In vivo genotoxicity of mercury chloride and lead acetate: Micronucleus test on acridine orange stained fish cells.

The genotoxic effects of mercury chloride and lead acetate were evaluated in vivo using the micronucleus (MN) assay on acridine-orange (AO) stained peripheral blood erythrocytes, gill and fin epithelial cells of Carassius auratus auratus. Fish were exposed to three different concentrations of mercury chloride (MC) (1 microg/, 5 microg/L and 10 microg/L) and lead acetate (LA) (10 microg/L, 50 microg/L and 100 microg/L) for 2, 4 and 6 days. A single dose of 5 mg/L cyclophosphamide was used as a positive control. In addition to micronuclei, nuclear buds (NBs) were assessed in the erythrocytes. The ratio of polychromatic and normochromatic erythrocytes (PCE/NCE) in peripheral blood was also evaluated to assess cytotoxicity. MN frequencies in all three tissues were elevated in fish exposed to both LA and MC. However, NBs showed different sensitivity to metal treatments. MN frequencies in both control and treated fish were highest in gill cells and generally lower in erythrocytes and fin cells. PCE/NCE rations decreased in relation to MC and LA treatments. The results of this study indicate that LA and MC have genotoxic and cytotoxic damage in fish and confirmed that AO staining is a suitable technique for in vivo MN test in fish.     

醋酸汞和醋酸铅对大鼠间质细胞功能的影响

研究结果发现，醋酸汞Ｈｇ２＋（１０－８－１０－５ｍｏｌ／Ｌ）和醋酸铅Ｐｂ２＋（１０－７－１０－４ｍｏｌ／Ｌ）分别使得经ｈＣＧ（１００ｍＩＵ）刺激处理２４小时的Ｌｅｙｄｉｇ细胞内ｃＡＭＰ含量显著下降；同时Ｈｇ２＋（１０－７－１０－５ｍｏｌ／Ｌ）和Ｐｂ２＋（１０－６－１０－４ｍｏｌ／Ｌ）也使得Ｌｅｙｄｉｇ细胞Ｔ含量明显降低并且具有明显的剂量－反应关系。醋酸锌（Ｚｎ２＋）对原代培养的Ｌｅｙｄｉｇ细胞的上述观察指标均无影响，表明用这些指标的变化可以评价Ｈｇ２＋和Ｐｂ２＋对大鼠睾丸Ｌｅｙｄｉｇ的某些毒性。     

Effect of treatment with mercury chloride and lead acetate during the second stage of rapid postnatal brain growth on δ-aminolevulinic acid dehydratase (ALA-D) activity in brain, liver, kidney and blood of suckling rats

The sensitivity of developing rodents to toxic metals differs considerably from that of adults. In the present study, we investigated the in vivo and in vitro effects of inorganic mercury and lead on δ-aminolevulinic acid dehydratase (ALA-D) from brain, liver, kidney and blood of young rats. Eight day-old rats were injected with one or five doses of lead acetate (0, 3.5, or 7.0 mg/kg) or HgCl₂ (0, 2.5, or 5.0 mg/kg). In vitro, the IC₅₀ for mercury inhibition of cerebral, renal and hepatic ALA-D was in the 124 to 160 μM range, while values for lead acetate was in the 7 to 12 μM range. The IC₅₀ of blood enzyme for lead (0.8 μM) and mercury (6.5 μM) was significantly lower than that observed for the other tissues. A single dose of lead did not affect the enzyme activity, but a single dose of HgCl₂ (5 mg/kg) caused a significant inhibition of ALA-D from kidney (40%, P < 0.01) and liver (25%, P < 0.05). Five doses of lead acetate (3.5 or 7 mg/kg) caused an inhibition of about 25 and 40%, respectively (P < 0.01), of hepatic ALA-D, and an increase of 1.4-fold (P < 0.05) and 2.6-fold (P < 0.01) of blood enzyme, respectively. Treatment with five doses of HgCl₂ (5 mg/kg) caused an inhibition of about 25, 60, 50, and 80% of ALA-D from brain, blood, liver and kidney, respectively (all P < 0.05). Five doses of 2.5 mg/kg HgCl₂ caused an inhibition of ALA-D from liver (40%, P < 0.01) and kidney (45%, P < 0.01). These results demonstrate that ALA-D from young rat tissues show different sensitivities to mercury and lead. The enzyme was more affected by mercury than by lead in vivo, while in vitro lead was more potent that mercury as an ALA-D inhibitor.     

