Doses Of Cadmium Research Articles

Atorvastatin prevents cadmium-induced renal toxicity in a rat model.

In many industrial processes, worker exposure to cadmium causes kidney damage; thus, protection against cadmium toxicity is important in workplace health. Cadmium toxicity involves oxidative stress by increasing the levels of reactive oxygen species. Statins have shown antioxidant effects that might prevent this increase in oxidative stress. We investigated the potential effects of atorvastatin pretreatment in protecting experimental rats against kidney toxicity caused by cadmium. Experiments were performed on 56 adult male Wistar rats (200 ± 20g), randomly assigned to eight groups. Atorvastatin was administered by oral gavage for 15days at 20mg/kg/day, starting 7days before cadmium chloride intra-peritoneal administration (at 1, 2, and 3mg/kg) for 8days. On day 16, blood samples were collected, and kidneys were excised to evaluate the biochemical and histopathological changes. Cadmium chloride significantly increased malondialdehyde, serum creatinine, blood urea nitrogen, and decreased superoxide dismutase, glutathione, and glutathione peroxidase levels. Pre-administration of rats with atorvastatin at a dose of 20mg/kg decreased blood urea nitrogen, creatinine, and lipid peroxidation, increased the activities of antioxidant enzymes, and prevented changes in physiological variables compared with animals that were not pretreated. Atorvastatin pretreatment prevented kidney damage following exposure to toxic doses of cadmium. In conclusion, atorvastatin pretreatment in rats with cadmium chloride-induced kidney toxicity could reduce oxidative stress by changing biochemical functions and thereby decreasing damage to kidney tissue.

Proteomic analysis reveals differential responsive mechanisms in Solanum nigrum exposed to low and high dose of cadmium

Cadmium (Cd) contamination is becoming a widespread environmental problem. However, the differential responsive mechanisms of Cd hyperaccumulator Solanum nigrum to low or high dose of Cd are not well documented. In this study, phenotypic and physiological analysis firstly suggested that the seedlings of S. nigrum showed slight leaf chlorosis symptoms under 25 μM Cd and severe inhibition on growth and photosynthesis under 100 μM Cd. Further proteomic analysis identified 105 differentially expressed proteins (DEPs) in the Cd-treated leaves. Under low dose of Cd stress, 47 DEPs are mainly involved in primary metabolic processes, while under high dose of Cd stress, 92 DEPs are mainly involved in photosynthesis, energy metabolism, production of phytochelatin and reactive oxygen species (ROS). Protein-protein interaction (PPI) network analysis of DEPs support above differential responses in the leaves of S. nigrum to low and high dose of Cd treatments. This work provides the differential responsive mechanisms in S. nigrum to low and high dose of Cd, and the theoretical foundation for the application of hyperaccumulating plants in the phytoremediation of Cd-contaminated soils.

Phenotypic aging mediates the association between blood cadmium and depression: a population-based study.

Depression is a serious public health problem today, especially in middle-aged and older adults. Although the etiology of the disease has not been fully elucidated, environmental factors are increasingly not negligible. Cadmium is widely used in industrial production. The general population may be chronically exposed to low doses of cadmium. This study aimed to investigate the association between blood cadmium and depression and to explore the mediating role of aging indicators in this process. We conducted a cross-sectional study on blood cadmium (N = 7195, age ≥ 20years) using data from the 2007-2010 National Health and Nutrition Examination Survey (NHANES). Aging indicators (biological and phenotypic age) are calculated by combining multiple biochemical and/or functional indicators. To determine the relationship between blood cadmium concentrations and depressive symptoms, we used weighted multivariate logistic regression and restricted cubic spline functions and employed mediation analysis to explore the possible mediating effects of aging indicators in the process. We found a significant positive association between blood cadmium and depression with an odds ratio (OR) and 95% confidence interval (CI): 1.22 (1.04,1.43). Restricted cubic spline analysis found a linear positive association between blood cadmium and depression. In the fully covariate-adjusted model, we found a positive association between blood cadmium and biological age and phenotypic age with β and 95% CI: 1.02 (0.65, 1.39) and 2.35 (1.70, 3.01), respectively. In the mediation analysis, we found that phenotypic age mediated 21.32% of the association between blood cadmium and depression. These results suggest that even exposure to low doses of cadmium can increase the risk of depression and that this process may be mediated by phenotypic aging.

