Calcium, zinc and vitamin E ameliorate cadmium-induced renal oxidative damage in albino Wistar rats

Mitigative effects of didymin against cadmium-induced renal injury via regulating Nrf-2/Keap-1, apoptosis, inflammation and oxidative stress

BACKGROUND

Cadmium (Cd) is a toxic heavy metal present in environment that has potential to instigate renal toxicity. Didymin (DDM) is a natural flavone, which shows anti-oxidant, anti-inflammatory and antiapoptotic nature. Therefore, the current study was formulated to appraise attenuative potential of DDM against Cd instigated nephrotoxicity.

METHODS

Forty-eight albino rats were divided into four equal groups, including control, Cd (5 mg/kg) inebriated group, Cd + DDM (5 mg/kg + 1 mg/kg) concurrent-treated group, as well as DDM (1 mg/kg) alone treated group. The trial was conducted for 30 days and then the rats were anesthetized, decapitated and further analyses were performed.

RESULTS

The results demonstrated that Cd treatment lowered the expressions of Nrf-2 and its anti-oxidant genes while escalating Keap-1 expression. Cd exposure downregulated the activities of antioxidant enzymes, SOD, GSR, CAT, HO-1, GPx, GST & GSH contents, while the levels of MDA and ROS were escalated. Furthermore, Cd exposure lowered the levels of creatinine clearance and albumin, while increasing the levels of urobilinogen, urinary proteins, urea, creatinine, NGAL and KIM-1. Moreover, Cd intoxication also augmented the levels of inflammatory indices including, IL-1β, NF-κB, TNF-α, IL-6 and COX-2. Additionally, Cd exposure reduced the expressions of Bcl-2, while increasing Bax and caspase-3 expressions. In addition to this, Cd also provoked multiple histological injuries in the renal tissues of the rats. However, DDM supplementation markedly recovered the renal tissues from the Cd induced damages.

CONCLUSION

In conclusion, DDM protected the renal tissues from Cd-provoked damages due to its antiapoptotic, anti-oxidant and anti-inflammatory efficacy.

Iron Administration Partially Ameliorates Cadmium-Induced Oxidative Damage in the Liver and Kidney of Rats

The protective effect of Fe against Cd-induced toxicity in the liver and kidney of rats during concurrent administration of both metals was investigated in this study. Fifty female rats (130-150 g) were distributed into five groups of 10 rats each (n = 10): Group I (control), received normal saline solution; Group II (1.2 mg CdCl2/kg b.w.); Group III (1.2 mg CdCl2 + 0.25 mg FeCl2/kg b.w.); Group IV (1.2 mg CdCl2 + 0.75 mg FeCl2/kg b.w.); and Group V (1.2 mg CdCl2 + 1.5 mg FeCl2/kg b.w.). Administration of both tested substances lasted for 47 days. Cd was injected intraperitoneally once a week, while Fe was administered to the Cd-exposed animals by oral gavage thrice weekly. The animals were killed at the end of the study, their blood was collected, and their liver and kidneys were harvested for biochemical and histological analysis. Following Cd administration, the kidney and liver showed a significant increase in Cd concentration, while Fe concentration in the kidney decreased. However, cotreatment with Fe decreased Cd concentration in the kidney and liver and increased Fe concentration in the kidney but not the liver, and the effect was more pronounced in the higher than lower doses. In the kidney, cotreatment with Fe especially at higher doses inhibited Cd-induced lipid peroxidation and plasma uric acid concentration. In the liver, lipid peroxidation which Cd did not alter was found to be elevated after cotreatment with the highest dose Fe. Inflammatory cell infiltrations of the central vein and renal tubular and glomeruli injury induced by Cd were not obviated by Fe cotreatment. It seems that both tissues respond differently to the concurrent administration of these metals and that Fe protected the kidney against oxidative injury-induced by Cd but not histopathological changes in both tissues.

Zinc Ameliorates Cadmium-Induced Immunotoxicity by Modulating Splenic Immunosuppressive Indoleamine 2,3-Dioxygenase Activity, Hematological Indices, and CD4+ T Cells via Inhibition of Cadmium Uptake in Male Wistar Rats

Cadmium (Cd)-induced immunotoxicity has become a matter of public health concern owing to its prevalence in the environment consequently, great potential for human exposure. Zinc (Zn) has been known to possess antioxidant, anti-inflammatory, and immune-boosting properties. However, the ameliorating influence of Zn against Cd-induced immunotoxicity connecting the IDO pathway is lacking. Adult male Wistar rats were exposed to normal drinking water with no metal contaminants (group 1), group 2 received drinking water containing 200 μg/L of Cd, group 3 received drinking water containing 200 μg/L of Zn, and group 4 received Cd and Zn as above in drinking water for 42 days. Cd exposure alone significantly triggered the splenic oxidative-inflammatory stress, increased activities of immunosuppressive tryptophan 2,3-dioxygenase (TDO), indoleamine 2,3-dioxygenases (IDO) activities/protein expression, and decreased CD4+ T cell count, and a corresponding increase in the serum kynurenine concentration, as well as alterations in the hematological parameters and histologic structure when compared with the control (p < 0.05). Zn alone did not have any effect relative to the control group while co-exposure significantly (p < 0.05) assuaged the Cd-induced alterations in the studied parameters relative to the control. Cd-induced modifications in IDO 1 protein expression, IDO/TDO activities, oxidative-inflammatory stress, hematological parameters/CD4+ T cell, and histological structure in the spleen of rats within the time course of the investigation were prevented by Zn co-exposure via inhibition of Cd uptake.