Protective effects of garlic extract and vitamin C against in vivo cypermethrin-induced teratogenic effects in rat offspring

Exposure of male (55.1 mg/kg b.wt. orally for 60 days) and/or pregnant female Wistar rats (55.1 mg/kg b.wt. orally at days 6–15 of gestation), to the insecticide cypermethrin (CYP); resulted in the development of a lot of external morphological deformities and visceral malformations in their offspring pubs, which signify the potential of such insecticide to induce reproductive toxicity and teratogenesis. Data cleared that CYP treatment induced significant increase in the percentages of post-implantation deaths, dwarf foeti and subcutaneous oedema beside significant decrease in percentages of live borne foeti and uterine implants. CYP also caused many visceral malformations among different treated groups including nasal, ophthalmic, cerebral, pulmonary, cardiac and renal malformations. Concomitant oral administration of garlic extract or vitamin C (5 days/week) to treated fathers and/or pregnant mothers with CYP provided significant reduction in the percentage of the foetal malformations induced by the insecticide, when compared with the control. The current study proves that garlic and ascorbic acid dampen the reproductive toxicity and/or teratogenicity of cypermethrin toxicity in rats; therefore might prove to be effective dietary supplements in developing countries where pesticide pollution is high.     

Cytotoxic, genotoxic and cell-cycle disruptive effects of thio-dimethylarsinate in cultured human cells and the role of glutathione

Thio-dimethylarsinate (thio-DMA), a recently discovered urine metabolite in humans, was investigated for its cytotoxic, genotoxic and cell-cycle disruptive effects in the cultured human hepatocarcinoma cell line, HepG2, and Syrian hamster embryo cells. In addition, the role of glutathione (GSH) on the cytotoxic effects of thio-DMA was investigated in terms of the effects of GSH depletion and the effects of exogenously added GSH. LC50 values of arsenicals for cells incubated for 48 h were 0.026 mM for thio-DMA, 0.343 mM for DMA and 3.66 mM for dithio-DMA. Depletion of cell GSH reduced the cytotoxic effects of thio-DMA. The cytotoxic effects of 0.02 mM and 0.05 mM thio-DMA were enhanced markedly when used in combination with 1 to 3 mM GSH, but decreased again when combined with 5 mM GSH. These results suggested that cytotoxic intermediates were generated by the interaction of thio-DMA with GSH, while an excessive amount of GSH suppressed the generation of these intermediates. Flow-cytometry showed that thio-DMA was an inducer of cells with 4N DNA and hypo 2N DNA. The results also demonstrated that cells arrested in the mitotic phase had abnormalities in their spindle organization and centrosome integrity. In addition, cells arrested in mitosis by thio-DMA had chromosome structural aberrations, such as chromatid gaps, chromatid breaks and chromatid exchanges. Moreover, the cytotoxic effects of thio-DMA may in part be associated with an apoptotic mode of cell death that was evaluated by the appearance of nucleosome level DNA fragmentations and an 85-kDa cleavage fragment of poly (ADP-ribose) polymerase. These findings suggest that the presence of thio-DMA in human urine has implications for human health in terms of arsenic metabolism and toxicity.     

Selective cytotoxic and genotoxic activities of 5-(2-bromo-5-methoxybenzylidene)-thiazolidine-2,4-dione against NCI-H292 human lung carcinoma cells

Background

Thiazolidine-2,4-dione ring system is used as a pharmacophore to build various heterocyclic compounds aimed to interact with biological targets. In the present study, benzylidene-2,4-thiazolidinedione derivatives (compounds 2–5) were synthesized and screened against cancer cell lines and the genotoxicity and cytotoxicity of the most active compound (5) was investigated on normal and lung cancer cell line.

