Prophylactic L arginine and ibuprofen delay the development of tactile allodynia and suppress spinal miR 155 in a rat model of diabetic neuropathy.
Diabetic neuropathy (DN) is a common complication of diabetes mellitus that is hardly reversible at the late stages. Since treatment of neuropathic pain is predominantly symptomatic, a prophylactic measure would be useful. Both ibuprofen and L arginine exert antiallodynic effects on chronic constriction injury (CCI) induced cold allodynia. Furthermore, ibuprofen is effective in CCI induced mechanical allodynia. The aim of the study was to assess the antiallodynic effect of prophylactic ibuprofen and L arginine in streptozotocin induced DN in rats and to further investigate the role of spinal miR 155 and nitric oxide (NO) in this effect. Tactile allodynia was assessed weekly by von Frey filaments. Oral daily administration of ibuprofen, L arginine and their combination, for 4 weeks starting 1 week after streptozotocin injection (ie, before the development of tactile allodynia) resulted in a significant decrease of tactile allodynia compared with the control diabetic group. This was evident in the fifth week of the experiment. The 3 treatments prevented the decrease in muscle fiber diameter and epidermal thickness, seen in the control diabetic group. Furthermore, ibuprofen, L arginine and their combination prevented the increase in the spinal NO level and miRNA 155, seen in the control diabetic group. In conclusion, both ibuprofen and L arginine delayed the development of behavioral and histologic changes of DN, with concomitant suppression of spinal miR 155 and NO level. L arginine being tolerable may be useful prophylactically in diabetic patients.
Translational research the journal of laboratory and clinical medicine