Toxicity of cadmium and protective effect of bee honey, vitamins C and B complex

Cadmium modulates steatosis, fibrosis, and oncogenic signaling in liver cancer cells by activating notch and AKT/mTOR pathways

Cadmium (Cd) is an environmental pollutant that increases hepatotoxicity and the risk of liver diseases. In the current study, we investigated the effect of a physiologically relevant, low concentration of Cd on the regulation of liver cancer cell proliferation, steatosis, and fibrogenic/oncogenic signaling. Exposure to low concentrations of Cd increased endogenous reactive oxygen species (ROS) production and enhanced cell proliferation in a human bipotent progenitor cell line HepaRG and hepatocellular carcinoma (HCC) cell lines. Acute exposure of Cd increased Jagged-1 expression and activated Notch signaling in HepaRG and HCC cells HepG2 and SK-Hep1. Cd activated AKT/mTOR signaling by increasing phosphorylation of AKT-S473 and mTOR-S-4448 residues. Moreover, a low concentration of Cd also promoted cell steatosis and induced fibrogenic signaling in HCC cells. Chronic exposure to low concentrations of Cd-activated Notch and AKT/mTOR signaling induced the expression of pro-inflammatory cytokines tumor necrosis factor-alpha (TNFα) and its downstream target TNF-α-Induced Protein 8 (TNFAIP8). RNA-Seq data revealed that chronic exposure to low concentrations of Cd modulated the expression of several fatty liver disease-related genes involved in cell steatosis/fibrosis in HepaRG and HepG2 cells. Collectively, our data suggest that low concentrations of Cd modulate steatosis along with fibrogenic and oncogenic signaling in HCC cells by activating Notch and AKT/mTOR pathways.

Honey Can Obviate Heavy Metal Toxicity: A Review

Toxicity caused by heavy metals inflicts a grave global menace to the habitat and inhabitants. Arsenic (As), cadmium (Cd), lead (Pb), and mercury (Hg) are the non-essential yet harmful heavy metals commonly associated with pollution and resultant health complications. Typical chelating/complexing agents are not worthy of combating heavy metal-induced sub-chronic and chronic toxicities. It transpires from scientific data mining that, honey obviates investigational heavy metal toxicity. This review aims to collate such investigations conducted against As, Cd, and Pb toxicity. There is a total of 19 pre-clinical works demonstrating the ameliorative effect of honey against empirical As, Cd, and Pb toxicity. Pre-clinical reports against Hg and clinical study against these heavy metals could not found. From the outcome of the current literature investigation, it seems that honey has a marked heavy metal toxicity meliorative effect which is chiefly ascribed to its innate antioxidant effect due to its diverse polyphenol content.

Cadmium Accumulation in the Goat Liver and Kidney Is Partially Promoted by the Upregulation of Metal Transporter Genes

Metal transporters, including divalent metal-ion transporter-1 (DMT1), Zrt-/Irt-like protein 8 and 14 (ZIP8 and ZIP14), and ferroportin-1 (FPN1), reportedly participate in cellular cadmium (Cd) uptake, but those in farm animals remain unclarified. This study aimed to examine the growth, plasma biochemical indices, Cd accumulation, and expression of metal transporter genes in the liver, kidney, and muscle of goats exposed to rice paddies contaminated with different levels of Cd. Twenty-four goats were randomly assigned across three dietary treatments: 0.23, 0.63, and 1.07 mg of Cd/kg of dry matter (DM) for 60 days. The results showed that dietary Cd exposure increased (p < 0.05) both Cd accumulation and the mRNA expressions of metal transporter genes (DMT1, ZIP, and FPN1) in the liver and kidney but not in the muscle, suggesting dietary Cd exhibited different deposition rates between goat liver, kidney, and muscle. These outcomes suggest that high levels of dietary Cd stimulated the expression of metal transporter genes and thereby enhanced the uptake and accumulation of Cd in the goat liver and kidney. As such, higher Cd concentrations in the liver and kidney observed with Cd diets could be partly explained by upregulation of metal transport genes expression.

