Murat Ozmen

Evaluation of the Toxicity and Teratogenity of Six Commercial Textile Dyes Using the Frog Embryo Teratogenesis Assay–Xenopus

Potential developmental toxicities of six different textile dyes were evaluated using the frog embryo teratogenesis assay–Xenopus (FETAX). Xenopus laevis embryos were exposed to astrazon red FBL, astrazon blue FGRL, remazol red RR, remazol turquoise blue G-A, cibacron red FN-3G, and cibacron blue FN-R from stage 8 to 11 for a 96-h exposure period in static renewal test conditions. A minimum of 17 concentration–response tests were performed with tested dyes, excluding a control group for each dye. Median lethal concentration (LC50), malformation (EC50), non observed adverse effect concentration (NOAEC), and lowest observed adverse effect concentration (LOAEC) were calculated. Also, teratogenic index (TI), minimum concentration to inhibit growth (MCIG), and MCIG/LC50 values were determined for each of the tested dyes. Characteristic abnormalities induced by a given test material were determined by the relationship between concentration and dye in the study. Results from these studies suggested that each tested dye is teratogenic for X. laevis embryos. The lowest LC50 was determined for astrazon red exposure corresponding to a value of 4.73 mg/L. The LC50 value was similar for this dye and astrazon blue; the highest TI was calculated for astrazon blue exposure. Tests with X. laevis indicated that each of the tested compounds possessed teratogenic potential with varying degrees of potency: astrazon blue FGRL > remazol turquoise blue G-A > astrazon red FBL > cibacron blue FN-R > cibacron red FN-3G > remazol red RR. Different types of malformationsoccurred in the embryos, depending on concentration and dye. From these results, we can suggest that astrazon blue is the most toxic compound, but that the others are also highly toxic and teratogenic substances for X. laevis embryos. Results of the study confirmed that the FETAX assay can be useful in an integrated biological hazard assesment for the preliminary screening of textile dye stuff.

Histopathological changes in the livers and kidneys of fish in Sariyar Reservoir, Turkey.

In this study, a total of 180 fish specimens (wels: Silurus glanis-60; common carp: Cyprinus carpio-60; bleak: Alburnus escherichii-60) of ages between one and two were caught at three different stations in Sariyar Reservoir. The histological changes in the livers and kidneys of three different species of fish were detected microscopically and evaluated with quantitative analyses. Also, organochlorine pesticide residues (OCP) have also been determined in the water and sediment samples and in the adipose tissues of fish caught in these stations. Results show that the reservoir was polluted by different kinds of OCP compounds and these chemicals have accumulated in the fish tissues. As a result of these analyses, histopathological changes were observed in the livers and kidneys of fish specimens, such as mononuclear cell infiltration, congestion and nuclear picnosis. Also intra-cytoplasmic cholestasis in their livers and tubular degenerations in the kidneys were observed. The incidences of the histopathological changes in wels and carps were found to be higher than bleak. Furthermore, histopathological changes in fish samples caught from Usakbuku were much more than the samples caught from other stations (Sariyar and Nallihan Bird Paradise Stations). In this study the possible reasons of histopathological changes were evaluated with respect to different fish species and localities and also the findings were evaluated in relation to OCP contamination.

Subacute toxicity of uranyl acetate in Swiss-Albino mice.

Subacute effects of uranyl acetate were investigated in laboratory mice (Mus musculus, Swiss-Albino). Uranyl acetate was administrated to mice during a period of 5 days with dietary consumption ad libitum. Effects of uranyl acetate on food and water consumption, body weight changes; plasma urea nitrogen (BUN), creatinine concentrations and activities of alkaline phosphatase (ALP), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were assayed by time-course experiment. Glutathione S-transferase (GST) and catalase (CAT) activities were also determined in liver tissues on day 5. Distribution of radioactivity in liver, kidney and brain was detected by scintillation spectrometry. The results indicated that uranyl acetate was accumulated in examined tissues, with highest accumulation being in brain. Some of the biochemical biomarkers (BUN, creatinine, ALP) were significantly increased (P<0.05) in the exposure group compared to control animals. Also, BUN and/or creatinine levels and/or ALT and AST activities significantly increased (P<0.01 or P<0.05) with UA exposure on day 3 and/or day 5 compared with results of day 1.

