Sleep Induced By A Herbal Agent Polygala tenuifolia Versus That By Alprazolam: A Review With New Data On EEG And Sleep Duration

This study is the first comparison of an herbal agent with a well-established hypnotic for sleep.The beneficial effects for sleep of the herb Polygala tenuifolia (with main sedative componentsbeing 3,4-methoxycinnamic acid and phenylpropanoids) and Alprazolam were investigated,and our results indicated that both could benefit sleep via the shortening of sleep induction time and the increase in wave forms of electroencephalogram (EEG) associated with stages 1, 2 and 3 of the non-rapid eye movement (NREM) sleep. Increase of numbers of theta waves,v waves, delta waves and k complex were observed in mice, indicating deeper and better quality of sleep. There was an obvious increase in the duration of theta plus delta waves in both Polygala and Alprazolam treated groups, while the wave duration was slightly longer in the Polygala group than the Alprazolam group. When the Alprazolam treated group was added with Polygala, the theta plus delta wave duration increased and exceeded that from Alprazolam treatment alone. Similarly, increase of duration of k complex was also observed in both Polygala and Alprazolam treated groups. This study illustrated that the herbal agent Polygala tenuifolia could have at least similar efficacy in the induction of sleep as the manufactured drug Alprazolam.