Essential oils of commonly used plants as inhibitors of peroxynitrite-induced tyrosine nitration.

The essential oils obtained from fifteen relevant and commonly used plants belonging to Cruciferae, Lamiaceae, Lauraceae, Apiaceae, and Zingiberaceae were screened using an in vitro model of peroxynitrite-induced tyrosine nitration. Almost complete inhibition of 3-nitrotyrosine formation (91% at 300 microg/ml) was achieved only with the essential oil obtained from the leaves of Laurus nobilis. 1,8-Cineol, accounting for a 50% of this essential oil, which resulted as inactive in this model, thus evidencing a major role for the minor volatile compounds present in the leaves.