Single dose toxicity study of beta-myrcene, a natural analgesic substance.

The present study was undertaken to provide data on acute toxicity of beta-myrcene, a peripheral analgesic substance found in the essential oils of several plants. Although myrcene has long been used in perfumes and as a food additive, there is almost no information on its toxicological hazards. The acute oral toxicity of myrcene was low in rodents, with approximate lethal doses (ALD) of 5.06 g/kg body weight for mice and greater than 11.39 g/kg body weight for rats. Necropsy data did not reveal any relevant alteration in rats but histopathology findings in mice suggested that the liver and stomach may be target organs for myrcene toxicity after oral administration. Myrcene is highly irritant to the peritoneum, and deaths after intraperitoneal injection of this monoterpene in rats (ALD 5.06 g/kg body weight) and in mice (ALD 2.25 g/kg body weight) were probably due to drug-induced chemical peritonitis.