Changes in selected immunological parameters and antioxidant status of rainbow trout exposed to malachite green (Oncorhynchus mykiss, Walbaum, 1792)

In this study, the effects of malachite green on selected immunological parameters, oxidative stress and antioxidant status biomarkers in blood, liver, kidney, spleen and gill of rainbow trout, Oncorhynchus mykiss, was examined. During 5 days the malachite green was applied at concentrations of 1/15,000 and 1/150,000 for 30 s and 60 min, respectively. Immunological parameters (nitroblue tetrazolium (NBT) activity, total plasma protein (TP), total immunoglobulin (TI)) and biochemical parameters (lipid peroxidation (MDA), catalase (CAT) activity, reduced glutathione (GSH) levels) were evaluated after exposed to malachite green. It has been observed that NBT activity (p < 0.05, p < 0.001), total protein (p < 0.01, p < 0.001) and total immunoglobulin (p < 0.05, p < 0.001) levels were decreased compared with control group. In the rainbow tout exposed to malachite green duration 5 days significantly increased lipid peroxidation, which might be associated to decreased levels of reduced glutathione and catalase activity in the whole tissues of O. mykiss (p < 0.05, p < 0.01, p < 0.001 for each cases).     

Mutagenic, genotoxic and enzyme inhibitory effects of carbosulfan in rainbow trout Oncorhynchus mykiss

Rainbow trout (Oncorhynchus mykiss; 116.88 ± 21.69 g) were exposed to sublethal concentrations (25 μg/L) of carbosulfan for 60 days to test if the long term exposure of fish to carbosulfan affects red blood cells acetylcholinesterase (AChE), δ-aminolevulinic acid dehydratase (ALA-D) and paraoxonase (PON) enzyme activity and induces genotoxic and/or mutagenic effects. The exposure resulted in inhibition of AChE and ALA-D activity of rainbow trout when compared to control fish. The activity of PON was not affected by carbosulfan. Interestingly, carbosulfan was found to induce DNA damage in red blood cells (comet assay) and proved to be mutagenic as revealed by the Ames test. Results indicate that blood AChE and ALA-D of rainbow trout may be a sensitive biomarker for assessment of carbosulfan contaminated water bodies. Furthermore, because the Ames test and comet assay were proven successful to detect the genotoxicity of carbosulfan, we proposed that nonlethal techniques such as blood collection from caudal vein of fish should be used to determine potential toxic effects of other pesticides to surrounding environment.     

Effects of carbaryl and azinphos methyl on juvenile rainbow trout (Oncorhynchus mykiss) detoxifying enzymes

In this study, the effects of sublethal exposures to the anticholinesterase insecticides azinphos methyl (AzMe) and carbaryl on the detoxifying responses of juvenile rainbow trout Oncorhynchus mykiss were investigated. Juvenile specimen were exposed to sublethal concentrations of AzMe (2.5 and 5 μg/L) and carbaryl (1 and 3 mg/L) for 24, 48 and 96 h. Carboxylesterase (CbE), catalase (CAT) and glutathione S-transferase (GST) activities as well as reduced glutathione (GSH) and cytochrome P450-1A (CYP1A) levels were monitored in liver and/or kidney. In all exposed groups liver CbE was significantly inhibited. Liver and kidney GSH level was reduced after sublethal exposure to both compounds. Carbaryl induced CAT activity during the first 48 h of exposure, followed by a significant decrease, whereas AzMe continuously decreased CAT activity. GST activity and CYP1A were transiently induced at 24 h by carbaryl exposure (3 mg/L) but sublethal exposure to AzMe did not affect GST activity or CYP1A. Our results show that the O. mykiss detoxifying system are a target for carbaryl and AzMe action, probably affecting redox balance. Although the responses showed similar trends in both organs, they were more important in liver than in kidney. The early inhibitory effect in CAT activity and GSH content produced by AzMe may be associated with a high degree of oxidative stress. Early induction of CYP1A, GST and CAT by carbaryl followed by enzyme inhibition suggests a milder or delayed oxidative stress, revealing differences between both pesticides metabolization. CbE inhibition is a good biomarker for AzMe and carbaryl exposure.     