An Analysis of the Reaction of Frogbit (Hydrocharis morsus-ranae L.) to Cadmium Contamination with a View to Its Use in the Phytoremediation of Water Bodies

Macrophytes play an important role in assessing the condition of aquatic ecosystems. The aim of the study was to assess the effectiveness of cadmium uptake by frogbit (Hydrocharis morsus-ranae) for the phytoremediation of aquatic ecosystems. The study examined cadmium (Cd) uptake by frogbit grown under conditions of low and high fertilizer dose and three cadmium dose levels over three- and six-week exposure times. Cadmium uptake was found to be influenced by water reactivity, mineral nutrient abundance, and exposure time. Its accumulation in frogbit is hence a good bioindicator of cadmium pollution in water bodies. Where the plant had greater access to phosphorus, nitrogen, potassium (PNK) compounds, i.e., high fertilizer level, a higher pH level (7.6) was associated with increased cadmium uptake and decreased plant biomass. A higher PNK level was also associated with greater tolerance to cadmium, while at lower PNK levels, more efficient cadmium uptake was noted after three weeks. Hydrocharis morsus-ranae can be used for water and wastewater treatment in the final stage of phytoremediation, but in combination with other species of pleustophytes that represent different biosorption sites.

Safflower (Carthamus tinctorius L.) Response to Cadmium Stress: Morpho-Physiological Traits and Mineral Concentrations.

Cadmium is a widely distributed heavy metal in agricultural soils that affects plant growth and productivity. In this context, the current study investigated the effects of different cadmium (Cd) doses (0, 25, 50, 75, and 100 mg L-1 of CdSO4) on the growth and physiological attributes of safflower (Carthamus tinctorius L.) including plant height (cm), root length (cm), fresh weight (g) of root, stem, and leaves, leaf number, macro and micro-nutrients, Se, and heavy metal (Cd, Cr, and Pb) content. The experiment was carried out in a completely randomized design (CRD) with four replicates. The results showed that Cd stress significantly negatively affected all growth indices, macro- and micro-nutrients, and heavy metal content. In addition, it increased the MDA and APX activities. The highest amounts of Fe, Mn, Ni, Pb, Zn, K, Na, Cd, Cr, and Cu were determined in plant roots, while the highest values of Ca and Mg were detected in plant stem tissues. High Cd doses decreased the content of Ca, K, Mg, Cr, Cu, Fe, Mn, Ni, Pb, Se, and Zn in safflower plant tissues by 45.47%, 39.33%, 79.28%, 68.21%, 37.06%, 66.67%, 45.62%, 50.38%, 54.37%, 33.33% and 65.87%, respectively, as compared to the control treatments.

The Effect of Some Heavy Metals on the Growth of Garlic under In Vitro Conditions

Garlic (Allium sativum L.) is an important plant species because of its nutritional and medical value. One of the important advantages of plant tissue culture is in vitro selection. The tolerance of garlic to some heavy metals under in vitro conditions was studied. In vitro experiments were carried out in Murashige and Skoog (MS) nutrient medium supplemented with different doses of cadmium (Cd), cobalt (Co), nickel (Ni), aluminum (Al), copper (Cu), chromium (Cr), and lead (Pb) at 100 µm, 200 µm, 300 µm, 400 µm, and 500 µm. During experiments, plant length, number of leaves, leaf length, root number, and root length parameters were considered. In the findings, there was a decrease in both leaf and root development as doses of heavy metals increased. In addition, it has been found that the decrease in plant development at doses of 400 µm and 500 µm was higher compared with other doses. There was no root formation at high doses of Cd, Co, Ni, and Cu (400 µm and 500 µm). As a recommendation, further research should be conducted under in vivo conditions to evaluate the level of tolerance to heavy metals in garlic.

