Effects of dietary selenium on the oxidative stress and pathological changes in tilapia (Oreochromis niloticus) exposed to a microcystin-producing cyanobacterial water bloom

The present study investigates the role of selenium (Se) supplementation (as sodium selenite) on the oxidative stress and histopathological changes induced by cyanobacterial cells containing microcystins (MCs) in tilapia fish (Oreochromis niloticus). Variation in lipid peroxidation (LPO) levels and carbonyl groups content, reduced glutathione/oxidized glutathione (GSH/GSSG) ratio, and catalase (CAT), superoxide dismutase (SOD), glutathione reductase (GR), glutathione peroxidase (GPx) and glutathione S-transferase (GST) activities in liver and kidney of tilapia fish exposed to a single oral dose of 120 μg MC-LR/fish and sacrificed in 24 h, were investigated in the absence and presence of 1.5, 3.0 and 6.0 μg Se/g diet. Results showed a protective role of Se depending on the dose and the biomarker considered. Thus, the lower Se dose made CAT, liver GR and kidney SOD converged to basal values, whereas LPO and liver SOD and GST needed the higher dose. Kidney GR, however, was not protected at any Se dose. Moreover, Se has also shown to have a pro-oxidant effect with increased kidney LPO values and liver and kidney GPx activities in MC-free fish. The microscopic study revealed tissue alterations induced by cyanobacterial cells in the liver, kidney, heart and gastrointestinal tract that were ameliorated by the highest Se dose assayed. The level of Se supplementation must be therefore carefully selected to provide beneficial effects and to avoid potential negative consequences.     

Soy isoflavones have antimutagenic activity on DNA damage induced by the antileishmanial Glucantime (meglumine antimoniate)

Isoflavones are phytoestrogens reported to be potent antioxidant agents. In contrast, the antileishmanial meglumine antimoniate has mutagenic activities. This study evaluated the ability of soy isoflavones to reduce DNA damage induced by meglumine antimoniate. Antimutagenic effects (by micronucleus test) were tested using Swiss mice divided into seven groups treated with meglumine antimoniate (425?mg/kg bw pentavalent antimony); cyclophosphamide (50?mg/kg bw); water (negative control); single isoflavones dose (1.6?mg/kg bw), and three groups received one dose of isoflavones via gavage (0.4?mg/kg bw, 0.8?mg/kg bw or 1.6?mg/kg bw) plus meglumine antimoniate via intraperitoneal, simultaneously. To evaluate antigenotoxicity (by Comet assay), each group with 10 animals received the above-mentioned control doses; single dose of isoflavones 0.8?mg/kg bw, and three groups received isoflavones (0.8?mg/kg bw) by gavage along with intraperitoneal meglumine antimoniate, which were treated with isoflavones 24?h before or after receiving meglumine antimoniate (pre-treatment and post-treatment, respectively) or simultaneously. Cells were harvested 24?h after the treatment, and the data were evaluated by ANOVA followed by Tukey’s test (p?相似文献   

Effects of thermal treatments during cooking, microwave oven and boiling, on the unconjugated microcystin concentration in muscle of fish (Oreochromis niloticus)

Understanding the factors that contribute to the risk from fish consumption is a relevant public health concern due to potential adverse effects of cyanobacterial toxins. The aim of this work was to study the influence of two usual cooking practices, microwave oven and boiling, on the microcystin (MCs) concentration in fish muscle (Tilapia, Oreochromis niloticus) spiked with a stock solution (500 μL) containing a mixture of three toxins (MC-LR, MC-RR, and MC-YR) (1.5 μg/mL of each toxin). Two different variables were investigated: time of cooking in the microwaves treatment (1 or 5 min), and way of boiling, “boiled muscle” or “continuously heated muscle”. All samples were then lyophilized and MCs were extracted and purified (Oasis HLB cartridge) and quantified by HPLC-MS. Furthermore, the waters in which the samples boiled were also analyzed after their purification. The results suggest a reduction on MC-LR (36%) and MC-YR (24.6%) in samples cooked in the microwave for 5 min. Major changes were found when the fish was cooked by the continuous boiling, with a decrease of 45.0% (MC-RR), 56.4% (MC-YR) and 59.3% (MC-LR). More studies are necessary to elucidate the mechanisms involved when aquatic food is submitted to usual cooking practices.     