In vitro and in vivo effects of some pesticides on carbonic anhydrase enzyme from rainbow trout (Oncorhynchus mykiss) gills

Here we investigated the in vitro and in vivo effects of the pesticides, deltamethrin, diazinon, propoxur and cypermethrin, on the activity of rainbow trout (rt) gill carbonic anhydrase (CA). The enzyme was purified from rainbow trout gills using Sepharose 4B-aniline-sulfanilamide affinity chromatography method. The overall purification was approx. 214-fold. SDS-polyacrylamide gel electrophoresis showed a single band corresponding to a molecular weight of approx. 29 kDa. The four pesticides dose-dependently inhibited in vitro CA activity. IC₅₀ values for deltamethrin, diazinon, propoxur and cypermethrin were 0.137, 0.267, 0.420 and 0.460 μM, respectively. In vitro results showed that pesticides inhibit rtCA activity with rank order of deltamethrin > diazinon > propoxur > cypermethrin. Besides, in vivo studies of deltamethrin were performed on CA activity of rainbow trout gill. rtCA was significantly inhibited at three concentrations (0.25, 1.0 and 2.5 μg/L) at 24 and 48 h.     

Acute toxicity of organophosphorous pesticide diazinon and its effects on behavior and some hematological parameters of fingerling European catfish (Silurus glanis L.)

Diazinon is commonly used for pest control in the agricultural fields surrounding freshwater reservoirs. So this study was conducted to determine the acute toxicity of this organophosphorous pesticide, contaminating aquatic ecosystems as a pollutant, and its effects on behavior, and some hematological parameters of fingerling European catfish, Silurus glanis. Diazinon was applied at concentrations of 1, 2, 4, 8, 16, 32, and 64 mg L⁻¹. The water temperature in the experimental units was kept at 16 ± 1 °C. The number of dead fishes significantly increased in response to diazinon concentrations 2-64 mg L⁻¹ (p < 0.05). With increasing diazinon concentrations, the fishes exposed duration 1 to 96 h significantly increased the number of dead fishes (p < 0.05 for each cases). The 1, 24, 48, 72, and 96 h LC₅₀ values (with 95% confidence limits) of diazinon for fingerling European catfish were estimated as 14.597 (12.985-16.340), 12.487 (11.079-14.471), 8.932 (7.907-10.348), 6.326 (no data because of p > 0.05), and 4.142 (no data because of p > 0.05) mg L⁻¹, respectively. Compared to the control specimens, fish after an acute exposure to diazinon was significantly lower erythrocyte, leukocyte, hemoglobin, hematocrit, MCV, MCH, and MCHC values (p < 0.05). In addition, it was also showed a significantly negative correlation between these hematological parameters and exposure times of diazinon (p < 0.01).     

Acute toxicity of diazinon on the common carp (Cyprinus carpio L.) embryos and larvae

In the present study, the toxic effects on the embryos and larvae of the common carp were used as a model to investigate the organophosphorus pesticide, diazinon, which contaminates aquatic ecosystems. Data obtained from the diazinon acute toxicity tests were evaluated using the Probit Analysis Statistical Method. The control and six test experiments were repeated five times. The number of dead embryos significantly increased in response to diazinon concentrations 0.25, 0.5, 1, 2, 4, and 8 mg L⁻¹ (p < 0.05 for each case). The 48 h LC₅₀ value (with 95% confidence limits) of diazinon for common carp embryos was estimated at 0.999 (0.698-1.427) mg L⁻¹. Dose-response decreases in hatching success were recorded as 84.60, 75.2, 54.1, 31.0, 6.0, and 0.0%, respectively (p < 0.05). The number of dead larvae significantly increased with increasing diazinon concentrations exposed for 24-96 h (p < 0.05). The 24, 48, 72, and 96 h LC₅₀ values (with 95% confidence limits) of diazinon for common carp larvae were estimated at 3.688 (2.464-8.495), 2.903 (2.019-5.433), 2.358 (1.672-4.005), and 1.530 (1.009-3.948) mg L⁻¹, respectively. There were significant differences in the LC₅₀ values obtained at different exposure times (p < 0.05). The results of the study suggest that low levels (0.25 mg L⁻¹) of diazinon in the aquatic environment may have a significant effect on the reproduction and development of carp.     

