Diphenyl diselenide elicits antidepressant-like activity in rats exposed to monosodium glutamate: A contribution of serotonin uptake and Na+, K+-ATPase activity

• MSG administration induced depressive-like behavioral, hyperexcitability and cerebral neurochemical alterations in rats
• Diphenyl diselenide (PhSe)2 elicited an antidepressant-like action in rats exposed to MSG
• (PhSe)2 improving neuronal plasticity reestablishing cortical 5-HT uptake and Na+, K+-ATPase activity in MSG-treated rats.

Depression is a disorder with symptoms manifested at the psychological, behavioral and physiological levels. Monosodium glutamate (MSG) is the most widely used additive in the food industry; however, some adverse effects induced by this additive have been demonstrated in experimental animals and humans, including functional and behavioral alterations. The aim of this study was to investigate the possible antidepressant-like effect of diphenyl diselenide (PhSe)2, an organoselenium compound with pharmacological properties already documented, in the depressive-like behavior induced by MSG in rats. Male and female newborn Wistar rats were divided in control and MSG groups, which received, respectively, a daily subcutaneous injection of saline (0.9%) or MSG (4 g/kg/day) from the 1st to 5th postnatal day. At 60th day of life, animals received (PhSe)2 (10 mg/kg, intragastrically) 25 min before spontaneous locomotor and forced swimming tests (FST). The cerebral cortices of rats were removed to determine [3H] serotonin (5-HT) uptake and Na+, K+-ATPase activity. A single administration of (PhSe)2 was effective against locomotor hyperactivity caused by MSG in rats. (PhSe)2 treatment protected against the increase in the immobility time and a decrease in the latency for the first episode of immobility in the FST induced by MSG. Furthermore, (PhSe)2 reduced the [3H] 5-HT uptake and restored Na+, K+-ATPase activity altered by MSG. In the present study a single administration of (PhSe)2 elicited an antidepressant-like effect and decrease the synaptosomal [3H] 5-HT uptake and an increase in the Na+, K+-ATPase activity in MSG-treated rats.