Effects of white mulberry (Morus alba) leaf tea investigated in a type 2 diabetes model of rats.

The present study was aimed to investigate the anti-diabetic effects of a low (0.25%) and a high (0.5%) dose of white mulberry leaf tea in a rat model of type 2 diabetes (T2D). Six week old male Sprague-Dawley rats were divided into four groups: Normal control (NC), Diabetic control (DBC), Diabetic mulberry tea low (DMTL, 0.25%) and Diabetic mulberry tea high (DMTH, 0.50%). T2D was induced by feeding a 10% fructose solution in drinking water for 2 weeks to induce insulin resistance, followed by a single injection (i.p.) of streptozotocin (40 mg/kg body weight (b.w.)) to induce partial pancreatic β-cell dysfunction in all groups except the NC group, which only received a normal drinking water and citrate buffer (pH 4.4) instead of fructose solution and STZ injection, respectively. After 4 weeks feeding of brewed mulberry leaf tea, there were no significant improvements in polyphagia, polydipsia, body weight gain, blood glucose, glucose intolerance, serum insulin, fructosamine, AST, ALT, creatinine, albumin and uric acid levels and liver parameters when serum total cholesterol was significantly and LDL-cholesterol and triglyceride concentrations were markedly decreased in the DMTH group compared to the DBC and DMTL groups. Serum total proteins were significantly reduced in DMTL and DMTH groups compared to the DBC group. These results suggest that brewed white mulberry leaf tea has hypolipidemic rather than antidiabetic effects at least in this experimental condition. However, the effects of the different brands of white mulberry leaf tea may be varied due to various factors.