Impacts of hypersaline water on the biotransformation and toxicity of fenthion on rainbow trout (Oncorhynchus mykiss), striped bass (Morone saxatilis X Morone chrysops) and tilapia (Oreochromis mossambicus)

Hypersaline water derived from agricultural practices primarily in arid landscapes can impact fisheries in streams receiving run-off from fields. Previous studies have indicated significant elevation in the toxicity of thio-ether pesticides by hypersaline water in certain species of euryhaline fish due to enhanced formation of sulfoxide metabolites which may be more toxic than the parent compounds. The objectives of this study were to evaluate the effects of salinity on the toxicity of the thio-ether organophosphate pesticide, fenthion in three species of euryhaline fish: rainbow trout (Oncorhynchus mykiss), striped bass (Morone saxatilis X Morone chrysops), tilapia (Oreochromis mossambicus) and determine whether a relationship was observed between toxicity and enantioselective sulfoxidation. Stereochemical formation and total sulfoxide formation did not mirror acute toxicity in the three species exposed in fresh or hypersaline conditions. Mortality of striped bass and rainbow trout due to fenthion exposure was enhanced by hypersaline treatments and a trend towards increased toxicity was observed in tilapia. In liver microsomes of rainbow trout, inhibition of cytochrome P450 (CYP) caused a respective 7- and 3-fold increase in sulfoxide formation in liver microsomes fresh and saltwater fish, and a significant increase in the formation of the (+)R-sulfoxide. CYP inhibition also caused a significant elevation of the (+)R-sulfoxide in freshwater striped bass, but not in hypersaline-treated bass. The results indicated contribution by CYP in the sulfoxidation of fenthion as well as the formation of other metabolites in all three species. In summary, hypersaline conditions impacted fenthion toxicity under conditions that appeared to be independent of fenthion sulfoxide formation indicating a much more complex mechanism of action for compounds with phosphorothioate and thio-ether structural features potentially involving multiple oxidative pathways.     

Involvement of esterases in diazinon resistance and biphasic effects of piperonyl butoxide on diazinon toxicity to Haematobia irritans irritans (Diptera: Muscidae)

Resistance to insecticides remains a major problem for the successful control of the horn fly, Haematobia irritans irritans (L.), one of the most important pests of cattle in many countries including the United States. The organophosphate (OP) insecticide diazinon has been used to control pyrethroid-resistant populations of the horn fly. There are only a few reported cases of horn fly resistance to diazinon in the United States and Mexico. Piperonyl butoxide (PBO) has been used successfully as a synergist of pyrethroid insecticides to control horn flies. PBO-synergized diazinon products are also available for horn fly control in the United States, although PBO is known to inhibit the bio-activation of certain OP insecticides including diazinon. A study was conducted to evaluate the effect of PBO on diazinon toxicity to horn flies using a filter paper bioassay technique. These bioassays in both the susceptible and diazinon-resistant horn fly strains revealed a biphasic effect of PBO on diazinon toxicity to horn flies. PBO inhibited diazinon toxicity when the PBO concentration used was high (5%), and no effect was observed when PBO concentration was intermediate (2%). However, at low concentrations (1% and lower), PBO significantly synergized diazinon toxicity. We demonstrated that enhanced esterase activity was associated with survivability of horn flies exposed to diazinon alone. PBO has been shown to inhibit esterase activity in other insect species. However, results of biochemical assays with esterases from this study suggest that PBO did not have significant effect on the overall esterase activity in the horn fly. The observed synergistic effect of PBO at lower concentrations on diazinon toxicity to horn flies could not be explained by reduced esterase activity due to PBO inhibition. It is likely that PBO synergized diazinon toxicity at lower concentrations by facilitating penetration of diazinon through the cuticle and/or inhibiting the oxidative detoxification of diazinon, and reduced diazinon toxicity at high PBO concentration by inhibiting the bio-activation of diazinon.     