Evaluation of consumer safety of Polish honey-the content of Cd and Pb in multifloral, monofloral and honeydew honeys

The paper aimed to evaluate the degree of contamination of honey available on the Polish market with cadmium (Cd) and lead (Pb). The analyses involved 49 samples of honey: monofloral (n = 24): linden, raspberry, goldenrod, bean, dandelion, buckwheat and rapeseed honey, multifloral honey (n = 17) and coniferous honeydew honey (n = 8). The content of Cd and Pb was determined using Inductively Coupled Plasma-Optical Emission Spectrometers (ICP-OES). The content of Cd and Pb was confirmed in all the analysed honeys, but in 18% of samples the level of Cd was < LOQ. The analysed honeys contained from < LOQ to ca. 0.09 mg Cd per 1 kg, on average 0.025 mg kg^-1. On average, they contained 0.193 mg Pb (range 0.014-1.007) per 1 kg of the raw product. The content of Cd and Pb can be presented as: honeydew honey > multifloral honey > monofloral honey. The content of Cd in monofloral honeys can be presented as follows: linden > other (raspberry, goldenrod, bean, linden + bean) > dandelion = buckwheat = rape, while the content of Pb as linden > other > rapeseed > buckwheat > dandelion honey. It should be emphasised that consuming 19 g of honey a week (mean honey consumption in Poland) is safe for human health, as it results in an intake of Cd at the level of 1.18E-04% PTWI and 0.553% PTWI for children and an intake of Pb at the level of 0.641% BMDL01 for adults and 5.916% BMDL for children. The obtained results lead to a conclusion that the risk of disorders related to chronic exposure to Cd and Pb ingested with honey is very low, which is demonstrated by the fact that both children and adults showed CDI, CR, THQ and HI that were lower than 1.

Evaluation of Cadmium Chloride-Induced Toxicity in Chicks Via Hematological, Biochemical Parameters, and Cadmium Level in Tissues

Cadmium is a heavy metal and a non-biodegradable environmental contaminant, and its omnipresence ensures its recurrent exposure to humans and animals. Its intake by chicks leads to fatal implications. Cadmium chloride (CdCl₂) because of its bio-accumulative nature is an emerging threat to the poultry industry as well as to the humans which consumes these cadmium-intoxicated chickens. In the current study, the target was to elucidate the toxic effects of CdCl₂on body weight, hematological, and biochemical parameters as well as its bioaccumulation in different organs of broiler chicks. Various concentrations of CdCl₂ (0, 12, 24, 38, and 48 mg/kg body weight) were administered orally to five groups (A, B, C, D, and E) of broiler chicks, respectively. The biometric screening of the exposed birds was carried out by hematological parameters such as packed cell volume (PCV), total erythrocyte count (TEC), mean corpuscular hemoglobin concentration (MCHC), total protein, white blood cells (WBC), and hemoglobin (Hb), as well as biochemical parameters superoxide dismutase (SOD), low-density lipoprotein (LDL), glutathione peroxidase (GPx), and high-density lipoprotein (HDL) with commercially available kits. Metal accumulation in different organs was detected using atomic absorption spectrophotometer. The compound exposure produced a varied impact on broiler birds. Hematological parameters showed a significant decrease except for WBC. Biochemical parameters also decreased significantly in a dose-dependent manner. However, it was revealed that the body weight of chickens was not affected considerably after CdCl₂ exposure. A direct relationship was detected between the accumulation of metal within tissues (lungs, heart, and flesh) and exposure frequency. It can be deduced that an increase in Cd deposition in tissues may lead to an alteration in hematological-biochemical markers which may significantly contribute to systemic toxicity in broilers.