Protein S-palmitoylation enhances profibrotic signaling in response to cadmium

Cadmium (Cd) is a naturally occurring, toxic environmental metal found in foods. Humans do not have an efficient mechanism for Cd elimination; thus, Cd burden in humans increases with age. Cell and mouse studies show that Cd burden from low environmental levels of exposure impacts lung cell metabolism, proliferation signaling and cell growth as part of disease-promoting profibrotic responses in the lungs. Prior integrative analysis of metabolomics and transcriptomics identified the zDHHC11 transcript as a central functional hub in response to Cd dose. zDHHC11 encodes a protein S-palmitoyltransferase, but no evidence is available for effects of Cd on protein S-palmitoylation. In the present research, we studied palmitoylation changes in response to Cd and found increased protein S-palmitoylation in human lung fibroblasts that was inhibited by 2-bromopalmitate (2-BP), an irreversible palmitoyltransferase inhibitor. Mass spectrometry-based proteomics showed palmitoylation of proteins involved in divalent metal transport and in fibrotic signaling. Mechanistic studies showed that 2-BP inhibited palmitoylation of divalent metal ion transporter ZIP14 and also inhibited cellular Cd uptake. Transcription analyses showed that Cd stimulated transforming growth factor (TGF)-β1 and β3 expression within 8 h and lung fibrotic markers α-smooth muscle actin, matrix metalloproteinase-2, and collagen 1α1 gene expression and that these effects were blocked by 2-BP. Because 2-BP also blocked palmitoylation of proteins controlled by TGFβ1, these results show that palmitoylation impacts Cd-dependent fibrotic signaling both by enhancing cellular Cd accumulation and by supporting post-translational processing of TGFβ1-dependent proteins.

Vitamin D and calcium co-therapy mitigates pre-established cadmium nephropathy by regulating renal calcium homeostatic molecules and improving anti-oxidative and anti-inflammatory activities in rat

BACKGROUND

Cadmium (Cd) is a major environmental pollutant and chronic toxicity could induce nephropathy by increasing renal oxidative stress and inflammation. Although vitamin D (VD) and calcium (Ca) prophylactic treatments attenuated Cd-induced cell injury, none of the prior studies measure their renoprotective effects against pre-established Cd-nephropathy.

AIMS

To measure the alleviating effects of VD and/or Ca single and dual therapies against pre-established nephrotoxicity induced by chronic Cd toxicity prior to treatment initiation.

METHODS

Forty male adult rats were allocated into: negative controls (NC), positive controls (PC), Ca, VD and VC groups. The study lasted for eight weeks and all animals, except the NC, received CdCl₂ in drinking water (44 mg/L) throughout the study. Ca (100 mg/kg) and/or VD (350 IU/kg) were given (five times/week) during the last four weeks to the designated groups. Subsequently, the expression of transforming growth factor-β (TGF-β1), inducible nitric oxide synthase (iNOS), neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1), VD synthesising (Cyp27b1) and catabolizing (Cyp24a1) enzymes with VD receptor (VDR) and binding protein (VDBP) was measured in renal tissues. Similarly, renal expression of Ca voltage-dependent channels (Ca_V1.1/Ca_V3.1), store-operated channels (RyR1/ITPR1), and binding proteins (CAM/CAMKIIA/S100A1/S100B) were measured. Serum markers of renal function alongside several markers of oxidative stress (MDA/H₂O₂/GSH/GPx/CAT) and inflammation (IL-6/TNF-α/IL-10) together with renal cell apoptosis and expression of caspase-3 were also measured.

RESULTS

The PC group exhibited hypovitaminosis D, hypocalcaemia, hypercalciuria, proteinuria, reduced creatinine clearance, and increased renal apoptosis/necrosis with higher caspase-3 expression. Markers of renal tissue damage (TGF-β1/iNOS/NGAL/KIM-1), oxidative stress (MDA/H₂O₂), and inflammation (TNF-α/IL-1β/IL-6) increased, whilst the antioxidants (GSH/GPx/CAT) and IL-10 decreased, in the PC group. The PC renal tissues also showed abnormal expression of Cyp27b1, Cyp24a1, VDR, and VDBP, alongside Ca-membranous (Ca_V1.1/Ca_V3.1) and store-operated channels (RyR1/ITPR1) and cytosolic Ca-binding proteins (CAM/CAMKIIA/S100A1/S100B). Although VD was superior to Ca monotherapy, their combination revealed the best mitigation effects by attenuating serum and renal tissue Cd concentrations, inflammation and oxidative stress, alongside modulating the expression of VD/Ca-molecules.

CONCLUSIONS

This study is the first to show improved alleviations against Cd-nephropathy by co-supplementing VD and Ca, possibly by better regulation of Ca-dependent anti-oxidative and anti-inflammatory actions.