Effects of cadmium ingestion on reproduction and maternal egg care in the European earwig

A growing number of studies show that anthropization can alter the behaviour, survival, physiology, cognition and reproduction of many animal species. However, its impact on parental care, a common behaviour where even subtle changes can have dramatic effects on the viability of future generations and thereby jeopardize population dynamics, remains surprisingly unclear. Here, we studied the effects of exposure to cadmium, a highly toxic chemical pollutant widely distributed in the trophic chain, on egg production and maternal egg care in the European earwig, Forficula auricularia . We fed 200 females with food containing cadmium at five different concentrations for several weeks, and then quantified the number of eggs produced, the expression of six forms of egg care and three forms of noncare behaviours, as well as maternal survival and egg development. In contrast to most results reported in other animal species, we found no evidence that ingestion of even substantial doses of cadmium affects egg production or maternal egg care in the form of grooming, antennation, displacement, gathering, defence or retrieval. Moreover, it neither affected maternal exploration, inactivity or self-grooming behaviours, nor egg development time, hatching rate or juvenile weight. Overall, these results reveal that egg care is resilient to environmental cadmium pollution in earwigs and suggest that females possess efficient and fast-acting physiological processes that help them reduce their sensitivity to heavy metal contamination. More generally, our findings may suggest that selection pressures associated with the necessity to express egg care has directly or indirectly selected for higher resistance/tolerance against certain chemical pollution, and thus that species with parental care could be more resilient in the face of increasing levels of anthropogenic pollution. • Egg care is an essential behaviour to ensure the viability of future generations. • Cadmium is highly toxic to organisms and affects numerous fitness-related traits. • We tested the effects of cadmium on egg care and reproduction in earwig females. • We found that egg care and female reproduction were independent of cadmium exposure. • The critical importance of egg care could explain the robustness of this behaviour.

Chronic Cadmium Exposure Induces Impaired Olfactory Learning and Altered Brain Gene Expression in Honey Bees (Apis mellifera).

The honey bee (Apis mellifera) plays vital ecological roles in the pollination of crops and the maintenance of ecological balance, and adult honey bees may be exposed to exogenous chemicals including heavy metals during their foraging activities. Cadmium (Cd) is regarded as a nonessential toxic metal and is readily accumulated in plants; honey bees can therefore acquire Cd through the collection of contaminated nectar. In the present study, honey bees were chronically exposed to Cd to investigate the effects of sublethal cadmium doses on the olfactory learning and brain gene expression profiles of honey bees. The results showed that Cd-treated bees exhibited significantly impaired olfactory learning performances in comparison with control bees. Moreover, the head weight was significantly lower in Cd-treated bees than in control bees after chronic exposure to Cd. Gene expression profiles between the Cd treatment and the control revealed that 79 genes were significantly differentially expressed. Genes encoding chemoreceptors and olfactory proteins were downregulated, whereas genes involved in response to oxidative stress were upregulated in Cd-treated bees. The results suggest that Cd exposure exerts oxidative stress in the brain of honey bees, and the dysregulated expression of genes encoding chemoreceptors, olfactory proteins, and cytochrome P450 enzymes is probably associated with impaired olfactory learning in honey bees.