Cardiac toxicity of heavy metals (cadmium and mercury) and pharmacological intervention by vitamin C in rabbits

Mercury and cadmium are highly dangerous metals that can lead to disastrous effects in animals and humans. The aim of the current research was to elucidate the poisonous effects of mercuric chloride and cadmium chloride individually and in combination on biochemical profiles of plasma and their accumulation in heart. The therapeutic effect of vitamin C against these metals in rabbits was also studied. Mercuric chloride (1.2 μg/g), cadmium chloride (1.5 μg/g), and vitamin C (150 μg/g of body weight) were orally given to treatment groups of the rabbits (1-control; 2-vitamin; 3-CdCl₂; 4-HgCl₂; 5-vitamin + CdCl₂; 6-vitamin + HgCl₂; 7-CdCl₂ + HgCl₂, and 8-vitamin + CdCl₂ + HgCl₂. After the biometric determination of all intoxicated rabbits, biochemical parameters, viz low-density lipoproteins (LDL), high-density lipoproteins (HDL), cholesterol, creatine kinase, and troponin T (TnT) were analyzed using available kits. Levels of cholesterol (0.7 ± 0.1 mmol/l), creatine kinase (2985.2 ± 11 IU/L), LDL (20.35 ± 1.31 mg/dl), and troponin T (1.22 ± 0.03 μg/l) were significantly (P < 0.05) increased. HDL (84.78 ± 4.30 mg/dl) was significantly (P < 0.05) decreased, while supplementation of vitamin C decreased the adverse effects of CdCl₂ and HgCl₂ on biochemical parameters in all metal-exposed groups. A similar trend was also seen in rabbits treated with CdCl₂ + vitamin and vitamin + CdCl₂ + HgCl₂. Accumulation of Cd and Hg was higher in heart tissues. This study, therefore, provides awareness on the cardiac toxicity of mercury and cadmium chlorides in the rabbits and the possible protective role of vitamin C against the perturbations induced by metals.

Therapeutical properties of Mimosa caesalpiniifolia in rat liver intoxicated with cadmium

The aim of this study was to evaluate the therapeutic properties of Mimosa caesalpiniifolia in liver of rats exposed to cadmium under morphological, oxidative, inflammatory, and mutagenic parameters. A total of 40 Wistar rats (90 days, ~ 250 g) were distributed into eight groups (n = 5) as follows: (i) control; (ii) cadmium: cadmium chloride injection at 1.2 mg/kg; (iii) Mimosa extract: treatment with Mimosa extract at 250 mg/kg; (iv) Mimosa fraction: treatment with Mimosa acetate fraction at 62.5 mg/kg; (v) cadmium and Mimosa extract 62.5: submitted to cadmium chloride at 1.2 mg/kg injection and treatment with Mimosa extract at 62.5 mg/kg; (vi) cadmium and Mimosa extract 125: subjected to cadmium chloride at 1.2 mg/kg injection and treatment with Mimosa extract at 125 mg/kg; (vii) cadmium and Mimosa 250 extract: submitted to cadmium chloride 1.2 mg/kg injection and treatment with Mimosa extract at 250 mg/kg; (viii) cadmium treated with fraction of Mimosa acetate: submitted to cadmium chloride 1.2 mg/kg injection and treatment with acetate fraction of Mimosa extract at 62.5 mg/kg. In the animals intoxicated with cadmium and treated with fraction [62.5], increased expression of SOD-Mn reduced frequency of binucleated hepatocytes, karyolysis, and karyorrhexis, besides the antimutagenic and antioxidant action. The extract [62.5] was cytoprotective, antimutagenic, and reduced karyolysis. The extract [125] was cytoprotective, antioxidant, antifibrotic, anti-inflammatory, and reduced frequency of binucleated hepatocytes, while extract [250] was cytotoxic and mutagenic. In summary, the extract of Mimosa exerts some therapeutic properties in hepatic tissue after Cd intoxication, but only when it is administrated at intermediate doses. Probably, a high content of polyphenols in the EHM [250] and Fr-EtOAc groups exert pro-oxidant activities in the liver particularly when associated with Cd.

Antidotal or protective effects of honey and one of its major polyphenols, chrysin, against natural and chemical toxicities

OBJECTIVE

Honey and its polyphenolic compounds are of main natural antioxidants that have been used in traditional medicine. The aim of this review was to identify the protective effects of honey and chrysin (a polyphenol available in honey) against the chemical and natural toxic agents.

