Tanacetum parthenium enhances pentobarbital-induced sleeping behaviors

Sleep disorders are among the most common psychiatric and medical conditions. In the present study, the hypnotic effect of Tanacetum parthenium was studied in mice.  The hydro-alcoholic extract (HAE) of T. parthenium and three fractions of it, namely water fraction (WF), ethyl acetate fraction (EAF), and n-hexane fraction (NHF), were intraperitoneally (ip) administrated to mice 30 min before injection of sodium pentobarbital (30 mg/kg, ip). Then, 30 min after administration of HAE, motor coordination (rota-rod test) was evaluated. Besides, LD50 of HAE was determined and the cytotoxicity of HAE was evaluated in PC12 cells using the MTT assay. HAE 50-200 mg/kg increased the sleeping time. EAF was the only fraction which could prolong the sleep duration and decrease sleep latency. The LD50 value was 4.8 g/kg. The extract induced no cytotoxic effects in PC12 cell line. The results suggested that T. parthenium potentiates pentobarbital hypnosis without causing toxic effects. Probably, its effects are mediated by the components present in EAF of this plant.