Acute effects of methyl parathion and diazinon as inducers for oxidative stress on certain biomarkers in various tissues of rainbowtrout (Oncorhynchus mykiss)

Present study aimed mainly to assess oxidative stress pesticides such as methyl parathion (MP) and diazinon, which are widely used insecticides and contaminate aquatic ecosystems, on certain biomarkers in various tissues of rainbowtrout (Oncorhynchcus mykiss). Biomarkers selected for stress monitoring were malondialdehyde (MDA) and antioxidant defense system (ADS) mainly reduced glutathione (GSH), glutathione reductase (GR), peroxidase (GSH-PX), transferase (GST) and superoxidedismutase (SOD) activities in the liver, gills and muscle of fishes exposed to 0.5 and 1 ppm dosages of MP and diazinon for 24, 48 and 72 h. According to these results, after the administrations of MP and diazinon promote MDA content in some of the tissues of fishes treated with both dosages of MP and diazinon. With regard to the ADS, GSH-Px, GST, SOD, GR activities and GSH levels fluctuated after 24, 48 and 72 h in all the treatment groups compared with controls. Collective results demonstrated that exposure of fish to pesticides induced an increase in MDA joined with fluctuated ADS. This may reflect the potential role of these parameters as useful biomarkers for assessment of water pollution.     

Biochemical alteration induced by monocrotophos in the blood plasma of fish, Channa punctatus (Bloch)

Monocrotophos (MCP), commonly known as azodrin, is one of the organophosphate (OP) pesticides extensively used in agricultural practices throughout the world. Channa punctatus were exposed to sublethal concentrations (0.96 and 1.86 mg/L) of monocrotophos for 15 and 60 days to assess the alterations in the level of some biochemical parameters in blood plasma. Significant alterations in all the biochemical parameters were found to be dose dependent. Hypoglycemia and hypocholesteremia were observed in plasma of fish at both exposure periods (15 and 60 days). Increased activities of glutamate-oxalacetate transaminase (GOT), glutamate-pyruvate transaminase (GPT), acid and alkaline phosphatase of blood plasma indicated hepatic tissue damage. Decrease in lactate dehydrogenase (LDH) content in plasma further indicated lower metabolic rate after 60 days of exposure. Significant decline in triglycerides content was observed in fish exposed to both sublethal concentrations of monocrotophos. We suggest that analysis of biochemical parameters in the fish blood may be useful in environmental biomonitoring.     

Acute toxicity of organochlorine insecticide endosulfan and its effect on behaviour and some hematological parameters of Asian swamp eel (Monopterus albus, Zuiew)

In Asia, Monopterus albus (Asian swamp eel) is commonly found in rice fields, muddy ponds and swamp areas. Because of its habitat, it is exposed to toxic pesticides used in rice fields, especially endosulfan, which is one of the most widely used insecticides. This study aims to determine the acute toxicity of endosulfan and its effect on the behaviour and some hematological parameters of the fish. The 96 h-LC₅₀ (with 95% confidence limits) obtained in this study for M. albus was 0.42 (0.35-0.50) μg L⁻¹. After 96 h exposure to endosulfan, the fish exhibited a series of abnormal behavioural responses; these included imbalanced position, restlessness of movement, erratic swimming, tremor, flashing and lethargy. When the swamp eels were exhausted, they were laterally recumbent on the bottom and had no opercula movement. Endosulfan toxicity also caused a significant lower (p < 0.05) value of erythrocyte count, leukocyte count, hemoglobin and hematocrit as compared to the control experiment. Nevertheless, the erythrocyte cell showed an increasing trend in size. The swollen erythrocyte cells may be impaired in their oxygen-carrying capacity. Severe blood loss through the gill capillary and hematemesis of the fish may be the main reasons for the hematological changes in the test organisms. Despite its relatively bigger size (30-40 cm in length) as compared to most of the other test organisms (<5 cm in length) for endosulfan toxicity, it is interesting to find that this fish is one of the most sensitive freshwater fishes to endosulfan.     

Evaluation of propolis effects on some biochemical parameters in rats treated with sodium fluoride

