Chromium-induced nephrotoxicity and ameliorative effect of carvedilol in rats: Involvement of oxidative stress, apoptosis and inflammation

Concentration and Distribution of Toxic and Essential Elements in Traditional Rice Varieties of Sri Lanka Grown on an Anuradhapura District Farm

Toxic heavy metals have been the focus of many investigations into chronic kidney disease of unknown aetiology (CKDu) within Sri Lanka. It has been hypothesised that exposure to nephrotoxic arsenic, cadmium and lead could play a role in the development of CKDu, and these metals have previously been found in unsafe concentrations in Sri Lankan rice. Traditional varieties of Sri Lankan rice remain popular due to their perceived health benefits, but their uptake of trace and toxic heavy metals remained unexplored. Here, we report a one-time, cross-sectional dataset on the concentrations of essential and toxic elements present in eleven samples of polished and unpolished traditional rice varieties, all regularly grown and sold in the Anuradhapura district, a CKDu hotspot. All rice was sourced from the same farm, with the exception of one store bought sample grown on another, unidentified farm. Cadmium concentrations varied significantly between varieties, and potentially unsafe concentrations of cadmium were detected in the store-bought sample (Suwadel, 113±13 μg kg-1). Elemental imaging of the grains revealed lead to be stored mainly in the rice bran, which is removed during polishing, while cadmium was distributed in the edible portion of the grain. Essential elements were generally higher in the traditional rice varieties than those reported for non-traditional varieties and are a potential source of trace elements for nutrient-deficient communities. The concentration of selenium, an element that plays a protective role in the kidneys, was too low to provide the minimum recommended intake. The methods developed in this study could be applied to a more comprehensive study of elemental uptake of rice under controlled growing conditions.

Echinacea purpurea root extract mitigates hepatotoxicity, genotoxicity, and ultrastructural changes induced by hexavalent chromium via oxidative stress suppression

Environmental and occupational exposure to hexavalent chromium (CrVI) is mostly renowned as a possible hepatotoxic in mammals. Echinacea purpurea (L.) Moench, a phenolic-rich plant, is recurrently used for its therapeutic properties. Therefore, this investigation was done to explore whether E. purpurea (EP) root extract would have any potential health benefits against an acute dose of CrVI-induced oxidative damage and hepatotoxicity. Results revealed that GC-MS analysis of EP root extract has 26 identified components with a significant amount of total phenolic and flavonoid contents. Twenty-four Male Wistar rats were divided into four groups: control, EP (50 mg/kg BW/day for 21 days), CrVI (15 mg/kg BW as a single intraperitoneal dosage), and EP + CrVI, respectively. Rats treated with CrVI displayed a remarkable rise in oxidative stress markers (TBARS, H2O2, PCC), bilirubin, and lactate dehydrogenase activity, and a marked decrease in enzymatic and non-enzymatic antioxidants, transaminases, and alkaline phosphatase activities, and serum protein level. Also, CrVI administration induced apoptosis and inflammation in addition to histological and ultrastructural abnormalities in the liver tissue. The examined parameters were improved significantly in rats pretreated with EP and then intoxicated with CrVI. Conclusively, EP had a potent antioxidant activity and could be used in the modulation of CrVI-induced hepatotoxicity.

Chronic low-dose chromium VI exposure induces oxidative stress and apoptosis with altered expressions of DNA repair genes and promoter hypermethylation in the liver of Swiss albino mice

The present investigation dealt with harmful effects of hexavalent chromium (Cr [VI]) on liver of Swiss albino mice. This variant exhibited cytotoxicity, mutagenicity, and carcinogenicity. Our study focused on elucidating the hepatotoxic effects of chronic low-dose exposure to Cr (VI) (2, 5, and 10 ppm) administered via drinking water for 4 and 8 months. The observed elevation in SGPT, ALP, and SGOT and increased oxidative stress markers unequivocally confirmed the severe disruption of liver homeostasis at these low treatment doses. Noteworthy alterations in histoarchitecture, body weight, and water intake provided further evidences of the harmful effects of Cr (VI). Production of reactive oxygen species (ROS) during metabolism led to DNA damages. Immunohistochemistry and qRT-PCR analyses revealed that chronic low-dose exposure of Cr (VI) induced apoptosis in liver tissue. Our study exhibited alterations in the expression pattern of DNA repair genes (Rad51, Mutyh, Mlh1, and Ogg1), coupled with promoter hypermethylation of Mutyh and Rad51, leading to transcriptional inhibition. Our findings underscored the potential of low-dose Cr (VI) exposure on hepatotoxicity by the intricate interplay between apoptosis induction and epigenetic alterations of DNA repair genes.

Protective Action Mechanisms of Launaea mucronata Extract and Its Nano-Formulation against Nephrotoxicity in Rats as Revealed via Biochemical, Histopathological, and UPLC-QTOF-MS/MS Analyses

Plants belonging to the Launaea genus have been extensively utilized ethnopharmacologically to treat a variety of diseases, including kidney disorders. Chromium is a common industrial pollutant that has been linked to kidney disease. The present work was designed for the investigation of the UPLC-QTOF-MS/MS metabolite profile of the L. mucronate ethanolic extract (LME), along with assessing the mechanistic protective actions of LME and its nano-silver formulation (LMNS) against K₂Cr₂O₇-induced nephrotoxicity in rats. LMNE was successfully biosynthesized and confirmed using UV-Visible (UV-Vis) spectroscopy and transmission electron microscopy (TEM). The nephroprotective effects of LME and LMNE was assessed in rats exposed to potassium dichromate (K₂Cr₂O₇, 15 mg/kg BW) to cause nephrotoxicity. LME and LMNS, separately, were administered twice daily for 14 days at doses of 200 and 400 mg/kg BW, respectively. The kidney function, catalase, UGT, Nrf2, PGE2, Cox-2, ERK, and MAPK levels in renal tissue were all assessed, along with histopathological examinations for exploring their ameliorative effects. Forty-five bioactive metabolites were annotated belonging to flavonoids, phenolic and organic acids, coumarins, and fatty acids. Metabolite profiling revealed that chlorogenic acid, apigenin, and luteolin glycosides were the main phenolics, with chlorogenic acid-O-hexoside reported for the first time in LME. The findings revealed that the serum kidney function indicators (urea and creatinine) were markedly elevated in K₂Cr₂O₇-intoxicated rats. Furthermore, inflammatory indicators (COX-2 and PGE2), MAPK, and ERK were all markedly elevated in kidney tissue, whereas catalase, UGT, and Nrf2 levels were downregulated. Histological and immunohistochemical assays confirmed the toxic effects of K₂Cr₂O₇ in the kidneys. In contrast, the administration of LME and LMNS prior to K₂Cr₂O₇ considerably improved the architecture of the renal tissue, while also restoring levels of most biochemical markers. Functioning via the inhibition of the MAPK/ERK pathway, activating Nrf2, and modifying the antioxidant and metabolic enzymes, LME and LMNS exerted their nephroprotective effects against K₂Cr₂O₇-induced toxicity.