Protective role of flax lignans against lead acetate induced oxidative damage and hyperlipidemia in rats

The results showed that the lead concentration was higher than Cr, Ni and Cd in roadside soil samples. Also, the present study was conducted to investigate the protective role of flax lignans against the effects of lead acetate on oxidative stress, antioxidant enzymes and lipid profile. Animals were divided into three groups; the first group was used as control. While, groups 2, and 3 were orally treated with 200 mg/L lead acetate in drinking water and the combination of lead acetate (200 mg/L) plus flax lignans (30 mg/100 g BW), respectively. Rats were administered their respective doses daily for 3 weeks. Results showed that lead acetate increased TBARS, and decreased the activities of GST, SOD, GR and CAT, and the contents of glutathione in liver extracts, compared to control. The present data indicated that total lipids, cholesterol, triglycerides and LDL-c were significantly increased by lead acetate treatment, while HDL-c levels were decreased in the serum and liver extracts. Animals treated with flax lignans in combination with lead acetate alleviated its toxic effects in the tested parameters. Also, the morph metric analysis of the dorsal aorta revealed that, the histological alterations induced after lead acetate treatments were markedly reduced.     

Beneficial effects of vitamin C and vitamin E on reserpine-induced oral dyskinesia in rats: critical role of striatal catalase activity

Oral dyskinesias are implicated in a series of neuropathologies and have been associated to an increase in oxidative stress. Several antioxidants, including vitamin E, decrease reserpine-induced oral dyskinesia (OD) in rodents and we have described a protective role of striatal catalase against the development of OD. The aim of this study was to verify the effects of vitamin C alone or in combination with vitamin E on reserpine-induced OD as well as to determine a possible role of catalase in the antidyskinetic property of these vitamins. Different doses of vitamin C attenuated reserpine-induced increase in OD. A similar treatment with an effective dose of vitamin C concomitant to an effective dose of vitamin E potentiated the antidyskinetic effect of both vitamins when administered alone. The administration of these vitamins alone produced an increase in striatal catalase activity that likewise was potentiated by their combined administration. In addition, the antidyskinetic property of vitamin E and vitamin C was abolished by a concomitant treatment with the catalase inhibitor aminotriazole. These results indicate a beneficial effect of these vitamins and reinforce the critical role of striatal catalase against the development of oral dyskinesias.     

Protective effects of vitamin E and C on cisplatin nephrotoxicity in developing rats

The kinetics of vitamin E was followed in serum, liver and kidney of 10- and 55-day-old rats after the administration of a single i.m. dose of 100 mg α-tocopherol acetate/100 g body wt. The basal levels without vitamin E administration were significantly higher in serum and liver of 10- than 55-day-old rats. The effect of vitamin E on cisplatin (CP; 0.6 mg/100 g body wt., i.p.) nephrotoxicity was investigated by determining urinary volume and protein excretion, as well as the concentration of blood urea nitrogen (BUN) and lipid peroxides in renal tissue (LPO). Previously described age differences in CP nephrotoxicity were confirmed. The administration of vitamin E, 12 h prior to CP, diminished the toxic effect of CP in young and adult rats. This effect could not be enhanced by a second administration of vitamin E. The simultaneous administration of vitamin E and C 12 h prior to CP intensified the protective effect of a single administration of vitamin E in 10- and 55-day-old rats without influencing the concentration of platinum in renal tissue. Received: 10 April 1997 / Accepted: 10 June 1997     

Mutagenic, cytotoxic, and genotoxic properties of tobacco smoke produced by cigarillos available on the Canadian market

Cigarillos (aka little cigars) have been increasing in popularity unlike cigarettes; but relatively little is known about the toxicology of the mainstream smoke (MSS) from such products. Therefore, the objective of this work was to compare the toxicological properties of the MSS (Health Canada Intensive smoking conditions) from a range of cigarillo products with the toxicological properties of MSS of cigarettes. Three in vitro assays were used to evaluate the toxicities of the MSS total particulate matter (TPM): (1) mutagenicity using Ames assay with Salmonella strains TA98 and TA100 with S9 metabolic activation (+S9); (2) cytotoxicity using the Neutral Red Uptake (NRU) assay with CHO (Chinese Hamster Ovary) cells; and (3) genotoxicity using the micronucleus assay with CHO cells and short-term exposures (3-h ± S9). The Ames assay (TA100 + S9) and the NRU assay were also applied to the gas/vapour phase of the MSS that passed through the Cambridge pad. On a per-milligram-nicotine basis, the preferred way of comparing toxicities of different types of tobacco products, the MSS from cigarillos was not less toxic, and in some cases more toxic (TPM fraction TA98 + S9, NRU), than the MSS from cigarettes. Thus, our findings support our prior work on smoke mutagenicity that showed MSS from cigarillos was not less toxic than MSS from cigarettes.     

