Open Access
Issue
BIO Web Conf.
Volume 27, 2020
International Scientific-Practical Conference “Agriculture and Food Security: Technology, Innovation, Markets, Human Resources” (FIES 2020)
Article Number 00110
Number of page(s) 6
DOI https://doi.org/10.1051/bioconf/20202700110
Published online 25 November 2020

© The Authors, published by EDP Sciences, 2020

Licence Creative Commons
This is an Open Access article distributed under the terms of the Creative Commons Attribution License 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

1 Introduction

Numerous industrial, agricultural, medical, and technological applications of heavy metals can lead to the widespread exposure of humans to potentially toxic environments [1, 2]. Consequently, public health issues revolving around food and health safety have gained considerable attention.

Due to its high level of toxicity to humans and its ubiquitous use in many consumer electronics, cadmium is one metal that has gained central importance in the context of public health [3].

The main sources of this element are air, soil, contaminated water and food – namely rice, cereals, vegetables, seafood and meat (including offal), all of which permit its entry into the human food chain [4]. Once it enters the body of animals and humans, cadmium accumulates in the liver and kidneys and can become the main cause of diseases of these organs.

In the liver, cadmium ions can cause liver failure associated with hepatocyte degeneration, focal necrosis and fat deposition. It can also accumulate within epithelial cells from the proximal tubules of the kidneys, where it can lead to generalized dysfunction of reabsorption and which is characterized by polyuria and low-molecular proteinuria [58]. In addition, cadmium ions can functionally impair cell-based protective antioxidant mechanisms and the human reproductive system [9].

In addressing these effects, significant evidence is accumulating to suggest that essential elements (such as magnesium and zinc) can counteract the effects of cadmium by exhibiting protective properties at the cellular level, thus helping to prevent or reduce its adverse effects on health. Conversely, their deficiency can also increase the accumulation of cadmium within internal organs, thereby increasing its toxic effects [1012].

Consequently, the aim of our research was to study the effectiveness of zinc in combination with magnesium on ionic changes associated with the exposure of animals to cadmium.

2 Materials and methods

Experiments were conducted in the Laboratory of Technogenic Ecotoxicants at the Federal Сenter for Toxicological, Radiation and Biological Safety (Russian Federation) over a period of 30 days.

Experimentally, 40 male rats (weighing 250–300 g) were randomly divided into five groups of 8 rats each: Group 1 was a biological negative control; Group 2 received cadmium chloride orally with feed at the rate of 0.6 mg per kg of feed; and Groups 3, 4 and 5 were fed cadmium chloride (at the same dose as Group 2), with the addition of magnesium/nitric acid (at a dose of 0.8 mg per head), zinc chloride (at a dose of 5 mg per head) and combined zinc chloride with magnesium/nitric acid) at the doses used for Groups 3 and 4, respectively.

Throughout the experiment, the animals were kept under standard sterile conditions with free access to drinking water and balanced granulated feed.

The amount of cadmium, zinc, magnesium and iron was tracked by atomic absorption methodology to study the elementary composition of the liver and kidneys, on an AAC Perkin Elmer Analyst 200 before the experiment and on the 10th, 20th and 30th days of the study. After the 30th day, the animals were subjected to hepatectomy and nephroectomy.

All euthanasia and surgical interventions were performed in accordance with the requirements outlined by the European Convention for the Protection of Vertebrate Animals used for Experimental and Other Scientific Purposes.

3 Results

As seen in Fig.1, liver cadmium levels were seen to proportionally increase in Group 2 over the 30 days course from day 10 (0.16 mg/kg) to day 30 (0.31 mg/kg, above control levels. At the same time, during the experiment, the addition of magnesium to the dietary supplements (Group 3) resulted in the accumulation of liver cadmium at a reduced rate and seen at 0.16 mg/kg (at day 10) rising to 0.24 mg/kg (at day 30).

Similarly, in Group 4 (cadmium and zinc), a relatively slower rate of cadmium accumulation was observed which rose from 0.08 mg/kg (Day 10) to 0.16 mg/kg on Day 30.

However, in Group 5 the rate of cadmium accumulation in the liver was observed to increase from 0.09 (Day 10) to 0.17 mg/kg at day 30. Collectively, such observations suggest that while magnesium significantly reduced the accumulation of cadmium in liver tissue, zinc or magnesium (with zinc) were almost twice as potent at reducing this effect.

Similar trends were also observed for the accumulation of cadmium in rat kidneys. As seen in Fig. 2, magnesium alone (Group 3) reduced cadmium accumulation by 0.17 mg/kg (Day 10) to around 0.06 mg/kg (Day 30). As seen with liver tissues, zinc alone (Group 4) or magnesium and zinc consumption (Group 5) reduced the accumulation of cadmium to a significantly lower rate, with Group 5 showing the lowest rates of accumulated cadmium in the kidney at 0.11 mg/kg over Group 2 levels by day 30.