The present study in which 42 female rats, each weighing 200−250 g, were used covered a period of 21 days. The animals were divided into six groups. The first group served as the control group, whereas Group 2 was administered propolis at a dose of 200 mg/kg/bw in drinking water for 21 days. Group 3 was first provided with normal drinking water for a period of 14 days, and was subsequently administered propolis at a dose of 200 mg/kg/bw in drinking water for 7 days. Group 4 was first given normal drinking water for 14 days, and was secondly administered 100 ppm fluoride as a sodium fluoride in drinking water for 7 days. Group 5 was first administered propolis alone at a dose of 200 mg/kg/bw in drinking water for 14 days, and was secondly administered 100 ppm fluoride in association with 200 mg/kg/bw propolis for 7 days. Finally, Group 6 was first provided with normal drinking water for 14 days, and was secondly administered 100 ppm fluoride in association 200 mg/kg/bw propolis for a period of 7 days. At the end of the 21st day, blood samples were collected from the heart of each animal into both heparinised tubes and tubes without anticoagulants. Glucose, triglyceride, cholesterol, total protein, and uric acid levels, and aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP) activities in the serum, as well as malondialdehyde (MDA) levels, glutathione peroxidase (GSH-Px) in the plasma, erythrocyte superoxide dismutase (SOD) and catalase (CAT) activities were measured. When compared to the control group, statistical differences were determined to exist with respect to oxidative stress parameters which involved increase in MDA levels in Groups 4−6, decrease in SOD activity in Groups 4 and 6, increase in CAT activity in Groups 5 and 6, and decrease in GSH-Px activity in Groups 4 and 6. Furthermore, in comparison to the control group, significant differences were observed with respect to certain serum biochemical parameters, including decrease in glucose levels in Groups 5 and 6, decrease in triglyceride levels in Groups 2 and 4, decrease in cholesterol levels in Groups 2 and 5, decrease in the total protein level of Groups 4−6, decrease in the ALT activity of Groups 5 and 6, increase in the AST activity of Group 4, decrease in the ALP activity of Groups 2−6 and increase in the uric acid level of Group 2. In the groups that were administered propolis in association with fluoride, improvement was observed in some oxidative stress parameters and certain other biochemical parameters. Changes determined in the oxidative stress parameters (especially MDA and SOD) were indicative of the anti-radical activity of propolis on the free radicals generated by sodium fluoride. However, the values not drawing completely close to those of the control group can be explained with propolis not being able to completely eliminate the free radicals and the other adverse effects generated by fluoride.     

Effects of deltamethrin on hematological parameters and enzymatic activity in Ancistrus multispinis (Pisces, Teleostei)

Deltamethrin (DM) is a pyrethroid insecticide widely used in Brazilian crops and in pest-control programs because of its low environmental persistence and toxicity. It has been shown to exert a wide range of effects on non-targeted organisms including fishes. The aim of this study to evaluate the effects of deltamethrin through the hematological and biochemical parameters using Ancistrus multispinis as animal model. First, blood of A. multispinis was collected by cardiac puncture in order to evaluate the basal values of the total cell counts, hemoglobin and hematocrit rates. A. multispinis showed low number leukocytes, red blood cells and hemoglobin compared to other species. The intoxication with DM (0.1 or 0.3 mg kg⁻¹) induced leukocytosis and increases the number of erythrocytes and hemoglobin levels 96 h after the injection when compared to vehicle-injected animals. The injection of lipopolysaccharide (LPS) also induced a significant leukocytosis and increased the erythrocytes number 4 h after the injection. The combination of the higher dose of DM with LPS showed an additional effect in the number of leukocytes and erythrocytes. The GST and EROD activities were also evaluated in the gills and liver, respectively, 96 h after intoxication with both doses of DM. The GST activity decreased after DM intoxication in both doses while EROD activity was not significantly different. These results suggest that A. multispinis is a valuable model for ecotoxicological studies. Also, DM can affect the metabolizing system (GST) and immunologic system of A. multispinis, a condition that can be worsened in the presence of inflammation or infection.     

Molecular and biochemical mechanisms of organophosphate resistance in laboratory-selected lines of the oriental fruit fly (Bactrocera dorsalis)