Cell death and cytotoxic effects in YAC-1 lymphoma cells following exposure to various forms of mercury

The effects of 1 min-4 h exposures to four Hg compounds (mercuric chloride [HgCl2], methyl mercuric chloride [CH3HgCl], p-chloromercuribenzoate [p-CMB] and thimerosal [TMS; ethylmercurithiosalicylate]) on cell death, microtubules, actin, CD3 receptor expression, protein tyrosine phosphorylation (PTyr-P) and intracellular calcium ([Ca2+]i) levels were investigated in YAC-1 lymphoma cells using flow cytometry. YOPRO-1 (YP) and propidium iodide (PI) dye uptake indicated all forms of Hg tested were toxic at concentrations ranging from 25.8-48.4 microM, with two distinct patterns of effects. Early apoptosis was prolonged for CH3HgCl- and TMS-treated cells, with more than 50% remaining YP+/PI- after 4h. Both CH3HgCl and TMS induced complete loss of beta-tubulin fluorescence, indicative of microtubule depolymerization and inhibition of tubulin synthesis and/or beta-tubulin degradation, while F-actin fluorescence diminished to a lesser degree and only after loss beta-tubulin. CH3HgCl and TMS induced an almost immediate two-fold increase in CD3 fluorescence, with levels returning to baseline within minutes. With continued exposure, CD3 fluorescence was reduced to approximately 50% of baseline values. Both compounds also increased PTyr-P two- to three-fold immediately, with levels returning to baseline at 4h. Similarly, two- to three-fold increases in [Ca2+]i were noted after 1 min exposure. [Ca2+]i increased progressively, reaching levels five- to eight-fold greater than control values. In contrast, dye uptake was delayed with HgCl2 and p-CMB, although cell death proceeded rapidly, with almost all non-viable cells being late apoptotic (YP+/PI+) by 4h. p-CMB produced early reductions in F-actin, and after 4h, complete loss of F-actin with only partial reduction of total beta-tubulin was seen with both p-CMB and HgCl2. HgCl2 reduced CD3 expression and PTyr-P slightly within minutes, while p-CMB produced similar effects on CD3 only at 4h, at which time PTyr-P was increased two- to three-fold. Both compounds increased [Ca2+]i within minutes, though levels remained under twice the baseline concentration after 15 min exposure. With continued exposure, [Ca2+]i increased to levels two- to five-fold greater than control values. These findings indicate the two groups of Hg compounds may induce cell death by distinct pathways, reflecting interactions with different cellular targets leading to cell death.     

维生素E和银杏叶提取物对3种氯代烯烃细胞毒性的拮抗作用

目的探讨维生素E和银杏叶提取物(ginkgo biloba extract，GbE)对三氯乙烯(trichloroethylene，TCE)、四氯乙烯(perchloroethylene，PCE)和二氯乙烯(diehloroethylene，DCE)所致人角质形成细胞(keratinocyte，Kc)细胞毒性的拮抗作用。方法利用中性红吸附(neutral red uptake，NRU)试验和乳酸脱氢酶(lactate dehydrogenase，LDH)释放试验分别测定细胞活力和细胞毒性，分析维生素E和GbE对3种氯代烯烃的细胞毒性拮抗作用。结果维生素E和GbE对3种氯代烯烃的细胞毒性具有明显的拮抗作用，在10～100mmol／L(mg／L)范围内呈明显的剂量．效应关系，当维生素E浓度达到50mmol／L，GbE浓度达到150mg／L时，细胞基本恢复为正常的状态。结论vE和GbE对3种氯代烯烃所致KC细胞毒性的拮抗作用可能与它们稳定细胞膜结构，减少细胞膜损伤有关。     

Cytotoxic and phenotypic effects of uranium and lead on osteoblastic cells are highly dependent on metal speciation

