Phytotoxicity and Cytotoxicity of Essential Oil from Leaves of Plectranthus amboinicus, Carvacrol, and Thymol in Plant Bioassays.

The essential oil of Plectranthus amboinicus and its chemotypes, carvacrol and thymol, were evaluated on the germination and root and aerial growth of Lactuca sativa and Sorghum bicolor and in acting on the cell cycle of meristematic root cells of L. sativa. The main component found in the oil by analysis in gas chromatography-mass spectrometry and gas chromatography flame ionization detection was carvacrol (88.