Cessation Restores Blood Pressure Levels and Endothelial Function Affected by Cadmium Exposure on Rats

Chronic cadmium exposure produces high blood pressure and endothelial damage; however, it is not known whether these effects could be reversed by interrupting the exposure to the metal. Therefore, we evaluate the systolic blood pressure (SBP) and vascular reactivity during and following chronic cadmium-exposure discontinuance. Rats received 100 mg.L^-1 cadmium chloride (CdCl₂) in the drinking water or tap water (Ct) for 30 days and/or tap water for 30 days more. The cadmium plasma content, blood pressure and vascular reactivity of isolated aorta were evaluated. Cadmium exposure increased cadmium plasma content, SBP and aorta contractile responses to phenylephrine, all reversed after suspending exposure. Endothelial removal and nitric oxide synthase (NOS) inhibition increased phenylephrine response both on control and Cd-discontinuation models. Cd-discontinuation group presented increased CAMKII and PKA protein expression, as peNOS^Ser1177. Superoxide dismutase (SOD) incubation reduced contractile response on control group, and catalase incubation enhanced the response to phenylephrine in this group. Meanwhile, both SOD2 and catalase protein expression were increased in Cd-cessation rats. Our findings provide evidence that increased SBP and endothelial dysfunction induced by Cd chronic exposure are reversed by suspending the metal exposure probably due to an improvement of antioxidant enzymes and eNOS function.

Atorvastatin prevents cadmium-induced renal toxicity in a rat model

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

Nephroprotective Efficacy of Selenium and Zinc Against Potassium Dichromate-Induced Renal Toxicity in Pregnant Wistar Albino Rats

Hexavalent chromium (CrVI) compounds are potent toxicants commonly used in numerous industries. Thus, potential toxic effects and health hazards are of high relevance. Selenium (Se) and zinc (Zn) are known for their antioxidant and chemoprotective properties. However, little is known about their protective effects against CrVI-induced renal damage during pregnancy. In this context, the present study aimed to investigate the protective efficacy of these two essential elements against potassium dichromate-induced nephrotoxicity in pregnant Wistar Albino rats. Female rats were divided into control and four treated groups of six each receiving subcutaneously on the 3rd day of pregnancy, K₂Cr₂O₇ (10 mg/kg, s.c. single dose) alone, or in association with Se (0.3 mg/kg, s.c. single dose), ZnCl₂ (20 mg/kg, s.c. single dose) or both of them simultaneously. The nephrotoxic effects were monitored by the evaluation of plasma renal parameters, oxidative stress biomarkers, DNA damage, and renal Cr content. The obtained results showed that K₂Cr₂O₇ disturbed renal biochemical markers, induced oxidative stress and DNA fragmentation in kidney tissues, and altered renal histoarchitecture. The co-administration of Se and/or ZnCl₂ has exhibited pronounced chelative, antioxidant, and genoprotective effects against K₂Cr₂O₇-induced renal damage and attenuated partially the histopathological alterations. These results suggest that Se and Zn can be used as efficient nephroprotective agents against K₂Cr₂O₇-induced toxicity in pregnant Wistar Albino rats.

Curative Potential of Substances with Bioactive Properties to Alleviate Cd Toxicity: A Review

Rapid urbanization and industrialization have led to alarming cadmium (Cd) pollution. Cd is a toxic heavy metal without any known physiological function in the organism, leading to severe health threat to the population. Cd has a long half-life (10-30 years) and thus it represents serious concern as it to a great extent accumulates in organs or organelles where it often causes irreversible damage. Moreover, Cd contamination might further lead to certain carcinogenic and non-carcinogenic health risks. Therefore, its negative effect on population health has to be minimalized. As Cd is able to enter the body through the air, water, soil, and food chain one possible way to defend and eliminate Cd toxicities is via dietary supplements that aim to eliminate the adverse effects of Cd to the organism. Naturally occurring bioactive compounds in food or medicinal plants with beneficial, mostly antioxidant, anti-inflammatory, anti-aging, or anti-tumorigenesis impact on the organism, have been described to mitigate the negative effect of various contaminants and pollutants, including Cd. This study summarizes the curative effect of recently studied bioactive substances and mineral elements capable to alleviate the negative impact of Cd on various model systems, supposing that not only the Cd-derived health threat can be reduced, but also prevention and control of Cd toxicity and elimination of Cd contamination can be achieved in the future.

The role of well-known antioxidant vitamins in the prevention of cadmium-induced toxicity

Long-term exposure to cadmium (Cd) leads to the development of a number of conditions associated with liver and kidney damage, reproductive and cardiovascular disorders, in addition to visual impairment, blindness and hearing loss, among others. Cadmium has been classified as a human carcinogen by the International Agency for Research on Cancer. The toxicity of Cd is related to its pro-oxidant properties and the associated increase in oxidative stress. Antioxidant ingredients may be helpful in preventing the adverse effects of Cd. The effect of well-known antioxidant vitamins (E, C, A and β-carotene) in the prevention of Cd-induced toxicity is presented in this study. Numerous studies in animal models have shown that the effects of vitamins: E, C, A, and β-carotene were effective in reducing Cd concentrations in organs and tissues and reduced Cd-induced changes in liver, kidney, and reproductive, circulatory, nervous, immune, and respiratory systems. In contrast, the limited number of human studies does not allow to accurately determine the role of these nutrients in reducing Cd-induced toxicity, indicating the need for further studies clarifying the role of antioxidant vitamins in reducing Cd-induced toxicity. However, it seems reasonable to promote the consumption of natural food products that are sources of antioxidant vitamins in groups of people with occupational and environmental exposure to Cd. Int J Occup Med Environ Health. 2022;35(4):367-92.

