Tocotrienols-rich diet decreases advanced glycosylation end-products in non-diabetic rats and improves glycemic control in streptozotocin-induced diabetic rats

This study determined the effects of palm vitamin E (TRF) diet on the levels of blood glucose, glycated hemoglobin (gHb), serum advanced glycosylation end-products (AGE) and malondialdehyde (MDA) of diabetic Sprague-Dawley rats. The rats received either control (normal rat chow), TRF diet (normal chow fortified with TRF at 1 g/kg) or Vitamin C diet (vitamin E-deficient but contained vitamin C at 45 g/kg). The animals were maintained on the respective diet for 4 weeks, made diabetic with streptozotocin (STZ), then followed-up for a further 8 weeks. At week-4, mean serum AGE levels of rats given TRF diet (0.7 +/- 0.3 units/ml) were significantly lower than those of control or Vitamin C diet rats (p pounds 0.03). The levels increased after STZ and became comparable to the other groups. At week 12, blood glucose (20.9 +/- 6.9 mM) and gHb (10.0 +/- 1.6%) of rats on TRF diet remained significantly low compared to that of control or Vitamin C diet rats (p pounds 0.03). MDA however, was not affected and remained comparable between groups throughout the study. This study showed that TRF may be a useful antioxidant; effectively prevented increase in AGE in normal rats, and caused decrease in blood glucose and gHb in diabetic rats. Further studies are needed to elucidate the mechanisms of action of TRF.