The data presented in Fig.3 and 4 show that zinc concentration was significantly decreased in the liver and kidneys of rats after cadmium intoxication by 4.78 mg/kg (Day 10) to around 11.08 mg/kg (Day 30) in the liver and by 4.83 mg/kg (Day 10) to around 8.06 mg/kg (Day 30) in kidneys. Magnesium or/with zinc supplementation partially corrected this changes and by day 30 the difference was 5.40 mg/kg, 1.36 mg/kg, 1.25 mg/kg in the liver; 3.07 mg/kg, 1.48 mg/kg and 0.32 mg/kg in kidneys, respectively.

As seen in Fig. 5 the level of manganese in the liver was significantly higher in the group of rats exposed to cadmium (Group 2), on day 30 it was 2.45 mg/kg, which is almost 2 times higher than the control parameters. At the same time, the accumulation of manganese gradually decreased in the kidneys (Fig. 6) and by the end of the experiment, its level was halved from the beginning of the experiment – 0.47 mg/kg.

Supplementation of magnesium, zinc, or a combination of them to feed animals that were exposed to cadmium throughout the experience reduced the accumulation of manganese in the liver, and increased it in the kidneys. By the end of the experiment, the rate was 0.68 mg/kg (Group 3), 1.27 mg/kg (Group 4) and 1.31 mg/kg in the liver, 0.72 mg/kg (Group 3), 0.92 mg/kg (Group 4) and 0.98 mg/kg in the kidneys.

The effects of cadmium on iron accumulation in the liver and kidneys were also analyzed for Groups 1–5. It can be noted that the accumulation of iron in the liver (Fig. 7) in rats exposed to cadmium first increased and reached the level of 123.72 mg / kg by 20 days, and by 30 days it decreased to 16.34 mg/kg, which is almost 5 times less than in the control group. Kidney iron levels (Fig. 8) were seen to proportionally increase and by the end of the experience was higher than the control parameters by more than 2 times.

At the same time, the addition of magnesium also increased the accumulation of iron in the liver to 100.30 mg/kg (20 Day) and then decreased by the end of the experiment to 51.96 mg/ kg, and in the kidneys increased its level to 60.63 mg/kg, but to a lesser extent than in group 2. Iron Levels in groups 4 and 5 were close to control parameters, which mean that the addition of zinc and zinc with magnesium is most effective against the effects of cadmium.

thumbnail Fig. 1.

Accumulation of cadmium in the liver

thumbnail Fig. 2.

Accumulation of cadmium in the kidneys

thumbnail Fig. 3.

Accumulation of zinc in the liver

thumbnail Fig. 4.

Accumulation of zinc in the kidneys

thumbnail Fig. 5.

Accumulation of manganese in the liver

thumbnail Fig. 6.

Accumulation of manganese in the kidneys

thumbnail Fig. 7.

Accumulation of iron in the liver

4 Discussion

It is well documented that cadmium has the detrimental property of accumulating in the liver and kidneys [5, 6]. Additionally, it has also been suggested that as a result of the toxic effect of this metal, the quantitative content of some vital elements in the body, such as zinc, manganese and iron, are also prone to fluctuate.

From our findings and presented herein, we confirm the ability of cadmium ions to accumulate in the liver and kidneys. Additionally, we also found that the amount of zinc, manganese and iron in these tissues vary significantly as a consequence of this. Collectively, at the physiological level such changes can contribute to a number of disorders in the body. For example, a decrease in the level of zinc can lead to deregulation of biologically-protective antioxidant pathways in addition to mechanisms protective for anti-tumor activity [9, 13].

Mechanistically, there is evidence to suggest that iron and manganese may compete for the same circulatory transport proteins. For example, reduced iron levels can lead to an observed increase in tissue-specific accumulation of manganese [10].

Our results support such a hypothesis particularly upon the ingestion of cadmium. Concurrently, low iron intake can cause iron-deficiency and the onset of anemia, while increased levels of manganese can cause neurotoxic and other pathological conditions [10, 14].

Consequently, the therapeutic use of magnesium and zinc significantly reduces the effects associated with exposure to cadmium and which confirms their potential protective properties against the pathological toxicity of cadmium [11].

thumbnail Fig. 8.

Accumulation of iron in the kidneys

5 Conclusion

Our studies have shown that ingestion of cadmium quantitatively reduces the levels of zinc in the liver and kidneys. It also decreases iron in the liver (but causes its accumulation in the kidneys) and reduces manganese in the kidney while increaing its levels in the liver. The ingestion of magnesium or zinc individually counteracts the effects of cadmium accumulation in the liver or kidneys while ingestion of magnesium and zinc together proved to be the most effective.

