Effect of Cyclooxygenase Inhibitors Etoricoxib and Diclofenac Sodium and Their Combinations with Mexidol on Behavior in Rats

Abstract The effect of nonsteroidal anti-inflammatory drugs (NSAIDs), selective cyclooxygenase (COX)-2 inhibitor etoricoxib and nonselective COX inhibitor diclofenac sodium, on the behavior of rats was evaluated with a single oral administration at doses of 1 and 10 mg/kg individually and in combination with 2-ethyl-6-methyl-3-hydroxypyridine succinate (mexidol). Both COX inhibitors at a dose of 10 mg/kg decrease locomotor activity in the open field test, and the selective COX-2 inhibitor at a dose of 10 mg/kg also increases the duration of immobility of animals in the tail suspension test. The use of etoricoxib and diclofenac sodium at a low dose (1 mg/kg) with mexidol at a dose of 25 mg/kg, in which the latter enhances the anti-inflammatory effect of the COX inhibitors, does not lead to behavioral deviations similar to those associated with the NSAIDs at a dose of 10 mg/kg. Moreover, combinations of COX inhibitors (1 mg/kg) and mexidol (25 mg/kg) increase the locomotor activity of rats. This justifies further research into the effect of antioxidants on the severity of the main and side effects of NSAIDs, especially when administered as a course.