Assessment of Oxidative Stress Indices in Tissues of Cadmium-challenged Female Wistar Rats Treated with Combined Ethanolic Leaf Extract of Manihot esculenta and Citrus sinensis

This research assessed the oxidative stress indices in tissues of cadmium-challenged female Wistar rats treated with combined ethanolic leaf extract of Manihot esculenta and Citrus sinensis. Eighteen female rats (150±20g) were divided put into three (3) groups: Group 1 (received feed and water only); Group 2 (received single dose of cadmium, 30mg/kg body weight at the start of the experiment) and Group 3 (received cadmium as in group 2 above and 200mg/kg body weight of combined extract of orange and cassava leaf, daily for two weeks). Cadmium load in the tissues of the rats were analyzed using AAS after acid digestion and oxidative stress indices were analyzed using standard procedures. Data obtained showed that the cadmium tissue load (𝑥̅±SD, μg/g tissue) were 0.005±0.0007 (liver), 0.007±0.0004 (kidney); 55.4±5.2 (liver), 28.3±4.6 (kidney); and 13.6±2.3 (liver), 20.7±2.5 (kidney) for Groups 1, 2 and 3 respectively. There was a higher concentration of Cd in the liver and kidney of rats exposed to Cd alone (Group 2) compared to the control (Group 1) and Cd-challenged rats treated with combined leaf extract of Manihot esculenta and Citrus sinensis (Group 3). Exposure to Cd alone caused significant (p<0.05) increase in lipid peroxidation and glutathione peroxidase in the liver and kidney compared to the control. Conversely, the administration of Cd alone to rats caused significant (p<0.05) reduction in the level of glutathione and the activities of superoxide dismutase and catalase compared to the control in both tissues. Significant amelioration was witnessed in all the parameters in Cd-challenged rats treated with the extract compared to rats challenged with Cd alone. The results show that Cd-induced oxidative stress can be countered effectively by combined leaf extract of Manihot esculenta and Citrus sinensis which is rich in antioxidant molecules.

Physiological and biochemical responses of Brassica napus L. cultivars exposed to Cd stress

Four different rapeseed (Brassica napus L.) cultivars CZL, Benefit, Iwas and ZhongZhuang9, were used to analyse physiological responses to higher doses of cadmium (Cd) and their ability of Cd accumulation. Plants were exposed for 30 days to different Cd dosages (0, 50, 100, and 150 mg Cd/kg) in soil under greenhouse conditions. Cadmium was accumulated more in roots than in shoots of all tested cultivars, with the highest Cd in ZhongZhuang9. After the lowest Cd dose, the highest translocation factor was for CZL (0.8) and Benefit (0.6). The content of both K and Ca varied between treatments and cultivars. The chlorophyll fluorescence parameters and relative chlorophyll content were affected minimally. High constant levels of salicylic acid and a sharp increase in proline content were found mostly in Iwas; therefore, it may be considered as a more tolerant cultivar.

Effects of Cadmium on Kidney Function of the Freshwater Turtles Mauremys reevesii.

This research studied the effects of cadmium on kidney function of the freshwater turtles Mauremys reevesii. Turtles were injected intraperitoneally with 0, 7.5, 15, and 30mgkg-1 cadmium separately for once. The samples were gathered to check the kidney index, the contents of TP in kidney tissue, and the levels of CRE and BUN in the plasma of the turtles. Results showed that the concentration of TP was overall decreased with the extension of cadmium exposure time and the increasing of the exposure dose of cadmium. The CRE content in the plasma of each treatment group increased with the prolongation of exposure time in a dose-dependent, and the BUN levels of all poisoned groups showed a trend of increasing. The kidney index of treated turtles increased. In summary, cadmium could induce the increase of turtle kidney index, the content of CRE and BUN in plasma, and the decrease of TP content in the kidney.

Chemical and biochemical responses to sub−lethal doses of mercury and cadmium in gilthead seabream (Sparus aurata)

