Introduction: The side-effects and short anesthesia caused by ketamine limit its individual application. Moreover, the anti-inflammatory, sedative and muscle relaxant effects of borneol as an analgesic and anesthetic have promoted its application in Chinese and Japanese medicine. This study examined the effects of co-administration of borneol and ketamine on anesthesia parameters in male rats.  
Materials and Methods: Twenty-four male rats were divided into four groups, and respectively received borneol (Bo), ketamine (K), borneol-ketamine (BoK) and diazepam-ketamine (DK). Parameters recorded included the heart rate, respiratory rate, body temperature and pain reflexes (ear, tail and pedal), induction time, duration of surgical anesthesia and walking time.
Results: Borneol did not individually induce surgical anesthesia, which was reached faster in group DK than in group BoK (P<0.05). Insignificant differences in duration of surgical anesthesia, walking time and pain reflexes were observed between groups BoK and DK (P>0.05). The heart rate, respiratory rate and body temperature were higher in group BoK than in group DK (P<0.05).
Conclusion: The pre-anesthetic and hypnotic effects of borneol were similar to those of diazepam. Further studies are, however, required for determining the exact pharmacological mechanism of borneol.