Histoenzymological study on the toxicity of copper sulphate in the digestive glands of Lymnaea luteola

During 24 and 48 hr of exposure, the digestive glands of Lymnaea treated with a lethal concentration of 0.038 mgl(-1) CuSO4 revealed intense activity of acid phosphatase in perilobular margin. On the other hand, same area of the gland showed moderate activity of ATPase during 24 and 48 hr of exposure. However, alkaline phosphatase showed average activity in perialveolar region and perilobular margin during 24 and 48, and 72 hr of exposure respectively The changes in the activity of these enzymes were nonsignificant in alveolar margin and perialveolar region of the gland. It is interesting to note moderate activity of acid phosphatase in perialveolar region during 24 hr of exposure.     

Hepatoprotective effects of taurine against mercury induced toxicity in rats

An attempt has been made to study the influence of taurine on mercury intoxicated rats. The animals were treated with sublethal dose of mercuric chloride (2 mg/kg body wt.) for 30 days. During the mercury treatment, the level ofAspartate transaminase(AST), Alanine transaminase (ALT) and Alkaline phosphatase(ALP) in serum and lipid peroxidation (LPO) in liver tissue significantly increased whereas Glutathione (GSH), Glutathione peroxidase(GPx), Catalase (CAT) and Superoxide dismutase (SOD) were simultaneously decreased in the liver tissue. Present results indicate that the liver tissue was completely damaged, after mercury treatment. In another group of animals, taurine (5 mg/kg body wt.) was administrated for another 15 days. Taurine administration was observed to improve the liver function in mercury intoxicated animal as indicated by the decline in increased levels of AST, ALT and ALP in serum and LPO content in liver tissue. The decreased level of antioxidant system (GSH, GPx, CATand SOD) has been promoted Results suggested that taurine played a vital role in reducing the mercury toxicity in intoxicated animals.     

Protective role of epigallocatechin 3-gallate against lead-induced toxicity in human neuroblastoma cells

Lead (Pb) is a heavy metal, known to induce oxidative stress and produce damage to the antioxidant defence system ultimately leading to cell death. Antioxidants such as epigallocatechin 3-gallate (EGCG), a green tea polyphenol, was shown to play a protective role during Pb-exposure. In this study, human SH-SY5Y neuroblastoma cells were exposed to different concentrations (0.01–10?µM) of Pb for 48?h to determine effects on the viability of cells. It was observed that IC₅₀ was at 5?µM and at this concentration the cells exhibited a significant increase in caspase-3 activity, an indicator of apoptosis at least by 10-fold and the decrease of 59.4% in glutathione (GSH) content. The total cellular prostaglandin-E₂ (PGE₂) level was found to be elevated at least 10-fold upon Pb exposure. However, the effects of Pb on cells pre-incubated with 50?µM EGCG followed by 5?µM Pb showed 40% inhibition in cell viability, 17.3% decrease in caspase-3 activity, 23% increase in GSH content, and 11.4% fall in PGE₂ levels when compared with cells exposed to Pb only. Data suggest that EGCG exerted a significant protection to cell viability in preventing cell death and elevation in levels of GSH in cells exposed to Pb. However, EGCG did not elicit any significant effect on release of PGE₂ indicating the nature of EGCG as an effective anti-apoptotic, antioxidant, and anti-inflammatory agent.     

吐纳麝香与镉联合暴露对赤子爱胜蚓体内谷胱甘肽与金属硫蛋白的影响

广泛应用于个人护理产品和香味添加剂中的吐纳麝香(6-乙酰基-1,1,2,4,4,7-六甲基四氢萘,AHTN)是一种新型污染物,重金属镉(Cd2+)是土壤中常见的污染物,两者在土壤生态系统中存在联合暴露的可能。实验以赤子爱胜蚓为受试生物,通过24h暴露滤纸染毒实验测试了AHTN单一,Cd2+单一,以及AHTN与Cd2+联合暴露条件下蚯蚓体内谷胱甘肽(GSH)和金属硫蛋白(MT)的变化趋势。结果显示:Cd2+单一暴露时,GSH与MT随Cd剂量增加有明显上升趋势;AHTN单一暴露时,随着AHTN剂量增加,GSH与MT同步呈现先增多后减少的趋势;联合暴露情况下,AHTN在高剂量下对MT与GSH同样产生了抑制作用,使Cd2+对MT的诱导未达到Cd2+单一染毒时的水平。     

