👤 Bagher Jafarvand

Parkinson's disease (PD) is a progressive neurological disorder characterized by the loss of dopaminergic neurons in the substantia nigra and is associated with neuroinflammation, apoptosis, oxidative stress, and motor impairment. Imipramine, a tricyclic antidepressant, has a wide range of biological effects such as anti-inflammatory, anti-apoptotic, and free radical scavenging activities. The present study was designed to investigate the neuroprotective effect of imipramine in a rat model of PD induced by 6-hydroxydopamine (6-OHDA). Male Wistar rats were treated with daily intraperitoneal administration of imipramine (20 mg/kg, for 14 days) starting 72 h after 6-OHDA injection (20 μg/rat; 4 μl in the right medial forebrain bundle (MFB)). The motor performance was assessed using the rotarod, beam, pole, and apomorphine-induced rotation tests. The protein levels of neurotrophic factors (BDNF, GDNF, and NT3) and factors involved in oxidative stress (MDA, CAT, SOD, GST, and GSH) were measured in the striatum by ELISA technique. The neuronal survival was also evaluated by Nissl staining. Our results showed that 6-OHDA caused motor impairments and neuronal cell death. It also significantly reduced the protein levels of neurotrophic factors and induced an oxidative stress response in the striatum of rats. Whereas, imipramine treatment effectively reduced 6-OHDA-induced motor deficits and neuronal cell death. This improvement was accompanied by an increase in neurotrophic factors, especially GDNF, as well as a reduction in oxidative stress through increased SOD levels. These findings provide direct evidence that imipramine treatment contributes to improve of neuronal cell death and motor deficits, perhaps by increasing the striatal levels of SOD and GDNF, which play a key role in the survival of dopaminergic neurons. Further studies are also needed to elucidate the precise underlying molecular mechanisms of neuroprotective effects of imipramine. Show less