Activated Nrf-2 Pathway by Vitamin E to Attenuate Testicular Injuries of Rats with Sub-chronic Cadmium Exposure

Cadmium (Cd), a heavy metal element, cumulates in the testis and can cause male reproductive toxicity. Although vitamin E (VE) as one of potential antioxidants protects the testis against toxicity of Cd, the underlying mechanism remained uncompleted clear. The aim of this study was to investigate whether the Nrf-2 pathway is involved with the protective effect of VE on testicular damages caused by sub-chronic Cd exposure. Thirty-two SD rats were divided into four groups and orally administrated with VE and/or Cd for 28 consecutive days: control group, VE group (100 mg VE/kg), Cd group (5 mg CdCl₂/kg), and VE + Cd group (100 mg VE/kg + 5 mg CdCl₂/kg). The results showed that 28-day exposure of Cd caused accumulation of Cd, histopathological lesions, and alternations of sperm parameters (elevated rate of abnormal sperm, decreased count of sperm, declined motility, and viability of sperm). Moreover, the rats exposed to Cd showed significant oxidative stress (increased contents of MDA and decreased levels or activities of T-AOC, GSH, CAT, SOD and GSH-Px) and inhibition of Nrf-2 signaling pathway (downregulation of Nrf-2, HO-1, NQO-1, GCLC, GCLM and GST) of the testes. In contrast, VE treatment significantly reduced the Cd accumulation, alleviated histopathological lesions and dysfunctions, activated Nrf-2 pathway, and attenuated the oxidative stress caused by Cd in the testes of rats. In conclusion, VE, through upregulating Nrf-2 pathway, could protect testis against oxidative damages induced by sub-chronic Cd exposure.

Natural self-emulsifying reversible hybrid-hydrogel delivery (N'SERH) of tocopherol enhances bioavailability and modulates alcohol-induced reproductive toxicity in rats

Alpha-tocopherol (α-Toc), an antioxidant vitamin, has been widely prescribing in the treatment of infertility, in spite of its limited oral bioavailability. The present study describes the enhanced bioavailability and efficacy of a novel 'natural self-emulsifying reversible hydrogel' (N'SERH)-based oral delivery form of α-Toc-rich sunflower oil (Tα-fen) using fenugreek galactomannan hydrogel scaffold (hybrid-FENUMATTM ). Tα-fen was characterised by FTIR, SEM, TEM and DLS as a hybrid-hydrogel powder. The bioavailability study on thirty (n = 30) male Sprague Dawley rats randomised into two groups indicated 4.84-fold increase in the oral bioavailability when the formulation was provided at 15 mg/kg b. wt. of α-Toc by oral gavage. The efficacy study on 24 animals randomised into four groups as control, ethanol treated (4 mg/kg b. wt.), ethanol+unformulated, UTα (15 mg/kg b. wt.) and ethanol+formulation, Tα-fen (15 mg/kg b. wt.) revealed significant improvement (*p < 0.05) and reversal of alcohol-induced reproductive toxicity as evident from the enhanced sperm count, motility and viability parameters, testosterone levels, fructose content, and SDH activity and plasma antioxidant status among Tα-fen-treated rats, compared with unformulated, UTα-treated group. Histopathology further confirmed the reversal of the alterations in the testes morphology of Tα-fen-treated animals, indicating its promising potential in the treatment of reproductive health issues.

Amelioration of Cadmium-Induced Oxidative Damage in Wistar Rats by Vitamin C, Zinc and N-Acetylcysteine

The present study was performed to determine the protective effects of vitamin C, zinc, and N-acetylcysteine, individually or in combination with Cd, to monitor their amelioration capability against Cd-induced oxidative damage in Wistar rats. We investigated and demonstrated that cadmium is a toxic element that damages rat liver and kidney tissues. Vitamin C, zinc, and NAC have been proven to have protective roles against Cd toxic effects. Nine groups of rats were studied as the experimental group. The present experiment was conducted for 45 days. Liver and kidneys were excised for biochemical evaluation by assaying antioxidant enzymes and lipid oxidation products to assess the impact of Cd toxicity and its amelioration by co-administration of vitamin C, zinc, and NAC along with Cd. Basal metabolic rates and tissue respiration rates of liver and kidney were significantly decreased (p < 0.05) during Cd toxicity. Serum biochemical parameters were also found to be significantly altered to cope with Cd toxicity. All the antioxidant enzymes and products were significant inhibited (p < 0.05) or elevated in rat liver and kidney tissues during Cd-induced toxicity. Our results suggest that co-administration of vitamin C, zinc, and NAC to rats ameliorates oxidative damage induced by Cd toxicity. From the results obtained in the present study, all the agents tested had protective effects against Cd-induced oxidative damage.

Protective Effect of Vitamin E on Cadmium-Induced Renal Oxidative Damage and Apoptosis in Rats

Cadmium (Cd), a widely distributed heavy metal, is extremely toxic to the kidney. Vitamin E (VE) is an important antioxidant in the body. It is known that VE exerts a protective effect on renal oxidative damage caused by Cd, but the effect and mechanism of VE on apoptosis are not fully understood. Thus, we conducted this study to explore the protective effect of VE on Cd-induced renal apoptosis and to elucidate its potential mechanism. Thirty-two 9-week-old male Sprague-Dawley rats were randomly divided into four groups, namely control, VE (100 mg/kg VE), Cd (5 mg/kg CdCl₂), and VE + Cd (100 mg/kg VE + 5 mg/kg CdCl₂), and received intragastric administration of Cd and/or VE for 4 weeks. The results showed that Cd exposure significantly reduced the weight of the body and kidney, elevated the accumulation of Cd in the kidney as well as the levels of BUN and Scr in serum, caused renal histological alterations, decreased the GSH and T-AOC contents and antioxidant enzyme (SOD, CAT, GSH-PX) activities, and increased renal MDA content. And the increased number of TUNEL-positive cells by Cd was accompanied by upregulated mRNA and protein expressions of apoptotic regulatory molecules (Bax, Caspase-3, GRP94, GRP78, Caspase-8) and downregulated Bcl-2 expressions. However, the combined treatment of Cd and VE could restore the above parameters to be close to those in the control rats. In conclusion, VE supplement could alleviate Cd-induced rat renal damage and oxidative stress through enhancing the antioxidant defense system and inhibiting apoptosis of renal cells.