METHOD

The scientific databases such as MEDLINE, PubMed, Scopus, Web of Science and Google Scholar were searched to identify studies on the antidotal effects of honey and chrysin against toxic agents.

RESULTS

This study found that honey had protective activity against toxic agents-induced organ damages by modulating oxidative stress, inflammation, and apoptosis pathways. However, clinical trial studies are needed to confirm the efficacy of honey and chrysin as antidote agents in human intoxication.

CONCLUSION

Honey and chrysin may be effective against toxic agents. (www.actabiomedica.it).

Renal toxicity of heavy metals (cadmium and mercury) and their amelioration with ascorbic acid in rabbits

Cadmium and mercury are among the most toxic and dangerous environmental pollutants that may cause fatal implications. Vitamin C is an important chain-breaking antioxidant and enzyme co-factor against heavy metals. The objective of the present study was to evaluate the toxicological effects of cadmium chloride, mercuric chloride, and their co-administration on biochemical parameters of blood serum and metal bioaccumulation in kidneys and also to elucidate the protective effect of vitamin C in rabbits against these metals. In the current research, cadmium chloride (1.5 mg/kg), mercuric chloride(1.2 mg/kg), and vitamin C (150 mg/kg of body weight) were orally administered to eight treatment groups of the rabbits (1, control; 2, vitamin; 3, CdCl₂; 4, HgCl₂; 5, vitamin + CdCl₂; 6, vitamin + HgCl₂; 7, CdCl₂ + HgCl₂, and 8, vitamin + CdCl₂ + HgCl₂). After the biometric measurements of all experimental rabbits, biochemical parameters viz. creatinine, cystatin C, uric acid, and alkaline phosphatase (ALP) and metal bioaccumulation were determined using commercially available kits and atomic absorption spectrophotometer, respectively. The levels of creatinine (28.3 ± 1.1 μmol/l), cystatin C (1932.5 ± 38.5 ηg/ml), uric acid (4.8 ± 0.1 mg/day), and ALP (51.6 ± 1.1 IU/l) were significantly (P < 0.05) increased due to administration of mercuric chloride but in the presence of vitamin C, the effects of mercuric chloride on creatinine (21.9 ± 1.4 μmol/l), cystatin C (1676.2 ± 42.2 ηg/ml), uric acid (3.9 ± 0.1 mg/day), and ALP (43.3 ± 0.8 IU/l) were less as compared to metal-exposed specimens. Similar results were found in rabbits treated with cadmium chloride and vitamin C and also with co-administration of both metals and vitamin C. Because of the bio-accumulative nature of cadmium chloride and mercuric chloride, these metals were accumulated in kidneys of rabbits, which might lead to deleterious effects. The results of the present study provide an insight into the toxicity of the cadmium chloride, mercuric chloride, and/or their combination on biochemical parameters as well as kidneys of the rabbits and the ameliorating potential of vitamin C against these metals is also evaluated.

Review of polyphenol-rich products as potential protective and therapeutic factors against cadmium hepatotoxicity

Recently, the growing attention of the scientific community has been focused on the threat to health created by environmental pollutants, including toxic metals such as cadmium (Cd), and on the need of finding effective ways to prevent and treat the unfavorable health effects of exposure to them. Particularly promising for Cd, and thus arousing the greatest interest, is the possibility of using various ingredients present in plants, including mainly polyphenolic compounds. As the liver is one of the target organs for this toxic metal and disturbances in the proper functioning of this organ have serious consequences for health, the aim of the present review was to discuss the possibility of using polyphenol-rich food products (e.g., chokeberry, black and green tea, blueberry, olive oil, rosemary and ginger) as the strategy in protection from this xenobiotic hepatotoxicity and treatment of this heavy metal-induced liver damage. Owing to the ability of polyphenols to bind ions of Cd and the strong antioxidative potential of these compounds, as well as their abundance in dietary products, it seems to be of high importance to consider the possibility of using polyphenols as potential preventive and therapeutic agents against Cd hepatotoxicity, determined by its strong pro-oxidative properties. Although most of the data on the effectiveness of polyphenols comes from studies in animals, the fact that some of them are derived from experimental models that reflect human exposure to this metal allows us to assume that some polyphenol-rich food products may be promising protective agents against Cd hepatotoxicity in humans.