Combined β-sitosterol and trimetazidine mitigate potassium dichromate-induced cardiotoxicity in rats through the interplay between NF-κB/AMPK/mTOR/TLR4 and HO-1/NADPH signaling pathways

Hexavalent chromium salt, like potassium dichromate (PD), is chromium's most precarious valence state in industrial wastes. Recently, there has been increasing interest in β-sitosterol (BSS), a bioactive phytosterol, as a dietary supplement. BSS is recommended in treating cardiovascular disorders due to its antioxidant effect. Trimetazidine (TMZ) was used traditionally for cardioprotection. Through the administration of BSS and TMZ, the cardiotoxic effects of PD were to be countered in this study, in addition to examining the precise mechanism of PD-induced cardiotoxicity. Thirty male albino rats were divided into five groups; the control group: administered normal saline daily (3 mL/kg); the PD group: administered normal saline daily (3 mL/kg); BSS group: administered BSS daily (20 mg/kg); TMZ group: administered TMZ daily (15 mg/kg); and the BSS + TMZ group: administered both BSS (20 mg/kg) and TMZ (15 mg/kg) daily. All experimental groups, except the control, received on the 19th day a single dose of PD (30 mg/kg/day, S.C.). Normal saline, BSS, and TMZ were received daily for 21 consecutive days p.o. The exposure to PD promoted different oxidative stresses, pro-inflammatory, and cardiotoxicity biomarkers. BSS or TMZ succeeded solely in reducing these deleterious effects; however, their combination notably returned measured biomarkers close to normal values. The histopathological investigations have supported the biochemical findings. The combination of BSS and TMZ protects against PD cardiotoxicity in rats by reducing oxidative stress and apoptotic and inflammatory biomarkers. It may be promising for alleviating and protecting against PD-induced cardiotoxicity in people at an early stage; however, these findings need further clinical studies to be confirmed. HIGHLIGHTS: • Potassium dichromate induces cardiotoxicity in rats through the upregulation of oxidative stress, proinflammatory, and apoptotic pathways biomarkers. • β-Sitosterol possesses a possible cardioprotective effect by modulating several signaling pathways. • Trimetazidine, the antianginal agent, has a potential cardioprotective impact on PD-intoxicated rat model. • The combination of β-Sitosterol and trimetazidine was the best in modulating different pathways involved in PD cardiotoxicity in rats via the interplay between NF-κB/AMPK/mTOR/TLR4 and HO-1/NADPH signaling pathways.

Insights into the antioxidative mechanisms of melatonin in ameliorating chromium-induced oxidative stress-mediated hepatic and renal tissue injuries in male Wistar rats

Chromium (Cr), a hazardous heavy metal, is toxic to human health and the environment. Severe detrimental effects of Cr on different physiological systems involve oxidative stress. In the current study, sodium dichromate di-hydrate was subcutaneously injected to male Wistar rats at a dose of 5 mg/kg b.w. and experimented up to 14 days to induce alterations in hepatic and renal tissues. Another group of rats was pre-treated with melatonin at three different doses (5, 10, and 20 mg/kg b.w.; orally) and 20 mg/kg b.w. dose was evidenced to provide maximal protection against Cr-induced alterations. The study demonstrated that melatonin efficiently preserved body weight, organ weight, intracellular antioxidant enzymes, and tissue morphology. Furthermore, melatonin was also found to protect organ damage markers, oxidative stress-biomarkers, activities of pro-oxidant enzymes, levels of reactive oxygen species (ROS), nitric oxide (NO), and collagen content through its antioxidative mechanisms. Moreover, melatonin effectively decreased tissue Cr content through its metal-chelating activity. Hence, the present study has established melatonin as a promising antioxidant for conserving the liver and kidney tissues from Cr-induced oxidative damage thereby strengthening the notion that this small indoleamine can act as a future therapeutic against Cr-induced oxidative stress-mediated tissue damage.

The possible protective role of vitamin C versus melatonin on potassium dichromate induced changes in rat thyroid gland: light and electron microscopic study

Potassium dichromate is widely used in various laboratory and industrial applications. Vitamin C and melatonin are well-known antioxidants. Study the microscopic and morphometric alterations in the thyroid gland in adult male albino rats after the administration of potassium dichromate for successive 2 months and also to assess the possible protective effect of vitamin C versus melatonin on these changes. Sixty adult male albino rats were randomly divided into four main groups. Group I (The control group). Group II received potassium dichromate (25 mg/kg/day) dissolved in distilled water by intraperitoneal (i.p) injection for 2 months. Group III received the same dose of potassium dichromate with vitamin C (120 mg/kg/day) orally through an intragastric intubation. Group IV received the same dose of potassium dichromate and melatonin (10 mg/kg/day) as an i.p injection. Thyroid gland samples were prepared for light and electron microscopic studies. Potassium dichromate group demonstrated congested blood vessels, follicular hyperplasia, follicular enlargement with degenerated lining cells that were exfoliated in the lumen. The parafollicular cells appeared with darkly stained nuclei. PAS reaction showed weak reaction in the colloid with an abnormal pattern of vacuolization. A highly significant increase in the percentage area of fibrosis was detected in Mallory trichrome sections. Ultrastructurally, follicular cells and parafollicular cells appeared irregular in shape with dark, small heterochromatic nuclei. Small, electron-dense granules in the parafollicular cells were found. Potassium dichromate and vitamin C-treated group III showed partial improvement of the thyroid gland. The PAS reaction showed that nearly all the follicles were more or less similar to those of the control group. A significant decrease in the percentage area of fibrosis in group III was found as compared to those in group II. Potassium dichromate and melatonin-treated group showed that the thyroid gland was nearly similar to that of the control group. Vitamin C and melatonin could partially protect against potassium dichromate induced changes in the thyroid gland and the protective effect of melatonin was better than that of vitamin C.

Toxic and carcinogenic effects of hexavalent chromium in mammalian cells in vivo and in vitro: a recent update

Chromium VI (Cr (VI)) can cross cell membranes readily and causes the formation of Cr-DNA adducts, genomic damages, elevation of reactive oxygen species (ROS) and alteration of survival signaling pathways, as evidenced by the modulation in p53 signaling pathway. Mammals, including humans are exposed to Cr, including Cr (VI), frequently through inhalation, drinking water, and food. Several studies demonstrated that Cr (VI) induces cellular death through apoptosis and autophagy, genotoxicity, functional alteration of mitochondria, endocrine and reproductive impairments. In the present review, studies on deleterious effects of Cr (VI) exposure to mammalian cells (in vivo and in vitro) have been documented. Special attention is paid to the underlying molecular mechanism of Cr (VI) toxicity.

Oxidative Stress and Mitochondrial Dysfunction in Chronic Kidney Disease

The kidney contains many mitochondria that generate ATP to provide energy for cellular processes. Oxidative stress injury can be caused by impaired mitochondria with excessive levels of reactive oxygen species. Accumulating evidence has indicated a relationship between oxidative stress and kidney diseases, and revealed new insights into mitochondria-targeted therapeutics for renal injury. Improving mitochondrial homeostasis, increasing mitochondrial biogenesis, and balancing mitochondrial turnover has the potential to protect renal function against oxidative stress. Although there are some reviews that addressed this issue, the articles summarizing the relationship between mitochondria-targeted effects and the risk factors of renal failure are still few. In this review, we integrate recent studies on oxidative stress and mitochondrial function in kidney diseases, especially chronic kidney disease. We organized the causes and risk factors of oxidative stress in the kidneys based in their mitochondria-targeted effects. This review also listed the possible candidates for clinical therapeutics of kidney diseases by modulating mitochondrial function.

