Acute or Chronic β-Caryophyllene Systemic Administration in Healthy Adult Male Mice Does Not Modulate Anxiety-Like Extinction Behavior Induced by Subsequent Re-Exposure to 3D Maze

Abstract

Pharmacotherapy for major anxiety disorders continues to present dangerous side effects, complicating precise treatment choices for each patient. In this context, β-caryophyllene (BCP), a selective agonist of the cannabinoid type II receptor (CB2R), is recognized as a safe immunomodulatory drug. CB2R has recently been identified in glutamatergic and dopaminergic neurons, supporting its potential as a pharmacotherapy for mood disorders. Thus, we propose to investigate the effects of systemic BCP treatment (50, 100, and 200 mg/kg) on anxiety-like behavior. To this end, we utilized 92 adult male Swiss mice across two acute and one chronic pharmacological assay using the 3D maze test. In the acute assay, 30 min after treatment (BCP or vehicle), we conducted the One-Trial Protocol (OTP) lasting 12 min and the Two-Trial Protocol (TTP) lasting 12 min (comprising two trials of 5 min, with a 2-min interval between them). In the chronic assay, after 10 days of treatment (once daily; BCP or vehicle), testing was performed over five consecutive days (once daily; 12 min), 30 min after administration of BCP or vehicle. Additionally, locomotion was assessed. Under these conditions, we observed no effects on locomotion, anxiety-like behavior, or anxiety-like extinction behavior following either acute or chronic oral administration of BCP. Furthermore, we propose the use of TTP in the 3D maze as a valuable method for assessing acute pharmacological effects in mice. Lastly, behavioral modulation induced by CB2R agonists, particularly BCP, must be further investigated to better understand its potential neurological treatment applications and associated side effects.