Chronic treatment of silymarin improves hyperalgesia and motor nerve conduction velocity in diabetic neuropathic rat.

The effect of chronic silymarin (SM) treatment on hyperalgesia, sciatic motor nerve conduction velocity (MNCV) and oxidative stress in streptozotocin (STZ)-diabetic neuropathic rat was evaluated. Rats were divided into control, diabetic, SM-treated control and diabetic, and sodium salisylate (SS)-treated control and diabetic. SM was administered daily at a dose of 100 mg/kg for two months. Finally, hyperalgesia and sciatic MNCV and oxidative stress markers were assessed. Diabetic rats showed a significant deficit in MNCV and markedly exhibited chemical and thermal hyperalgesia, indicating development of diabetic neuropathy. Antioxidant enzyme superoxide dismutase (SOD) level significantly reduced and malondialdehyde (MDA) level significantly increased in diabetic rats compared to control rats; SM treatment significantly ameliorated the alteration in MNCV, hyperalgesia, MDA level and antioxidant enzyme SOD in diabetic rats. These results clearly suggest the potential effect of SM in prevention and treatment of diabetic neuropathy.