Lead-Induced Genotoxicity in Lymphocytes from Peripheral Blood Samples of Humans: In Vitro Studies

Lead is a known toxicant that has been implicated in encephalopathy in children and may affect the gastrointestinal and hematopoietic and other systems in adults. In fact, lead has been shown to compete with calcium for entry into the synaptosome and induce toxic effects. The aim of the current study was to evaluate the cytotoxic and genotoxic effects of lead by using lymphocytes from human peripheral blood in vitro. The LC₅₀ for lead nitrate as determined by Trypan blue dye exclusion technique was found to be 3.14 mM. Chromosomal aberration frequency at sublethal doses (1/10 of LC₅₀) as determined by examining the metaphase chromosomes (karyotyping) did not show significant aberrations except for some aneuploidy and about 2–4% gaps, breaks (3–4%), and about 5% satellite associations. However, significant DNA damage was determined by SCGE (Comet assay). The comet tail length proportionately increased with increasing lead nitrate concentration. Thus, Pb can induce single-strand DNA breaks, possibly by competing with metal binding sites.     

Antioxidant enzyme activity and lipid peroxidation in liver and gill tissues of Nile tilapia (Oreochromis niloticus) following in vivo exposure to domoic acid

Domoic acid (DA) is a neurotoxicant produced by Pseudo-nitzschia from diatomeae. Although the neurotoxic and genotoxic effects of DA have been well documented, the number of in vivo studies regarding the oxidative stress inducing effects of DA is quite limited. In this study, in vivo toxic effects of DA were investigated on fish Oreochromis niloticus (Fam: Cichlidae), using oxidative stress biomarkers. Fish were exposed to three different concentrations (1, 5 and 10 μg/g body weight) of DA via intraperitoneal injections and the tissues were sampled at 24, 48 and 72 h post-treatment. Changes in the level of lipid peroxidation, and activities of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione reductase (GRd) were evaluated in liver and gill tissues. Our results revealed dose and time dependent increases in the oxidative stress parameters. It was also observed that the toxic effects were more pronounced in liver than in gill tissue.     

Intraperitoneal injection of extracted microcystins results in hypovolemia and hypotension in crucian carp (Carassius auratus)

Circulatory responses of crucian carp injected intraperitoneally with extracted microcystins (MCs) were studied at sublethal and lethal doses (150 and 600 μg MC kg⁻¹ body mass, respectively). Mean arterial blood pressure (MAP), heart rate, hematocrit (Hct), red blood cell (RBC) counts, and circulating blood volume (BV) were assayed at 0, 1, 3, 12, 24, and 48 h post-toxin administration. MAP decreased significantly in a dose-dependent manner over time. Within the 48-h test period, the lethal dose as well as the sublethal dose resulted in a steady decline of MAP without recovery. Heart rate significantly increased within 24 h post-injection as blood pressure significantly dropped, then showed a terminal decline to the control level. The dose-dependent decreases in BV and Hct were directly related to the drop in MAP. Intraperitoneal injection of a lethal dose of MCs led to hepatic and gill hemorrhage. Consequently, crucian carp given MCs suffered from hypovolemic hypotensive shock.     

Genotoxic effect of Catha edulis (khat) crude extract after sub-chronic administration in rats

The aim of this study was to evaluate the genotoxic effects of a crude extract of khat (Catha edulis, Forsk) leaves in rats. Two groups were fed khat crude extract, 1000 and 2000 mg/kg body weight, for 90 days and were compared with a control group. The alkaline (pH > 13) version of comet assay was used in this study. However, no previous published work has been undertaken and showed the effect of khat on DNA migration in the comet assay. To compare the comet assay results with another genetic endpoint, blood samples were analyzed for chromosomal aberrations. These results showed no DNA damage detected using comet assay in both the khat treated groups, while the results of chromosomal aberrations assay showed a significant increase (P < 0.05) in the 2000 mg/kg body weight treated group compared to the control group.     