Gender-specific differences of interaction between cadmium exposure and obesity on prediabetes in the NHANES 2007-2012 population

PURPOSE

Data from National Health and Nutrition Examination Survey (NHANES) for the years 2007-2012 were used to evaluate the interactions of cadmium (Cd) exposure with being overweight/obesity on the risk of prediabetes among adults 20 years older.

METHODS

A total of 3552 subjects were included in the analysis. Urinary cadmium levels (UCd) was used as a biomarker for long-term exposure to Cd. Additive interaction was estimated using relative excess risk due to interaction (RERI), attributable proportion due to interaction (AP) and synergy index (S).

RESULTS

Following covariates adjustments, we found significant associations of UCd with higher prediabetes prevalence, and this association was more apparent in males (Q4 vs Q1: OR = 1.95, 95%CI: 1.34-2.84); while overweight/obesity was associated with prediabetes both in males and in females. Additionally, there was a significant interaction between Cd exposure and being overweight/obesity on prediabetes risk among males (RERI = 1.18, 95% CI: 0.42-1.93; AP = 0.35, 95% CI: 0.12-0.58; S = 2.00, 95% CI: 0.92-4.34).

CONCLUSIONS

Our results suggest that being overweight/obesity may substantially amplify the adverse effects of long-term cadmium exposure on prediabetes risk, and this interaction is more severe in male adults. Further studies are needed to confirm these findings.

Protective role of nebivolol in cadmium-induced hepatotoxicity via downregulation of oxidative stress, apoptosis and inflammatory pathways

Cadmium (Cd) intoxication in human occurs through inhalation of cigarette smoke and ingestion of contaminated water and food. We investigated the role of nebivolol (NEB) in Cd induced hepatotoxicity. In our study; NEB was given as (10 mg/kg/d) orally to rats for 6 weeks, in the presence or absence of hepatotoxicity induced by oral administration of Cd (7 mg/kg/d) for 6 weeks. Levels of serum liver enzyme biomarkers; alanine transaminase (ALT), aspartate transaminase (AST) and serum total antioxidant capacity (TAC) were measured. In addition; mean arterial pressure and total cholesterol levels were measured. Hepatic superoxide dismutase (SOD) and malondialdehyde (MDA) were detected. Hepatic histopathological features, inducible nitric oxide synthase (iNOS) and endothelial nitric oxide synthase (eNOS) immunoexpressions were evaluated. Tumor necrosis factor alpha (TNF-α) and B-cell lymphoma-2 (Bcl-2) mRNA gene expressions were detected using real time-PCR (rt-PCR). Our results showed marked increase in all measured parameters except SOD, TAC, eNOS immunoexpression and Bcl2 mRNA gene expression which decreased in Cd induced hepatotoxicity group. NEB showed marvelous protective effect against Cd induced changes. NEB decreased liver enzymes (ALT and AST), mean arterial pressure, total cholesterol levels, MDA, iNOS immunoexpression and TNF-α gene expression but significantly increased SOD, TAC, eNOS immunoexpression and Bcl-2 gene expression. Moreover; NEB markedly improved the histopathological changes induced by Cd. These findings prove the antioxidant, anti-apoptotic and anti-inflammatory properties of NEB and its protective role in Cd induced hepatotoxicity.