Nephroprotective role of Echinacea purpurea against potassium dichromate-induced oxidative stress, inflammation, and apoptosis in rats

Environmental and occupational exposure to chromium compounds, especially hexavalent chromium [Cr(VI)], is widely recognized as a potential nephrotoxic in humans and animals. Its toxicity is associated with the overproduction of free radicals, which induces oxidative damage. Echinacea purpurea (L.) Moench is an herbaceous perennial plant rich in phenolic components and frequently used for its medicinal benefits. The current work evaluated the effectiveness of E. purpurea (EP) against oxidative stress and nephrotoxicity induced by potassium dichromate in male rats. Male Wistar rats were divided into four groups: control, E. purpurea (EP; 50 mg/kg; once daily for 3 weeks), hexavalent chromium (Cr(VI); 15 mg/kg; single intraperitoneal dose), and EP + Cr(VI) where rats were pretreated with EP for 3 weeks before receiving CrVI, respectively. Results revealed that rats exposed to Cr(VI) showed a significant increase in PC, TBARS, and H₂ O₂ , kidney function biomarkers (Urea, creatinine, and uric acid), lactate dehydrogenase activity (LDH), TNF-α, IL-18, nuclear factor kappa B (NFκB), and IGF-1 (Insulin-like growth factor-1) levels as well as a considerable decline in metallothionein (MT), glutathione (GSH) content, enzymatic antioxidants (SOD, CAT, GPx, GR, and GST), alkaline phosphatase (ALP) activities, and protein content. Cr(VI) induced apoptosis in kidney tissues as revealed by upregulation of Bax and caspase 3 and downregulation of Bcl-2. Furthermore, EP treatment ameliorated the Cr(VI)-induced histopathological and ultrastructure variations of kidney tissue, which was confirmed by the biochemical and molecular data. It is clear from the results of this study that EP exerts nephroprotective effects by improving the redox state, suppressing inflammatory reaction and cell apoptosis as well as ameliorating the performance of kidney tissue architecture, which is eventually reflected by the improvement of kidney function in rats.

Mechanism of chromium-induced toxicity in lungs, liver, and kidney and their ameliorative agents

Heavy metal Chromium (Cr), can adversely affect humans and their health if accumulated in organs of the body, such as the lungs, liver, and kidneys. Cr (VI) is highly toxic and has a higher solubility in water than Cr (III). One of the most common routes for Cr exposure is through inhalation and is associated with liver, lung, kidney damage, widespread dermatitis, GI tract damage, human lung cancer, cardiomyopathies, and cardiovascular disease. The increase in ROS production has been attributed to most of the damage caused by Cr toxicity. Cr-induced ROS-mediated oxidative stress has been seen to cause a redox imbalance affecting the antioxidant system balance in the body. The Nrf2 pathway dysregulation has been implicated in the same. Deregulation of histone acetylation and methylation has been observed, together with gene methylation in genes such as p16, MGMT, APC, hMLH1, and also miR-143 repression. Several ultra-structural changes have been observed following Cr (VI)-toxicity, including rough ER dilation, alteration in the mitochondrial membrane and nuclear membrane, pycnotic nuclei formation, and cytoplasm vacuolization. A significant change was observed in the metabolism of lipid, glucose, and the metabolism of protein after exposure to Cr. Cr-toxicity also leads to immune system dysregulations with changes seen in the expression of IL-8, IL-4, IgM, lymphocytes, and leukocytes among others. P53, as well as pro-and anti-apoptotic proteins, are involved in apoptosis. These Cr-induced damages can be alleviated via agents that restore antioxidant balance, regulate Nrf-2 levels, or increase anti-apoptotic proteins while decreasing pro-apoptotic proteins.

Rosmarinus officinalis essential oil modulates renal toxicity and oxidative stress induced by potassium dichromate in rats

BACKGROUND

Chromium hexavalent (CrVI) is known as a toxic contaminant that induced oxidative stress and nephrotoxicity in humans and animals. Rosmarinus officinalis is a perennial herb rich in biologically active constituents that have powerful antioxidant properties. So, the current work evaluated the effectiveness of Rosmarinus officinalis essential oil (REO) against alterations induced by potassium dichromate in the kidney of male rats.

METHODS

GC-MS analysis, in vitro total phenol contents, and DPPH scavenging activity of REO were estimated. Thirty-five Wistar male rats were categorized into 5 groups. The first group was the control, the second one was orally administered rosemary essential oil (REO; 0.5 mL/kg BW), the third group was injected intraperitoneally with hexavalent chromium (CrVI; 2 mg/kg BW) for 14 days, the fourth group used as the protective group (REO was administrated 30 min before i.p. injection of CrVI) and the fifth group applied as the therapeutic group (rats injected with CrVI 30 min followed by oral administration of REO), respectively.

RESULTS

Twenty-nine components were detected with high total phenolic contents and high DPPH scavenging activity. Results revealed that CrVI- intoxicated rats showed a valuable increase in oxidative stress profile (TBARS and H₂O₂) and a notable decline in glutathione (GSH), total protein content, and enzymatic antioxidants (SOD, CAT, GPx, and GST). Furthermore, serum kidney functions biomarkers (urea, creatinine, and uric acid) were increased significantly. Also, the administration of CrVI showed histological and immunohistochemical (PCNA-ir) changes in rat kidney tissue. Otherwise, administration of REO pre or post-treatment with CrVI significantly restored most of the biochemical parameters in addition to improvement in kidney tissue architecture. Moreover, individual intake with REO exhibited an amendment in oxidative stress markers.

CONCLUSION

Conclusively, REO had a potential antioxidant capacity in ameliorating K₂Cr₂O₇-induced nephrotoxicity, especially in the protection group.

Carvedilol induces the antiapoptotic proteins Nrf2 and Bcl2 and inhibits cellular apoptosis in aluminum-induced testicular toxicity in male Wistar rats

The present study was carried out to explore the protective effect of carvedilol (CARV) on aluminum chloride-induced testicular damage in Westar rats. Forty adult male rats, aged 8 weeks, were randomly divided into 4 groups (10 rats each). Group I (control group) received normal saline; whereas group II animals were supplemented with CARV in a dose of 10 mg/kg/day. Group III received AlCl3 (30 mg/kg/day) whereas group IV was co-administered CARV and AlCl3 as the same doses in group II and III respectively. The route of the application was oral gavage for CARV and I.P for AlCl3 for 20 successive days. Exposure of rats to AlCl3 for 20 consecutive days resulted in a significant decrease in serum and testicular superoxide dismutase and catalase activities, serum testosterone level, and sperm count and motility; on the other hand, an increase in nitric oxide, malondialdehyde, aluminum, and serum tumor necrosis factor-alpha levels. Furthermore, histopathological changes in the testis exhibited marked testicular damage. In addition, it revealed a significant up-regulation in the level of the expression for the apoptotic marker; Caspase-3, and down-regulation in antiapoptotic marker Bcl2 and Nrf2 genes. On the other hand, the co-administration of CARV modulated the biochemical parameters, saved sperm count and motility, and the histopathological findings, also, restored the observed changes in Caspase-3, Bcl2, and Nrf2 transcriptional genes. These data suggested that administration of CARV protects against AlCl3 induced testicular oxidative, inflammatory, and apoptosis damage.