Specimens of Sparus aurata were exposed to sub−lethal concentrations of Hg and Cd for 25 days and the levels of both metals were investigated in organs and tissues. Bioaccumulation of Hg decreased as follow: gills > kidney > liver > skin > muscle, while the order of Cd bioaccumulation was: liver > kidney > gills > skin > muscle. Immediately after exposure, both metals showed the highest bioaccumulation in gills and skin indicating that these organs are reliable targets for biomonitoring studies after short term exposure. Metals introduction caused a significant time-dependent concentrations increase in kidney and liver, while in the muscle a significant increase of Hg was recorded only at the end of the experimentation.The effects of exposure were also investigated, at biochemical level, in the liver, which represents the main target of xenobiotics biotransformation and metabolism in fish. Exposed fishes exhibited a reduction of total lipid level, a decrease of polyunsaturated fatty acids (PUFA), together with a MDA increase. This suggests a direct effect of contaminants on oxidative stress induction that, through the MDA increase, altered the membrane fatty acids composition decreasing the PUFA content. As it regards molecular markers related to oxidative stress and lipid metanolism, a significant increase of Nrf2, Hif−1α and Ampk and a decrease of Fas were observed after exposure to both metals, while an Nf−kB increase was recorded in specimens exposed to Hg, docuemnting a correlation with oxidative stress and consequent metabolism adaptation. Finally, these results suggest the possibility to adopt these biomarkers to explore fish metabolic responses to environmental pollution.

Cadmium exposure induces pyroptosis in testicular tissue by increasing oxidative stress and activating the AIM2 inflammasome pathway

High doses of cadmium (Cd) cause irreversible injury to the reproductive system, especially testicular tissue. Studies have shown that pyroptosis is involved in Cd-induced tissue damage, but whether pyroptosis is involved in damage to testicular tissue following Cd exposure remains unclear. To investigate the mechanism of pyroptosis in testicular injury induced by Cd exposure, we used 8-week-old male C57BL/6J mice subjected to consecutive 7 days of intraperitoneal injection of cadmium chloride (CdCl2) at concentrations of 0, 1.0 and 3.0 mg/kg. The results indicated that 3.0 mg/kg CdCl2 significantly decreased serum testosterone levels, sperm concentration and sperm motility, while increased LDH and IL-1β levels. Testicular HE staining indicated that Cd exposure damaged the interstitial cells and increased the atypical residual bodies. Fluorescence results indicated that 3.0 mg/kg CdCl2 increased ROS levels, DNA damage, and the number of TUNEL-positive seminiferous tubule cells in testicular tissue. Transcriptome analysis showed that Cd exposure mainly induced inflammatory and chemokine signaling pathways in testicular tissue, with upregulated mRNA levels of Aim2, and reduced mRNA levels of Nlrp3. Further analysis showed that 3.0 mg/kg CdCl2 increased the expression of testicular HO-1, SOD2, γH2AX and PARP-1, as well as the pyroptosis-related factors GSDMD, GSDME, Caspase-1, ASC and IL-1β. In conclusion, our results provide a possible mechanism by which Cd exposure activates the AIM2 pathway by increasing oxidative stress injury to induce pyroptosis in testicular tissue. This provides a new perspective on testicular damage caused by Cd exposure.

Effect of different doses of heavy metals on quality and safety indices of meat and pig fat