Genotoxicity of acrylamide in human hepatoma G2 (HepG2) cells

The recent finding that acrylamide (AA), a carcinogen in animal experiments and a probable human carcinogen, is formed in foods during cooking raises human health concerns. The relevance of dietary exposure for humans is still under debate. The purpose of the study was to evaluate the possible genotoxicity of acrylamide in human hepatoma G2 (HepG2) cells, a cell line of great relevance to detect genotoxic/antigenotoxic substances, using single cell gel electrophoresis (SCGE) assay and micronucleus test (MNT). In order to clarify the underlying mechanism(s) we evaluated the intracellular generation of reactive oxygen species (ROS) and the level of oxidative DNA damage by immunocytochemical analysis of 8-hydroxydeoxyguanosine (8-OHdG). The involvement of glutathione (GSH) in the AA-induced oxidative stress was examined through treatment with buthionine sulfoximine (BSO) to deplete GSH. The results indicate that AA caused DNA strand breaks and increase in frequency of MN in HepG2 cells in a dose-dependent manner. The possible mechanism underlies the increased levels of ROS, depletion of GSH and increase of 8-OHdG formation in HepG2 cells treated with AA. We conclude that AA exerts genotoxic effects in HepG2 cells, probably through oxidative DNA damage induced by intracellular ROS and depletion of GSH.     

Tissue-specific genotoxicity and antioxidant imbalance of titanium dioxide nanoparticles (NPTiO2) and inorganic lead (PbII) in a neotropical fish species

The aquatic environment is the major recipient of wastes containing nanoparticles and other contaminants. Titanium dioxide nanoparticles (NPTiO₂) are one of the most produced and used nanoparticle worldwide. This study investigated the toxicity of NPTiO₂, as well as the toxicity interaction between NPTiO₂ and lead (Pb), in response to genetic and biochemical biomarkers using freshwater fish Rhamdia quelen, as an animal model. The results showed genotoxicity in blood and kidney tissues. No effect of NPTiO₂ alone or in co-exposure with Pb on liver genotoxicity were observed. Alterations in the antioxidant hepatic enzymes activities, as well as alterations in glutathione levels indicated that NPTiO₂ alone or in co-exposure with Pb can cause antioxidant imbalance. The lipid peroxidation was also raised after exposure to NPTiO₂. In general, the results of this study indicated that both NPTiO₂ alone and their co-exposure with Pb are capable of producing significant toxic effects in short-term exposure.     

Genotoxicity assessment of NIM-76 and its formulation (pessary) in an in vitro Ames Salmonella/microsome assay and in vivo mouse bone marrow micronucleus test

Abstract

The possible genotoxic potential of NIM-76, a volatile fraction obtained from neem oil, having promising contraceptive activity, as well as its formulation product, called pessary (7.5% NIM-76 in polyethylene glycol), were evaluated in the Ames assay and mouse bone marrow micronucleus (MN) assay. Genotoxicity of NIM-76 (0.1–1000?µg/plate) and pessary (0.1–10?000?µg/plate) were studied using the liquid preincubation protocol of the Ames assay both in the presence and absence of S9. Likewise, the ability of NIM-76 [1–1000?mg/kg body weight (b.w.)] and its formulation product (18.75–300?mg/kg b.w.) to induce clastogenic effects were studied in the female mouse bone marrow MN test by using a two-dose intraperitoneal treatment protocol. There was no increase in the number of revertant colonies resulting from NIM-76 or pessary at any of their doses over the respective negative control plates, either in the presence or absence of S9. Similarly, in the MN assay, neither of them showed any clastogenic activity because there was no significant increase in the frequency of micronucleated polychromatic erythrocytes, over the negative control group of animals. The use of this compound in humans is therefore not likely to have mutagenic effects and may be considered as safe with regard to genotoxic potential.     

