Experimental lead nephropathy: treatment with calcium disodium ethylenediaminetetraacetate

Protective role of savory essential oil on vital organs in rats against deleterious effects induced by lead acetate

The damaging effects of heavy metal exposure on vital organs like the heart, liver, kidneys, and brain can be lowered by natural compounds' anti-inflammatory and anti-oxidant capacity. In the current investigation, the protective potential of savory(Saturejahortensis)essential oil (EO) against lead acetate-induced multi-organ damage in rats was evaluated. Thirty female Wister Albino rats were divided into the following groups: normal, positive control given lead acetate without concomitant treatment, reference given ethylene-diamine-tetra-acetic acid and groups treated with savory EO (0.5 and 1 ml/rat), treatments were administered concomitantly with lead acetate for ten successive days. Electrocardiogram (ECG), open field, and rota-rod tests for evaluation of behaviour, as well as TNF-α, R-GSH & MDA were measured in brain and liver homogenates respectively, CRP, liver, kidney, and heart function tests, were measured in serum. Histopathology of vital organs was conducted at the end of the experiment.A high dose of savory EO, significantly improved the cardiac electrophysiology, psychological state, and locomotor activity of rats; moreover, it lowered inflammatory, oxidative biomarkers, liver, kidney, and cardiac function tests of the rats. Savory EO protects vital organs against heavy metal damage with the superiority of the high dose.

Heavy Metal Toxicity in Chronic Renal Failure and Cardiovascular Disease: Possible Role for Chelation Therapy

Exposure to heavy metals is common. This exposure is related to environmental contamination of air, water and soil, occupational exposure, accumulation in food, tobacco, and other factors. Cadmium and lead are notable for their widespread contamination, long-lasting effects in the body, and renal as well as cardiovascular toxicity. Acute toxicity due to high-level exposure, as well as chronic low-level exposure are now well-established pathogenic entities. Both chronic renal failure and ischemic heart disease patients have been treated separately in recent studies with ethylenediaminetetraacetic acid (EDTA) chelation therapy. In patients with chronic kidney disease (serum creatinine: 1.5-4.0 mg/dL) and increased body lead burden, weekly low-dose chelation with calcium EDTA slowed the rate of decline in renal function in patients with diabetes and in non-diabetic patients. In patients with a history of myocardial infarction, the Trial to Assess Chelation Therapy study showed that EDTA chelation decreased the likelihood of cardiovascular events, particularly in patients with diabetes. However, heavy metal levels were not measured in this study. It is clear that more research is needed in this area. There is also a need to more frequently consider and test for the possibility of cadmium and lead toxicity in patients with increased risk, such as those with hypertension, diabetes mellitus, and chronic renal disease.

The Case For Cadmium and Lead Heavy Metal Screening

Exposure to cadmium and lead is widespread, and is related to environmental contamination, occupational sources, food, tobacco and other consumer products. Lower socioeconomic status increases the risk of heavy metal exposure and the diseases associated with cadmium and lead toxicity. Concurrent toxicity with both cadmium and lead is likely but has not often been assessed. There is now substantial evidence linking cadmium and lead to many diseases including hypertension, diabetes mellitus, obesity, cancer, coronary artery disease, chronic kidney disease (CKD) and lung disease. Both chronic renal failure and ischemic heart disease patients have been treated separately in recent studies with calcium disodium ethylenediaminetetraacetic acid (Ca EDTA) chelation therapy. In patients with CKD, serum creatinine 1.5-4.0 mg/dL, and increased body lead burden, weekly low dose chelation with Ca EDTA slowed the rate of decline in renal function in diabetics and non-diabetics. In patients with a history of myocardial infarction, the Trial to Assess Chelation Therapy (TACT) study showed that Ca EDTA chelation decreased the likelihood of cardiovascular events, particularly in diabetics. Ca EDTA chelation administered carefully at lower dosage (<50 mg/kg per week) is generally safe. In the past, acute renal failure associated with much higher dosage was reported. We suggest that the preponderance of the evidence favors a more activist approach towards diagnosis and possible intervention in heavy metal toxicity.

