Heavy metals content in leaves and extracts of wild-growing Salvia officinalis from Montenegro

Salvia officinalis L. (Dalmatian sage) is used traditionally in medicine as herbal tea and as a tonic, antiseptic and for inflammations and infections in the mouth. Also, sage is widely used as food flavouring, either as dried leaves or as the essential oil or oleoresin. Thus, any heavy metal accumulation by this plant would increase the possibility of heavy metal toxicity to consumers. In Montenegro, sage and some other aromatic herbs grow wild in close proximity to major roads. This study aims to establish the impact of pollution on the composition of sage leaves and this first investigation acts as a platform from which further work will follow. The total contents of Pb, Cd, Cu and Zn in Salvia officinalis leaves and in essential oil, solvent extract, tea brew and tea infusion at selected distances from a heavy metal pollution source was examined. Generally, it was found that the concentration of heavy metals decreases at 50 m, i.e. 100 m from the edge of a major road. Therefore the impact of road traffic through the pollution of aromatic herbs was noted. The concentration of hazardous heavy metals Pb and Cd in all investigated sage extracts was bellow detection limits of the analytical technique used while the solubility of heavy metals Zn and Cu was the highest in tea infusion extract.