Heavy metals: a source of contamination for medicinal plants and possible implications to human health

Abstract

Due to the antioxidant properties of medicinal plants and their beneficial effects on human health, theyare used and consumed as natural medical sources. Despite this, due to the current pollution of environmental compartments (soil, water, air), they can be contaminated with various pollutants. Heavy metals are a category of toxic compounds of great interest, due to the negative action on the environment and human health. Although some heavy metals are important in maintaining the proper functioning of plants, in high concentrations, they can become toxic. In the context of heavy metal pollution of the environment and possible contamination of medicinal plants with these pollutants, the need for chemical analysis of toxic plant compounds is necessary. This paper approaches results from literature which show that medicinal plants can be subjected to contamination with heavy metals, and this has the consequence of altering the normal functions of medicinal plants. Moreover, following consumption through the food chain (soil -plant -human or soil -plant -animal -human), human health may be endangered. This paper also investigates the toxic action of heavy metals in plants, represented, in principle, by the production of reactive oxygen species (ROS), enzyme inhibition and damage to antioxidants.