Genetic and biochemical factors leading to resistance to various organophosphate (OP) based insecticides were studied in lines selected for OP-resistance in the oriental fruit fly Bactrocera dorsalis. Lines were separately selected for resistance to naled, trichlorfon, fenitrothion, fenthion, formothion, and malathion. Overall, these lines showed increased resistance ratios ranging from 13.7- to 814-fold relative to a susceptible (S) line. Also, in these newly selected lines the same three point mutations in the ace gene, previously identified in resistance studies and designated as I214V, G488S and Q643R, were found. As expected, the enzyme from the resistant lines showed lower overall activity and reduced sensitivity to inhibition by fenitrothion, methyl-paraoxon and paraoxon compared to the wild type acetylcholinesterase (AChE) enzyme. The apparent V_max values for esterase from the resistant lines were 1.2-3.69 times higher than that of the S line. Although only the naled-, trichlorfon- and fenthion-r lines showed lower esterase affinities (based on apparent K_m values) compared with the S line, all of the V_max/K_m ratios were higher in the resistant lines compared to that of the S line. The OP-resistant lines also displayed an overall similar pattern of isozyme expression, except for one additional band found only in the naled-r line and one band that was absent in the trichlorfon-, malathion-, and fenthion-r lines. Our results also show that overall, multiple examples of high OP resistance in selected lines of B. dorsalis exhibiting the same genetic alterations in the ace gene seen previously resulted in different effects on esterase enzyme activity in relation to various OP compounds.     

In vitro and in vivo effects of some pesticides on glucose-6-phosphate dehydrogenase enzyme activity from rainbow trout (Oncorhynchus mykiss) erythrocytes

We investigated the in vitro and in vivo effects of some pesticides on rainbow trout erythrocyte glucose-6-phosphate dehydrogenase enzyme. The enzyme was purified 1691-fold with a specific activity of 16.235 U/mg protein and a yield of 63%. Cypermethrin, and propoxur inhibited glucose-6-phosphate dehydrogenase enzyme in vitro and deltamethrin inhibited both in vivo and in vitro. The obtained IC₅₀ values for deltamethrin, cypermethrin, and propoxur were 0.63, 1.02, and 12 mM, respectively. The activity of the control was determined as 5.17 ± 0.62 U/g Hb in in vivo studies. The enzyme activities of the groups treated with 0.25 g/L deltamethrin were measured at 6, 12, 24, 48, and 72 h, and found to be 4.32 ± 0.47, 3.57 ± 0.39, 3.47 ± 0.45, 2.86 ± 0.37, and 2.31 ± 0.32 U/g Hb. In vivo experiments showed that deltamethrin significantly inhibited the G6PD enzyme activity after the 48th h (p < 0.05).     

Effect of short term exposure of fenvalerate on biochemical and haematological responses in Labeo rohita (Hamilton) fingerlings

Experiment was carried out to determine the median lethal concentration (LC₅₀) of fenvalerate to Labeo rohita fingerlings. After determining the LC₅₀ value of fenvalerate, a sub-lethal concentration (1/3rd of LC₅₀) of fenvalerate was exposed for 15 days. Significant alterations in SOD (P < 0.05) activity of liver and gill was observed due to fenvalerate. Catalase activity in gills of fishes was also affected significantly (P < 0.05). WBC, NBT and Hct values were reduced significantly in fenvalerate exposed fishes as compared to control group, whereas blood glucose level showed higher values in fenvalerate exposed group. Serum total protein and albumin were also reduced significantly as a result of fenvalerate exposure. Significant increase in the serum GOT, serum GPT, creatinine, triglyceride and serum ACP was noticed after 15 days of fenvalerate exposure. Results indicated that short term exposure of fenvalerate can induce biochemical and haematological alterations causing stress to L. rohita fingerlings.     

Fumigant and contact toxicity of Myrtaceae plant essential oils and blends of their constituents against adults of German cockroach (Blattella germanica) and their acetylcholinesterase inhibitory activity

Fumigant and contact toxicities of 11 Myrtaceae plant essential oils and their constituents against adult male and female Blattella germanica were evaluated. Of 11 Myrtaceae plant essential oils, Eucalyptus polybractea, Eucalyptussmithii, Eucalyptusradiata, Eucalyptusdives, Eucalyptusglobulus, and Melaleuca uncinata, showed 100% fumigant toxicity against adult male German cockroaches at a concentration of 7.5 mg/liter air concentration. In contact toxicity tests, E. polybractea, E. smithii, E. radiata, E. dives, E. globulus, Melaleucadissitiflora, and M. uncinata produced strong insecticidal activity against adult male and female German cockroaches. Of the essential oil constituents, terpinolene, α-terpinene, and terpinen-4-ol demonstrated strong fumigant toxicity against adult male and female B. germanica. Eugenol, isoeugenol, methyl eugenol, and terpinen-4-ol showed strong contact toxicity against adult male B. germanica. The toxicity of the constituent blends identified from M. dissitiflora essential oils indicated that terpinen-4-ol were major contributor to the fumigant activity or contact toxicity of the artificial blend. Only isoeugenol exhibited inhibition activity against male acetylcholinesterase. IC₅₀ values of isoeugenol were 0.22 mg/mL against male acetylcholinesterase.     