Genotoxicity assessment of chromium(III) propionate complex in the rat model using the comet assay

The aim of the study was to assess genotoxicity of a chromium(III) propionate complex in rat’s peripheral blood lymphocytes by the comet assay. The study was carried out on 18 12-weeks old female Wistar rats that were divided into three equal groups (six animals each): control (0), control-Cr(VI) and Cr(III)-tested rat fed ad libitum a basal diet and the diet supplemented either with 10 mg Cr(VI)/kg diet (given as K₂Cr₂O₇, equivalent of 1 mg/kg body mass/day) or 1000 mg Cr(III)/kg diet (given as [Cr₃O(O₂CCH₂CH₃)6(H₂O)₃]NO₃), equivalent of 100 mg Cr/kg body mass/day) for 4 weeks. High doses of supplementary Cr(III) were found to not affect body mass gain, feeding efficiency ratio and internal organ masses. Treatment of rats with the Cr(III) propionate complex, in contrast to Cr(VI), did not affect significantly the comet assay results in lymphocytes, which suggests that the compound does not exert genotoxic effects in rats.     

Comparison Between the Genotoxicity of cis-Pt(II) Complex of 3-Aminoflavone and cis-DDP in Lymphocytes Evaluated by the Comet Assay

cis-bis(3-aminoflavone)dichloroplatinum(II) [cis-Pt(II) complex of 3-aminoflavone] is an analog of cis-DDP characterized by low cytotoxicity and anticancer properties in vivo. In order to evaluate genotoxic properties of this chemical compound, the comet assay in human lymphocytes was used. The analysis of DNA damage after 1-h cell incubation with cis-Pt(II) complex of 3-aminoflavone and cis-DDP was carried out, and DNA repair kinetics were evaluated after 0.5-h, 1-h, and 1.5-h postexposure incubation. It has been shown that cis-Pt(II) complex of 3-aminoflavone causes the increase in tail moments in comparison with cis-DDP. On the other hand, the decrease in these values caused by cis-DDP was connected mainly with the presence of DNA and DNA–protein cross-links. The decrease in tail moments after cis-Pt(II) complex of 3-aminoflavone lymphocyte treatment was already observed after 0.5-h postexposure incubation, whereas in the variant with hydrogen peroxide application these values after cis-Pt(II) complex of 3-aminoflavone addition were higher in comparison with cis-DDP. Results obtained on the basis of the comet assay could confirm the occurrence of DNA breaks and cross-links induced by cis-Pt(II) complex of 3-aminoflavone.     

Antioxidant imbalance and genotoxicity detected in fish induced by titanium dioxide nanoparticles (NpTiO2) and inorganic lead (PbII)

Titanium dioxide nanoparticles (NpTiO₂) are the most widely-used nanoparticle type and the adsorption of metals such as lead (PbII) onto their surface is a major source of concern to scientists. This study evaluated the effects of the associated exposure to both types of contaminant, i.e., lead (a known genotoxic metal) and NpTiO₂, in a freshwater fish (Astyanax serratus) through intraperitoneal injection for an acute assay of 96 h. The effects of this exposure were evaluated using the comet assay, DNA diffusion assay and piscine micronucleus test, as well as the quantification of antioxidant enzymes (SOD, CAT, and GST) and metallothioneins. Our findings indicate that co-exposure of PbII with NpTiO₂ can provoke ROS imbalances, leading to DNA damage in the blood and liver tissue of A. serratus, as well as modifying erythropoiesis in this species, inducing necrosis and changing the nuclear morphology of the erythrocytes.     

