Antiinflammatory and antinociceptive effects of 1,8-cineole a terpenoid oxide present in many plant essential oils

1.8-Cineole (cineole), a terpenoid oxide present in many plant essential oi ls displays an inhibitory effect on some types of experimental inflammation in rats, i.e. paw oedema induced by carrageenan and cotton pellet-induced granuloma, Cineole also inhibits in mice, the acetic acid-induced increase in peritoneal capillary permeability and the chemical nociception induced b y intraplantar formalin and intraperitoneal acetic acid, Activity was prese nt in these tests, at an oral dose range of 100-400 mg/kg, In the formalin test, the antinociceptive effect of cineole mas not reversed by pretreatmen t of mice with naloxone (1 mg/kg, s.c.), a mu-opioid receptor antagonist, s uggesting the involvement of a non-opioid mechanism. Cineole demonstrated a significant inhibitory effect on locomotion and also potentiated the pento barbital sleeping time in mice, indicating a plausible depressant effect on the central nervous system. The present results, when taken together with the recent reports that describe the inhibitory effects of cineole on the f ormation of prostagtandins and cytokines by stimulated monocytes in vitro, may provide additional evidence for its potential beneficial use in therapy as an antiinflammatory and analgesic agent. Copyright (C) 2000 John Wiley & Sons, Ltd.