Environmental exposure to cadmium-a risk for health of the general population in industrialized countries and preventive strategies

Cadmium (Cd) is a heavy metal belonging to the group of the main chemical pollutants of the natural and occupational environment in economically developed countries. The forecasts indicate that contamination of the environment with this toxic metal, and thus the exposure of the general population, will increase. Food (particularly plant products) is the main source of the general population exposure to this element. Moreover, an important, and often the main, source of intoxication with Cd is habitual tobacco smoking. Recent epidemiological studies have provided numerous evidence that even low-level environmental exposure to this toxic metal, nowadays occurring in numerous economically developed countries, creates a risk for health of the general population. The low-level lifetime exposure to this metal may lead to the damage to the kidneys, liver, skeletal system, and cardiovascular system, as well as to the deterioration of the sight and hearing. Moreover, it has been suggested that environmental exposure to this xenobiotic may contribute to the development of cancer of the lung, breast, prostate, pancreas, urinary bladder, and nasopharynx. Taking the above into account, the aim of this review article is to draw more attention to Cd as an environmental risk factor for the health of the general population and the need to undertake preventive actions allowing to reduce the risk of health damage due to a lifetime exposure to this toxic metal.

Cadmium-Induced Oxidative Stress Impairs Glycemic Control in Adolescents

Experimental evidence suggests that cadmium (Cd) boosts oxidative stress that may result in toxicity on the endocrine system also in humans. The aim of this study was to investigate the glycemic control and oxidative stress markers in male adolescents with increased urinary levels of cadmium. We investigated 111 males, aged 12–14 years, living in a polluted area of Sicily and a control age-matched population (n = 60) living 28–45 km far from the polluted site. Malondialdehyde (MDA), total antioxidant activity (TAC), metallothionein-1A (MT-1A) gene expression, insulin resistance by the homeostatic model assessment (HOMA-IR), and urinary cadmium were investigated. Cd levels were significantly higher in adolescents living in the polluted area than in control age-matched subjects. Adolescents with elevated Cd levels had a significant increase in MDA, MT-1A, and HOMA-IR and reduced TAC compared to the control group. A robust correlation was found between urinary cadmium and MT-1A, HOMA-IR, and MDA whereas an inverse correlation was identified between urinary cadmium and TAC. This study indicates that cadmium burden alters glycemic control in adolescents and suggests that oxidative stress plays a key role in cadmium-induced insulin resistance, increasing the risk of developing metabolic disorders.

Toxicity of cadmium and its health risks from leafy vegetable consumption

Cadmium (Cd) is a highly toxic heavy metal and has spread widely in the environment in recent decades. This review summarizes current knowledge about Cd contamination of leafy vegetables, its toxicity, exposure, health risks, and approaches to reducing its toxicity in humans. Leafy vegetable consumption has been identified as a dominant exposure pathway of Cd in the human body. An overview of Cd pollution in leafy vegetables as well as the main sources of Cd is given. Notable estimated daily intakes and health risks of Cd exposure through vegetable consumption for humans are revealed in occupational exposure areas and even in some reference areas. Vegetable consumption is one of the most significant sources of exposure to Cd, particularly in occupational exposure regions. Therefore, numerous approaches have been developed to minimize the accumulation of Cd in leafy vegetables, among which the breeding of Cd pollution-safe cultivars is one of the most effective tools. Furthermore, dietary supplements from leafy vegetables perform positive roles in alleviating Cd toxicity in humans with regard to the effects of essential mineral elements, vitamins and phytochemicals taken into the human body via leafy vegetable consumption.

Pollution by metals: Is there a relationship in glycemic control?

There are evidences of environmental pollution and health effects. Metals are pollutants implicated in systemic toxicity. One of the least studied effects, but which is currently becoming more important, is the effect of metals on glycemic control. Metals have been implicated as causes of chronic inflammation and oxidative stress and are associated to obesity, hyperglycemia and even diabetes. Arsenic, iron, mercury, lead, cadmium and nickel have been studied as a risk factor for hyperglycemia and diabetes. There is another group of metals that causes hypoglycemia such as vanadium, chromium, zinc and magnesium by different mechanisms. Zinc, magnesium and chromium deficiency is associated with increased risk of diabetes. This review summarizes some metals involved in glycemic control and pretends to alert health professionals about considering environmental metals as an important factor that could explain the poor glycemic control in patients. Further studies are needed to understand this poorly assessed problem.