Investigating the antidepressant effects of amantadine combined with amitriptyline in a chronic unpredictable mild stress model in mice

Amantadine, an N-Methyl-D-Aspartate (NMDA) receptor antagonist traditionally used as an antiviral drug, was investigated for its potential antidepressant effect in combination with amitriptyline, a well-established tricyclic antidepressant, in a Chronic Unpredictable Mild Stress (CUMS) animal model of depression. This study aimed to evaluate the efficacy of this drug combination in alleviating depression-like symptoms. Behavioral assessments were conducted using the Forced Swim Test, Tail Suspension Test, Actophotometer test, and Sucrose Preference Test to measure depressive effect. Further biochemical analyses revealed a marked reduction in Brain-derived neurotrophic factor (BDNF) and norepinephrine (NE) levels in the CUMS group compared with the control group. BDNF is crucial for neuroplasticity, synaptic regulation, and neuronal survival and its reduced level is linked to the development of depression. Similarly, NE, a key neurotransmitter involved in mood regulation, is often decreased in depressive states. Conversely, the CUMS group exhibited a significant increase in Tumour necrosis factor-alpha (TNF-alpha) levels, indicating enhanced inflammatory response, which is also associated with depression. Treatment with the combination of amantadine and amitriptyline resulted in a significant antidepressant-like effect, as demonstrated by improved behavioral parameters and normalization of this biomarker the increase in BDNF and NE levels along with a reduction in TNF-alpha.