Evaluation of Anxiolytic Activity of Angiotensin Receptor Blockers Using Actophotometer Test in Wistar Rats

Cureus. 2024 Sep 20;16(9):e69798. doi: 10.7759/cureus.69798. eCollection 2024 Sep.

Abstract

Introduction Anxiety disorders are common mental illnesses impacting quality of life, with current treatments like benzodiazepines and selective serotonin reuptake inhibitors (SSRIs) facing limitations due to side effects. Angiotensin receptor blockers (ARBs), used primarily for hypertension, have shown potential neuropsychiatric benefits, including anxiolytic effects. This study explores the anxiolytic effects of two ARBs, telmisartan and losartan, by evaluating locomotor activity in Wistar rats, aiming to identify new treatment options for anxiety through modulation of the renin-angiotensin system. Aim To evaluate the anxiolytic activity of telmisartan and losartan in experimental Wistar rats. Materials and methods The study was carried out after consent was obtained from the Institutional Animal Ethics Committee (IAEC). The rats were divided into four groups: group 1 (control group) received distilled water (2 ml/kg), group 2 (diazepam 2 mg/kg group) received diazepam (2 mg/kg), group 3 (telmisartan 5 mg/kg group) received telmisartan (5 mg/kg), and group 4 (losartan 5 mg/kg group) received losartan (5 mg/kg). The actophotometer test, which measures the locomotor activity levels of rats, was utilized to evaluate their anxiolytic activity. The percent decrease in locomotor activity was calculated for statistical evaluation. Results Our investigation found that the telmisartan 5 mg/kg and losartan 5 mg/kg groups had considerable anxiolytic activity (p<0.05) compared to the control group, and it was comparable to the diazepam 2 mg/kg (p>0.05) group. Conclusion The findings of our study indicate that ARBs, specifically telmisartan 5 mg/kg and losartan 5 mg/kg, exhibit potential anxiolytic effects, evidenced by a significant reduction in locomotor activity in the actophotometer test. These results imply that ARBs could be considered as possible therapeutic agents for anxiety, providing a new perspective on their use beyond traditional cardiovascular applications.

Keywords: actophotometer; angiotensin receptor blockers; anxiolytic; diazepam; locomotor activity; losartan; telmisartan; wistar rats.