title: Oral toxicity of an essential oil from myrtle and adaptive liver stimulation.
abstract: The acute oral toxicity of an essential oil from the leaves of Myrtus communis (M) in rats was 3.7 ml/kg, and 2.2 ml/kg in mice. After repeated daily doses the toxicity decreased considerably and was calculated to be approx. 6.6 ml/kg after 10 days or 3 weeks pretreatment with M. Daily application of M during 10 days increased the relative liver weight of rats by 10, 18 and 28% at the dose levels of 0.5, 1.0 and 2.0 ml/kg. The hepatic endoplasmic reticulum (microsomal fraction) in the rats increased by 13.5, 24 and 33% after 10 days oral application of 0.5, 1.0 and 2.0 ml/kg of M, respectively. Hepatic cytochrome P-450 started to increase after 0.2 ml/kg, and reached 65% above controls after 10 days application of 2.0 ml/kg. Cytochrome b5 responded in a similar manner. The microsomal N-dealkylation of N-methylaniline increased 2.8-fold after daily administration of 2.0 ml/kg during 10 days. Continuous therapeutic application of M to humans in the magnitude of 1--2 ml daily is considered to be too low to influence the hepatic parameters.
mesh_terms: D000814:Aniline Compounds / Q000378:metabolism; D000818:Animals; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D008099:Liver / Q000378:metabolism*; D008297:Male; D008862:Microsomes, Liver / Q000378:metabolism; D009822:Oils, Volatile / Q000633:toxicity*; D009929:Organ Size; D010944:Plants; D051381:Rats
chemical_list: D000814:Aniline Compounds; D009822:Oils, Volatile; D003577:Cytochrome P-450 Enzyme System; C021313:methylaniline