Comparative Analysis of the Trace Element Content of the Leaves and Roots of Three Plantago Species

Using Plantago major and Plantago lanceolata in environmental pollution research in an urban area of Southern Poland

The aim of this study was to perform a complex assessment of changes in the elements of an ecosystem that are caused by environmental pollution in industrial and urban biotopes. The study focused on three sites: a park, a road and the site of the metallurgical plant "Pokój" in the city of Ruda Śląska (Southern Poland), which are each under a different level of anthropogenic load. Soil and plant material samples (Plantago major and Plantago lanceolata leaves) were investigated by performing biochemical, ecophysiological and scanning electron microscopy (SEM) analyses. A significant difference was observed in all of the study samples. The content of Pb, Zn and Cd in the soil samples that had been collected at the site of the metallurgical plant exceeded the permitted limits (Cd > 4 mg kg^-1, Pb > 100 mg kg^-1, Zn > 300 mg kg^-1). The content of Fe, Mn, Pb, Cd and Zn in the plant material was much higher in unwashed samples than in washed samples. The concentrations of potentially toxic elements (PTEs) were below the permitted level in the leaves of Plantago lanceolata for Cd (> 5 mg kg^-1) and in the leaves of Plantago major for Zn (> 100 mg kg^-1). The SEM observations revealed a significant decrease in the stomata pore length (SPL) in the Plantago lanceolata leaves that had been collected at the road site compared with the plants from the park site. The elemental content on the leaf surface was also determined using X-ray microanalysis. The total chlorophyll (Chl) content, ascorbic acid (AA), proline, guaiacol peroxidase (GPX) activity, pH, relative water content (RWC) and air pollution tolerance index (APTI) were evaluated. The APTI for the investigated species ranged from 5.6 to 7.4, which demonstrated that the studied plant species are sensitive to air pollutants.

Trace elements in Plantago lanceolata L., a plant used for herbal and food preparations: new data and literature review

Plantago lanceolata L. is a common grassland and roadside plant, widely used in many countries in food and herbal preparations. In this study, samples of this wild plant were collected from rural, suburban/urban, and industrial environments; the concentrations of As, Cd, Co, Cu, Fe, Mn, Ni, P, Pb, V, and Zn were measured in the edible parts of the plant (leaves), in the roots, and in the soils in order to calculate the bioaccumulation and translocation factors. The data obtained were compared with literature data available. Except for samples collected near mines and smelting plants, where Cd, Pb, and Zn concentrations were up to 15 times higher, in all other cases, no differences were observed with respect to samples from rural areas, except for Pb concentration, which was 3 times higher in urban areas. In the samples collected in our study area, the metal content does not pose particular health risks; however, even within a quite restricted region like the investigated area, high metal concentrations, possibly due to the presence of particular substrates, were observed in some samples collected from areas considered "clean" and suitable for wild food plant gathering.

Comparative Analysis on the Effect of Plantago Species Aqueous Extracts on Tissue Trace Element Content in Rats

The primary objective of this study is to assess the influence of water extracts of Plantago major L., Plantago lanceolata L., and Plantago maxima Juss. ex Jacq. leaves on tissue trace element content in healthy adult Wistar rats. Twenty-eight female Wistar rats consumed pure drinking water or one of the three aqueous extracts of Plantago for 1 month. The extracts and liver, serum, hair, and adipose tissue of the rats were examined for trace element contents using inductively coupled plasma mass spectrometry. The aqueous extracts of Plantago species contained significant levels of trace elements, which were highest in P. lanceolata and P. major. The administration of every extract led to an increase in V and Si levels in the rats. At the same time, the consumption of P. lanceolata aqueous extract resulted in the accumulation of toxic elements (As, Pb) in the rats' tissues. Despite the rather high concentration of heavy metals in the P. major leaf extract, its administration did not result in the accumulation of these elements. In turn, P. maxima extract induced a significant decrease in the tissue levels of Al, Cr, I, Li, and Mn in the rats. The beneficial effect of the P. major and P. maxima preparations may be at least partially associated with the increased supply of essential trace elements, whereas the use of P. lanceolata may be harmful due to the possibility of heavy metal overexposure.