The results of studies of the effect of toxic doses of heavy metals, namely Cadmium and Lead (jointly and separately) at the dose of 10 and 20 maximum allowable concentrations on the chemical composition and quality of the muscle and adipose tissues of pigs are presented. The assessment is given of the use of the experimental herbal supplement as protective agent for chronic intoxication with heavy metals. When animals consumed diets with the high level of heavy metals, both jointly and separately, there were changes in the chemical composition and technological properties of muscle tissue and bacon. The content of dry matter, fat, and protein in meat decreased, and these changes were more significant in the organisms of animals receiving increased doses of Cadmium in series I and when heavy metals were fed together in series II, where their content in diets was 20 maximum allowable concentrations. Along with this, in the meat of the animals of the experimental groups, compared with the control, the calorie content and protein-quality index decreased. The active acidity of meat and its water-retaining capacity in animals of all groups were within the normal range. However, in animals that received high doses of heavy metals with the diet, the pH of the meat slightly changed towards neutral environment (pH - 5.3 - 5.5, with pH control - 5.1 - 5.2), the water-holding capacity of the meat of experimental animals ranged from 55.24% to 56.5% (control - 55.0 - 55.1%). Studies of the qualitative indicators of pig bacon experimentally showed that under the influence of Cadmium and Lead there was the decrease in the amount of dry matter (up to 2.84%) and fat (up to 2.7%) in the bacon, the increase in moisture and % of cell membranes compared to control animal groups. With the increase in the dose of heavy metals, negative changes in the chemical composition and technological properties of the meat and bacon of experimental animals were more noticeable. The intake of heavy metals into the organism of animals led to the accumulation of these toxicants in meat, and with the increase in the dose of heavy metals, their accumulation also increased. Thus, the content of Cadmium and Lead in the meat of animals of the experimental groups in both series of experiments exceeded the established MPC for these toxicants, while the excess for Lead was maximum 1.9 times (Group II), and for Cadmium 4.0 times (Group IV). Feeding the experimental feed additive helped to improve the chemical composition and technological properties of meat and bacon of fattening pigs, and to reduce the accumulation of toxins in muscle tissue. Key words: pork, bacon, quality, Cadmium, Lead, water-holding capacity, experimental herbal supplement.

TISSUE-SPECIFIC RESPONSES IN SOYBEAN PLANTS EXPOSED TO CADMIUM

Cadmium seriously affects plant growth, development, homeostasis and yield production. The effect of two doses of cadmium (10 and 100 mg.kg-1 Cd2+) on plants of sensitive soybean variety (Glycine max L. cv. Kyivska 98) were studied after short treatment in a pot experiment. Several parameters were determined in roots and leaves, including cell viability, the content of malondialdehyde and proline, and activity of defense proteins (catalases, guaiacol peroxidases, ascorbate peroxidases, superoxide dismutases, chitinases, β-1,3-glucanases). Changes caused by cadmium depended both on the concentration of cadmium, as well as on the type of plant organ and its developmental stage. Soybean tissues generally showed low levels of oxidative stress and reduced proline content likely due to activity or depletion by different mechanisms (respectively). The activity of catalases and guaiacol peroxidases was inhibited by cadmium concentrations only in younger leaves. The enzymatic activities of superoxide dismutases, chitinases and β-1,3-glucanases were highly variable depending on the cadmium concentration as well as the soybean organ analyzed. Our experiments revealed differences in defense strategies and regulatory mechanisms between plant organs as well as developmental stages of leaves in response to cadmium toxicity.

Ingestion of subtoxic doses of cadmium induces persistent dysbiosis and enhances susceptibility to DSS-induced colitis long after exposure

Abstract Health officials often focus on intoxication by high doses of heavy metal pollutants. However, most people will more likely be exposed to subtoxic doses via contaminated water or food. We addressed the effects exposure to subtoxic doses of heavy metal pollutants could have on the gut immune homeostasis. We report that chronic ingestion of environmentally relevant subtoxic doses of cadmium does not impair the barrier function of the intestine in mice. On the other hand, chronic exposure to subtoxic doses of this heavy metal stimulates the growth of intestinal epithelial cells including Paneth cells, and increases the production of antimicrobial peptides by Paneth cells. We also found that subtoxic doses of cadmium induce a dysbiosis of the gut microbiota that persist months after the end of the exposure. Importantly, 12–14 months after exposure to cadmium, the cadmium-exposed mice weighed more and had more fat content than age-matched controls mice suggesting that they have developed a state of chronic inflammation. Cadmium is also known to accumulate in soft tissues with a half-life of 10–20 years. Thus, to investigate the long-term effect of exposure to subtoxic doses of cadmium, control and post-menopausal mice (> 15 months old) previously exposed to cadmium were treated with dextran sodium sulfate (DSS) in drinking water. Post-menopausal mice previously exposed to cadmium developed more severe signs of DSS-induced colitis including weight loss, shortened large intestine. Furthermore, they exhibited enhanced Th17 responses in mucosal tissues. Our results provide new insights into the impact of chronic exposure to subtoxic doses of cadmium, and possibly other heavy metals on gut homeostasis and colitis or colon cancer. Supported by Ohio State University NIH

Investigation on Immune-Related Protein (Heat Shock Proteins and Metallothionein) Gene Expression Changes and Liver Histopathology in Cadmium-Stressed Fish.