Effects of ammonia, nitrite and nitrate on hemoglobin content and oxygen consumption of freshwater fish, Cyprinus carpio (Linnaeus)

Lethal effects of nitrogenous compounds ammonia, nitrite and nitrate on freshwater fish Cyprinus carpio were studied and the static LC50 values obtained for these 3 toxicants for 24 hr were 0.80 ppb, 171.36 ppm; 1075.10 ppm and continuous flowthrough LC50 values for 24 hr were 0.72 ppb, 154.31 ppm; 967.63 ppm respectively. The fish were exposed to lethal concentrations to study the changes in hematological parameters and the rate of oxygen consumption. During the period of exposure general decline in the content of hemoglobin was observed. Methemoglobin content increased in case of nitrite exposure consequently the hemoglobin levels decreased drastically. It is also observed that rate of oxygen consumption decreased progressively with the increase of toxicant concentration and duration of the exposure.     

Assessment of deposition of MEMC (seed dressing fungicide) in exposed rice grain through study of seedling growth parameters

Rice seed grains exposed to 240 ppm of seed dressing fungicide, MEMC showed increase in deposition of mercury with increase in period of observation (0h to 48h) in 765+/-5 mg of intact endosperm. The gradual increase in mercury deposition in intact endosperm caused simultaneous decrease in mercury content of the seed coat. Exposure periods of 5 to 20 min with 240 ppm of MEMC showed 5.5 to 8.72 microg of mercury deposition in 765+/-5 mg of intact endosperm. Increase in period of exposure (3 to 20 min) to 240 ppm of MEMC and also increase in chronic treatment to lower concentrations (1.5 ppm to 24 ppm) to seed grains have shown similar results in seedling growth parameters. Lower period of exposure or exposure to lower concentrations, both showed a significant inhibition of root growth, however the shoot growth showed stimulation. But higher exposure period or exposure to higher concentrations brought inhibition of both root and shoot growth. The exposure period showing 50% of root growth inhibition of 72h old seedling was calculated to be 10 min So also the chronic treatment showing the 50% of root growth inhibition was calculated to be 9 ppm. Ten min exposure of rice grain to 240 ppm of MEMC showed deposition of 7.11 microg of mercury in 765+/-5 mg of intact endosperm at 48h of observation (optimal phase of germinating process). Regression analysis indicated that by the time of 72h the intact endosperm and developing seedling might have acquired with a minimum amount of 10.23 microg of mercury from the seed coat. Finally it can be said that 10.23 microg of MEMC might be bringing 50% root growth inhibition in 72h old seedlings and 16.71 microg of mercury causing 50% inhibition of both root and shoot growth of 120h old seedlings.     

Induction of apoptosis and cytokine markers in colon cancer cells by magnesium oxide (MgO) nanoparticles

Magnesium oxide nanoparticles (MgONP) are predominantly utilized in industrial products. This study was undertaken to elucidate the mechanisms underlying toxic effect of MgONP in human colon cancer (HT 29) cells over 48 hr period. Cytotoxicity was evaluated by using MTT and neutral red uptake assays. Data demonstrated that MgONP reduced cell viability in concentration- and time-dependent manner. MgONP induced oxidative stress by decreasing glutathione (GSH) concentrations and elevation of reactive oxygen species (ROS) and lipid peroxidation levels. Increased caspase-3 enzyme activity and greater condensed, damaged chromosome was observed following MgONP exposure in HT 29 cells. The level of interleukin-4 (IL-4), tumor necrosis factor (TNF-α), and DNA fragmentation were significantly higher in MgONP incubated cells. The results showed that MgONP-induced toxicity in HT 29 cells may be mediated through oxidative stress.     