Chlorophenols,chlorocatechols and chloroguaiacols induce DNA base oxidation in human lymphocytes (in vitro)

Phenolic compounds are strong environmental toxicants, which are found in food, drinking water as well as in the indoor and outdoor air environment. In this work we investigated the effect of low concentrations of 0.2, 1 and 5 μg/ml of 2,4,5-trichlorophenol (2,4,5-TCP), pentachlorophenol (PCP), 4,6-dichloroguaiacol (4,6-DCG), tetrachloroguaiacol (TeCG), 4,5-dichlorocatechol (4,5-DCC) and tetrachlorocatechol (TeCC) on DNA bases oxidation in human peripheral blood lymphocytes. The analysis was performed using alkaline single cell gel electrophoresis (the comet assay). To detect oxidized pyrimidynes and purines we used the repair enzymes such as endonuclease III and formamidopyrimidine-DNA glycosylase. DNA oxidation was expressed as a percentage of comet tail, which was formed after the xenobiotics treatment. The obtained results showed that all the compounds examined were able to oxidize DNA bases in human lymphocytes. It was also observed that pyrimidine bases were more strongly oxidized in comparison to purine ones. Finally, it was found that chlorinated catechols and TeCC in particular, revealed a higher oxidative potential in comparison to chlorophenols and chloroguaiacols, and a rise in the number of chlorine atoms in the compound from each group examined led to an increase in DNA bases damage.     

Evaluation of cytotoxic,genotoxic and antigenotoxic potential of Solanum lycocarpum fruits glicoalkaloid extract in V79 cells

Solanum lycocarpum St.-Hil (Solanaceae) is a hairy shrub or small much-branched tree of the Brazilian Cerrado, popularly known as “fruit-of-wolf”. Considering that the induction of chromosomal mutations is involved in the process of carcinogenesis, and that S. lycocarpum is often used in folk medicine, it becomes relevant to study its effect on genetic material. In this sense, the aim of present study was to determine the possible cytotoxic, genotoxic and antigenotoxic potentials of S. lycocarpum fruits glycoalkaloid extract (SL) in Chinese hamster lung fibroblasts (V79 cells). The cytotoxicity was evaluated by the colony forming assay, apoptosis and necrosis assay, Trypan blue exclusion dye method and mitotic index. Genotoxic and antigenotoxic potential were evaluated by comet and chromosomal aberrations assays. Four concentrations of SL (4, 8, 16 and 32 μg/mL) were used for the evaluation of its genotoxic potential. The DNA damage-inducing agent methyl methanesulfonate (MMS, 22 μg/mL) was utilized in combination with extract to evaluate a possible protective effect. The results showed that SL was cytotoxic at concentrations above 32 μg/mL by the colony forming assay. For apoptosis and necrosis assay, the concentration of 64 μg/mL of SL showed statistically significant increase in cell death by apoptosis and necrosis, while the concentrations of 128 and 256 μg/mL of SL demonstrated statistically significant increase in cell death by necrosis, compared with the control group. Analysis of cell viability by Trypan blue exclusion indicated >96% viability for treatments with concentrations up to 32 μg/mL of SL. No significant differences in MI were observed between cultures treated with different concentrations of SL (4, 8, 16 and 32 μg/mL) alone or in combination with MMS and the negative control, indicating that these treatments were not cytotoxic. The comet and chromosomal aberrations assays revealed that SL does not display genotoxic activity. Moreover, the different concentrations of SL showed protective effect against both genomic and chromosomal damages induced by MMS.     

The role of organic anion transporting polypeptides (OATPs/SLCOs) in the toxicity of different microcystin congeners in vitro: A comparison of primary human hepatocytes and OATP-transfected HEK293 cells

