Koumine exhibits anxiolytic properties without inducing adverse neurological effects on functional observation battery, open-field and Vogel conflict tests in rodents

Koumine, an active alkaloid of neurotoxic plant Gelsemium, has been focused on its therapeutic uses, especially in central nervous system. Nevertheless, less is known about the neurological effects of koumine, which hampers its potential therapeutic exploitation. Moreover, as the anxiolytic potential of Gelsemium has raised many critical issues, its active principles on the anxiolytic and other neurological effects need to be further investigated. Here, we used functional observation battery (FOB) of mice to systematically measure the neurological effects of koumine at the effective doses, and then further confirmed its anxiolytic properties in open-field test (OFT) of mice and Vogel conflict test (VCT) of rats. Koumine exhibited anxiolytic-like activities but did not affect other autonomic, neurological and physical functions in FOB. Furthermore, koumine released anxiolytic responses and anti-punishment action in a manner similar to diazepam in OFT and VCT, respectively. The results constitutes solid set of fundamental data further demonstrating anxiolytic properties of koumine at the therapeutic doses without inducing adverse neurological effects, which supports the perspectives for the development of safe and effective koumine medicine against pathological anxiety.