Heat shock proteins (HSP) are highly conserved in their structure and released in case of stress. Increased metallothionein (MT) synthesis is associated with increased capacity for binding heavy metals. Healthy juveniles of grass carp were exposed to sublethal dose (1.495 mg L−1) of cadmium for 28 days. Simultaneously, a control group was also run to compare difference of total RNA expression levels in cadmium-treated and control groups. The cadmium levels in the tissues of treated fish recorded were 1.78 ± 0.10 mg L−1, 1.60 ± 0.04 mg L−1, and 2.00 ± 0.05 mg L−1, respectively. Several histological alterations including edema, hemorrhage, dilated sinusoids, hypertrophy, hyperplasia, congestion of central vein, and nuclear alterations were observed in cadmium-exposed fish. Stress gene (metallothionein and heat shock proteins) mRNA transcription levels were studied by mRNA extraction and cDNA preparation by using PCR. The expression level of heat shock protein gene was higher as compared to metallothionein and beta-2-microglobulin gene after cadmium exposure. This study reports various stress-related immune-responsive changes of immune proteins, heat shock proteins, metallothionein, and histopathological changes in fish due to cadmium toxicity that make the fish immunocompromised which may be considered as the biomarkers of cadmium toxicity in other experimental species.

Токсичний вплив кадмію на репродуктивну функцію чоловіків

The purpose of the review of foreign literature was to analyze current research on the effects of cadmium on male reproductive function. Results. According to the researcher data, at least 15–20% of cases of fertility decline in males fall on infertility. The etiology of this phenomenon in 50% of cases remains unknown, however, increasing environmental pollution contributes to a constant increase in male infertility. One of the most toxic pollutants is cadmium. Numerous animal model studies and human epidemiological studies indicate an adverse effect of cadmium on male fertility. Smoking is an important source of cadmium, which is absorbed into the human body. In vitro studies confirm the deleterious effects of cigarette smoke compounds on sperm motility and spermatozoon parameters. Depending on the concentration, nicotine suppresses the progressive motility of the spermatozoon parameters, starting from the lowest concentration used (1 ng/ml). Likewise, it decreases the percentage of viable spermatozoon parameters and increases the amount of spermatozoon parameters in late apoptosis with altered chromatin compactness or DNA fragmentation already after 3 hours of incubation. On average, the daily intake of cadmium in humans is 1.06 μg/kg body weight, the half-life of cadmium is more than 20-40 years, which causes its accumulation in the body. The testicles are the organ in which cadmium is stored in large quantities. Studies have shown that the testicles are extremely sensitive to cadmium because these organs are characterized by intense cellular activity, where vital spermatogenesis processes take place. Exposure to cadmium leads to reproductive tract abnormalities such as cryptorchidism and hypospadias, testicular cancer, subfertility or infertility, called testicular dysgenesis syndrome. In the genesis of the testicles during the embryonic and neonatal periods, Sertoli’s cells play a critical role, the development of which is influenced by cadmium. Exposure to cadmium (1-2 mg/kg, subcutaneously) in pregnant and lactating rats causes vacuolization of Sertoli’s cells and loss of cells in the epithelium of the seminiferous tubules in adult animals. Cadmium inhibits proliferation, induces apoptosis and DNA damage in immature Sertoli’s cells. Perinatal exposure to cadmium affects the development and function of fetal Leydig cells, which are endocrine cells in the testicle. In pregnant rats that received a single dose of cadmium (0.25, 0.5, and 1.0 mg/kg, intraperitoneally), synthesis of testosterone in the fetal tests was significantly reduced, while gene expression in cells was suppressed, and the androgen-dependent formation process was reduced. The mechanism by which cadmium mediates impaired male fertility is also associated with the production of reactive oxygen species in the testicles, which leads to oxidative stress that interferes with the development and functioning of the spermatozoon parameters. Exposure to cadmium, for both environmental and occupational reasons, can contribute to a decrease in the quality of human sperm, which confirms high toxicity of cadmium. Conclusion. Thus, in humans and other mammals, cadmium damages the male reproductive system, disrupts its structure, including the vascular system of the testicles, leads to DNA damage, inhibits functions of germ cells, leads to loss of sperm quality and quantity, sub-fertility or infertility

