Pharmacological effect of gelsemine on anxiety-like behavior in rat.

The chemical compound gelsemine is the major active principle of the yellow jasmine (Gelsemium) that is generally claimed as possessing anxiolytic properties based on empirical and indirect knowledge. Surprisingly, gelsemine effect on anxiety has until now received only little attention. Here, we used the well-validated method for anxiety assessment, the elevated plus-maze combined with video-tracking, to measure gelsemine action on rat anxiety-like behavior. Rats were intraperitoneally injected (500μl/daily/7days) with gelsemine (10(-6), 10(-10) or 10(-14)M) or control solution. Diazepam (DZP) was used as positive standard anxiolytic and additional controls were naive rats similarly manipulated except being injected. Gelsemine or diazepam treatment did not affect the number of closed arm entries and rears illustrating the rat general activity. In contrast, gelsemine (10(-6) to 10(-10)M) or DZP increased dose-dependently the number of entries and the percent of time spent in the open arms indicating that gelsemine is an anxiolytic. Consistently, we observed that gelsemine (10(-6) to 10(-10)M) or DZP also decreased dose-dependently the percent of protected stretched attend postures, an ethological index of anxiety-like state. Altogether, our results constitute a solid set of fundamental data directly demonstrating anxiolytic properties of gelsemine. The report also opens new perspectives for the development of safe and effective gelsemine- or Gelsemium-based strategies against pathological anxiety.