Carvedilol Exerts Neuroprotective Effect on Rat Model of Diabetic Neuropathy

Diabetic neuropathy (DN) commonly occurs in diabetics, affecting approximately 50% of both type 1 and 2 diabetic patients. It is a leading cause of non-traumatic amputations. Oxidative stress could play a key role in the pathophysiology of DN. This study aimed to investigate the potential neuroprotective effect of carvedilol on STZ-induced DN in rats. Thirty male Sprague Dawley rats (weighing 200–250 g) were randomly divided into five groups (six/group), where group 1 (negative control) received only the vehicle (0.5% of carboxymethyl cellulose orally 1 ml/kg). DN was induced by a single injection of remaining rats with streptozotocin (STZ; 50 mg/kg, i.p.). After diabetes induction, group 2 served as the diabetic untreated animals; while groups 3 and 4 were treated with carvedilol (1 and 10 mg/kg/d, orally, respectively). Group 5 received a-lipoic acid as a reference neuroprotective (100 mg/kg/d, orally). All treatments were continued for 45 days after diabetes induction, followed by behavioural tests. After sacrificing the animals, dorsal root ganglia, and sciatic nerves were collected for histopathological examination and biochemical assessments. Briefly, STZ administration caused cold allodynia, induced oxidative stress, and increased nerve growth factor (NGF) concentration. Nevertheless, carvedilol improved the behavioural tests, ameliorated the oxidative imbalance as manifested by reducing malondialdehyde, restoring glutathione content, and superoxide dismutase activity. Carvedilol also decreased NGF concentration in DRG homogenate. In conclusion, this study demonstrates the neuroprotective effect of carvedilol in an experimentally induced DN rat model through–at least partly–its antioxidant effect and reduced NGF concentration in DRG.

Associations among Heavy Metals and Proteinuria and Chronic Kidney Disease

Background: The prevalence of chronic kidney disease (CKD) is increasing annually in Taiwan. In addition to traditional risk factors, heavy metals contribute to the development of CKD. The aim of this study was to investigate associations among heavy metals and proteinuria and CKD in the general population in Southern Taiwan. We also explored the interaction and synergetic effects among heavy metals on proteinuria. Methods: We conducted a health survey in the general population living in Southern Taiwan between June 2016 and September 2018. Seven heavy metals were measured: blood lead (Pb) and urine nickel (Ni), chromium (Cr), manganese (Mn), arsenic (As), copper (Cu), and cadmium (Cd). Proteinuria was measured using reagent strips. CKD was defined as an estimated glomerular filtration rate (eGFR) of <60 mL/min/1.73 m². Results: The mean age of the 2447 participants was 55.1 ± 13.2 years and included 977 males and 1470 females. Participants with high blood Pb and high urine Ni, Mn, Cu, and Cd were significantly associated with proteinuria. Interactions between blood Pb and urine Cr, and between urine Cd and Cu, had significant effects on proteinuria. The participants with high blood Pb and high urine Cu were significantly associated with an eGFR of <60 mL/min/1.73 m². Conclusion: High blood Pb and high urine Cu may be associated with proteinuria and an eGFR of <60 mL/min/1.73 m². High urine Ni, Mn, and Cd were significantly associated with proteinuria. Co-exposure to Cd and Cu, and Pb and Cr, may have synergistic effects on proteinuria.

The Double Face of Metals: The Intriguing Case of Chromium

Chromium (Cr) is a common element in the Earth’s crust. It may exist in different oxidation states, Cr(0), Cr(III) and Cr(VI), with Cr(III) and Cr(VI) being relatively stable and largely predominant. Chromium’s peculiarity is that its behavior relies on its valence state. Cr(III) is a trace element in humans and plays a major role in glucose and fat metabolism. The beneficial effects of Cr(III) in obesity and types 2 diabetes are known. It has been long considered an essential element, but now it has been reclassified as a nutritional supplement. On the other hand, Cr(VI) is a human carcinogen and exposure to it occurs both in occupational and environmental contexts. It induces also epigenetic effects on DNA, histone tails and microRNA; its toxicity seems to be related to its higher mobility in soil and swifter penetration through cell membranes than Cr(III). The microorganisms Acinetobacter sp. Cr1 and Pseudomonas sp. Cr13 have been suggested as a promising agent for bioremediation of Cr(VI). This review intends to underline the important role of Cr(III) for human health and the dangerousness of Cr(VI) as a toxic element. The dual and opposing roles of this metal make it particularly interesting. An overview of the recent literature is reported in support.

Attenuation of potassium dichromate and sodium arsenite toxicities by methanol extract of Rauvolfia vomitoria in mice

OBJECTIVES

Exposure to arsenic and hexavalent chromium is a major public health concern especially in the developing part of the world and there is paucity of information on reliable treatment modalilities. It is in this regard that this study evaluates the efficacy of methanol leaf extract of Rauvolfia vomitoria (MRV) when used as pretreatment agent against potassium dichromate (K₂Cr₂O₇) and sodium arsenite (NaAsO₂) exposure.

METHODS

Swiss albino mice between 7 and 10 weeks old were divided into eight cohorts of five animals each. Treatment groups consisted of a distilled water control, MRV alone (275 mg/kg po daily), K₂Cr₂O₇ (12.0 mg/kg, single ip injection) +/- MRV pretreatment, NaAsO₂ (2.5 mg/kg, single ip injection) +/- MRV pretreatment, Na₂AsO₂ + K₂Cr₂O₇ +/- MRV pretreatment. MRV was given for seven consecutive days, while K₂Cr₂O₇ and NaAsO₂ were injected on day seven of the experiment. The frequency of micronucleated polychromatic erythrocytes (mPCEs) was determined in bone marrow cells, while aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities were assessed in the plasma. Hepatic glutathione (GSH), malondialdehyde (MDA), catalase (CAT) and glutathione-S-transferase (GST) levels were also determined.

RESULTS

The NaAsO₂ and K₂Cr₂O₇ significantly (p<0.05) increased mPCE formation, AST, ALT, and CAT when compared with the control. Simultaneous exposure to NaAsO₂ and K₂Cr₂O₇ further increased the levels of the markers. Furthermore, GSH and GST were significantly reduced by NaAsO₂ or K₂Cr₂O₇ or their combination. Pretreatment with MRV reversed the markers towards that of control.

CONCLUSIONS

Methanol extract of Rauvolfia vomitoria may therefore ameliorate NaAsO₂ and K₂Cr₂O₇-induced toxicities via reduction of oxidative stress and fortification of anti-oxidant system.