EXTRAÇÃO DE METAIS TÓXICOS EM SOLOS CONTAMINADOS UTILIZANDO O MILHO COMO POSSÍVEL FITORREMEDIADOR

The phytoremediation is an alternative in the decontamination of the environment, in which plants capable of absorbing contaminating ions are used. Thereby, the scientific research aims to verify if the corn can phytoextract, accumulate, hyperaccumulate and tolerate toxic metals in the plant biomass in anthropically contaminated soils. The experimental design was completely randomized, consisting of four treatments with four replications, totaling sixteen portions for each contaminant. The application of metals and EDTA were carried out in the form of a solution, contaminating the soil 46 days after maize maturation in pots. The concentrations were above the intervention values of CETESB. Soil and plant tissues analyzes were performed by the Atomic Absorption Spectrometer, which resulted in significant concentrations. The results of the Analysis of Variance and post-hoc Tukey's Test, suffered a reduction in dry biomass and an increase in the accumulated amount. Corn was tolerant to the highest dose of lead, but it was intolerant to the highest doses of cadmium and chromium. Thus, the results indicated that the maize phytoextracted contaminants efficiently, but it cannot be used as a phytoremediator in contaminated sites because they cause food poisoning for the living beings, once corn is used in Brazil and worldwide for animal feed and for the food industry of high nutritional and energy qualities.

Protecting Effects of N-acetyl Cysteine Supplementation Against Lead and Cadmium-Induced Brain Toxicity in Rat Models

We aimed to investigate mitigating effects of N-acetylcysteine (NAC) on the oxidative stress, apoptosis and Parkinson's disease (PD)-related genes in the brain tissue of male rats exposed to continuous doses of cadmium and lead. Rats were randomly divided into five groups, including G1 (control), G2 (continuous dose of Cd), G3 (continuous dose of Pb), G4 (continuous dose of Cd + NAC), and G5 (continuous dose of Pb + NAC). Biomarkers of oxidative stress, malondialdehyde (MDA), and total antioxidant capacity (TAC) were measured. Expression of PD- and apoptosis-related genes was considered using RT-PCR. Chronic exposure to these heavy metals was associated with accumulation of Pb and Cd in the brain and blood and caused severe morphological changes in the brain, as well as decreased body and brain weights. Continuous exposure to Cd and Pb significantly decreased TAC content and SOD expression but increased MDA level in the brain tissues (P < 0.001). A significant increase was observed in expression of PD-related genes, Parkin, Pink1, LRRK2, SNCA, and Caspase-3 in the brain tissues following exposure to Cd and Pb. Pb exhibited stronger toxicity on the brain tissue compared to Cd. NAC supplementation not only improved morphological changes, but also compensated antioxidant capacity and expression of apoptosis- and PD-related genes in the brain tissues when compared to rats exposed to Pb and Cd alone. Chronic exposure to Pb and Cd is strongly associated with accumulation of these heavy metals in the brain, morphological changes, antioxidants depletion, oxidative stress, and brain cells apoptosis. Changes in expression of PD-related genes indicate the higher risk of PD among individuals who are chronically exposed to these heavy metals. NAC can protect brain tissue against Pb and Cd toxicity by elevating antioxidants capacity, mitigating oxidative stress, apoptosis, and down-regulating of PD-related genes.