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Papers by Valerija Vujčić

Research paper thumbnail of Toxicity and antioxidant capacity of Frangula alnus Mill. bark and its active component emodin

Regulatory toxicology and pharmacology : RTP, Jan 20, 2015

In the present study toxicity of Frangula alnus Mill. bark, widely used as laxative, was investig... more In the present study toxicity of Frangula alnus Mill. bark, widely used as laxative, was investigated. Human peripheral blood lymphocytes (HPBLs) were treated with F. alnus bark extract or emodin (emodin is bark component with laxative property), and cytotoxicity, genotoxicity and parameters of oxidative stress were assessed. Also, polyphenol content of bark extract and antioxidant activity of the extract and emodin measured by DPPH, ABTS and FRAP methods were examined. The bark extract (500 μg/ml) produced cell death and DNA damage, while level of ROS changed at 250 μg/ml. Emodin induced cell death and DNA damage at 150 μg/ml and 200 μg/ml, respectively, and the increase of ROS was observed at 25 μg/ml. These results suggest that both, bark extract and emodin, are cyto/genotoxic to HPBLs and that oxidative stress is involved in the mechanism of their toxicity. The results on antioxidant activity showed that, unlike emodin, bark extract possess moderate antioxidant capacity (44.6%, ...

Research paper thumbnail of Removal of landfill leachate toxicity and genotoxicity by two treatment methods

Archives of Industrial Hygiene and Toxicology, 2014

Leachates from active and closed municipal solid waste landfills can be a major source of contami... more Leachates from active and closed municipal solid waste landfills can be a major source of contamination to groundwater and surface waters. In the present study the toxic and genotoxic potential of leachate from an old sanitary landfill prior to and following chemical and electrochemical treatments were assessed using Lemna, Allium, and comet tests. Photosynthetic pigments, malondialdehyde (indicator of lipid peroxidation) and antioxidant enzyme activities were evaluated as additional indicators of toxicity in duckweed. Following duckweed exposure to 25 % dilution of landfill leachate, growth rate and photosynthetic pigments content significantly decreased while lipid peroxidation increased despite stimulation of antioxidative defence mechanisms. Diluted leachate induced DNA strand breaks in duckweed cells as evidenced by the comet assay. Regarding the Allium test, untreated leachate caused inhibition of Allium cepa cell division and induction of mitotic and chromosomal aberrations. Although both water treatments completely reduced genotoxicity of leachate, the electrochemical method was found to be more efficient in removing toxic substances present in landfill leachate and thus more suitable for treating such leachates prior to their discharge into the environment. As landfill leachates pose a risk to human health and environment in general due to their (geno)toxicity, the present study demonstrates that the ecotoxicity/genotoxicity assays should be used in leachate risk assessment together with physicochemical analysis.

Research paper thumbnail of Physiological and Biochemical Responses of Fibigia Triquetra (DC.) Boiss. to Osmotic Stress

Acta Botanica Croatica, 2014

Water defi cit in the soil leads to osmotic stress in plants. The type of stress affects plant wa... more Water defi cit in the soil leads to osmotic stress in plants. The type of stress affects plant water relations, osmolyte accumulation and oxidative stress balance. The present study aimed to investigate the effects of osmotic stress on the Croatian perennial species Fibigia triquetra (DC.) Boiss, adapted to a hot and dry habitat. Plants grown in culture conditions were subjected to isoosmotic concentrations of mannitol and polyethylene glycol (PEG) and certain physiological and oxidative stress parameters were analyzed during a period of 14 days. Dry weight and proline content in Fibigia triquetra shoots increased in response to osmotic stress while the relative water content decreased. After an initial rise, chlorophyll and carotenoid levels in treated plants dropped to untreated plant levels. Oxidative damage to proteins and especially to lipids was evident upon PEG-induced osmotic stress. Superoxide dismutase and ascorbate peroxidase appear to play an essential protective role in stressed plants. Regardless of the osmotic agent, accumulation of heatshock proteins of 70 kDa was noticed under osmotic stress. The tolerance of the plant species to osmotic stress seems to be associated with increased capacity of the antioxidative system and effi cient photoprotective system.

Research paper thumbnail of The efficiency of combined CaO/electrochemical treatment in removal of acid mine drainage induced toxicity and genotoxicity

Science of The Total Environment, 2014

Acute geno(toxic) impacts of treated and untreated acid mine drainage were assessed.

