Potential anxiolytic-like activity of some amino acid derivatives

Three derivatives of amino acids: (R)-Ac-Pro-BZA (1), Ac-beta Ala-BZA (2) and (S)-Ac-Arg(NO2)-BZA (3) were evaluated as potential anxiolytics. In the conflict drinking test in rats used as a model of anxiety, the tested compounds exhibited anxiolytic-like activity. Compounds 1 and 2 administered in doses of 50-100 mg/kg produced an anticonflict effect in a dose-dependent manner. A distinct effect is observed after dose of 100 mg/kg of 1 and 2, comparable to those induced by 10 mg/kg of diazepam. The anticonflict effect of 3 was weak and dose independent. It was revealed only in one mean dose (50 mg/kg) but not in the higher doses.