Evaluating toxicity impacts of environmental exposed chromium on small Indian mongoose (Urva auropunctatus) hematological, biochemical and histopathological functioning

Sub-lethal toxic impacts of chromium on hematological, biochemical and histological parameters were analyzed in the female small Indian mongoose (Urva auropuctatus) residing contaminated environment of tannery industry. Chromium bioaccumulation in the blood, liver and kidney tissue of the exposed mongooses was found elevated compared to the control mongooses' tissues. Total body weight (75.7%), liver weight (83.6%) as well as HSI (68.1%), RSI (86.2%) and the platelets counts (59.7%) were found significantly elevated, with significantly reduced RBCs (59.6%), and WBCs (64%). LFT and RFT were also found abnormal, moreover, the histopathological injuries had been distinct inside the kidney (>75%) and hepatic (>75%) tissues of exposed animals. Shrinkage and vacuolization (>75%) inside the hepatocyte expanded sinusoidal spaces and nuclear pyknosis (>75%) was evident within the hepatic tissue. Hypertrophy of epithelial cells of renal tubules and inter-renal cells of the head kidney with a reduction in tubular lumens (>75%) and vacuolization of tubules were witnessed within the kidney section. Atrophy inside the kidney inter-renal cells, glomeruli compression within the Bowman's capsules (>75%) following the necrosis in hematopoietic tissues were found in exposed animals. The present findings indicate that chronic exposure to chromium induces severe anemia, decreased serum protein concentration, hepatic and renal tissue histopathology, impairing the vital capabilities of liver, metabolic regulation, excretion, and stress homeostasis maintenance of which within the long-run may posture a severe risk to animal well-being then distress their inhabitants.

Carvedilol Promotes Retinal Ganglion Cell Survival Following Optic Nerve Injury via ASK1-p38 MAPK Pathway

BACKGROUND

Carvedilol, which is considered as a nonselective β-adrenoreceptor blocker, has many pleiotropic activities. It also causes great impact on neuroprotection because of its antioxidant ability, which suggested that carvedilol may be effective in protecting RGCs from increased oxidative stress.

OBJECTIVE

To examine the effects of carvedilol on preventing Retinal Ganglion Cell (RGC) death in a mouse model of Optic Nerve Injury (ONI).

METHODS

C57BL/6J mice were subjected to Optic Nerve Injury (ONI) model and treated with carvedilol or placebo. Histological and morphometric studies were performed; the RGC number, the amount of neurons in the ganglion cell layer and the thickness of the Inner Retinal Layer (IRL) was quantified. The average thickness of Ganglion Cell Complex (GCC) was determined by the Spectral- Domain OCT (SD-OCT) assay. Immunohistochemistry, western blot and quantitative real-time PCR analysis were also applied.

RESULTS

Daily treatment of carvedilol reduced RGC death following ONI, and in vivo retinal imaging revealed that carvedilol can effectively prevent retinal degeneration. The expression of chemokines important for micorglia recruitment was deceased with carvedilol ingestion and the accumulation of retinal microglia is reduced consequently. In addition, the ONI-induced expression of inducible nitric oxide synthase in the retina was inhibited with carvedilol treatment in the retina. We also discovered that carvedilol suppressed ONI-induced activation of Apoptosis Signal-regulating Kinase-1 (ASK1) and p38 Mitogen-Activated Protein Kinase (MAPK) pathway.

CONCLUSION

The results of this study indicate that carvedilol can stimulate neuroprotection and neuroregeneration, and may be useful for treatment of various neurodegenerative diseases.

Nephroprotective Effect of Pleurotus ostreatus and Agaricus bisporus Extracts and Carvedilol on Ethylene Glycol-Induced Urolithiasis: Roles of NF-κB, p53, Bcl-2, Bax and Bak

This study was designed to assess the nephroprotective effects of Pleurotus ostreatus and Agaricus bisporus aqueous extracts and carvedilol on hyperoxaluria-induced urolithiasis and to scrutinize the possible roles of NF-κB, p53, Bcl-2, Bax and Bak. Phytochemical screening and GC-MS analysis of mushrooms’ aqueous extracts were also performed and revealed the presence of multiple antioxidant and anti-inflammatory components. Hyperoxaluria was induced in Wistar rats through the addition of 0.75% (v/v) ethylene glycol in drinking water for nine weeks. The ethylene glycol-administered rats were orally treated with Pleurotus ostreatus and Agaricus bisporus aqueous extracts (100 mg/kg) and carvedilol (30 mg/kg) daily during the last seven weeks. The study showed that Pleurotus ostreatus, Agaricus bisporus and carvedilol all successfully inhibited ethylene glycol-induced histological perturbations and the elevation of serum creatinine, serum urea, serum and urinary uric acid, serum, urinary and kidney oxalate, urine specific gravity, kidney calcium, kidney NF-κB, NF-κB p65, NF-κB p50, p53, Bax and Bak expressions as well as serum TNF-α and IL-1β levels. Moreover, the treatment decreased the reduction in urinary creatinine, urinary urea, ratios of urinary creatinine to serum creatinine and urinary urea to serum urea, Fex Urea and Bcl-2 expression in kidney. In conclusion, although Pleurotus ostreatus and Agaricus bisporus extracts and carvedilol all significantly inhibited the progression of nephrolithiasis and showed nephroprotective effects against ethylene glycol-induced kidney dysfunction, Pleurotus ostreatus and Agaricus bisporus seemed to be more effective than carvedilol. Moreover, the nephroprotective effects may be mediated via affecting NF-κB activation, extrinsic apoptosis and intrinsic apoptosis pathways.

4HNE Impairs Myocardial Bioenergetics in Congenital Heart Disease-Induced Right Ventricular Failure

BACKGROUND

In patients with complex congenital heart disease, such as those with tetralogy of Fallot, the right ventricle (RV) is subject to pressure overload stress, leading to RV hypertrophy and eventually RV failure. The role of lipid peroxidation, a potent form of oxidative stress, in mediating RV hypertrophy and failure in congenital heart disease is unknown.

METHODS

Lipid peroxidation and mitochondrial function and structure were assessed in right ventricle (RV) myocardium collected from patients with RV hypertrophy with normal RV systolic function (RV fractional area change, 47.3±3.8%) and in patients with RV failure showing decreased RV systolic function (RV fractional area change, 26.6±3.1%). The mechanism of the effect of lipid peroxidation, mediated by 4-hydroxynonenal ([4HNE] a byproduct of lipid peroxidation) on mitochondrial function and structure was assessed in HL1 murine cardiomyocytes and human induced pluripotent stem cell-derived cardiomyocytes.

RESULTS

RV failure was characterized by an increase in 4HNE adduction of metabolic and mitochondrial proteins (16 of 27 identified proteins), in particular electron transport chain proteins. Sarcomeric (myosin) and cytoskeletal proteins (desmin, tubulin) also underwent 4HNE adduction. RV failure showed lower oxidative phosphorylation (moderate RV hypertrophy, 287.6±19.75 versus RV failure, 137.8±11.57 pmol/[sec×mL]; P=0.0004), and mitochondrial structural damage. Using a cell model, we show that 4HNE decreases cell number and oxidative phosphorylation (control, 388.1±23.54 versus 4HNE, 143.7±11.64 pmol/[sec×mL]; P<0.0001). Carvedilol, a known antioxidant did not decrease 4HNE adduction of metabolic and mitochondrial proteins and did not improve oxidative phosphorylation.