Effect of terbutryn at environmental concentrations on early life stages of common carp (Cyprinus carpio L.)

The aim of this study was to assess the toxicity of terbutryn to early developmental stages of common carp (Cyprinus carpio). Based on accumulated mortality in the experimental groups, lethal concentrations of terbutryn were estimated at 36 day LC50 = 3.06 mg l⁻¹ terbutryn. Based on inhibition of growth in the experimental groups, lowest observed-effect concentration (LOEC) = 0.005 mg l⁻¹ terbutryn; and no observed-effect concentration (NOEC) = 0.0007 mg l⁻¹ terbutryn. Fulton’s condition factors were significantly lower in fish exposed to 2 mg l⁻¹ compared with controls. By day 30, fish exposed to 0.00002 mg l⁻¹ - real environmental concentration in Czech rivers - 0.02, 0.2, and 2 mg l⁻¹ terbutryn showed significantly lower mass and total length compared with controls. No significant negative effects on hatching or embryo viability were demonstrated at the concentrations tested, but significant differences in early ontogeny among groups were noted. Fish from the two highest tested concentrations (0.2 and 2 mg l⁻¹) showed a dose-related delay in development compared with the controls. At concentrations of 0.02, 0.2, and 2 mg l⁻¹ damage to caudal kidney tubules when compared to control fish was found.     

Cellular and biochemical effects induced by atrazine on blood of male Japanese quail (Coturnix japonica)

Atrazine a potent endocrine disruptor herbicide is broadly used to control rapidly growing unwanted weeds in various cereals crops which induce adverse effects both in mammalian and avian species. In present study 96 mature male Japanese quail (Coturnix japonica) were procured and randomly kept in eight groups (A to H) each having 12 birds. Atrazine was administered orally at 0, 10, 25, 50, 100, 250 and 500 mg/kg body weight to all experimental groups. The mitomycin C at 2 mg/kg body weight was given to the birds of group B which served as a positive control. From each group 4 birds were randomly selected and harvested at day 15, 30 and 45. A significant (P < 0.05) decrease in serum total protein, serum albumin and serum testosterone values were recorded at day 45 in all treated groups. A significant increase in serum ALT and AST concentration was also recorded. Moreover, morphological alterations in nucleus of erythrocytes were also observed including blebbed nuclei, notched nuclei, lobed nuclei, vacuolated cells, binucleated cell, and cell with pear shaped and micronucleus. Overall, our results show that atrazine at higher doses induces significant serum biochemical alterations and changes in nucleus of erythrocytes.     

Biochemical effects of acute phoxim administration on antioxidant system and acetylcholinesterase in Oxya chinensis (Thunberg) (Orthoptera: Acrididae)

The study was undertaken to evaluate the effects of different concentrations of phoxim on acetylcholinesterase (AChE) and esterase (EST) activities, and antioxidant system after topical application to Oxya chinensis. The results showed that phoxim inhibited AChE activity, and did not cause significant changes in the EST activity and the levels of malondialdehyde (MDA) and reduced glutathione (GSH). After phoxim administration, superoxide (SOD) and catalase (CAT) activities showed a biphasic response with an initial increase followed by a decline in their activities. Glutathione reductase (GR) and glutathione peroxidase (GPx) activities were inhibited in comparison with the control. Glutathione S-transferase (GST) activity showed irregular changes. Its activity increased significantly at the concentrations of 0.06 and 0.12 μg/μL and decreased at the concentrations of 0.09 and 0.24 μg/μL compared with the control. Changes in SOD, CAT, GST, GPx, and GR activities indicated that phoxim caused oxidative damage in O. chinensis. However, no significant changes in MDA content suggested that these enzymes played important roles in scavenging the oxidative free radicals induced by phoxim in O. chinensis. The formation of oxygen free radicals might be a factor in the toxicity of phoxim.