纳米Fe3O4对小鼠肺细胞的氧化损伤

纳米Fe3O4作为一种功能材料,在生物医药、生物靶向材料、微波吸收材料和高梯度磁分离器等方面应用前景广阔,其潜在的生物毒性也备受关注。为研究纳米Fe3O4对生物体可能造成的氧化损伤,以昆明小鼠为受试体,设置5、10、20和40mg·kg-14个染毒组,腹腔注射染毒7d后,测定小鼠肺组织中活性氧(reactive oxygen species,ROS)、还原型谷胱甘肽(glutathione,GSH)和丙二醛(malondialdehyde,MDA)的含量。结果显示,随着纳米Fe3O4染毒剂量的升高,肺组织ROS和MDA含量逐渐上升,GSH含量逐渐降低,各指标均呈一定的剂量-效应关系。剂量≥10mg·kg-1,肺组织ROS含量与对照组相比有显著差异(p<0.05);剂量≥20mg·kg-1,肺组织MDA含量与对照组相比有显著差异(p<0.05);剂量≥40mg·kg-1,肺组织GSH含量与对照组相比有显著差异(p<0.05)。研究表明,较高剂量(≥20mg·kg-1)的纳米Fe3O4颗粒材料会引起小鼠肺细胞的氧化损伤。     

Nanosilica exerts cytotoxicity and apoptotic response via oxidative stress in mouse embryonic fibroblasts

Nanoscale silica is an important industrial material and extensively used in medicines. The objective of this study was to determine potential cytotoxicity and genotoxic effects attributed to nanosilica exposure in mouse embryonic fibroblasts (L929) cells. Nanosilica produced mild cytotoxicity in L929 cells. Results showed that nanosilica increased thiobarbituric acid reactive substance levels and enhanced superoxide dismutase activity but decreased levels of glutathione. This was accompanied by a concomitant generation of reactive oxygen species, loss of mitochondrial membrane potential, and activation of caspase-3 activity. In addition, in the single-cell gel test, nanosilica (50–300 μg/ml) at two treatment times 24 and 48 hr produced concentration- and time-dependent increase of DNA damage. Therefore, the obtained results indicate that nanosilica may induce genotoxic effects in cultured L929 cells associated with induction of oxidative stress.     

Evaluation of hemopoietic responses in Labeo rohita Hamilton following acute copper toxicity

Fish are often exposed to highly contaminated water, especially in areas where the dilution rate of waste water is low. Environmental pollutants or other stress may affect one or more of the immunological functions in fish. Effective control of toxic substances is essential for the success of fish culture, which requires fish health monitoring using biomarkers. This study evaluated the effects of heavy metal copper (Cu) at environmentally relevant concentrations on the hematopoiesis in Labeo rohita. L. rohita fingerlings were exposed to different Cu concentrations for 6, 24, 48, or 72 hr. Following exposure, percentage blast cells was found to be increased after 6 and decreased after 24, 48, and 72 hr both at sublethal and LC₅₀ concentrations, whereas percentage mature erythrocytes decreased after 6 and increased after 24, 48, and 72 hr. Erythropoietic and leukopoietic efficiencies were also affected upon exposure. Erythropoietic and leucopoietic efficiencies increased markedly after 6, 24, and 48 hr but decreased after 72 hr in sublethal-treated fish. Erythropoietic efficiency decreased significantly after 6, 24 and 48 hr but increased after 72 hr in LC₅₀-treated fish. Leukopoietic efficiency decreased significantly after 6 hr exposure and increased after 24 and 48 hr but decreased after 72 hr. Flow cytometric studies of head kidney cell cycle phase distribution revealed cell death and DNA synthesis. The percentage cell death increased in fish exposed to sublethal concentrations and rose further at LC₅₀ during the earlier hours of exposure. Synthesis of DNA was increased at sublethal concentrations but was significantly reduced at LC₅₀ dose.     

Acute toxicity levels and ethological responses of Channa striatus to fertilizer industrial wastewater

The present paper deals with the toxicity of fertilizer's industrial wastewater on snake head fish Channa striatus (Bloch) previously named as Ophiocephalus sp., at different concentrations viz., 20, 40, 60, 80 and 100 percent on the behavioural changes and mortality. The exposed fish showed hyperactivity viz., jumping, operculum movement, distance travelling, somersaulting at higher concentration such as 60, 80, and 100 percent within 48 hr. At lower concentrations such as 20 and 40 percent exposed fish showed hyperactivities viz., linear movement and eye movement within 48 hr. The LC50 values of industrial wastewater were also determined viz. 89, 75, 70 and 69 percent at different duration of exposure time i.e. 48, 72, 96 and 120 hr respectively. The obtained data revealed that LC50 value decreased with increase of exposure.     