CONCLUSIONS

Metabolic, mitochondrial, sarcomeric, and cytoskeletal proteins are susceptible to 4HNE-adduction in patients with RV failure. 4HNE decreases mitochondrial oxygen consumption by inhibiting electron transport chain complexes. Carvedilol did not improve the 4HNE-mediated decrease in oxygen consumption. Strategies to decrease lipid peroxidation could improve mitochondrial energy generation and cardiomyocyte survival and improve RV failure in patients with congenital heart disease.

Ameliorative effects of Annona muricata Linn. (Annonaceae) against potassium dichromate-induced hypertension in vivo: involvement of Kim-1/p38 MAPK/Nrf2 signaling

Background Recently, the incidences of hypertension and environmental pollution have increased significantly. This study investigates the antihypertensive effect of Annona muricata extract against K2Cr2O7-induced hypertension. Methods Fifty rats were used for this study, which were divided into five groups of 10 rats each. Rats in Group A received normal saline, and those in Groups B, C, D, and E were treated with A. muricata extract alone at 250 mg/kg, K2Cr2O7 at 30 mg/kg, pretreated with the extract at 250 mg/kg, and pretreated with gallic acid at 60 mg/kg for 14 days, respectively, and thereafter administered with a single intraperitoneal injection of K2Cr2O7 at 30 mg/kg. Results Administration of K2Cr2O7 significantly increased systolic, diastolic, and mean arterial pressure and caused prolonged QT and QTc intervals. Further, pretreatment with the extract at 250 mg/kg and gallic acid at 60 mg/kg significantly reduced high blood pressure to near-normal values. K2Cr2O7 intoxication led to significant increases in serum advanced oxidative protein products, myeloperoxidase, and xanthine oxidase, while serum nitric oxide (NO) also reduced significantly. Immunohistochemistry of the renal kidney injury molecule (Kim-1) and p38 MAPK showed increased expressions following the administration of K2Cr2O7 together with the downregulation of nuclear factor erythroid 2-related factor 2 (Nrf2). Pretreatment with the extract at 250 mg/kg and gallic acid at 60 mg/kg also increased the expressions of Nrf2 and downregulated Kim-1 and p38. Conclusion Together, we found that pretreatment with the extract at 250 mg/kg and gallic acid at 60 mg/kg normalized the blood pressure, reduced the markers of oxidative stress, and improved the antioxidant defense system and serum NO bioavailability.

Evaluation of Potassium Dichromate (K2Cr2O7)-Induced Liver Oxidative Stress and Ameliorative Effect of Picrorhiza kurroa Extract in Wistar Albino Rats

The aim of the study was to assess the protective effect of Picrorhiza kurroa hydroalcoholic extract (PCK), a glycoside-rich extract, against potassium dichromate (PDC)-induced liver oxidative stress in Wistar albino rats. Thirty-six male Wistar rats were divided into six groups: the control group (which received distilled water), the SIL group (which received 60 mg/kg silymarin), the PDC group (which received 30 mg/kg K₂Cr₂O₇), and the treatment groups (which received 25, 50, 100 mg/kg PCK). Administration of PDC resulted in increased levels of liver enzymes such as alanine transaminase (ALT), aspartate transaminase (AST), and alkaline phosphatase (ALP); up-regulated peroxidation biomarkers, i.e., thiobarbutric acid-reactive species (TBARS) and protein carbonyls in serum; and decreased activities of antioxidant enzymes like superoxide dismutase (SOD) and catalase (CAT) significantly in the liver tissue. Gene expression studies of tumor necrosis factor (TNF), mitogen-activated protein kinase (MAPK), growth arrest, and DNA damage-inducible protein (GADD45) revealed that there was a liver damage at the molecular level, and histopathological studies further confirmed the morphological changes by PDC administration. However, PCKs at 50 and 100 mg/kg promoted significant restoration of liver enzyme levels and the activities of antioxidant enzymes were kept close to the values of the control and SIL groups. Our current study confirms that the active compounds present in the PCK might have conferred a strong protection against potassium dichromate-induced oxidative stress.

Association of co-exposure to heavy metals with renal function in a hypertensive population

BACKGROUND

Chronic kidney disease (CKD) is an increasing health problem worldwide. Recent studies have suggested the potential associations between exposure to metals and CKD events, particularly in participants with hypertension. However, relevant studies are limited.

OBJECTIVES

We aimed to explore the associations of metal exposure with renal function in participants with essential hypertension.

METHODS

Nine hundred and thirty-four participants with essential hypertension were recruited at the Department of Cardiology, Union Hospital, Wuhan, China. We measured the levels of chromium, cadmium, thallium and uranium in urine and calculated the estimated glomerular filtration rate (eGFR) for renal function. Multivariable linear regression models adjusted for potential confounders were applied.

RESULTS

After adjusting for potential confounders and other metals, doubling of urinary chromium or uranium levels decreased eGFR by 2.90 (95% confidence interval, 2.04 to 3.76) and 1.87 (0.58 to 3.15) mL/min per 1.73m², respectively. Co-exposure to chromium and uranium was found to greatly decrease eGFR, particularly in women. Compared with those in the low exposure group, women with high exposure to chromium and uranium had a 11.36 (3.66 to 19.07) mL/min per 1.73m² adjusted decline in eGFR. Higher urinary thallium levels were positively related to elevated eGFR in men. The adjusted increase in eGFR with doubling of thallium levels was 3.12 (1.14 to 5.10) mL/min per 1.73m². Sex-difference in the associations of exposure to heavy metals with eGFR was also suggested.

CONCLUSIONS

Our findings suggest that environmental exposure to chromium and uranium might contribute to a decline in eGFR in individuals with hypertension. The associations of exposure to heavy metals with eGFR might be sex-different. Further studies are warranted to confirm our findings and clarify the underlying mechanisms.

Carvedilol abrogates hypoxia-induced oxidative stress and neuroinflammation in microglial BV2 cells

Microglia initially undergo rapid activation in response to injury and stressful stimuli, such as hypoxia. Oxidative stress and the inflammatory response play critical roles in hypoxic-ischemic brain injury. Carvedilol is a β-blocker used to treat high blood pressure and heart failure. In this study, we investigated whether carvedilol had a protective effect against hypoxia-induced oxidative stress and inflammation in microglial BV2 cells. Our results indicate that hypoxic exposure significantly reduced mean cell viability of BV2 microglia, which was significantly restored by carvedilol (10 and 50μM). In addition, carvedilol treatment significantly inhibited the hypoxia-induced increase in reactive oxygen species (ROS) and 4-hydroxy-2-nonenal (4-HNE). Administration of carvedilol significantly inhibited expression of IL-1β, TNF-α, and IL-6 at both the mRNA and protein levels. Mechanistically, we found that hypoxia significantly increased phosphorylation of IKK, IκBα, and NF-κB p65. However, treatment with carvedilol inhibited phosphorylation of these molecules. Notably, hypoxia resulted in a significant nuclear translocation of NF-κB p65, which was inhibited by administration of carvedilol. Luciferase reporter assay results demonstrate that treatment with carvedilol inhibited the hypoxia-induced increase in NF-κB binding activity. These data suggest that carvedilol may be of potential use as a novel therapy against hypoxia or ischemia.

