Beneficial effects of ferulic acid alone and in combination with insulin in streptozotocin induced diabetic neuropathy in Sprague Dawley rats.

BACKGROUND

Ferulic acid (FA) is a phenolic phytochemical known to protect against various diabetic complications. However, its role in diabetic neuropathy is still unclear. The present study investigated the potential protective effects of FA alone and its combination with insulin against streptozotocin (STZ)-induced diabetic neuropathy in rats.

METHODS

STZ (55 mg/kg) was injected in adult Sprague-Dawley rats to induce diabetes. Diabetic rats were treated with FA (25, 50, and 100 mg/kg, p.o), insulin (10 IU/kg, s.c.) and the combination of FA (100 mg/kg, p.o.) with insulin (10 IU/kg, s.c.) for four weeks. Body weight, blood glucose, insulin, glycosylated hemoglobin, nerve conduction velocity and pain parameters were measured. Moreover, oxidative stress, inflammatory (TNF-α, IL-1β, COX-2) and apoptotic markers (Bcl-2, Bax, caspase 3) were assessed in the sciatic nerve tissue. Na-K-ATPase activity and nerve growth factor (NGF) levels were also determined.

RESULTS

FA attenuated STZ induced alteration in metabolic parameters, nociceptive threshold, motor nerve conduction velocity, NGF levels and Na-K-ATPase activity. In addition, FA boosted anti-oxidant defenses and suppressed oxidative stress, pro-inflammatory mediators and apoptotic markers. Furthermore, diabetic rats treated with insulin-FA (100 mg/kg) combination demonstrated more pronounced beneficial effects as compared to either agent alone.

CONCLUSIONS

Collectively, our results suggest that FA either alone or in combination with insulin therapy could serve as an efficacious agent for treating diabetic neuropathy.