Bone is one of the main retention organs for uranium (U) and lead (Pb). The clinical effects of U or Pb poisoning are well known: acute and chronic intoxications impair bone formation. However, only few studies dealt with the cellular and molecular mechanisms of their toxicity. The purpose of this study was to investigate acute cytotoxicity of U and Pb and their phenotypic effects on rat and human osteoblasts, the cells responsible for bone formation. The most likely species of the toxicants in contact with cells after blood contamination were selected for cell exposure. Results showed that the cytotoxic effect of U and Pb is highly dependent on their speciation. Thus, Pb was cytotoxic when left free in the exposure medium or when complexed with carbonate, cysteine or citrate, but not when complexed with albumin or phosphate, under an insoluble form. U was cytotoxic whatever its speciation, but differences in sensitivity were observed as a function of speciation. Population growth recovery could be obtained after exposure to low doses of U or Pb, except for some U-carbonate complexes which had irreversible effects whatever the dose. The activation of two markers of bone formation and mineralization, osteocalcin and bone sialoprotein (BSP), was observed after exposure to non-toxic doses or non-toxic species of U or Pb while their inhibition was observed after toxic exposure to both metals. This work provides new elements to better understand the complex mechanisms of U and Pb toxicity to osteoblasts. Our results also illustrate the importance of a strictly controlled speciation of the metals in toxicological studies.     

茎叶人参皂甙和维生素E对百草枯所致大鼠急性肺损伤保护作用的比较研究

目的研究茎叶人参皂甙和维生素E（VE）对百草枯所致大鼠急性肺损伤（ALI）的保护作用。方法采用百草枯所致大鼠急性肺损伤模型,随机分为正常对照组（NS组）、肺损伤组（ALI组）、维生素E干预组（VE组）和皂甙干预组（GS组）。观察皂甙和VE对大鼠急性肺损伤时MDA等水平、病理改变及肺系数等影响。结果GS组和VE组可明显降低肺损伤所致血浆、组织中MDA等水平的升高,并能降低肺系数;同时又能显著升高肺组织中SOD、GSH-PX的水平,且GS组和VE组之间差异无统计学意义（P〉0.05）。结论茎叶人参皂甙和VE可通过抑制MDA的表达,改善SOD、GSH-PX等方式减少氧自由基的产生,减轻肺损伤程度,对百草枯所致急性肺损伤有明显的保护作用。     

Comparative analysis on the effect of Lycopersicon esculentum (tomato) in reducing cadmium,mercury and lead accumulation in liver

Scope

L. esculentum (tomato) contain compounds with anti-oxidant and anti-inflammatory properties, able to synthesize metal chelating proteins. We examined the ability of fruit extract to protect against mercury (Hg), lead (Pb) and cadmium (Cd) accumulation in the liver.

Methods and results

Rats were fed on tomato mixed with rat chow (10% w/w), while Hg (10 ppm), Cd (200 ppm) and Pb (100 ppm) was given in drinking water. Tomato was administered together with the metals (group 2), a week after exposure (group 3) or a week before metal exposure (group 4) for a period of six weeks. The metal accumulations in the liver were determined using AAS. There was a significant (P < 0.05) increase in protection by tomato to Cd and Hg accumulation but not to Pb (P < 0.05) in weeks 2 and 4 for groups 2 and 3. The protective ability was significantly (P < 0.05) increased for Pb in group 4, but was less comparable to Cd and Hg.

Conclusion

Tomato reduces uptake while enhancing the elimination of these metals in a time dependent manner. The highest hepatoprotective effect was to Cd followed by Hg and least to Pb. Its administration is beneficial in reducing heavy metal accumulation in the liver.     

VES对人胃癌细胞中细胞周期调控因子蛋白表达的影响

本研究采用免疫细胞化学方法检测了维生素Ｅ琥珀酸酯（ＶＥＳ）处理人胃癌（ＳＧＣ－７９０１）细胞４８小时后某些细胞周期调控因子及细胞凋亡调控基因的蛋白表达。结果表明ＶＥＳ能明显抑制ＳＧＣ－７９０１细胞的ｐ１６、ｐ５３、ｐ２１和ＰＣＮＡ的蛋白表达并均有明显的剂量－效应关系。以ｐ１６的降低作用最为明显，依次顺序为ｐ２１、ｐ５３和ＰＣＮＡ。与此相反，在ＶＥＳ处理后ｃ－ｆｏｓ蛋白表达被明显诱导。上述结果提示在离体试验条件下ＶＥＳ具有潜在的抗癌作用。     