Research paper thumbnail of The evaluation of surface and wastewater genotoxicity using the Allium cepa test

Science of The Total Environment, 2010

Screening for mutagens in complex environmental mixtures, such as surface water or industrial was... more Screening for mutagens in complex environmental mixtures, such as surface water or industrial wastewater, is gradually being accepted as a routine method in environmental monitoring programs. In the present work, the simplified Allium cepa root assay was utilized to evaluate the possible cyto-and genotoxic effects of surface and wastewaters collected near the Sava River (Croatia) over a three-month monitoring period. Physicochemical characterization of the water samples included measurements of conductivity, chemical and biological oxygen demand, levels of suspended matter and salts, nitrate, nitrite, ammonium, total nitrogen and total phosphorus. Morphological modifications of the A. cepa roots, inhibition of root growth, cell division and induction of mitotic and chromosomal aberrations were observed. The most highly polluted water samples (industrial effluents) caused an inhibition of root growth of over 50%, a decrease in the mitotic index of over 40%, and a considerable increase in chromosomal aberrations compared to the control. The measured biological effects of some water samples appeared related to the physicochemical characteristics. Therefore, mutagenicity/genotoxicity assays should be included, along with conventional chemical analysis, in water quality monitoring programs. Their use would allow the quantification of mutagenic hazards in surface and wastewaters.

Research paper thumbnail of Assessment of surface water in the vicinity of fertilizer factory using fish and plants

Ecotoxicology and Environmental Safety, 2013

The genotoxic and toxic potential of polluted surface water exposed to a fertilizer factory efflu... more The genotoxic and toxic potential of polluted surface water exposed to a fertilizer factory effluent was evaluated using assays with fish (Cyprinus carpio) and plant (Lemna minor) model organisms. Beside classical physicochemical parameters, the contents of fluorides, some heavy metals and polycyclic aromatic hydrocarbons were analyzed as well. Surface water caused inhibition of plant growth and decrease of photosynthetic pigment content. Regarding DNA damage and oxidative stress parameters, both fish and plants showed similar response to the surface water. In confirmation to biochemical markers, histopathological analysis of gill and liver tissues revealed a higher incidence of lesions in fish exposed to polluted surface water. Generally, results obtained by biological monitoring were mostly in agreement with chemical analysis of the surface water, although several discrepancies were observed which might be due to difference in sensitivity of model organisms or in experimental conditions (laboratory and field exposure). The results imply that conventional chemical analysis should be extended to genotoxicity/toxicity assays as measured biological effects and the potential health hazard cannot be predicted based on the physicochemical characteristics of water samples alone.

Research paper thumbnail of Toxicity and antioxidant capacity of Frangula alnus Mill. bark and its active component emodin

Regulatory toxicology and pharmacology : RTP, Jan 20, 2015

In the present study toxicity of Frangula alnus Mill. bark, widely used as laxative, was investig... more In the present study toxicity of Frangula alnus Mill. bark, widely used as laxative, was investigated. Human peripheral blood lymphocytes (HPBLs) were treated with F. alnus bark extract or emodin (emodin is bark component with laxative property), and cytotoxicity, genotoxicity and parameters of oxidative stress were assessed. Also, polyphenol content of bark extract and antioxidant activity of the extract and emodin measured by DPPH, ABTS and FRAP methods were examined. The bark extract (500 μg/ml) produced cell death and DNA damage, while level of ROS changed at 250 μg/ml. Emodin induced cell death and DNA damage at 150 μg/ml and 200 μg/ml, respectively, and the increase of ROS was observed at 25 μg/ml. These results suggest that both, bark extract and emodin, are cyto/genotoxic to HPBLs and that oxidative stress is involved in the mechanism of their toxicity. The results on antioxidant activity showed that, unlike emodin, bark extract possess moderate antioxidant capacity (44.6%, ...

Research paper thumbnail of Removal of landfill leachate toxicity and genotoxicity by two treatment methods

Archives of Industrial Hygiene and Toxicology, 2014

Leachates from active and closed municipal solid waste landfills can be a major source of contami... more Leachates from active and closed municipal solid waste landfills can be a major source of contamination to groundwater and surface waters. In the present study the toxic and genotoxic potential of leachate from an old sanitary landfill prior to and following chemical and electrochemical treatments were assessed using Lemna, Allium, and comet tests. Photosynthetic pigments, malondialdehyde (indicator of lipid peroxidation) and antioxidant enzyme activities were evaluated as additional indicators of toxicity in duckweed. Following duckweed exposure to 25 % dilution of landfill leachate, growth rate and photosynthetic pigments content significantly decreased while lipid peroxidation increased despite stimulation of antioxidative defence mechanisms. Diluted leachate induced DNA strand breaks in duckweed cells as evidenced by the comet assay. Regarding the Allium test, untreated leachate caused inhibition of Allium cepa cell division and induction of mitotic and chromosomal aberrations. Although both water treatments completely reduced genotoxicity of leachate, the electrochemical method was found to be more efficient in removing toxic substances present in landfill leachate and thus more suitable for treating such leachates prior to their discharge into the environment. As landfill leachates pose a risk to human health and environment in general due to their (geno)toxicity, the present study demonstrates that the ecotoxicity/genotoxicity assays should be used in leachate risk assessment together with physicochemical analysis.