EVALUATION OF THE CHELATING EFFECT OF METHANOLIC EXTRACT OF CORIANDRUM SATIVUM AND ITS FRACTIONS ON WISTAR RATS POISONED WITH LEAD ACETATE

Background:

The rate of lead poisoning has decreased in recent years due to increased health control in industries that use this metal. However, it is still a public health problem worldwide. The use of various plants with chelating properties has been a topic of research today. In traditional medicine, it is said that Coriandrum sativum has chelating properties, but there is no scientific evidence to support this fact. The purpose of this research is to evaluate the chelating effect of methanol extract of coriander and its fractions on Wistar rats intoxicated with lead.

Materials and Methods:

In this research, male Wistar rats were poisoned with 50 mg/kg of lead acetate and treated with 50 mg/kg of methanol extract and its fractions. The extract and its fractions were administered to four treatment groups. Positive and negative controls were established. Hemoglobin, hematocrit and lead concentrations were analyzed; liver was evaluated histologically in control and treatment groups.

Results:

The methanol extract of coriander presented a LD₅₀ >1000 mg/dL. The group administered with the methanol extract showed significant difference in the levels of hemoglobin and hematocrit compared to the negative control group. Lead concentration in treatment groups showed a decrease compared to the positive control. Histological evaluation of tissue showed less damage in groups administered with methanolic extract and its fractions compared to the positive control which presented structural alterations.

Conclusion:

Coriander extracts protect liver and lower lead concentration in rats intoxicated with lead in contrast to the positive control group.

Rationale for the Successful Management of EDTA Chelation Therapy in Human Burden by Toxic Metals

Exposure to environmental and occupational toxicants is responsible for adverse effects on human health. Chelation therapy is the only procedure able to remove toxic metals from human organs and tissue, aiming to treat damage related to acute and/or chronic intoxication. The present review focuses on the most recent evidence of the successful use of the chelating agent ethylenediaminetetraacetic acid (EDTA). Assessment of toxic-metal presence in humans, as well as the rationale of EDTA therapy in cardiovascular and neurodegenerative diseases, is reported.

In vitro and in vivo activity of EDTA and antibacterial agents against the biofilm of mucoid Pseudomonas aeruginosa

PURPOSE

Refractory infection caused by bacterial biofilm is an important clinical problem. Pseudomonas aeruginosa is a common pathogen responsible for persistent and chronic biofilm infections. We aimed to explore the in vitro and in vivo activity of ethylenediamine tetraacetic acid (EDTA) in combination with antibacterial agents against mucoid P. aeruginosa biofilm.

METHODS

The minimal inhibitory concentration (MIC) and minimal bactericidal concentration of ciprofloxacin, gentamicin, and ampicillin alone or with EDTA against P. aeruginosa were determined in vitro. Extracellular polysaccharides (EPS) and structural parameters of the biofilm were monitored. P. aeruginosa was aerosolized and delivered into the lungs of guinea pigs, which were treated with ciprofloxacin with or without EDTA. The colony-forming units (CFUs) of P. aeruginosa were determined from the lungs.

RESULTS

EDTA reduced the MIC of ciprofloxacin and ampicillin by about 30-fold and that of gentamicin by twofold. EDTA reduced the biofilm EPS and the proportion of viable bacteria. The thickness, average diffusion distance, and textural entropy of EDTA-treated biofilm were significantly decreased. EDTA plus antibiotics reduced the colony counting from 10⁷ to 10³ CFU/mL. In vivo, EDTA plus ciprofloxacin had a significantly lower mean CFU/g of lung tissue (EDTA + ciprofloxacin 1.3 ± 0.19; EDTA 4.4 ± 0.57; ciprofloxacin 4.2 ± 0.47), and lung lesions were less severe compared with the single treatment groups.

CONCLUSIONS

EDTA can destroy the biofilm structures of mucoid P. aeruginosa in vitro. Moreover, EDTA and ciprofloxacin had a significant bactericidal effect against biofilm in vivo.

