Pycnogenol^®efficiency on glycaemia, motor nerve conduction velocity and markers of oxidative stress in mild type diabetes in rats

The aim of this study was to describe the effects of Pycnogenol (R) at various doses on preprandial and postprandial glucose levels, the levels of thiobarbituric acid reactive substances (TBARs) and N-acetyl-beta-D-glucosaminidase (NAGA) and on motor nerve conduction velocity (MNCV) in streptozotocin (STZ)-induced diabetic rats. Pycnogenol (R) treatment (10, 20, 50 mg/kg body weight (b.w.)/day) lasted for 8 weeks after induction of diabetes. Pycnogenol (R) significantly decreased elevated levels of preprandial glycaemia in treated animals at all doses. At doses of 10 mg/kg b.w./day and 20 mg/kg b.w./day it significantly decreased elevated levels of postprandial glycaemia compared with diabetic non-treated animals. Pycnogenol (R) failed to induce a significant decrease of postprandial glycaemia at a dose of 50 mg/kg b.w./day. Pycnogenol (R) improved significantly the impaired MNCV at doses of 10 and 20 mg/kg b.w./day compared with non-treated animals. The levels of TBARs were elevated in diabetic rats. The levels of NAGA increased gradually despite the treatment. Pycnogenol (R) failed to affect the increased levels of TBARs and NAGA. Pycnogenol (R) lowered the elevated levels of glycaemia and reduced the decline in motor nerve conduction velocity in STZ-induced diabetic rats. The effect of Pycnogenol (R) on postprandial glycaemic levels and MNCV was not dose-dependent. Copyright (C) 2009 John Wiley & Sons, Ltd.