Effect of jinkoh-eremol and agarospirol from agarwood on the central nervous system in mice

Agarwood (Jinkoh in Japanese), one of the Oriental medicines, is used as a sedative. The benzene extract of this medicine showed a prolonged effect on the hexobarbital-induced sleeping time, and hypothermic effects in terms of rectal temperature, a suppressive effect on acetic acid-writhing, and a reduction of the spontaneous motility in mice. By repeated fractionation, oral administration in mice, and pharmacological screening, the active principles, jinkoh-eremol and agarospirol, were obtained from the benzene extract. They also gave positive effects on the central nervous system by peritoneal and intracerebroventricular administration. They decreased both methamphetamine- and apomorphine-induced spontaneous motility. The level of homovanillic acid in the brain was increased by them, while the levels of monoamines and other metabolites were unchanged. Similar results were seen in chlorpromazine-administered mice. Therefore, jinkoh-eremol and agarospirol can be considered to be neuroleptic.