Translational value of animal models of kidney failure

Acute kidney injury (AKI) and chronic kidney disease (CKD) are associated with decreased renal function and increased mortality risk, while the therapeutic armamentarium is unsatisfactory. The availability of adequate animal models may speed up the discovery of biomarkers for disease staging and therapy individualization as well as design and testing of novel therapeutic strategies. Some longstanding animal models have failed to result in therapeutic advances in the clinical setting, such as kidney ischemia-reperfusion injury and diabetic nephropathy models. In this regard, most models for diabetic nephropathy are unsatisfactory in that they do not evolve to renal failure. Satisfactory models for additional nephropathies are needed. These include anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis, IgA nephropathy, anti-phospholipase-A2-receptor (PLA2R) membranous nephropathy and Fabry nephropathy. However, recent novel models hold promise for clinical translation. Thus, the AKI to CKD translation has been modeled, in some cases with toxins of interest for human CKD such as aristolochic acid. Genetically modified mice provide models for Alport syndrome evolving to renal failure that have resulted in clinical recommendations, polycystic kidney disease models that have provided clues for the development of tolvaptan, that was recently approved for the human disease in Japan; and animal models also contributed to target C5 with eculizumab in hemolytic uremic syndrome. Some ongoing trials explore novel concepts derived from models, such TWEAK targeting as tissue protection for lupus nephritis. We now review animal models reproducing diverse, genetic and acquired, causes of AKI and CKD evolving to kidney failure and discuss the contribution to clinical translation and prospects for the future.

In vitro evaluation of combination of polyenes with EDTA against Aspergillus spp. by different methods (FICI and CI Model)

AIMS

We investigated in vitro activity of polyene drugs (amphotericin B, Amp B; and nystatin, NYS;) in combination with ethylene diamine tetra acetic acid (EDTA) against 8 pathogenic isolates of Aspergillus spp.

METHODS AND RESULTS

The intensity of the drug interactions was assessed using Fractional Inhibitory Concentration Index (FICI) model and Combination Index (CI) model. The interactions were further confirmed by time-kill curve study. The best combination ratio was subjected for toxicity analysis by MTT and haemolytic assay. A significant synergy was found between each of two polyenes with EDTA against Aspergillus fumigatus and Aspergillus flavus at one ratio four. The FICI ranged from 0·29 to 0·38 against A. fumigatus and A. flavus. The FICI value ranged from 0·78 to 1·26 showed no interaction against Aspergillus niger. The CI value (0·21-0·30) and time-kill curve analysis also confirmed synergistic interaction. Antagonism was not detected. There was reduction in toxicity of Amp B and NYS when used with EDTA.

CONCLUSIONS

Subsequently, the chelating agent (EDTA) can be used in combination with Amp B and NYS with increased antifungal potential and reduced toxicity.

SIGNIFICANCE AND IMPACT OF THE STUDY

To emphasize new development in antifungal drug discovery, combination therapy can be used as a tool box to expand drug development.

Oxidative stress: a possible mechanism for lead-induced apoptosis and nephrotoxicity

Lead-induced nephrotoxicity is a human health hazard problem. In this study, Human mesangial cells (HMCs) were treated with different concentration of lead acetate (5, 10, 20 μmol/l) in order to investigate the oxidative stress and apoptotic changes. It was revealed that lead acetate could induce a progressive loss in HMCs viability together with a significant increase in the number of apoptotic cells using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl tetrazolium (MTT) assay and flow cytometry, respectively. The apoptotic morphological changes induced by lead exposure in HMCs were demonstrated by PI-Hochest33342 staining. A DNA laddering pattern in lead-treated cells was shown, which could indicate nuclear fragmentation. In addition, lead acetate significantly increased the levels of malondialehyde (MDA) content and lactate dehydrogenase (LDH) activity. Therefore, it might be concluded that lead could promote HMCs' oxidative stress and apoptosis, which may be the chief mechanisms of lead-induced nephrotoxicity.

Effect of chelation therapy on progressive diabetic nephropathy in patients with type 2 diabetes and high-normal body lead burdens

BACKGROUND

A previous study in type 2 diabetic patients with high-normal body lead burdens showed that EDTA chelation therapy for 3 months slows progressive diabetic nephropathy during a 12-month follow-up. The effect of a longer course of therapy on kidney function decrease over a longer follow-up is not known.

STUDY DESIGN

A 12-month run-in phase, then a randomized single-blind study with a 27-month intervention.

SETTING & PARTICIPANTS

University medical center; 50 patients (serum creatinine, 1.5-3.9 mg/dL) with high-normal body lead burden (≥80-<600 μg) were randomly assigned to the treatment and control groups.