Antioxidant, Anti-Inflammatory, and Immunomodulatory Properties of Tea-The Positive Impact of Tea Consumption on Patients with Autoimmune Diabetes

The physiological markers of autoimmune diabetes include functional disorders of the antioxidative system as well as progressing inflammation and the presence of autoantibodies. Even though people with type 1 diabetes show genetic predispositions facilitating the onset of the disease, it is believed that dietary factors can stimulate the initiation and progression of the disease. This paper analyses the possibility of using tea as an element of diet therapy in the treatment of type 1 diabetes. Based on information available in literature covering the last 10 years, the impact of regular tea consumption or diet supplements containing tea polyphenols on the oxidative status as well as inflammatory and autoimmune response of the organism was analyzed. Studies conducted on laboratory animals, human patients, and in vitro revealed positive effects of the consumption of tea or polyphenols isolated therefrom on the diabetic body. Few reports available in the literature pertain to the impact of tea on organisms affected by type 1 diabetes as most (over 85%) have focused on cases of type 2 diabetes. It has been concluded that by introducing tea into the diet, it is possible to alleviate some of the consequences of oxidative stress and inflammation, thus limiting their destructive impact on the patients' organisms, consequently improving their quality of life, regardless of the type of diabetes. Furthermore, elimination of inflammation should reduce the incidence of immune response. One should consider more widespread promotion of tea consumption by individuals genetically predisposed to diabetes, especially considering the drink's low price, easy availability, overall benefits to human health, and above all, the fact that it can be safely used over extended periods of time, regardless of the patient's age.

Nephroprotective and anti-inflammatory potential of aqueous extract from Persea americana seeds against cadmium-induced nephrotoxicity in Wistar rats

Cadmium is a toxic metal and poses a high environmental risk to animals and humans, alike. It is thus pertinent to search for medicinal plants in protecting against cadmium toxicity. This study aims at investigating the ability of aqueous extract of Persea americana seeds (AEPA) in ameliorating the toxic effects of cadmium in the kidneys of cadmium-exposed Wistar rats. Male Wistar rats were grouped into five, of six animals each. Different groups of animals received normal saline (control group), 200 mg/kg body weight AEPA, 400 mg/kg AEPA, and standard drug, Livolin Forte, respectively. A last group of animals was left untreated. To induce toxicity, all animals, except the control group, were exposed to cadmium (200 mg/L, as CdCl₂) in their main drinking water for 21 days. Biochemical analysis of serum kidney markers, oxidative stress and antioxidant status, as well as anti-inflammatory activities, was done using standard methods and kits. In silico analysis was performed on phytochemicals reported to be abundant in AEPA. Treatment with 400 mg/kg AEPA significantly reversed (P ≤ 0.05) the adverse effect of cadmium on serum creatinine, urea, uric acid and blood urea nitrogen, and restored (P ≤ 0.05) antioxidant status, evidenced by its significant effect on superoxide dismutase, catalase, glutathione-S-transferase, glutathione peroxidase, reduced glutathione, and lipid peroxidation activities. AEPA, at 400 mg/kg also exhibited significant anti-inflammatory effects, which was shown by reduced interleukin-2 and tumour necrosis factor α activities. Molecular docking of phytochemicals with the selected protein target also confirmed the therapeutic potential of AEPA. The study concluded that aqueous extract of AEPA protects against cadmium-induced kidney toxicity and inflammation.

Cadmium-induced hypertension is associated with renal myosin light chain phosphatase inhibition via increased T697 phosphorylation and p44 mitogen-activated protein kinase levels

Dietary intake of the heavy metal cadmium (Cd²⁺) is implicated in hypertension, but potassium supplementation reportedly mitigates hypertension. This study aims to elucidate the hypertensive mechanism of Cd²⁺. Vascular reactivity and protein expression were assessed in Cd²⁺-exposed rats for 8 weeks to determine the calcium-handling effect of Cd²⁺ and the possible signaling pathways and mechanisms involved. Cd²⁺ induced hypertension in vivo by significantly (p < 0.001) elevating systolic blood pressure (160 ± 2 and 155 ± 1 vs 120 ± 1 mm Hg), diastolic blood pressure (119 ± 2 and 110 ± 1 vs 81 ± 1 mm Hg), and mean arterial pressure (133 ± 2 and 125 ± 1 vs 94 ± 1 mm Hg) (SBP, DBP, and MAP, respectively), while potassium supplementation protected against elevation of these parameters. The mechanism involved augmentation of the phosphorylation of renal myosin light chain phosphatase targeting subunit 1 (MYPT1) at threonine 697 (T697) (2.58 ± 0.36 vs 1 ± 0) and the expression of p44 mitogen-activated protein kinase (MAPK) (1.78 ± 0.20 vs 1 ± 0). While acetylcholine (ACh)-induced relaxation was unaffected, 5 mg/kg b.w. Cd²⁺ significantly (p < 0.001) attenuated phenylephrine (Phe)-induced contraction of the aorta, and 2.5 mg/kg b.w. Cd²⁺ significantly (p < 0.05) augmented sodium nitroprusside (SNP)-induced relaxation of the aorta. These results support the vital role of the kidney in regulating blood pressure changes after Cd²⁺ exposure, which may be a key drug target for hypertension management. Given the differential response to Cd²⁺, it is apparent that its hypertensive effects could be mediated by myosin light chain phosphatase (MLCP) inhibition via phosphorylation of renal MYPT1-T697 and p44 MAPK. Further investigation of small arteries and the Rho-kinase/MYPT1 interaction is recommended.

