Determination of heavy metal contents in stinging nettle from different localities in Serbia

Abstract

The stinging nettle (Urtica dioica L.) belongs to the Urticaceae family and represents a perennial plant. Stinging nettle is abundant species occurring in various types of forest, road verges and grassland sites. In many countries is used as both medicine and food. Stinging nettle is a weed and its seeds, leaves and even roots are used for medicinal purpose. Thanks to its high content of nutrients and bioactive compounds like poly phenols, vitamins and minerals, nettle possesses a great nutritional value and a large number of pharmacological effects, including anti-proliferative, anti-inflammatory, antioxidant, analgesic, immunostimulatory, anti-infectious, hypotensive, antiulcer activities and cardiovascular disease prevention. It is a reservoir of minerals (especially iron), vitamin C and pro-vitamin A. Last decades the popularity of herbal medicine is rapidly increasing all over the world. However, heavy metal toxicity in plant materials has a great impact and importance on herbal plants and consequently affects the quality of herbal raw materials, herbal extracts, the safety and marketability of drugs. This paper presents determination of content seven heavy metals (Cu, Fe, Mn, Ni, Zn, Cd and Pb) in leaves samples Urtica dioica L. collected from five localities in Republic of Serbia. The sample preparation procedure involved dry digestion in triplicate and dissolution of the ash in 6M HCl and then in 0.1 M HNO3. All elements were analyzed using an inductively coupled plasma-optical emission spectrometry (ICP-OES). The contents of Ni, Cu, Zn, Mn and Fe in the leaves were found to be in the ranges of 0.54±0.00 to 1.87±0.10 ˂ 2.12±0.69-12.79±0.53 ˂ 18.18±0.46-28.48±1.37 ˂ 30.63±1.45-68.44±5.11, and 109.75±4.01-244.41±13.50 mg/kg dry weight, respectively. Value of toxic heavy metal Pb in two samples is 0.37±0.0 mg/kg dry weight, whiles content Cd has been below the detection limit. The content of heavy metals in samples were used to calculate target hazard quotients values (THQ) and hazard index (HI).