Protective role of vitamin E on nickel and/or chromium induced oxidative stress in the mouse ovary

In the present study, we report the invivo effects of nickel chloride (NiCl₂; 8 and 16 mg/kg body weight) and/or potassium dichromate (K₂Cr₂O₇; 5 and 10 mg/kg body weight) in the ovary of adult mice. The protective role of vitamin E (2 mg/kg body weight) along with their combination was also studied. Nickel and/or chromium to mice enhanced the levels of lipid peroxides in the ovary, which was accompanied by a significant decline in the levels of protein, glutathione, total ascorbic acid and activities of superoxide dismutase and catalase. Supplementation of vitamin E along with NiCl₂ + K₂Cr₂O₇ significantly lowered the levels of lipid peroxidation and enhanced the antioxidant status. Findings of the present study suggest that vitamin E exerts its protective effect against nickel and/or chromium induced toxicity by preventing lipid peroxidation and protecting antioxidant system in the mouse ovary.     

The inhibitory effects of garlic and <Emphasis Type="Italic">Panax ginseng</Emphasis> extract standardized with ginsenoside Rg3 on the genotoxicity,biochemical, and histological changes induced by ethylenediaminetetraacetic acid in male rats

Ethylenediaminetetraacetic acid (EDTA) is widely used in food and other industries to sequester metal ions and to prevent their disadvantageous effects. The objective of the current study was to evaluate the protective effect of Panax ginseng extract standardized with ginsenoside Rg3 (ginsenoside Rg3 content was 3.6% w/w, i.e., 36 μg/mg P. ginseng extract) and garlic against EDTA-induced biochemical, genotoxic, and histological changes in rats. Forty male rats were divided into eight treatment groups and treated for 7 days as follows: the control group, the group treated with EDTA (20 mg/kg b.w) and the groups treated with P. ginseng extract (20 mg/kg b.w), garlic (5 mg/kg b.w), P. ginseng plus garlic alone or in combination with EDTA. In vivo bone marrow micronucleus test and random amplified polymorphism DNA-PCR (RAPD-PCR) method were performed to assess the antigenotoxic effect of both protective agents. The results indicated that EDTA administration caused a significant decrease in the serum biochemical parameters and antioxidant enzymes activity. The administration also increased lipid peroxidation and the incidence of micronucleated polychromatic erythrocytes (MnPCEs), caused appearance of some changes in polymorphism band patterns, and induced different histopathological lesions in the livers, kidneys, and testis. Treatment with P. ginseng, garlic alone or plus EDTA significantly improved all the tested parameters. Moreover, P. ginseng extract was found to be more effective than garlic in restoring the parameters that were altered by EDTA.     

水飞蓟素和维生素E对维持性血液透析患者氧化应激、炎症反应及血红蛋白的影响

目的探讨水飞蓟素和维生素E对维持性血液透析(MHD)患者氧化应激、炎症反应及血红蛋白的影响。方法选择80例维持性血液透析的患者,随机分为水飞蓟素组、维生素E组、联合组和对照组。水飞蓟素组口服水飞蓟素140 mg,3次/d;维生素E组口服维生素E软胶囊400 mg,1次/d;联合用药组口服水飞蓟素140 mg,3次/d,维生素E胶囊400 mg,1次/d;对照组予以安慰剂治疗。治疗前及治疗4周后,采血检测血清丙二醛(MDA)、C反应蛋白(CRP)、红细胞沉降率(ESR)及血红蛋白(HGB)水平。结果与对照组比较,治疗4周后,水飞蓟素组和联合组血清MDA、CRP和ESR水平明显降低,HGB水平明显上升(P<0.05)。结论水飞蓟素或水飞蓟素联合维生素E可以减轻MHD患者体内氧化应激及炎症反应水平,提高血红蛋白浓度。     

The effects of lead,d-amphetamine,and time of day on activity levels in the mouse

Mice were exposed to lead acetate (0.5%) pre- and postnatally, and activity levels were assessed at 21 days of age. Two measures of open field activity were employed at two different times of day across three doses of d-amphetamine. These factors influence the results observed in lead exposed mice and demonstrate that lead's effects on activity are not invariant. Implications for future research as well as the suggestion of an animal model for childhood hyperactivity are discussed.