Nephroprotective effect of Pleurotus ostreatus extract against cadmium chloride toxicity in rats

Cadmium, present in the environment, accumulates in different organs of animals and humans, and has deleterious effects on the kidney. In this study, we investigated the protective effects of the methanolic extract of Pleurotus ostreatus in comparison with silymarin on renal function in cadmium-intoxicated rats for five days. Rats intraperitoneally injected with cadmium chloride (1 mg/kg). These rats were treated with either P. ostreatus extract (200 mg/kg) or silymarin to investigate the protective effects of the extract. Cadmium treatment induced significant histopathological impairments and increased cadmium levels, DNA fragmentation, and renal oxidative stress. However, treatment with P. ostreatus extract or silymarin improved the pathology, reduced the level of cadmium in renal tissue, and restored DNA fragmentation. In addition, a significant reduction in lipid peroxidation and reactive oxygen species levels, and a significant increase in the levels of glutathione and catalase activity were observed. Thus, protective effects of P. ostreatus extract to its components. Chromatographic analysis of the P. ostreatus confirmed the presence of five phenolics (gallic acid, chlorogenic acid, catechin, propyl gallate, and cinnamic acid) that exhibit strong antioxidant properties as free radical scavengers. Therefore, our findings demonstrate that treatment with P. ostreatus extract protects against cadmium-induced nephrotoxicity in female rats.

The Role of Natural Antioxidants Against Reactive Oxygen Species Produced by Cadmium Toxicity: A Review

Cadmium (Cd) is a significant ecotoxic heavy metal that adversely affects all biological processes of humans, animals and plants. Exposure to acute and chronic Cd damages many organs in humans and animals (e.g. lung, liver, brain, kidney, and testes). In humans, the Cd concentration at birth is zero, but because the biological half-life is long (about 30 years in humans), the concentration increases with age. The industrial developments of the last century have significantly increased the use of this metal. Especially in developing countries, this consumption is higher. Oxidative stress is the imbalance between antioxidants and oxidants. Cd increases reactive oxygen species (ROS) production and causes oxidative stress. Excess cellular levels of ROS cause damage to proteins, nucleic acids, lipids, membranes and organelles. This damage has been associated with various diseases. These include cancer, hypertension, ischemia/perfusion, cardiovascular diseases, chronic obstructive pulmonary disease, diabetes, insulin resistance, acute respiratory distress syndrome, idiopathic pulmonary fibrosis, asthma, skin diseases, chronic kidney disease, eye diseases, neurodegenerative diseases (amyotrophic lateral sclerosis, Parkinson's disease, Alzheimer's disease, and Huntington disease). Natural antioxidants are popular drugs that are used by the majority of people and have few side effects. Natural antioxidants play an important role in reducing free radicals caused by Cd toxicity. Our goal in this review is to establish the relationship between Cd and oxidative stress and to discuss the role of natural antioxidants in reducing Cd toxicity.

The Role of Dietary Antioxidants in the Pathogenesis of Neurodegenerative Diseases and Their Impact on Cerebral Oxidoreductive Balance

Neurodegenerative diseases are progressive diseases of the nervous system that lead to neuron loss or functional disorders. Neurodegenerative diseases require long-term, sometimes life-long pharmacological treatment, which increases the risk of adverse effects and a negative impact of pharmaceuticals on the patients’ general condition. One of the main problems related to the treatment of this type of condition is the limited ability to deliver drugs to the brain due to their poor solubility, low bioavailability, and the effects of the blood-brain barrier. Given the above, one of the main objectives of contemporary scientific research focuses on the prevention of neurodegenerative diseases. As disorders related to the competence of the antioxidative system are a marker in all diseases of this type, the primary prophylactics should entail the use of exogenous antioxidants, particularly ones that can be used over extended periods, regardless of the patient’s age, and that are easily available, e.g., as part of a diet or as diet supplements. The paper analyzes the significance of the oxidoreductive balance in the pathogenesis of neurodegenerative diseases. Based on information published globally in the last 10 years, an analysis is also provided with regard to the impact of exogenous antioxidants on brain functions with respect to the prevention of this type of diseases.

Vitamin D3 and calcium cosupplementation alleviates cadmium hepatotoxicity in the rat: Enhanced antioxidative and anti-inflammatory actions by remodeling cellular calcium pathways

