Effect of Gastrodia elata on improving sleep in mice and its mechanism / 中草药

ABSTRACT

Objective: To investigate the sleep promoting effect of Gastrodia elata on mice and its effect on the central dopamine (DA) system, and study the mechanisms of gastrodin, the active constituent of G. elata. Methods: Five groups of mice were treated by gavage with saline, gastrodia, olive oil, gastrodia mixed with olive oil and positive control Estazolam, respectively, for 20 d (10 mice per group). Hypnosis induced by suprathreshold and subthreshold doses of Pentobarbital sodium were used to evaluate the effect of G. elata on sleep in mice. Sleep latency, occurrence rate and duration were recorded at the 7th and 20th day. The DA content in the brain tested by ELISA and the expression of DA receptor subtypes detected by qRT-PCR were used to determine the effect of G. elata on central DA system. Western blotting was further used to detect the expression levels of ERK pathway related protein. Results: After 20 d of gavage, the sleep latency of mice was significantly shortened, the sleep occurrence rate was increased, the sleep duration was prolonged, and the content of brain DA was significantly increased. At the same time, the expression levels of all the dopamine receptor subtypes were significantly up-regulated. Furthermore, the gastrodin, the active constituent of G. elata, could activate the dopamine receptor D2 rather than the D1-mediated signaling pathway. Conclusion: G. elata might regulate sleep by up-regulating the activity of central DA system. Gastrodin, the active constituent of G. elata, could play a regulating role through D2-mediated signaling pathway.