UTTAR PRADESH JOURNAL OF ZOOLOGY

Background: Anxiety disorders are among the most prevalent neuropsychiatric conditions, and the development of effective anxiolytic agents relies heavily on reliable preclinical screening models. Conventional models such as the Elevated Plus Maze (EPM) and Light–Dark Box possess limitations related to habituation and restricted exploratory dynamics. To overcome these constraints, a Modified Elevated Circular Maze (MECM) was developed to provide continuous exploratory freedom while retaining anxiety-inducing open vs. closed zone contrast.

Methodology: Swiss albino mice were divided into four groups (n = 6 per group): Control (0.9% saline), Standard (Diazepam 1 mg/kg), Test I (Rhynchosia minima extract 100 mg/kg), and Test II (Rhynchosia minima extract 200 mg/kg). Each animal was placed individually on the MECM apparatus consisting of two open and two closed sectors at an elevated height. The time spent in open areas (in seconds) was recorded at 2, 4, 6, 8, 12, and 24 hours post-administration. Increased open zone exploration was interpreted as anxiolytic behavior.

Results: Diazepam-treated mice exhibited a 3- to 5-fold increase in open area retention compared to control across all time points, confirming model validity. Rhynchosia minima demonstrated dose-dependent anxiolytic activity, with the 200 mg/kg group showing comparable efficacy to Diazepam at 2, 6, and 8 hours (82.75 s, 95.0 s, 93.0 s, respectively). The 100 mg/kg dose showed moderate anxiolytic activity but remained inferior to the standard. Control animals consistently avoided open areas, confirming inherent anxiety in the elevated setting.

Conclusion: The Modified Elevated Circular Maze successfully differentiated anxiolytic effects in both standard and herbal drug-treated groups, proving its suitability as a rapid and sensitive screening model. Rhynchosia minima extract, particularly at 200 mg/kg, exhibited promising natural anxiolytic potential comparable to Diazepam. Further studies involving neurochemical correlation and chronic exposure models are warranted.