Cellular uptake of microcystins (MCs), a family of cyclic cyanobacterial heptapeptide toxins, occurs via specific organic anion transporting polypeptides (OATPs), where MCs inhibit serine/threonine-specific protein phosphatase (PP). Despite comparable PP-inhibitory capacity, MCs differ greatly in their acute toxicity, thus raising the question whether this discrepancy results from MC-specific toxikokinetic rather than toxicodynamic differences. OATP-mediated uptake of MC congeners MCLR, -RR, -LW and -LF was compared in primary human hepatocytes and HEK293 cells stably expressing recombinant human OATP1B1/SLCO1B1 and OATP1B3/SLCO1B3 in the presence/absence of OATP substrates taurocholate (TC) and bromosulfophthalein (BSP) and measuring PP-inhibition and cytotoxicity. Control vector expressing HEK293 were resistant to MC cytotoxicity, while TC and BSP competition experiments reduced MC cytotoxicity in HEK293-OATP transfectants, thus confirming the requirement of OATPs for trans-membrane transport. Despite comparable PP-inhibiting capabilities, MCLW and -LF elicited cytotoxic effects at lower equimolar concentrations than MCLR and MCRR, hence suggesting congener selective transport into HEK293-OATP transfectants and primary human hepatocytes. Primary human hepatocytes appeared one order of magnitude more sensitive to MC congeners than the corresponding HEK293 -OATP transfectants. Although the latter maybe due to a much lower level of PPs in primary human hepatocytes, the presence of OATPs other than 1B1 or 1B3 may have added to an increased uptake of MCs. In view of the high sensitivity of human hepatocytes and currently MCLR-only based risk calculations, the actual risk of human MC-intoxication and ensuing liver damage could be underestimated in freshwater cyanobacterial blooms where MCLW and-LF predominate.     

Prevention by vitamin E of DNA fragmentation and apoptosis induced by fumonisin B1 in C6 glioma cells

Fumonisin B₁ (FB₁), produced by the fungus Fusarium moniliforme, belongs to a class of sphingosine analogue mycotoxins that occur widely in the food chain. Epidemiological studies have associated consumption of Fusarium moniliforme-contaminated food with human oesophageal cancer in China and South Africa. FB₁ also causes equine leucoencephalomalacia. Evidence for induction of apoptosis by FB₁ was first obtained when C6 glioma cells were incubated with fumonisin B₁ (3–27 μM) causing DNA fragmentation profiles showing DNA laddering in gel electrophoresis and apoptotic bodies revealed by chromatin staining with acridine orange and ethidium bromide. Further confirmation experiments and comet assays have been performed under similar conditions. The results of the comet test show that FB₁ at 9 and 18 μM induces respectively 50 ± 2% and 40 ± 1% of cells with a comet with an increased tail length of 93 ± 9 μm and 102 ± 17 μm respectively. Under these concentrations, FB₁ induced DNA fragmentation and laddering and many apoptotic bodies. Pre-incubation of the cells with vitamin E (25 μM) for 24 h before FB₁ (18 μM) significantly reduced DNA fragmentation and apoptotic bodies induced by FB₁. Received: 30 August 1999 / Accepted: 18 January 2000     

Assessment of genotoxic and mutagenic effects of chlorpyrifos in freshwater fish Channa punctatus (Bloch) using micronucleus assay and alkaline single-cell gel electrophoresis

Chlorpyrifos (CPF) is the single largest selling agrochemical that has been widely detected in surface waters in India. The studies on long-term genotoxic effects of CPF in different tissues of fish using genotoxic biomarkers are limited. Therefore, in the present study DNA damage by CPF in freshwater fish Channapunctatus using micronucleus (MN) and comet assays was investigated. The LC₅₀ – 96 h of CPF was estimated for the fish in a semi-static system. On this basis of LC₅₀ value sublethal and nonlethal concentrations were determined. The DNA damage was measured in lymphocytes and gill cells as the percentage of DNA in comet tails and micronuclei were scored in erythrocytes of fishes exposed to above concentrations of CPF. In general, significant effects for both the concentrations and time of exposure were observed in treated fish. It was found that MN induction in the blood was highest on day 14 at 203.0 μg/l of CPF. The highest DNA damage was observed on day 5, followed by a gradual non-linear decline in the lymphocytes and gill cells. The study indicated MN and comet assays to be sensitive and rapid methods to detect mutagenicity and genotoxicity of CPF and other pollutants in fishes.     