References

  • V.A. Konychova, I.R. Kadikov, K.H. Papunidi, Evaluation of the contamination level of feed and water in Ryazan regions of the Russian Federation, Veterinary physician, 3, 7–11 (2018) [Google Scholar]
  • V.A. Konychova, I.R. Kadikov, A.A. Korchemkin, K.H. Papunidi, R.M. Aslanov, E.L. Matveeva, The results of monitoring of heavy metals in feed and water in some regions of the Russian Federation, Scientific Notes of Kazan State Academy of Veterinary Medicine, 240(4), 109–114 (2019) [CrossRef] [Google Scholar]
  • P.B. Tchounwou, C.G. Yedjou, A.K. Patlolla, D.J. Sutton, Heavy Metals Toxicity and the Environment, EXS, 101, 133–164 (2012) DOI: 10.1007/978-3-7643-8340-4_6 [PubMed] [Google Scholar]
  • R. Chunhabundit, Cadmium Exposure and Potential Health Risk from Foods in Contaminated Area, Thailand, Toxicol. Res., 32(1), 65–72 (2016) DOI: 10.5487/TR.2016.32.1.065 [CrossRef] [Google Scholar]
  • M.F. Elkhadragy, A.E. Abdel Moneim, Protective Effect of Fragaria Ananassa Methanolic Extract on Cadmium Chloride (CdCl2)-Induced Hepatotoxicity in Rats, Toxicol. Mechan. and Methods, 27, 335–345 (2017), DOI: 10.1080/15376516.2017.1285973 [CrossRef] [Google Scholar]
  • R.B. Jain, Cadmium and kidney function: Concentrations, variabilities, and associations across various stages of glomerular function, Environ. Pollut., 256, 113361 (2019) DOI: org/10.1016/j.envpol.2019.113361 [CrossRef] [Google Scholar]
  • V.S. Arroyo, K.M. Flores, L.B. Ortiz, L.E. GómezQuiroz, M.C. Gutiérrez-Ruiz, Liver and Cadmium Toxicity, J. of Drug Metabol. & Toxicol., S5, 001 (2012) DOI: 10.4172/2157-7609.S5-001 [Google Scholar]
  • W.C. Prozialeck, J.R. Edwards, Mechanisms of Cadmium-Induced Proximal Tubule Injury: New Insights with Implications for Biomonitoring and Therapeutic Interventions, J. of Pharmacol. and Experim. Therap., 343(1), 2–12 (2012) DOI: 10.1124/jpet.110.166769 [CrossRef] [Google Scholar]
  • H. Jemaia, I. Messaoudib, A. Chaouchc, A. Kerkeni, Protective effect of zinc supplementation on blood antioxidant defense system in rats exposed to cadmium, J. of Trace Elem. in Med. and Biol., 21, 269–273 (2007) DOI: 10.1016/j.jtemb.2007.08.001 [CrossRef] [Google Scholar]
  • K.J. Horning, S.W. Caito, K. Grace Tipps, A.B. Bowman, M. Aschner, Manganese Is Essential for Neuronal Health, Annu. Rev. Nutr., 35, 71–108 (2015) DOI: 10.1146/annurev-nutr-071714-034419. [CrossRef] [PubMed] [Google Scholar]
  • N. Babaknejad, S. Bahrami, A. Asghar Moshtaghie, H. Nayeri, P. Rajabi, F. Golshan Iranpour, Cadmium Testicular Toxicity in Male Wistar Rats: Protective Roles of Zinc and Magnesium, Biol. Trace Elem.t Res., 185, 106–115 (2018) DOI: org/10.1007/s12011-017-1218-5 [CrossRef] [Google Scholar]
  • Z. Bulat, D. DukicCosi, B. Antonijevic et al., Effect of Magnesium Supplementation on the Distribution Patterns of Zinc, Copper, and Magnesium in Rabbits Exposed to Prolonged Cadmium Intoxication, Sci. World J., 572514 (2012) DOI: 10.1100/2012/572514 [Google Scholar]
  • D. Skrajnowska, B. Bobrowska-Korczak, Role of Zinc in Immune System and Anti-Cancer Defense Mechanisms, Nutrients, 11(10), 2273 (2019) DOI: 10.3390/nu11102273 [CrossRef] [Google Scholar]
  • J. Baird-Gunning, J. Bromley, Correcting iron deficiency, Austral. Prescribe, 39(6), 193–199 (2016) DOI: 10.18773/austprescr.2016.069 [CrossRef] [Google Scholar]

All Figures

thumbnail Fig. 1.

Accumulation of cadmium in the liver

In the text
thumbnail Fig. 2.

Accumulation of cadmium in the kidneys

In the text
thumbnail Fig. 3.

Accumulation of zinc in the liver

In the text
thumbnail Fig. 4.

Accumulation of zinc in the kidneys

In the text
thumbnail Fig. 5.

Accumulation of manganese in the liver

In the text
thumbnail Fig. 6.

Accumulation of manganese in the kidneys

In the text
thumbnail Fig. 7.

Accumulation of iron in the liver

In the text
thumbnail Fig. 8.

Accumulation of iron in the kidneys

In the text

Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.

Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.

Initial download of the metrics may take a while.