INTERVENTION

The treatment group received weekly chelation therapy for 3 months to reduce their body lead burden to <60 μg and then as needed for 24 months to maintain this level. The control group received placebo for 3 months and then weekly for 5 weeks at 6-month intervals for 24 months.

OUTCOMES

The primary end point was change in estimated glomerular filtration rate (eGFR) over time. A secondary end point was a 2-fold increase in baseline serum creatinine level or the requirement for renal replacement therapy.

MEASUREMENTS

Body lead burdens were assessed by EDTA mobilization tests and eGFR was calculated using the equation for Chinese patients with type 2 diabetes.

RESULTS

Mean baseline eGFRs in the treatment and control groups were similar. After 3 months of chelation therapy, the change in eGFR in the treatment group (+1.0 ± 4.8 mL/min/1.73 m(2)) differed significantly from that in the control group (-1.5 ± 4.8 mL/min/1.73 m(2); P = 0.04). In the subsequent 24-month intervention, the yearly rate of decrease in eGFR (5.6 ± 5.0 mL/min/1.73 m(2) per year) in the treatment group was slower than that (9.2 ± 3.6 mL/min/1.73 m(2) per year; P = 0.04) in the control group. 17 (68%) control-group patients and 9 (36%) treatment-group patients achieved the secondary end point.

LIMITATIONS

Small sample size, not double blind.

CONCLUSIONS

A 27-month course of EDTA chelation therapy retards the progression of diabetic nephropathy in type 2 diabetic patients with high-normal body lead burdens.

Chronic renal failure from lead: myth or evidence-based fact?

In this mini review, we would like to challenge the well-established 'fact' that lead exposure causes chronic renal failure (CRF). Even though only scarce evidence exists of the relationship between lead and renal failure, a World Health Organization Environmental Health Criteria document summarizes that 'Lead has been a very common cause of acute or chronic renal failure'. It is also written and cited in textbooks and numerous publications that chronic lead nephropathy causes a slowly progressive interstitial nephritis manifested by a reduced glomerular filtration rate, and that there is a growing consensus that lead contributes to hypertension in the general population. We will argue that, when published reports are carefully scrutinized, such statements on lead and CRF are not evidence based but are rather founded on a few narrative reports on lead-exposed individuals and statistical associations between lead and serum creatinine (or urea) in a few population studies. We will, however, not argue that lead is not toxic and that lead does not cause other types of severe health effects where the evidence is unquestionable, but we do not believe that the kidneys are an early victim after lead exposure.

Non-drug-induced nephrotoxicity

Several drugs and other compounds can induce acute and/or chronic nephrotoxicity. The goal of this study was to review clinical features of nephrotoxicity induced by 'atypical' or 'unconventional' agents, such as environmental agents (metals, minerals, animals), food agents (mushrooms, aristolochic acid, medicinal traditional herbals, dietary supplements, melamine), drugs, and other products (ethylene glycol). Nephrotoxicity varies according to local background, dependent on different food and cultural customs, as well as to differences in local fauna and flora. The incidence of such a phenomenon is not well known. Many different pathophysiological pathways are involved, and the spectrum of renal lesions is rather wide. 'Epidemic nephrotoxicity' may occur, as recently illustrated by the melamine epidemics in Chinese infants receiving powdered milk formulas; a rapid reaction to unusual increased frequency of acute kidney injury and nephrolithiasis in young children has led to a rapid analysis from international experts, with subsequent recommendations for diagnosis and care. Nephrotoxicity should be considered when there is any unexplained renal impairment, especially in children.

Lead, at low levels, accelerates arteriolopathy and tubulointerstitial injury in chronic kidney disease

