Neuroprotective effect of paeonol in streptozotocin-induced diabetes in rats

Background: Diabetic neuropathy is one of the most common microvascular complication of diabetes. It is associated with neuronal dysfunction and pain. Paeonol is an important natural product reported for its antioxidant, anti-inflammatory and antidiabetic activities. Aim: The present research was planned to study effect of paeonol in diabetic peripheral neuropathy in rats. Methods: Diabetes was induced in Sprague Dawley rats by using Streptozotocin (55 mg/kg, i.p.). After six weeks, diabetic animals were treated daily with paeonol at a dose of 50, 100 and 200 mg/kg for four weeks. At the end of the treatment, plasma glucose, mechanical allodynia, mechanical hyperalgesia, thermal hyperalgesia and nerve conduction velocities were recorded. Oxidative stress parameters were studied in sciatic nerve. Histopathology study of sciatic nerve, NF-kappa B and MCP-1 expression were also studied at the end of study. Key findings: Paeonol treatment significantly lowered the plasma glucose levels, mechanical allodynia, mechanical hyperalgesia and thermal hyperalgesia as compared to diabetic control group. Paeonol treatment also enhanced the motor and sensory nerve conduction velocity. Paeonol treated diabetic animals showed significant changes in oxidative stress parameters. Histopathology study indicated that paeonol treatment prevented the neuronal damage, lowered demyelination and leukocyte infiltration. NF-kappa B and MCP-1 expression was significantly decreased in sciatic nerve of diabetic animals treated with paeonol. Significance: Results of the present study indicate that paeonol may be considered as effective option for management of diabetic neuropathy.