Anti-Diabetic Effects of TongGuanWan, a Chinese Traditional Herbal Formula, in C57BL/KsJ-db/db Mice

In the present study, the anti-diabetic effects of a traditional Chinese medicinal formula extract, TongGuanWan, were investigated in type 2 diabetic animals. It was orally administered to C57BL/KsJ-db/db mice once a day for 4 weeks at the doses of 62, 125, and 250 mg/kg body weight. TongGuanWan significantly lowered the blood glucose and glycosylated haemoglobin levels as well as improved the glucose tolerance in db/db mice. The serum triglyceride levels in the db/db mice were significantly decreased, whereas the high-density lipoprotein cholesterol levels were significantly increased, after treatment with this herbal formula. TongGuanWan also markedly decreased the animals 'body weights compared to those of the control db/db group but did not alter food intake. The effects of TongGuanWan were compared to those of the drug rosiglitazone. In addition, five main constituents of TongGuanWan, mangiferin, berberine, cinnamic aldehyde, timosaponin BII, and timosaponin AIII, were quantified using high performance liquid chromatography coupled with a diode array and an evaporative light scattering detector (HPLC-DAD-ELSD). These results suggest that TongGuanWan may be useful for the treatment of type 2 diabetes.