Chronic lead exposure has been epidemiologically linked with hypertension and renal disease. Clinical studies suggest that low lead levels may contribute to renal progression. However, experimental studies have not examined whether low levels of lead accelerate progression in experimental chronic renal disease. Sprague-Dawley rats were administered lead (L; 150 ppm in drinking water, n = 16) for 4 wk, followed by remnant kidney (RK) surgery with continuation of lead for an additional 12 wk; control rats (n = 9) were treated similarly but did not receive lead. Lead treatment was well tolerated and resulted in modest elevations in whole blood lead levels (26.4 +/- 4.5 vs. 1 +/- 0 mug/dl, week 16, P < 0.001). Lead treatment was associated with higher systolic blood pressure (P < 0.05) and worse renal function (creatinine clearance 1.4 +/- 0.4 vs. 1.8 +/- 0.5 ml/min, RK+L vs. RK, P < 0.05), and with a tendency for greater proteinuria (6.6 +/- 6.1 vs. 3.6 +/- 1.5 mg protein/mg creatinine, RK+L vs. RK, P = 0.08). While glomerulosclerosis tended to be worse in lead-treated rats (37.6 +/- 11 vs. 28.8 +/- 2.3%, RK+L vs. RK, P = 0.06), the most striking finding was the development of worse arteriolar disease (P < 0.05), peritubular capillary loss (P < 0.05), tubulointerstitial damage, and macrophage infiltration (P < 0.05) in association with significantly increased renal expression of monocyte chemoattractant protein-1 mRNA. In conclusion, lead accelerates chronic renal disease, primarily by raising blood pressure and accelerating microvascular and tubulointerstitial injury.

Lead-related nephrotoxicity: a review of the epidemiologic evidence

Chronic kidney disease (CKD) represents a major global public health concern. Efforts to prevent and/or slow progression of CKD are essential. Lead nephropathy, characterized by chronic tubulointerstitial nephritis, is a well-known risk of chronic, high-level lead exposure. However, in recent years, lead exposure has declined sharply, particularly in developed countries. We reviewed epidemiologic research in general, occupational, and patient populations to assess whether lead, at current exposure levels, still contributes to nephrotoxicity. Other pertinent topics, such as risk in children, genetic susceptibility, and co-exposure to cadmium, are also considered. The data reviewed indicate that lead contributes to nephrotoxicity, even at blood lead levels below 5 microg/dl. This is particularly true in susceptible populations, such as those with hypertension (HTN), diabetes, and/or CKD. Low socioeconomic status is a risk factor for both lead exposure and diseases that increase susceptibility. Future public health risk for lead-related nephrotoxicity may be most significant in those rapidly developing countries where risk factors for CKD, including obesity and secondary HTN and diabetes mellitus, are increasing more rapidly than lead exposure is declining. Global efforts to reduce lead exposure remain important. Research is also needed to determine whether specific therapies, such as chelation, are beneficial in susceptible populations.

EDTA as an adjunct antifungal agent for invasive pulmonary aspergillosis in a rodent model

Rats immunosuppressed by the administration of cyclophosphamide and cortisone acetate and then infected with Aspergillus fumigatus were treated with an antifungal drug, EDTA, or a combination of one of the antifungal agents, amphotericin B lipid complex (ABLC; 5 mg/kg of body weight/day for 7 days), and EDTA (30 mg/kg/day for 7 days). The mortality rate was reduced, the duration of survival was increased, fewer A. fumigatus organisms were recovered from the lungs, and less-severe lung lesions were seen histopathologically in the rats receiving the combination treatment than in the rats receiving either an antifungal agent or EDTA alone. Further studies regarding the mechanisms of EDTA and its interactions with ABLC are warranted, and further studies are needed to more fully examine the safety, tolerance, and optimal dosing of EDTA in the treatment of this and other fungal infections.

Associations among lead dose biomarkers, uric acid, and renal function in Korean lead workers

Recent research suggests that both uric acid and lead may be nephrotoxic at lower levels than previously recognized. We analyzed data from 803 current and former lead workers to determine whether lead biomarkers were associated with uric acid and whether previously reported associations between lead dose and renal outcomes were altered after adjustment for uric acid. Outcomes included uric acid, blood urea nitrogen, serum creatinine, measured and calculated creatinine clearances, and urinary N-acetyl-ss-d-glucosaminidase (NAG) and retinol-binding protein. Mean (+/- SD) uric acid, tibia lead, and blood lead levels were 4.8 +/- 1.2 mg/dL, 37.2 +/- 40.4 microg/g bone mineral, and 32.0 +/- 15.0 microg/dL, respectively. None of the lead measures (tibia, blood, and dimercaptosuccinic-acid-chelatable lead) was associated with uric acid, after adjustment for age, sex, body mass index, and alcohol use. However, when we examined effect modification by age on these relations, both blood and tibia lead were significantly associated (ss = 0.0111, p < 0.01 and ss = 0.0036, p = 0.04, respectively) in participants in the oldest age tertile. These associations decreased after adjustment for blood pressure and renal function, although blood lead remained significantly associated with uric acid (ss = 0.0156, p = 0.01) when the population was restricted to the oldest tertile of workers with serum creatinine greater than the median (0.86 mg/dL). Next, in models of renal function in all workers, uric acid was significantly (p < 0.05) associated with all renal outcomes except NAG. Finally, in the oldest tertile of workers, associations between lead dose and NAG were unchanged, but fewer associations between the lead biomarkers and the clinical renal outcomes remained significant (p less than or equal to 0.05) after adjustment for uric acid. In conclusion, our data suggest that older workers comprise a susceptible population for increased uric acid due to lead. Uric acid may be one, but not the only, mechanism for lead-related nephrotoxicity.

