In the present investigation, we examined the cytotoxic effect of methanolic extract from Origanum vulgare on HCT-116 and MDA-MB-231 cell line in vitro. In order to determine the cytotoxic effects we used an MTT viability assay. The results showed that cell growth is significantly lower in extract treated cells compared to untreated control. The effect of inhibition of cell growth was higher in the treatment of HCT-116 cell line than in MDA-MB-231. Based on the results it is determined that O. vulgare is a significant source of biologically active substances that have cytotoxic and antiproliferative activity in vitro.

The objective of this study was to determine the allelopathic potential of Robinia pseudoacacia L., Ailanthus altissima (Mill.) Swingle and Amorpha fruticosa L. that grow on the fly-ash deposits at the ?Nikola Tesla ? A? thermoelectric power plant in Obrenovac. The chemical characteristics of fly ash, such as pH, electrical conductivity (EC), content of carbon (C) and nitrogen (N), contents of available phosphorus (P2O5) and potassium (K2O), the contents of total and available Fe, Cu, Mn, Ni and Zn as well as of phenolic acids (3,5 dihydroxybenzoic acid (3,5-DHBA) and ferulic acid) and flavonoids (rutin and quercetin) were analyzed in control fly ash (bare zones without vegetation cover) and plant rhizospheric fly ash. In order to determine the allelopathic activity of phenolic compounds in fly ash, modified soil sandwich allelopathic biotests were performed, and Trifolium pratense L. (red clover) was used as the indicator species. A. fruticosa showed the highest allelopathic activity, followed by A. altissima whereas R. pseudoacacia showed the lowest allelopathic potential. Negative correlation was noted between radicle and hypocotyl growth inhibition of red clover and the pH of fly ash. Positive correlations were found between radicle growth inhibition and the content of C, P2O5, total concentrations of Cu, available concentrations of Mn and Ni, the contents of ferulic acid, 3,5-DHBA, and rutin. Our results indicate that A. fruticosa and A. altissima increased the content of phenolics in fly ash, which can act as allelochemicals leading to radicle growth inhibition of red clover in the pioneer plant community on fly-ash deposits. These woody species that colonized fly-ash deposits can initiate the beginning of pedogenetic processes altering the ecosystem processes at degraded sites.

The aim of this study was to determine the ability of roots and above-ground parts of three plant species of the Asteraceae family (Matricaria inodora L., Achillea millefolium L., Crepis setosa Haller fill.) for bioaccumulation and translocation of eight metals (Ca, Mg, Fe, Mn, Cu, Zn, Pb, Cr). Those plants were sampled directly along the lanes of the highway at the entrance into the City of Kragujevac, Republic of Serbia. The investigated metals are emitted into the air from road traffic and are deposited in the surrounding soil. Many of them are toxic to the living organism, and it is, therefore, necessary to apply effective, economical, sustainable methods for their removal from the environment. An example of such a method is as phytoremediation, based on the use of metal hyperaccumulator plants. The results of this research showed the species studied differ in the absorption, translocation and accumulation of investigated metals. They also showed that species M. inodora and A. millefolium (leaves) can be used for the phytoextraction of Ca, Mg, Fe, Mn, Cu, Zn and Cr, species C. setosa (leaves) for Ca, Mg and Cu species M. inodora (stem) for Cr. The results further indicate that all three species absorb Zn from the soil and translocate it to the stems and leaves. All three of the studied species are suitable for phytostabilization of soils loaded with Zn, but only the species M. inodora and C. setosa can be applied in phytoremediation of this metal.

This study aimed to determine the concentrations of ten metals (Mn, Ni, Ca, Mg, Fe, Zn, Cr, Pb, Cd, Cu) in the soil at depths of 10 and 20 cm and selected plant species (Populus nigra L., Fraxinus ornus L., Salix alba L., Salix caprea L.), as well as to assess the ability of these plants of metal bioaccumulation, translocation and phytoremediation on the location of the mine pit and flotation tailings of the selected mine (in the center of the Republic of Serbia). The concentrations of Pb and Cu in the investigated soil at a depth of 10 cm were above remediation values stated in the regulations of the Republic of Serbia. At the same time, the concentration of Cd, Cr, Pb and Cu was above the limit values in both of the examined soil depths, while Ni in the soil at a depth of 10 cm was above the limit value determined in the Directives of the European Union. The species F. ornus shows the ability to phytoextract Ca, species P. nigra Zn, Ca and Cd, while both Salix species have the capacity to phytoextract Zn and Ca. The results showed that species S. alba is an efficient bioaccumulator of Mn, Fe, Cr, Pb, Zn and Ca, S. caprea of Fe, Cu, Cr, Mg and Pb, and P. nigra of Mn and Cd. The bioaccumulation and translocation of the investigated elements depend on plant species and their organ. The selection of plant species adequate for remediation should take this into account.

Asbestos is widely mined and used around the globe posing a great risk to environment and human health. The main objective of this study was to determine allelopathic potential of Robinia pseudoacacia L. and Ailanthus altissima (Mill.) Swingle growing on the asbestos deposits at abandoned mine ?Stragari? in central Serbia. The pH, content of carbon, nitrogen, calcium carbonate, available phosphorous and potassium, content of Fe, Ni, Cu, Zn, Pb, Mn, and phenolics were analyzed in the control asbestos (zones without vegetation cover) and plant rhizospheric asbestos. Allelopathic activity of plant species was assessed by ?rhizosphere soil method?, and Trifolium pratense L. and Medicago sativa L. were used as the indicator species. A. altissima showed higher allelopathic potential compared to R. pseudoacacia for T. pratense and M. sativa due to greater content of phenolics. Alleopathic activity of phenolics in rhizospheric asbestos was highly correlated with pH, content of carbon and nitrogen, available phosphate and potassium, and content of Ni, Cu, Zn, Pb and Mn. A. altissima increased phenolics content in rhizospheric asbestos inhibiting the plant growth. This woody plant in spite of high allelopathic potential is suitable for revegetation of distrurbed ecosystems because it initiates pedogenesis and affects the asbestos chemistry.