Depression-related behavior and mechanical allodynia are blocked by 3-(4-fluorophenylselenyl)-2,5-diphenylselenophene in a mouse model of neuropathic pain induced by partial sciatic nerve ligation

Clinically, it is suggested that chronic pain might induce mood disorders like depression and anxiety. Based on this antidepressant drugs have emerged as a new therapy for pain. In this study, the effect of acute and subchronic treatments with 3-(4-fluorophenylselenyl)-2,5-diphenylselenophene (F-DPS) on behavioral changes induced by partial sciatic nerve ligation (PSNL) was evaluated. At the 4th week after surgery, PSNL caused a significant depression-like behavior in mice evaluated in the forced swimming test (FST) and the tail suspension test (TST), which was accompanied by increased pain sensitivity. The anxiety-like behavior assessed in the light-dark test (LDT) was not modified by PSNL. Acute treatment with F-DPS, at a dose of 1 mg/kg, intragastrically (i.g.) administered 30 min before the FST, produced a significant anti-immobility effect in PSNL mice. The antidepressant drug paroxetine showed acute antidepressant-like action at a dose 10 times higher than F-DPS. Subchronic treatment with F-DPS (0.1 mg/kg, i.g.) reversed depression-like behavior of sciatic nerve-ligated mice in the TST and FST and produced a significant anxiolytic-like action in both sham-operated and PSNL animals. Although the acute F-DPS treatment did not produce anti-allodynic effect, F-DPS subchronic treatment significantly reduced pain sensitivity in PSNL mice. These findings demonstrated that F-DPS blocked behavioral changes induced by neuropathic pain, suggesting that it might be attractive in the pharmacological approach of pain-emotion diseases.