Neuroprotective effect of paeonol on cognition deficits of diabetic encephalopathy in streptozotocin-induced diabetic rat

• Paeonol improves cognitive impairment in diabetic encephalopathy rats.
• Paeonol attenuates significantly oxidant stress and apoptosis responses in hippocampus.
• Paeonol affect ChAT and AchE activity.
• Paeonol increases BDNF and IGF expressions in the hippocampus and cerebral cortex.
• Paeonol ameliorates Aβ deposition in the hippocampus and cerebral cortex.

Diabetic encephalopathy (DE) has been characterized by the impaired cognition and the abnormalities of neurochemistry and neurostructure. The study was conducted to evaluate the neuroprotective effect of paeonol on STZ-induced DE rats. Paeonol of 25, 50, 100 mg/kg (p.o.) could decrease the latency time and path length, and enhance significantly the spent time in the target quadrant and platform crossings in Morris water maze test. The treatment with paeonol could also increase significantly Na+-K+-ATP enzyme and ChAT activities, as well as decreasing significantly AchE activity in hippocampal tissue. Immunohistochemistry and TUNEL staining showed that paeonol could attenuate apoptosis of neurons and caspase 3 expression, improve two neurotrophic factors BDNF and IGF expressions, and also ameliorate Aβ deposition in the hippocampus and cerebral cortex. In conclusion, the present study demonstrated diabetic rats treated with paeonol could ameliorate the cognition deficits. These findings indicated paeonol might act as a beneficial agent for the prevention and treatment of DE.