A Review of Chronic Lead Intoxication: An Unrecognized Cause of Chronic Kidney Disease

Chronic lead nephropathy occurs as a result of years of lead exposure. This disease has been prevalent throughout human history. It is important that primary care providers and internists recognize this disorder because it can contribute to progressive loss of kidney function. Diagnosis is made by a thorough history in combination with physical examination. A history of lead intoxication often requires knowledge of the various sources of lead exposure. Laboratory tests, many previously known and some newly described, are available to further support this diagnosis. Therapy to reduce lead burden may be useful when employed early in the disease; new data sheds more light on which patients should be treated and when such patients should undergo chelation therapy. In particular, treatment with calcium EDTA chelation may benefit certain patients with chronic kidney disease by slowing the progression to end-stage renal disease.

Therapeutic efficacy of lipoic acid in combination with dimercaptosuccinic acid against lead-induced renal tubular defects and on isolated brush-border enzyme activities

The combined therapeutic potentials of lipoic acid and dimercaptosuccinic acid were compared against their sole administrations in restoring the altered lead sensitive indices in urine and isolated renal brush-border preparations. Toxicity was induced in male albino rats (Wistar strain) by administering lead acetate (0.2%) in drinking water for 5 weeks, followed by therapy comprising lipoic acid (25 mg/kg body weight) and dimercaptosuccinic acid (20 mg/kg body weight) solely as well as combined during the 6th week. Changes in kidney weights encountered upon lead administration improved after therapy with lipoic acid and dimercaptosuccinic acid. Renal integrity was assessed by measuring the activities of alkaline phosphatase, acid phosphatase, lactate dehydrogenase, leucine aminopeptidase, N-acetyl-beta-D-glucosaminidase, gamma-glutamyl transferase and beta-glucuronidase in urine along with some urinary constituents (urea, uric acid, creatinine, protein and phosphorous). The effects of lead were also studied on isolated brush-border enzymes (alkaline phosphatase, acid phosphatase, gamma-glutamyl transferase and beta-glucuronidase) that showed a decline upon its administration. Increased activities of urinary enzymes were accompanied by increase in the urinary constituents. Increase in renal lead content was paralleled by a drastic fall in the renal delta-aminolevulinic acid dehydratase and a rise in urinary lead levels. Relative to the administration of lead, the combined therapy showed betterment on the renal integrity with respect to the functional parameters assessed, thereby indicating its efficacy over the monotherapies.

Multifactorial determination of hypertensive nephroangiosclerosis

Essential hypertension causes renal injury. Hypertensive nephroangiosclerosis (HN) or hypertensive nephropathy are terms most commonly used to describe this renal pathology. Although specific histological lesions occurring in affected kidneys are well known, pathogenesis of hypertension-related renal scarring is not completely understood. Evidence exists to support the theory that other factors such as aging, black race or smoking, beside blood pressure, contribute to the development and progression of HN. Metabolic disturbances, cocaine and nonsteroidal anti-inflammatory drug abuse, ochratoxin A exposure, dietary salt intake, heavy metal toxicity, hantavirus infection and perinatal programming are also considered risk factors. Renal susceptibility genes may determine whether hypertension-induced progressive renal damage occurs and how severe it is. Determination of all risk factors may identify patients at high risk of renal failure and help tailor an appropriate management. In the present paper, the knowledge available on this clinically important objective is discussed.