ABSTRACT
Depression and epilepsy are debilitating neurological disorders that affect millions of individuals worldwide. Depression is characterized by persistent feelings of sadness, hopelessness, and changes in behavior, while epilepsy involves recurrent seizures stemming from abnormal brain activity. Emerging evidence suggests a potential pharmacological and biological link between antihistamines and these conditions. This research project aims to explore and understand this connection by utilizing two established behavioural tests, the Forced Swim Test (FST) and the Tail Suspension Test (TST), to evaluate the antidepressant properties of antihistamines and the Pentylenetetrazol (PTZ)-induced seizure model to examine the anti-epileptic properties of antihistamines. The pharmacological link between antihistamines and depression and epilepsy arises from the interactions between histamine receptors and neurotransmitter systems in the brain. Antihistamines, traditionally used to treat allergies, antagonize histamine receptors, affecting not only allergic responses but also neurotransmission. This project seeks to investigate whether antihistamines, through their histamine receptor modulation, may exert an influence on depressive symptoms and seizure activity.
The Forced Swim Test (FST) and Tail Suspension Test (TST) are widely accepted preclinical models for assessing antidepressant efficacy in rodents. In the FST, animals are placed in a water-filled chamber and observed for mobility behaviors, a correlate of behavioural despair. The TST involves suspending animals by their tails and recording their mobility. Antidepressant drugs are known to increase mobility time in both tests. In this study, these behavioural paradigms will be applied to assess the potential antidepressant effects of antihistamines in animal models. Also the Pentylenetetrazol (PTZ)-induced seizure model involves accessing the protective ability of a compound against Pentylenetetrazol (PTZ)-induced seizures. And a drug with antiepileptic properties will protect the animal used from the effects of PTZ.
The findings revealed that Chlorpheniramine exhibited notable antidepressant effects comparable to Amitriptyline, as demonstrated by a significant reduction in depressive-like behaviors in the forced swim and tail suspension tests. However, the study did not observe any antiepileptic effects associated with Chlorpheniramine, unlike Amitriptyline, which displayed a significant reduction in PTZ-induced seizures.
These findings suggest that Chlorpheniramine possesses antidepressant effect comparable to Amitriptyline, which may have implications for its potential use in depressive disorders. However, its lack of antiepileptic properties implies that caution should be exercised when considering Chlorpheniramine for comorbid conditions involving epilepsy. Further research is warranted to elucidate the underlying mechanisms of Chlorpheniramine's antidepressant action and explore its therapeutic potential in clinical settings.
