Allelopathic and toxicological effects of Origanum vulgare L. essential oil

Origanum vulgare L. has been proven to be the strongest herbal antiseptic in the world, native to the Mediterranean region, but is widely naturalized elsewhere in the temperate Northern Hemisphere. This study aimed to estimate the phytotoxic effect of three different concentrations of oregano essential oil (O. vulgare) on three selected plant species namely, wheat, tomato and mint using biotest germination and effects on seedling growth, as well as its toxicological properties using Allium test. Our results revealed that oregano essential oil exhibits allelopathic effect on selected species. All three tested concentrations of oregano essential oil caused a significant inhibition of Allium cepa L. root growth, as well as a reduction in the mitotic index values in A. cepa meristem cells. O. vulgare essential oil demonstrated phytotoxic and antiproliferative effects. Further research is needed to confirm our results.