镉胁迫对脊尾白虾的毒性效应研究

为揭示重金属镉对脊尾白虾的毒性效应,采用急性毒性实验方法,研究了不同浓度镉(Cd~(2+))对脊尾白虾(Exopalaemon carinicauda)血清氧化应激相关生理指标的活性以及肌肉组织中腺苷酸转移酶基因(ANT)和热激蛋白70基因(HSC70)表达水平的影响。共设置4个Cd2+浓度胁迫(0、0.0002、0.001、0.005 mmol·L~(-1)),分别在0、3、6、9、12、24、36、48、72和96 h共10个时间点对相关指标进行测定。结果显示:不同浓度镉胁迫下,脊尾白虾血清中H_2O_2含量、MDA含量和GSH含量均表现为先升高后降低的趋势,H2O2含量在胁迫3 h时即出现明显的升高,而MDA和GSH则均在9 h时出现升高趋势,表现为一定的滞后性。H2O2含量在0.005 mmol·L~(-1)胁迫3 h时出现峰值,MDA含量在0.005 mmol·L~(-1)胁迫9 h时出现峰值,GSH含量在0.001mmol·L~(-1)胁迫48 h时出现峰值,且均与对照组存在显著性差异(P0.05)。HSC70基因的表达量在不同浓度胁迫下均表现为先升高后降低的趋势,且均在24 h时达到峰值,具体表达量水平的顺序为:0.0002 mmol·L~(-1)0.001 mmol·L~(-1)0.005 mmol·L~(-1)。ANT基因的表达量在不同浓度下则均表现为明显的下调趋势。由此可见,急性Cd~(2+)胁迫不仅影响脊尾白虾的氧化应激相关生理指标,还影响机体内组成型HSC70及与能量传递有关的ANT基因的表达水平。     

毒死蜱对雄性小鼠生殖毒性的影响

为研究毒死蜱对雄性小鼠生殖毒性的影响,利用不同浓度毒死蜱染毒小鼠.以昆明小鼠为受试动物,毒死蜱按3、6和12mg·kg-13个剂量水平,灌胃染毒小鼠7d.以睾丸组织匀浆测定活性氧(reactive oxygen species,ROS)和还原型谷胱甘肽(glutathione,GSH)的含量;以睾丸细胞测定DNA-蛋白...     

低浓度五氯酚暴露对稀有鮈鲫体内SOD活性、GSH和HSP70含量的影响

为筛选检测低浓度五氯酚(PCP)对水生生物毒性效应较敏感的指标,将稀有鮈鲫(Gobiocypris rarus)暴露于浓度分别为0.5、1.5、5.0、15和50μg·L-1的PCP中2、7、14、21d,同时设乙醇对照组,检测稀有鮈鲫体内(整体匀浆)超氧化物歧化酶(SOD)活性、谷胱甘肽(GSH)、热激蛋白70(HSP70)含量等生化指标.结果表明,相同暴露时间下,随着PCP暴露浓度的升高,SOD活性均表现为先抑制后激活趋势,GSH和HSP70含量无明显变化;相同暴露浓度下,随着PCP暴露时间的延长,SOD活性均表现为先激活后抑制趋势,GSH和HSP70含量无明显变化.初步认定相对于GSH、HSP70含量,SOD活性的变化可以更有效地反映低浓度PCP对稀有鮈鲫的毒性效应.     

纳米硫化镉对A549细胞的损伤研究

研究纳米硫化镉(Nano-Cd S)材料对肺癌细胞系A549的毒性及氧化损伤作用。培养A549细胞,经传代后接种于6孔板中,每孔2 m L完全培养基,接种次日进行染毒。用直径20~30 nm、长度80~100 nm的Nano-Cd S进行染毒,染毒浓度分别为0、5、10、20、40和80 mg·L~(-1)。染毒24 h后用MTT检测细胞存活率,以存活率在80%左右的浓度为后续实验染毒浓度。应用流式细胞技术,用荧光探针法检测A549细胞的活性氧(reactive oxygen species,ROS)含量,PI-Annexin-V法检测细胞凋亡情况;用试剂盒检测细胞中超氧化物岐化酶(superoxide dismutase,SOD)和过氧化氢酶(catalase,CAT)活性以及丙二醛(malondialdehyde,MDA)含量,判断细胞氧化损伤情况。不同浓度Nano-Cd S处理细胞24 h之后,细胞存活率随剂量的增加而下降,浓度为10、20、40和80μg·L~(-1)时,存活率分别为(88.71%±0.80%)、(81.93%±3.06%)、(75.23%±1.13%)和(70.66%±5.63%),且各组间差异均具有统计学意义(P0.05)。以浓度为10和20 mg·L~(-1)的Nano-Cd S染毒24 h后,胞内ROS含量和细胞凋亡率随染毒剂量的增加而增加(P0.05);浓度为10 mg·L~(-1)时,细胞凋亡率为(6.26%±0.44%)。与对照相比,各染毒组SOD和CAT活性和MDA含量升高,20 mg·L~(-1)染毒组SOD和CAT活性和MDA含量高于10 mg·L~(-1)染毒组(P0.05)。研究表明,纳米硫化镉能引起A549细胞的氧化损伤和细胞凋亡,具有明显的细胞毒性。     

