Effects of the ethanol extract of the roots of Brassica rapa on glucose and lipid metabolism in C57BL/KsJ-db/dbmice

Background & aims: The antidiabetic efficacy of turnip (Brassica rapa) roots ethanol extract (TE) was investigated in type 2 diabetic animals. Methods: C57BL/KsJ-db/db (db/db) mice and db/+ mice were used and the db/db mice were divided into control., TE (0.26g/100g diet) and rosiglitazone (RG, 0.005g/100g diet) groups. Results: Despite hyperinsulinemia, the glucokinase activity was lower in the liver of the db/db mice than the db/+ mice, while the glucose-6-phosphatase activity was higher. TE and RG improved the glucose and insulin tolerance and lowered the blood glycosylated hemoglobin, plasma insulin, C-peptide and glucagon levels as well. as reversed these hepatic glucose regulating enzyme activities in db/db mice. TE also increased the insulin/glucagon ratio and hepatic glycogen content. The plasma free fatty acid and plasma and hepatic cholesterol and triglyceride Levels were higher in the db/db mice than db/+ mice. Interestingly, TE and RG Lowered these plasma and hepatic lipids, and simultaneously reduced the hepatic phosphatidate phosphohydrolase, HMG-CoA reductase, ACAT, beta-oxidation and carnitine palmitoyl transferase activities. Furthermore, TE towered the hepatic fatty acid synthase activity, hepatic lipid droplets accumulation, and adipose tissue weight and size. Conclusions: We suggest TE may exert an antidiabetic effect in type 2 diabetic mice by enhancing the glucose and lipid metabolism. (C) 2007 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. ALL rights reserved.