Carvedilol prevents functional deficits in peripheral nerve mitochondria of rats with oxaliplatin-evoked painful peripheral neuropathy

Oxaliplatin use as chemotherapeutic agent is frequently limited by cumulative neurotoxicity which may compromise quality of life. Reports relate this neurotoxic effect to oxidative stress and mitochondrial dysfunction in peripheral nerves and dorsal root ganglion (DRG). Carvedilol is an antihypertensive drug, has also been appreciated for its antioxidant and mitoprotective properties. Carvedilol co-treatment did not reduce the anti-tumor effects of oxaliplatin in human colon cancer cells (HT-29), but exhibited free radical scavenging activity against oxaliplatin-induced oxidative stress in neuronal cells (Neuro-2a). Hence, the present study was designed to investigate the effect of carvedilol in the experimental model of oxaliplatin-induced peripheral neuropathy (OIPN) in Sprague-Dawley rats. Oxaliplatin reduced the sensory nerve conduction velocity and produced the thermal and mechanical nociception. Carvedilol significantly (P<0.001) attenuated these functional and sensorimotor deficits. It also counteracted oxidative/nitrosative stress by reducing the levels of nitrotyrosine and improving the mitochondrial superoxide dismutase expression in both sciatic nerve and DRG tissues. It improved the mitochondrial function and prevented the oxaliplatin-induced alteration in mitochondrial membrane potential in sciatic nerve thus prevented loss of intra epidermal nerve fiber density in the foot pads. Together the results prompt the use of carvedilol along with chemotherapy with oxaliplatin to prevent the peripheral neuropathy.

Granisetron and carvedilol can protect experimental rats againstadjuvant-induced arthritis

CONTEXT

Rheumatoid arthritis (RA), a disabling autoimmune disorder of the joints as well as other organs, affects about 1% of population. Unfortunately, all current treatments of RA cause severe gastrointestinal, renal and other complications.

OBJECTIVE

We aimed to evaluate the possible antiarthritic effects of a serotonin 5-HT₃ receptor blocker, granisetron, and a nonselective adrenergic receptor blocker, carvedilol, on complete Freund's adjuvant-induced RA in adult female albino rats.

MATERIALS AND METHODS

Rats were allocated into a normal control group, an arthritis control group, two reference treatment groups receiving dexamethasone (1.5 mg/kg/day) and methotrexate (1 mg/kg/day), and two treatment groups receiving granisetron (2.5 mg/kg/day) and carvedilol (10 mg/kg/day). Serum-specific rheumatoid, immunological, inflammatory and oxidative stress biomarkers were assessed. A confirmatory histopathological study on joints and spleens was performed.

RESULTS

Granisetron administration significantly improved all the measured biomarkers, with the values of rheumatoid factor, matrix metalloproteinase-3, cartilage oligomeric matrix protein, immunoglobulin G, antinuclear antibody and myeloperoxidase being restored back to normal levels. Carvedilol administration significantly improved all biomarkers, with serum MPO value restored back to normal levels.

DISCUSSION AND CONCLUSIONS

Serotonin 5-HT₃ receptor blockers and adrenergic receptor blockers, represented by granisetron and carvedilol, may represent new promising protective strategies against RA, at least owing to immune-modulator, anti-inflammatory and antioxidant potentials.

Gallic acid attenuates chromium-induced thyroid dysfunction by modulating antioxidant status and inflammatory cytokines

Hexavalent chromium-mediated oxidative stress causes severe organ damage. The present study was designed to investigate the possible thyroprotective effect and underlying mechanisms of gallic acid using rat model of potassium dichromate-induced thyroid dysfunction. Forty adult male albino rats were divided into 4 groups: control, gallic acid (20mg GA/kg b. wt), potassium dichromate (2mg PD/kg b. wt) and the fourth group was co-treated with PD and GA. PD-injection resulted in decreased serum free triiodothyonine (FT3), free thyroxine (FT4) with concomitant significant increase in thyroid stimulating hormone (TSH) levels. Superoxide dismutase (SOD), glutathione-S-transferase (GST) activities and their respective mRNA expression and reduced glutathione (GSH) content were significantly decreased. Thyroid nitrosative stress marker (NO level and iNOS mRNA and protein expression) and pro-inflammatory cytokines (serum TNF-α, IL-6 and thyroid TNF-α, IL-6 and COX-2 gene and protein expression levels) were disturbed. Histopathological changes revealed distended, collapsed and degenerated follicles with vacuolated cytoplasm. GA co-treatment attenuated pro-inflammatory cytokines, the thyroid expression of iNOS, TNF-α, IL-6 and COX-2, decreased the elevated lipid peroxidation biomarkers and NO level and up- regulated SOD and GST mRNA expression levels. In conclusion, GA has shown strong modulatory potential against PD-induced inflammation and oxidative stress in albino rats.

Simvastatin attenuates chromium-induced nephrotoxicity in rats

Background

Hexavalent Chromium (Cr (VI)) compounds are extremely toxic and have been demonstrated to induce nephrotoxicity associated with oxidative stress in humans and animals. The wide environmental distribution of these agents lead to an increase interest of preventive effects of its adverse effects.

Objectives

The propose of the present study was to determine the potential protective effects of simvastatin (SIMV) on Cr (VI)-induced nephrotoxicity in rat.

Materials and Methods

Forty-eight adult male Wistar rats (180-220 g BW) were randomly assigned to eight groups (n = 6). Group one received SIMV 20 mg/kg/day. Group two was given vehicle only. Groups three, five and seven received intraperitoneally (i.p) sodium dichromate (Cr (VI)) at doses of 8, 12 and 16 mg/kg body weight. Groups four, six and eight pretreated with the 20 mg/kg SIMV 30 minutes to prior administration of Cr (VI) at doses of 8, 12 and 16 mg/kg, respectively. The experiment repeated for eight consecutive days. Twenty-four hours after the last administration, animals were killed with overdose of sodium pentobarbital. Kidney tissues were excised for measuring malondialdehyde (MDA), glutathione (GSH) and histopathological examination.

Results

Chromium induced a dose dependent elevation of MDA and reduction of GSH levels. Histopathological manifestations were observed in Cr (VI)-treated rats. SIMV administration restored Cr (VI) produced biochemical and morphological changes in rat kidney. SIMV decreased MDA values and increased GSH levels in Cr (VI)-treated rats. SIMV clearly reversed the microscopic damage, demonstrating its protective effects against Cr (VI)-induced kidney injury.

Conclusions

This observation suggests that SIMV may have a protective effect against Cr (VI)-induced oxidative stress in rat kidney.