丙烯腈诱导的氧化应激对大鼠肝脏内质网应激信号通路的影响

为探讨丙烯腈(acrylonitrile,ACN)诱导的大鼠肝脏氧化损伤对内质网应激(endoplasmic reticulum stress,ERS)信号通路的影响,我们将50只SPF级成年雄性SD大鼠按体重随机分为5组,每组10只。各组分别以12.5、25.0、50.0 mg·kg~(-1)ACN灌胃染毒,N-乙酰半胱氨酸(N-acetylcysteine,NAC)干预组先用300.0 mg·kg~(-1)NAC灌胃30 min后再灌50.0 mg·kg~(-1)ACN,对照组以0.5 mL·(100 g)~(-1)的玉米油灌胃,1次·天~(-1),6天·周~(-1),共计13周。染毒结束后,检测肝脏组织氧化还原酶活力及丙二醛(malondialdehyde,MDA)含量,GRP78、CHOP及caspase-12 mRNA及蛋白表达水平。结果显示:低、中ACN组大鼠肝脏GSH含量显著低于对照组(P0.05);低ACN组大鼠肝脏GSH-Px活力、SOD活力及MDA含量均显著高于对照组(P0.05);中、高ACN组大鼠肝脏CAT活力明显低于对照组(P0.05)。NAC干预后可逆转ACN诱导的大鼠肝脏GSH含量、MDA含量及SOD活力的变化。RT-PCR结果显示,高ACN组大鼠肝脏GRP78、CHOP、caspase-12 mRNA表达水平与对照组比较均升高(P0.05)。NAC干预后,CHOP、caspase-12 mRNA表达水平与高ACN组比较均降低(P0.05)。Western Blot结果显示,高ACN组大鼠肝脏GRP78、CHOP、caspase-12蛋白表达水平与对照组比较均升高(P0.05),NAC干预后可逆转以上作用。结果表明,ACN慢性染毒对大鼠肝脏的氧化损伤可激活ERS信号通路,NAC可减轻氧化损伤的程度而阻断ERS信号通路,这可能是ACN产生肝脏毒性的机制之一。     

壬基酚聚氧乙烯醚暴露下赤子爱胜蚓（Eisenia foetida）的生理损伤

利用急性接触试验和人工土壤试验分别研究了壬基酚聚氧乙烯醚（NPEO）对赤子爱胜蚓（Eisenia foetida）的致死性和氧化损伤.急性接触试验结果显示,NPEO对赤子爱胜蚓的48 h毒性半致死剂量p（48 h,LD50）为0.58 mg·L^-1;人工土壤试验结果显示,NPEO可诱导赤子爱胜蚓CAT酶活力、GST酶活力、GSH含量和氧化产物（MDA）含量上升,暴露28 d时,NPEO浓度与赤子爱胜蚓CAT酶活力、GST酶活力、GSH含量和MDA含量呈正相关,且均存在显著的剂量-效应关系（P＜0.05）,NPEO剂量增加对赤子爱胜蚓SOD酶活性和Cu-Zn SOD酶活性有轻微抑制作用.以上结果表明NPEO在亚致死暴露浓度下＜0.50 mg· kg^-1）会对赤子爱胜蚓产生生理胁迫并导致一定程度的氧化损伤.     

