Sedative effects of Iranian Artemisia annua in mice: possible benzodiazepine receptors involvement.

CONTEXT: Artemisia annua L. (Asteraceae), commonly known as sweet wormwood or Qinghao, is an annual herb/shrub native of Asia. The plant grows broadly in Caspian Sea shores in North of Iran. In China, the aerial parts of this plant are source of artemisinin, which is an antimalarial compound.

OBJECTIVE

This study aimed to establish the scientific basis of reported ethnomedicinal use of A. annua as sedative agent.

MATERIAL AND

METHODS

The plants were gathered from Gilan Province in Iran. Plant aerial parts were extracted with methanol and concentrated in vacuum. Methanol extract was partitioned into chloroform, petroleum ether, and ethyl acetate. Each fraction was administered intraperitoneally (i.p.) in male mice with different concentrations (50, 100, and 200 mg/kg), and for evaluation of sedative activity, immobility time was determined. In effort to clarify the mechanism of action, flumazenil (3 mg/kg, i.p.) as a benzodiazepine (BZD) receptor antagonist was injected 15 min before chloroform fraction (200 mg/kg, i.p.).

RESULTS

Compared with control group (saline-treated mice), the chloroform fraction significantly increased immobility time in a dose-dependent manner. Flumazenil decreased immobility time induced by chloroform fraction significantly.

DISCUSSION AND

CONCLUSION

The results of the present study suggest that A. annua growing in Iran has sedative effects, which are probably mediated via BZD receptors pathways.