Potassium Dichromate Toxicities: Protective Effect of Methanol Extract of Corchorus olitorius in Albino Rats

Exposure to hexavalent chromate compounds such as other human carcinogens is unavoidable in the developing countries of the world. Research efforts are being directed toward minimizing exposure to them, intercepting their activity in vivo, and/or prophylaxis. The present study therefore evaluates the effect of methanol extract of the leafy vegetable, Corchorus olitorius (MECO), against potassium dichromate (K2Cr2O7)-induced toxicities. Negative control animals were fed distilled water, while the positive control rats received 12 mg/kg body weight K2Cr2O7 once a week for 6 weeks. Test rats were exposed daily to 25, 50, and 100 mg/kg body weight MECO alone for 6 weeks and 12 mg/kg body weight of K2Cr2O7 once a week for 6 weeks before sacrifice. The frequency of micronucleated polychromatic erythrocytes (mPCEs) was monitored in bone marrow cells, while induction of aspartate aminotransferase (AST), alanine aminotransferase (ALT), creatinine levels, and hematological parameters were assessed in the plasma. The phytochemical analysis of MECO was also carried out. K2Cr2O7 significantly (P < .05) increased the levels of mPCEs, AST, ALT, creatinine, total white blood cells, and lymphocytes compared with the control. The percentage pack cell volume and neutrophils were, however, reduced. In contrast, MECO at different doses restored the markers toward the levels of the negative control. MECO is rich in flavonoids, saponins, anthraquinones, terpenoids, and phenols, and they might be responsible for the protective effect observed in this study. Our results suggest that MECO has a promising potential in the treatment/management of chromate-induced toxicities.

Simultaneous exposure to multiple heavy metals and glyphosate may contribute to Sri Lankan agricultural nephropathy

BACKGROUND

Sri Lankan Agricultural Nephropathy (SAN), a new form of chronic kidney disease among paddy farmers was first reported in 1994. It has now become the most debilitating public health issue in the dry zone of Sri Lanka. Previous studies showed SAN is a tubulo-interstitial type nephropathy and exposure to arsenic and cadmium may play a role in pathogenesis of the disease.

METHODS

Urine samples of patients with SAN (N = 10) from Padavi-Sripura, a disease endemic area, and from two sets of controls, one from healthy participants (N = 10) from the same endemic area and the other from a non-endemic area (N = 10; Colombo district) were analyzed for 19 heavy metals and for the presence of the pesticide- glyphosate.

RESULTS

In both cases and the controls who live in the endemic region, median concentrations of urinary Sb, As, Cd, Co, Pb, Mn, Ni, Ti and V exceed the reference range. With the exception of Mo in patients and Al, Cu, Mo, Se, Ti and Zn in endemic controls, creatinine adjusted values of urinary heavy metals and glyphosate were significantly higher when compared to non-endemic controls. Creatinine unadjusted values were significant higher for 14 of the 20 chemicals studied in endemic controls and 7 in patients, compared to non-endemic controls. The highest urinary glyphosate concentration was recorded in SAN patients (range 61.0-195.1 μg/g creatinine).

CONCLUSIONS

People in disease endemic area exposed to multiple heavy metals and glyphosate. Results are supportive of toxicological origin of SAN that is confined to specific geographical areas. Although we could not localize a single nephrotoxin as the culprit for SAN, multiple heavy metals and glyphosates may play a role in the pathogenesis. Heavy metals excessively present in the urine samples of patients with SAN are capable of causing damage to kidneys. Synergistic effects of multiple heavy metals and agrochemicals may be nephrotoxic.

Phosphate fertilizer is a main source of arsenic in areas affected with chronic kidney disease of unknown etiology in Sri Lanka

Chronic Kidney Disease of unknown etiology (CKDu) has escalated into an epidemic in North Central Province (NCP) and adjacent farming areas in the dry zone of Sri Lanka. Studies have shown that this special type of CKD is a toxic nephropathy and arsenic may play a causative role along with a number of other heavy metals. We investigated the hypothesis that chemical fertilizers and pesticide could be a source of arsenic. 226 samples of Fertilizers and 273 samples of pesticides were collected and analyzed using atomic absorption spectrometry and inductively coupled plasma mass spectrometry for arsenic and other heavy metals in two university laboratories. Almost all the agrochemicals available to the farmers in the study area are contaminated with arsenic. The highest amount was in triple super phosphate (TSP) with a mean value of 31 mg/kg. Also TSP is a rich source of other nephrotoxic metals including Cr, Co, Ni, Pb and V. Annually more than 0.1 million tons of TSP is imported to Sri Lanka containing approximately 2100 kg of arsenic. The next highest concentration was seen in the rock phosphate obtained from an open pit mine in NCP (8.56 mg/kg). Organic fertilizer contained very low amounts of arsenic. Arsenic contamination in pesticides varied from 0.18 mg/kg to 2.53 mg/kg although arsenic containing pesticides are banned in Sri Lanka. Glyphosate the most widely used pesticide in Sri Lanka contains average of 1.9 mg/kg arsenic. Findings suggest that agrochemicals especially phosphate fertilizers are a major source of inorganic arsenic in CKDu endemic areas. Organic fertilizer available in Sri Lanka is comparatively very low in arsenic and hence the farmers in CKDu endemic areas in Sri Lanka should be encouraged to minimize the use of imported chemical fertilizer and use organic fertilizers instead.

Phosphate fertilizer is a main source of arsenic in areas affected with chronic kidney disease of unknown etiology in Sri Lanka

Chronic Kidney Disease of unknown etiology (CKDu) has escalated into an epidemic in North Central Province (NCP) and adjacent farming areas in the dry zone of Sri Lanka. Studies have shown that this special type of CKD is a toxic nephropathy and arsenic may play a causative role along with a number of other heavy metals. We investigated the hypothesis that chemical fertilizers and pesticide could be a source of arsenic. 226 samples of Fertilizers and 273 samples of pesticides were collected and analyzed using atomic absorption spectrometry and inductively coupled plasma mass spectrometry for arsenic and other heavy metals in two university laboratories. Almost all the agrochemicals available to the farmers in the study area are contaminated with arsenic. The highest amount was in triple super phosphate (TSP) with a mean value of 31 mg/kg. Also TSP is a rich source of other nephrotoxic metals including Cr, Co, Ni, Pb and V. Annually more than 0.1 million tons of TSP is imported to Sri Lanka containing approximately 2100 kg of arsenic. The next highest concentration was seen in the rock phosphate obtained from an open pit mine in NCP (8.56 mg/kg). Organic fertilizer contained very low amounts of arsenic. Arsenic contamination in pesticides varied from 0.18 mg/kg to 2.53 mg/kg although arsenic containing pesticides are banned in Sri Lanka. Glyphosate the most widely used pesticide in Sri Lanka contains average of 1.9 mg/kg arsenic. Findings suggest that agrochemicals especially phosphate fertilizers are a major source of inorganic arsenic in CKDu endemic areas. Organic fertilizer available in Sri Lanka is comparatively very low in arsenic and hence the farmers in CKDu endemic areas in Sri Lanka should be encouraged to minimize the use of imported chemical fertilizer and use organic fertilizers instead.