ROS介导的氧化应激在INH诱导的细胞毒性中的作用及槲皮素的干预

为探讨ROS介导的氧化应激在异烟肼(INH)诱导L-02细胞毒性中的作用及槲皮素的干预作用,建立体外培养INH诱导L-02细胞氧化损伤模型,实验分为对照组(A)、INH组(B)、槲皮素低剂量组(C)及槲皮素高剂量组(D)。采用生化分析法检测L-02细胞培养液中天冬氨酸氨基转移酶(AST)和丙氨酸氨基转移酶(ALT)的活性;利用荧光探针检测L-02细胞线粒体内活性氧(ROS)水平;应用比色法检测L-02细胞内丙二醛(MDA)、谷胱甘肽(GSH)的含量以及主要抗氧化物酶的活性。结果表明,与对照组相比,INH能显著增加L-02细胞培养液中AST和ALT的活性、细胞线粒体内ROS水平及细胞内MDA的含量(P0.01),并显著减少L-02细胞内GSH的含量及超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)的活性(P0.01)。与INH组比较,槲皮素低剂量组L-02细胞培养液中AST的活性、线粒体内ROS水平及细胞内MDA的含量明显降低(P0.05),而细胞内SOD的活性明显增加(P0.05);高剂量槲皮素能显著降低L-02细胞培养液中AST和ALT的活性、细胞线粒体内ROS水平及细胞内MDA的含量(P0.01),并能显著增高L-02细胞内GSH的含量和主要抗氧化物酶的活性(P0.01)。与槲皮素低剂量组相比,槲皮素高剂量组的保护效应更明显(P0.05)。可见,ROS介导的氧化应激在INH诱导的L-02细胞毒性中发挥了重要作用,且槲皮素对INH诱导的L-02细胞氧化损伤具有保护作用。     

Single walled carbon nanotubes induce cytotoxicity and oxidative stress in HEK293 cells

The aim of the present study was to evaluate the potential toxicity and general mechanisms involved in single walled carbon nanotubes (SWCNTs)-induced cytotoxicity using human embryonic kidney cell line (HEK293) cells. Carbon nanotubes (coded as CNT) used in this study were synthesized by the chemical vapor deposition method. To elucidate the possible mechanisms underlying SWCNT-induced cytotoxicity, cell viability, cell membrane damage (lactate dehydrogenase activity (LDH) assay), reduced glutathione (GSH), interleukin-8 (IL-8) and lipid peroxidation products levels were quantitatively assessed following SWCNT exposure for 48 hr using HEK293 cells. Exposure of cells to SWCNT at 3–300 μg/ml produced significant reduction in cell viability in a concentration-dependent manner. The IC₅₀ value of SWCNT was found to be 87.58 μg/ml. Exposure of HEK cells to SWCNT at 10–100 μg/ml resulted in concentration-dependent cell membrane damage, increased production of IL-8, elevated levels of thiobarbituric acid reactive substances like malondialdehyde and decreased intracellular GSH levels. In summary, exposure to SWCNT resulted in a concentration-dependent cytotoxicity in cultured HEK293 cells that was associated with increased oxidative stress.     

Histopathological alterations of Nile tilapia, Oreochromis niloticus in acute and subchronic alachlor exposure

Histopathological alterations in Nile tilapia, Oreochromis niloticus, aged 3 months and subjected to acute and subchronic alachlor exposure were studied by light microscopy LC50 values of alachlor for 24 hr 48 hr, 72 hr and 96 hr were 963.6, 563, 448, and 381.9 microg l(-1), respectively and the maximum acceptable toxicant concentration (MATC) was 350 microg l(-1). Fish were exposed to 381.9 (acute) and 35 microg l(-1) (sub-chronic) of alachlor for 24, 48, 72 and 96 hr and 90 days, respectively Gill lamellae and kidney tubules were the primary target organs for the acute toxic effect of alachlor while in the subchronic exposure, the toxic effect on the gills was less marked than that of the kidneys and liver Gill alterations included edema of the epithelial cell system, aneurisms with some ruptures, hypertrophy and hyperplasia of epithelial cells. The liver showed hydropic swelling of hepatocytes and vacuolation. Lipid vacuoles were observed in hepatocytes in the second and third month of subchronic exposure. The kidney showed hydropic swelling of tubular cells, lipid vacuole accumulation in many tubules, and nuclear pyknosis. The findings of this study could be used as a guideline forbiomonitoring programs on populations of Nile tilapia cultured near alachlor contaminated areas.