Although vitamin D (VD) and calcium (Ca) attenuate cadmium (Cd) metabolism, their combined antioxidant and anti-inflammatory actions against Cd toxicity have not been previously explored. Hence, this study measured the protective effects of VD ± Ca supplements against Cd hepatotoxicity. Forty adult male rats were distributed to: negative controls (NCs), positive controls (PCs), VD, Ca, and VD₃ and Ca (VDC) groups. All groups, except NC, received CdCl₂ in drinking water (44 mg/L) for 4 weeks individually or concurrently with intramuscular VD₃ (600 IU/kg; three times per week) and/or oral Ca (100 mg/kg; five times per week). The PC group showed abnormal hepatic biochemical parameters and increase in cellular cytochrome C, caspase-9, and caspase-3 alongside the apoptotic/necrotic cell numbers by terminal deoxynucleotidyl transferase dUTP nick end labeling technique. The PC hepatic tissue also had substantially elevated pro-oxidants (malondialdehyde [MDA]/H₂ O₂ /protein carbonyls) and inflammatory cytokines (interleukin 1β [IL-1β]/IL-6/IL17A/tumor necrosis factor-α), whereas the anti-inflammatory (IL-10/IL-22) and antioxidants (glutathione [GSH]/GPx/catalase enzyme [CAT]) markers declined. Hypovitaminosis D, low hepatic tissue Ca, aberrant hepatic expression of VD-metabolizing enzymes (Cyp2R1/Cyp27a1/cyp24a1), receptor and binding protein alongside Ca-membrane (Ca_V 1.1/Ca_V 3.1), and store-operated (RyR1/ITPR1) channels, and Ca-binding proteins (CAM/CAMKIIA/S100A1/S100B) were observed in the PC group. Both monotherapies decreased serum, but not tissue Cd levels, restored the targeted hepatic VD/Ca molecules' expression. However, these effects were more prominent in the VD group than the Ca group. The VDC group, contrariwise, disclosed the greatest alleviations on serum and tissue Cd, inflammatory and oxidative markers, the VD/Ca molecules and tissue integrity. In conclusion, this report is the first to reveal boosted protection for cosupplementing VD and Ca against Cd hepatotoxicity that could be due to enhanced antioxidative, anti-inflammatory, and modulation of the Ca pathways.

Development of a Novel Pharmaceutical Formula of Nanoparticle Lipid Carriers of Gentamicin/α-Tocopherol and In Vivo Assessment of the Antioxidant Protective Effect of α-Tocopherol in Gentamicin-Induced Nephrotoxicity

Gentamicin is a potent antibiotic with a nephrotoxicity drawback which limits its use. D-α-tocopherol polyethylene glycol succinate (α-tocopherol) is widely used as a surfactant and have potent antioxidant properties. This study aimed to assess the protective effect of α-tocopherol on gentamicin-induced nephrotoxicity by loading gentamicin on nanostructured lipid carriers (NLC). In vivo, the product was administered intravenously to three groups of rabbits (control, gentamicin and gentamicin/α-tocopherol NLC) for 10 consecutive days. Blood was collected on days 1, 5 and 10 to assess renal function. A significant difference in all plasma parameters related to kidney function were observed in the gentamicin group compared to the control by day 5 and 10, confirming the nephrotoxicity effect. On the other hand, the same parameter levels of the NLC group were significantly different compared to the gentamicin group, confirming the protective effect on kidney function. Gentamicin also caused significant decreases in plasma levels of glutathione sulfhydryl (GSH) and superoxide dismutase (SOD) activity. However, gentamicin-α-tocopherol NLC significantly elevates both plasma levels of GSH as well as SOD activity. The present work indicates that, loading of gentamicin on NLC by using α-tocopherol, is an innovative strategy to protect against aminoglycoside-induced nephrotoxicity due to its antioxidant activity.

Morin ameliorates the testicular apoptosis, oxidative stress, and impact on blood-testis barrier induced by photo-extracellularly synthesized silver nanoparticles

Silver nanoparticles (AgNPs) have been widely produced for different industrial purposes. Recently, biogenic synthesis of AgNPs has emerged although the extent of effects from exposure, oral exposure in particular, to nanomaterials synthesized in such a manner remains elusive. The main objective of this study was to evaluate the effects of oral administration of a dose of 50 mg/Kg body weight AgNPs biosynthesized in baker's yeast (Saccharomyces cerevisiae) over a period of eight weeks on the reproductive performance and the possibility of a protective effect through co-administration of morin. Forty-eight male Sprague-Dawley rats were used in four experimental groups (control, morin-treated group, AgNP-treated, and AgNP + morin co-treatment). AgNPs produced no significant alteration in daily food intake or body weight. Both the absolute and relative testicular weights were significantly reduced but not the epididymal weight. Also, serum levels of urea, creatinine, uric acid, and liver enzymes were significantly elevated. Furthermore, AgNPs significantly downregulated the hypothalamic-pituitary-gonadal axis. This corresponds to lower motility and viability percent, reduced sperm concentration, and a higher abnormality ratio as well as a prominent alteration in the blood-testis barrier (BTB) and testicular histology and induction of testicular apoptosis and oxidative stress. The supplementation of morin evidently restored most of the reproductive characters to its physiological range. We can conclude that exposure to the biologically synthesized AgNPs for an extended period of time has proven to be a health risk that can be ameliorated via oral administration of some bioactive agents including morin.

Protective role of (Bronco-T) against formaldehyde induced antioxidant, oxidative and histopathological changes in lung of male Wistar rats

The present study was sought to evaluate the oxidative, antioxidant status and histopathological changes by the acute chronic exposure of formaldehyde. Bronco-T a poly-herbal formulation treatment, changes the oxidative, antioxidant status and histopathology of rat lungs with antioxidant and regenerative property. In this experiment thirty adult male albino Wister rats were used for the study and subdivided in to five groups consist of 6 rats for each group. Group-I served as control and the other 4 groups such as II, III, IV and V are considered as experimental. The control and treatment rats are maintained for 21 days of experimental period. Experimental rats are exposed to 40 percent formaldehyde for 1 h treated with Bronco-T and salbutamol. In the present investigation, the formaldehyde exposed rats a series of free radical chain reactions were grimly provoked, the evaluation of antioxidant enzymes (SOD, CAT), other enzymes oxidative enzymes (G-6-PDH, SDH) and (ALT, ALAT and LDH) were measured. A clear assertive imbalance between oxidation and anti-oxidation status was critically observed, and oxidative stress was clearly exacerbated in lung tissue leading to altrations in architecture of lung histopathology. Oral gavage Bronco-T exhibits a beneficial action by bringing normal architecture in lung tissue of formaldehyde inhaled rats with antioxidant properties. Bronco-T treatment may be a suitable remedy for formalin occupational diseases.