Micro-organic pollutants and biological response of mussels in marinas and ship building/breaking yards in Turkey

Concentrations of PAHs, PCBs and OCPs in sediments and mussels (caged and/or native) were determined at 16 stations in six major sites of coastal Turkey. The biological effects of pollution were evaluated using sediment toxicity tests and enzyme activity assays. EROD, PROD, GST, AChE, CaE, and GR activities were evaluated using the digestive glands of mussels. The total PAH concentrations in the sediments varied between nd and 79,674 ng g(-1) dw, while the total OCP concentrations were in the range of nd to 53.7 ng g(-1) dw. The total PAH concentrations in mussels varied between 22.3 and 37.4 ng g(-1) ww. The average concentrations of total PCBs in mussels were 2795 pg g(-1) ww in the shipyard, 797 pg g(-1) ww in Marina 2 and 53 pg g(-1) ww in Marina 1 stations. The results of whole-sediment toxicity tests showed a strong correlation between toxicity test results and pollutant concentrations. Selected cytosolic enzyme activities in digestive glands differed significantly depending on localities. These differences in enzyme activities were mainly related to the different pollutant levels of the sampling sites. The micro-organic contaminant profile patterns, toxicity tests and biomarker studies showed that shipyards and shipbreaking yards are the major potential sources of organic pollution in coastal areas.

Low concentrations of metal mixture exposures have adverse effects on selected biomarkers of Xenopus laevis tadpoles.

Polluted ecosystems may contain mixtures of metals, such that the combinations of metals, even in low concentrations, may cause adverse effects. In the present study, we focused on toxic effects of mixtures of selected metals, the LC50 values, and also their safety limit in aquatic systems imposed by the European legislation using a model organism. Xenopus laevis tadpoles were used as test organisms. They were exposed to metals or their combinations due to 96-h LC50 values. Glutathione S-transferase (GST), glutathione reductase (GR), acetylcholinesterase (AChE), carboxylesterase (CaE), glutathione peroxidase (GPx), and catalase (CAT) levels were evaluated. Metallothionein concentrations were also determined. The LC50s for Cd, Pb, and Cu were calculated as 5.81mg AI/L, 123.05mg AI/L, and 0.85mg AI/L, respectively. Low lethality ratios were observed with unary exposure of each metal in lower concentrations. Double or triple combinations of LC50 and LC50/2 concentrations caused 100% lethality with Cd+Cu and Pb+Cd+Cu mixtures, while the Pb+Cu mixture also caused high lethal ratios. The selected enzyme activities were significantly affected by metals or mixtures, and dose-related effects were determined. The metallothionein levels generally increased as related to concentration in unary metals and mixtures. Acceptable limit values of unary metals and mixtures did not significantly change metallothionein levels. The results suggest that oxidative stress-related mechanisms are involved in the toxicity induced by selected metals with combinations of very low concentrations.

Assessment of seasonal and sex-related variability of biomarkers in carp (Cyprinus carpio L.) from Karakaya Dam Lake, Turkey.

This study examines seasonal changes in the activities of selected biomarkers in carp (Cyprinus carpio L.) from Karakaya Dam Lake and evaluates the influence of gender and environmental factors on those activities. Physicochemical characteristics of water were evaluated in the lakewater. Fish were sampled on seasonal basis, and liver ethoxyresorufin-O-deethylase (EROD), glutathione-S-transferase, glutathione reductase, plasma lactate dehydrogenase, aspartate and alanine aminotransferase, and brain acetylcholinesterase (AChE) activities were assayed. Plasma vitellogenin level and hepatosomatic index and condition factors were also determined. Strong seasonal variations were observed but there were no gender differences among selected markers. The highest vitellogenin level of male fish was detected as 606ng/mL which represents the estrogenicity of water in the lake in September 2005. In addition, the seasonal changes of some biomarkers such as EROD and AChE showed that the lake may be at risk of pollution by some xenobiotics arising from agricultural and/or industrial activities.

Evaluation of in vitro and in vivo toxic effects of newly synthesized benzimidazole-based organophosphorus compounds.