Research paper thumbnail of Physiological and Biochemical Responses of Fibigia Triquetra (DC.) Boiss. to Osmotic Stress

Acta Botanica Croatica, 2014

Water defi cit in the soil leads to osmotic stress in plants. The type of stress affects plant wa... more Water defi cit in the soil leads to osmotic stress in plants. The type of stress affects plant water relations, osmolyte accumulation and oxidative stress balance. The present study aimed to investigate the effects of osmotic stress on the Croatian perennial species Fibigia triquetra (DC.) Boiss, adapted to a hot and dry habitat. Plants grown in culture conditions were subjected to isoosmotic concentrations of mannitol and polyethylene glycol (PEG) and certain physiological and oxidative stress parameters were analyzed during a period of 14 days. Dry weight and proline content in Fibigia triquetra shoots increased in response to osmotic stress while the relative water content decreased. After an initial rise, chlorophyll and carotenoid levels in treated plants dropped to untreated plant levels. Oxidative damage to proteins and especially to lipids was evident upon PEG-induced osmotic stress. Superoxide dismutase and ascorbate peroxidase appear to play an essential protective role in stressed plants. Regardless of the osmotic agent, accumulation of heatshock proteins of 70 kDa was noticed under osmotic stress. The tolerance of the plant species to osmotic stress seems to be associated with increased capacity of the antioxidative system and effi cient photoprotective system.

Research paper thumbnail of The efficiency of combined CaO/electrochemical treatment in removal of acid mine drainage induced toxicity and genotoxicity

Science of The Total Environment, 2014

Acute geno(toxic) impacts of treated and untreated acid mine drainage were assessed.

Research paper thumbnail of The evaluation of surface and wastewater genotoxicity using the Allium cepa test

Science of The Total Environment, 2010

Screening for mutagens in complex environmental mixtures, such as surface water or industrial was... more Screening for mutagens in complex environmental mixtures, such as surface water or industrial wastewater, is gradually being accepted as a routine method in environmental monitoring programs. In the present work, the simplified Allium cepa root assay was utilized to evaluate the possible cyto-and genotoxic effects of surface and wastewaters collected near the Sava River (Croatia) over a three-month monitoring period. Physicochemical characterization of the water samples included measurements of conductivity, chemical and biological oxygen demand, levels of suspended matter and salts, nitrate, nitrite, ammonium, total nitrogen and total phosphorus. Morphological modifications of the A. cepa roots, inhibition of root growth, cell division and induction of mitotic and chromosomal aberrations were observed. The most highly polluted water samples (industrial effluents) caused an inhibition of root growth of over 50%, a decrease in the mitotic index of over 40%, and a considerable increase in chromosomal aberrations compared to the control. The measured biological effects of some water samples appeared related to the physicochemical characteristics. Therefore, mutagenicity/genotoxicity assays should be included, along with conventional chemical analysis, in water quality monitoring programs. Their use would allow the quantification of mutagenic hazards in surface and wastewaters.

Research paper thumbnail of Assessment of surface water in the vicinity of fertilizer factory using fish and plants

Ecotoxicology and Environmental Safety, 2013

The genotoxic and toxic potential of polluted surface water exposed to a fertilizer factory efflu... more The genotoxic and toxic potential of polluted surface water exposed to a fertilizer factory effluent was evaluated using assays with fish (Cyprinus carpio) and plant (Lemna minor) model organisms. Beside classical physicochemical parameters, the contents of fluorides, some heavy metals and polycyclic aromatic hydrocarbons were analyzed as well. Surface water caused inhibition of plant growth and decrease of photosynthetic pigment content. Regarding DNA damage and oxidative stress parameters, both fish and plants showed similar response to the surface water. In confirmation to biochemical markers, histopathological analysis of gill and liver tissues revealed a higher incidence of lesions in fish exposed to polluted surface water. Generally, results obtained by biological monitoring were mostly in agreement with chemical analysis of the surface water, although several discrepancies were observed which might be due to difference in sensitivity of model organisms or in experimental conditions (laboratory and field exposure). The results imply that conventional chemical analysis should be extended to genotoxicity/toxicity assays as measured biological effects and the potential health hazard cannot be predicted based on the physicochemical characteristics of water samples alone.