Isolation of phytate from Jatropha curcas kernel meal and effects of isolated phytate on growth, digestive physiology and metabolic changes in Nile tilapia (Oreochromis niloticus L.)

Jatropha curcas seeds are rich in oil and protein. The oil is used for biodiesel production. The defatted Jatropha kernel meal obtained after oil extraction is rich in protein (58-66%) and phytate (9-11%). The phytate rich fraction was isolated from defatted kernel meal using organic solvents (acetone and carbon tetracholride). It had 66% phytate and 22% crude protein. The fingerlings (n = 50, 16.2 ± 0.64 g) were randomly distributed into five groups containing 10 replicates and fed iso-nitrogenous diets (crude protein 36%): control diet containing casein and gelatin as proteins; control diet containing 1.5% and 3% Jatropha phytate (PWP_1.5 and PWP₃, respectively); and control diet containing 1.5% and 3% Jatropha phytate supplemented with phytase (1500 FTU/kg) (PWP_{1.5 + Phytase} and PWP_{3 + Phytase}, respectively). Significantly lower (P < 0.05) growth and feed utilization in PWP_1.5 and PWP₃ groups than for control and both phytase containing groups were observed; whereas feed gain ratio exhibited opposite trend. Protein and lipid digestibilities of the diets, amylase and protease enzyme activities in the intestine were significantly higher (P < 0.05) in PWP_{1.5 + Phytase} and PWP_{3 + Phytase} groups than for PWP_1.5 and PWP₃ groups. Lowest red blood cell counts, and hemoglobin and hematocrit concentrations were observed in PWP₃ group which were not statistically different to those for PWP_1.5 group, but were significantly (P < 0.05) lower than those for all other groups. Highest albumin, globulin and total protein concentrations were observed in PP_{3 + Phytase} group and lowest in PWP_1.5 group; and values for the latter were statistically similar to those for control group. Calcium, phosphorus and glucose concentrations in blood and cholesterol concentration in plasma were significantly lower (P < 0.05) in the phytate enriched groups compared with control and phytase treated groups (PP_{1.5 + Phytase} and PP_{3 + Phytase}). Higher (P < 0.05) alkaline phosphatase activity was observed in phytase supplemented groups compared with that in non-supplemented groups which (PP_{1.5 + Phytase}) was statistically similar to that in control group, whereas alanine transaminase activity in blood exhibited opposite trend. In conclusion, Jatropha phytate present in DJKM is an antinutrient and addition of phytase in the diet containing DJKM is recommended.     

Mutagenic and genotoxic effects of carbosulfan in freshwater fish Channa punctatus (Bloch) using micronucleus assay and alkaline single-cell gel electrophoresis

Carbosulfan insecticide is widely used in agriculture and was recently proposed for treatment against pyrethroid-resistant mosquitoes. The mutagenic and genotoxic effect of carbosulfan was carried out in fish Channa punctatus using micronucleus (MN) test and comet assay. The 96 h LC₅₀, estimated by probit analysis in a semi-static bioassay experiment, was 0.268 mg l⁻¹. Based on the LC₅₀ value, three sub-lethal concentrations of carbosulfan (1/4th LC₅₀ = ∼67 μg l⁻¹, 1/2nd LC₅₀ = ∼134 μg l⁻¹ and 3/4th LC₅₀ = ∼201 μg l⁻¹) were selected and fishes were exposed to the said concentrations for 96 h and the samplings were done at regular intervals of 24 h for assessment of the MN frequencies and DNA damage. In general, significant effects (P < 0.01) from both concentrations and time of exposure were observed in exposed fishes. The MN induction was highest on 96 h at all the concentrations in the peripheral blood. Similar trend was observed for the DNA damage measured in terms of the percentage of tail DNA in the erythrocyte and gill cells. This study confirmed that the comet and micronucleus assays are useful tools in determining potential genotoxicity of water pollutants and might be appropriate as a part of monitoring program.