187:drug effects; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008817:Mice, Mutant Strains; D019764:Phosphoenolpyruvate Carboxykinase (ATP) / Q000235:genetics; D010936:Plant Extracts / Q000494:pharmacology*; D015430:Weight Gain / Q000187:drug effects
D001786:Blood Glucose; D004798:Enzymes; D010936:Plant Extracts; D006003:Glycogen; D019764:Phosphoenolpyruvate Carboxykinase (ATP)