This paper reports the toxic properties of eight newly synthesized benzimidazole-based organophosphorus (OP) compounds in Xenopus laevis in both in vivo and in vitro conditions. For both experiments, a commercial solution of azinphos methyl (AzM, Gusathion M WP25) was used as a reference compound. The 24-h median lethal concentrations (LC₅₀) of all tested compounds were determined for 46th stage tadpoles in the range of 9.54-140.0 μM. For evaluation of the lethality of the compounds, the activity of the enzyme biomarkers acetylcholinesterase (AChE), carboxylesterase, glutathione S-transferase (GST), glutathione peroxidase, glutathione reductase, lactate dehydrogenase, aspartate aminotransferase, and alanine aminotransferase were determined in vivo in X. laevis tadpoles exposed to three concentrations (LC₅₀, LC₅₀/2, and LC₅₀/4) of tested compounds. All exposure concentrations of AzM and seven of eight tested compounds caused CaE inhibition in in vivo conditions. Furthermore, the AChE inhibition capacity of tested compounds in commercial electric eel AChE and in X. laevis homogenates and also CaE inhibition capacity in only X. laevis homogenates were assayed for a 30-min in vitro exposure period. Eight OP compounds did not inhibit AChE activity more than 23 percent, but AzM exposure inhibited AChE activity by 26 percent for X. laevis homogenates and 97 percent for electric fish AChE in in vitro conditions. Also, CaE inhibition levels in X. laevis tadpole homogenates were 46 percent for AzM and between 8 percent and 33 percent for other compounds in in vitro conditions.

Toxicological aspects of photocatalytic degradation of selected xenobiotics with nano-sized Mn-doped TiO2.

The toxic effects of two selected xenobiotics, bisphenol A (BPA) and atrazine (ATZ), were evaluated after photocatalytic degradation using nano-sized, Mn-doped TiO2. Undoped and Mn-doped TiO2 nanoparticles were synthesized. The samples were characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), UV-vis-diffuse reflectance spectra (DRS), X-ray fluorescence spectroscopy (XRF), and BET surface area. The photocatalytic efficiency of the undoped and Mn-doped TiO2 was evaluated for BPA and ATZ. The toxicity of the synthesized photocatalysts and photocatalytic by-products of BPA and ATZ was determined using frog embryos and tadpoles, zebrafish embryos, and bioluminescent bacteria. Possible toxic effects were also evaluated using selected enzyme biomarkers. The results showed that Mn-doped TiO2 nanoparticles did not cause significant lethality in Xenopus laevis embryos and tadpoles, but nonfiltered samples caused lethality in zebrafish. Furthermore, Mn-doping of TiO2 increased the photocatalytic degradation capability of nanoparticles, and it successfully degraded BPA and AZT, but degradation of AZT caused an increase of the lethal effects on both tadpoles and fish embryos. Degradation of BPA caused a significant reduction of lethal effects, especially after 2-4h of degradation. However, biochemical assays showed that both Mn-doped TiO2 and the degradation by-products caused a significant change of selected biomarkers on X. laevis tadpoles; thus, the ecological risks of Mn-doped TiO2 should be considered due to nanomaterial applications and for spilled nanoparticles in an aquatic ecosystem. Also, the risk of nanoparticles should be considered using indicator reference biochemical markers to verify the environmental health impacts.

Heavy metal pollution in sediments and mussels: assessment by using pollution indices and metallothionein levels

In the present work, the concentration of eight metals (Cd, Cr, Cu, Fe, Mn, Ni, Pb, Zn) was determined in the sediments and transplanted and native mussels (Mytilus galloprovincialis). The study was conducted in Turkish marinas, shipyards, and shipbreaking yards. The effect of metal pollution was evaluated by determining the levels of metallothionein (MT) in the mussels. The extent of contamination for each single metal was assessed by using the geoaccumulation index (Igeo) and enrichment factor (EF). Whereas, to evaluate the overall metal pollution and effect, the pollution load index (PLI), modified contamination degree (mCd), potential toxicity response index (RI), mean effects range median (ERM) quotient (m-ERM-Q), and mean PEL quotient (m-PEL-Q) were calculated. The influence of different background values on the calculations was discussed. The results indicated a significant metal pollution caused by Cu, Pb, and Zn especially in shipyard and shipbreaking sites. Higher concentrations of MT were observed in the ship/breaking yard samples after the transplantation.

Analysis of gibberellic acid, abscisic acid, indole‐3‐acetic acid and zeatin from the selected tissues of albino mice

This paper reports the presence of gibberellic acid (GA3), abscisic acid (ABA), indole‐3‐acetic acid (IAA) and zeatin in the brain, liver and kidney of laboratory mice. The identification of these plant growth regulators (PGRs) in animal tissues after the dietary treatment by GA3 or ABA on F1 offsprings in two different exposure periods was studied. Thin layer chro‐matographic (TLC) techniques and spectrophotometric assay methods were used for this study. Results show that assayed PGRs accumulate in animal tissues and accumulation of these substances is being attributed to their feed source and exposure to PGR as an effective factor.