Hepato-Renal protective Effects of Egyptian Purslane Extract against Experimental Cadmium Toxicity in Rats with Special Emphasis on the Functional and Histopathological Changes

The study was designed to clarify the hapato-nephroprotective effects of purslane ethanolic extract (PEE) against cadmium toxicity. Cadmium (Cd) is a toxic heavy metal. Cd occurs as environmental and food/ feed contamination causing public and animals health hazards. Liver and kidney are the main target organs for acute and chronic cadmium toxicity. Portulaca oleracea is rich in several vitamins, minerals, antioxidant components, and omega-3 fatty acids mainly α-linolenic acid and eicosapentaenoic acid. Results showed significant elevation of the liver and kidney functions, lipid profile and lipid peroxidation. In contrast to the antioxidants enzymatic were greatly decreased. The hepatic and renal tissues showed severe degeneration and necrosis accompanied by severe congestion and multifocal hemorrhages in Cd intoxicated rats. All parameters and tissues showed no changes in rates-treated with both Cd and purslane extract as compared with the control rats. The administration of PEE provided a significantly protection against Cd-induced hepato-nephrotoxicity.

Extract from Aronia melanocarpa L. Berries Prevents Cadmium-Induced Oxidative Stress in the Liver: A Study in A Rat Model of Low-Level and Moderate Lifetime Human Exposure to this Toxic Metal

The study investigated, in a rat model of low-level and moderate environmental exposure to cadmium (Cd; 1 or 5 mg Cd/kg diet, respectively, for 3 to 24 months), whether the co-administration of 0.1% extract from Aronia melanocarpa L. berries (AE) may protect against oxidative stress in the liver and in this way mediate this organ status. The intoxication with Cd, dose- and duration-dependently, weakened the enzymatic antioxidative barrier, decreased the concentrations of reduced glutathione and total thiol groups, and increased the concentrations of oxidized glutathione, hydrogen peroxide, xanthine oxidase, and myeloperoxidase in this organ. These resulted in a decrease in the total antioxidative status, increase in the total oxidative status and development of oxidative stress (increased oxidative stress index and malondialdehyde concentration) and histopathological changes in the liver. The administration of AE at both levels of Cd treatment significantly improved the enzymatic and nonenzymatic antioxidative barrier, decreased pro-oxidant concentration, and protected from the development of oxidative stress in the liver and changes in its morphology, as well as normalized the serum activities of liver enzymes markers. In conclusion, consumption of aronia products may prevent Cd-induced destroying the oxidative/antioxidative balance and development of oxidative stress in the liver protecting against this organ damage.

Protective effect of tea against lead and cadmium-induced oxidative stress-a review

Exposure to Cd and Pb reduces the activity of antioxidant enzymes, which points to a decrease in the antioxidant potential of the body as a result of supplying factors which enhance cellular oxidation processes. Man is exposed to the effects of toxic metals because they are present in the environment, including in food. Since no effective ways to reduce the concentrations of Cd an Pb in food exist, studies are undertaken to develop methods of reducing their toxic effect on the body through chelating these metals using nutrients (which reduces their absorption by tissues) or increasing the oxidative capacity of the body (which decreases the possibility of inducing oxidative damage to internal organs). Studies performed on laboratory animals have shown that the use of tea infusions fulfil both functions.

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.

An evaluation of the antioxidant properties of iodinated radiographic contrast media: An in vitro study

This study reveals the antioxidant properties of iodinated radiographic contrast media to be used in diagnostic radiology. Di(phenyl)-(2,4,6-trinitrophenyl) iminoazanium (DPPH), ferric reducing ability of plasma (FRAP), and 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) assays were used for determining in vitro the antioxidant properties of five iodinated radiographic contrast media such as iobitridol (xenetix), iodixanol (visipaque), iohexol (omnipaque), ioxaglate (hexabrix), and isovue (iopamiro). An ascorbic acid and Trolox solution served as a positive control. The absorbance intensity of the colored product was recorded using a spectrophotometer. For DPPH and ABTS assay, the absorbance intensity at 533 and 752 nm, respectively was decreased when compared to control; it indicated an increase in antioxidant activity. For FRAP assay, the absorbance intensity at 593 nm was increased when compared to control; it indicated an increase in antioxidant activity. The results showed that five iodinated radiographic contrast media did not differ in DPPH^• radical-scavenging activity when compared to a corresponding control. The ferric reducing ability of all of these iodinated radiographic contrast media also did not differ when compared to a corresponding control, except for iobitridol at 200 mgI/mL and ioxaglate at 50-200 mgI/mL. All iodinated radiographic contrast media showed ABTS^•+ radical-scavenging activity. This finding suggested that iobitridol, iodixanol, iohexol, ioxaglate, and isovue exhibited weak in vitro antioxidant properties. The antioxidant ability depended on the type of free radical production and the concentration of iodinated radiographic contrast media.