Abstract
Cadmium (Cd) is a serious pollutant in the environment. Candesartan is an angiotensin II (Ang II) receptor antagonist with promising diverse health benefits. The current study is planned to investigate the hepatorenal protective effects of candesartan against Cd-induced hepatic and renal intoxication. Our results demonstrated that candesartan effectively attenuated Cd-induced hepatorenal intoxication, as evidenced by improving hepatic and renal function biomarkers. Besides, candesartan reversed hepatic and renal histopathological abrasions induced by Cd toxicity. Candesartan antioxidant effect was mediated by Nrf2 activation. Also, candesartan suppressed hepatorenal inflammation by modulating NF-κB/IκB. Moreover, candesartan attenuated Cd hepatorenal apoptosis by upregulating Bcl-2 and downregulating Bax and Cyt-C proteins. Interestingly, these effects are suggested to be an outcome of modulating of Ang II/Ang 1–7 signal. Overall, our findings revealed that candesartan could attenuate Cd-induced hepatorenal intoxication through modulation of Nrf2, NF-κB/IκB, Bax/Bcl-2/Cyt-c, and Ang II/Ang 1–7 signaling pathways.
Similar content being viewed by others
Avoid common mistakes on your manuscript.
Introduction
Cadmium (Cd) is a toxic, non-essential metal used in industrial processes such as plastics, rechargeable batteries, and agricultural fertilizers. It causes a significant health risk to humans and animals [1, 2]. Now, it is broadly acknowledged that Cd accumulates in many organs, such as the liver, kidney, and other organs, resulting in physical and structural damage [1, 3]. Notably, Cd excessively induces ROS production that can throw off the balance between oxidative stress and antioxidant status, resulting in oxidative damage to lipids and proteins and loss of endogenous antioxidants [4, 5]. Moreover, a robust body of evidence demonstrated that Cd cellular oxidative damage results in cellular proliferation and apoptosis inductions [6,7,8].
Although ROS can kill cells by causing massive lipid peroxidation, they usually affect signal transduction through modulating redox-sensitive signals like nuclear factor kappa B (NF-κB) [9]. Various pro-inflammatory cytokines have a critical role in initiating and progressing of inflammatory diseases, such as cytokines being activated and modulated by altering the redox states [10]. Cd causes inflammation by attracting innate immune cells, which then produces pro-inflammatory cytokines like interleukin (IL)-1β [11]. On the other side, the nuclear-factor-E2-related factor 2 (Nrf2) signal plays a crucial role in the attenuation of Cd-induced renal [12] and hepatic oxidative injury [13].
Recently, several studies demonstrated that Cd intoxication triggers intrinsic apoptosis by releasing pro-apoptotic cytochrome C (Cyt-C) into the cytosol and activating the caspase cascade. Oxidative stress has been linked to increased mitochondrial ROS production [14, 15]. Indeed, the mitochondrial apoptotic pathway is regulated by B-cell lymphoma 2 (Bcl-2) family proteins and classified based on their structure and function. Bcl-2, an anti-apoptotic protein that prevents mitochondrial membrane depolarization and blocks the release of Cyt-C, inhibits apoptosis, whereas Bcl-2-associated X protein (Bax), a pro-apoptotic protein, promotes Cyt-C release and apoptosis [16,17,18].
Importantly, in different diseases, the renin–angiotensin–aldosterone system (RAAS) and its vital component, angiotensin II (Ang II), are potent inducers of ROS and oxidative stress as well as inflammation [19, 20]. Therefore, blocking the RAAS has become a reasonable therapeutic strategy for managing the disease’s underlying oxidative stress and/or inflammation. Interestingly, candesartan is an angiotensin II receptor antagonist, and it binds to the angiotensin II receptor type 1 selectively and non-competitively to block angiotensin II’s actions [21, 22]. Notably, several studies reported promising renal and hepatic properties primarily due to Ang II blockade and/or suppression of oxidative stress and inflammation [23,24,25].
Even though candesartan’s antioxidant and anti-inflammatory properties and promising renal protective effects have been well established, no studies have focused on its impact on heavy metal–induced hepatic and renal intoxication and the underlying mechanisms. Therefore, in this study, we want to investigate the possible protective effects of candesartan against Cd-induced oxidative stress, inflammation, and apoptosis in liver and kidney tissues through modulation of Nrf2, NF-κB, Bax/Bcl-2/Cyt-C, and Ang II/Ang 1–7 signals.
Materials and Methods
Drugs and Chemicals
Candesartan was purchased from AstraZeneca (Cairo, Egypt). Anhydrous CdCl2 was purchased from Sigma-Aldrich Chemical Co. (St. Louis, MO, USA). Assay kits for SGPT, SGOT, ALKP, albumin, creatinine, urea, and uric acid were obtained from SPINREACT (Barcelona, Spain). ELISA kits for rats’ kidney injury molecule-1 (KIM-1), neutrophil gelatinase–associated lipocalin (NGAL), IL-1β, TNF-α, IL-6, IL-10, Ang II, and Ang 1–7 were purchased from ELABSCIENCE (Wuhan, China). Antibodies for NF-κB, an inhibitor of nuclear factor kappa B (IκB), Bax, Bcl-2, Cyt-C, and β-actin were obtained from Santa Cruz Biotechnology (TX, USA).
Animals
The animal house unit of Assiut University, Egypt, provided us with thirty-two healthy adult male Wistar albino rats weighing 190–210 g. The animals were kept in metal cages with free access to a basal feed diet and drinking water in a controlled environment with an optimum temperature, humidity, and a dark/light cycle. The diet contained not less than 19% proteins, 6% fibers, 3.5% fats, and 6.5% ash (standard diet pellets, EL Nasr Chemical Company, Abou-Zaabal, Egypt). For acclimatization, all animals were housed for 2 weeks prior to the experiment. The Faculty of Medicine Ethics Committee of Assiut University, Egypt, approved our experimental study following the “NIH Guide for the Care and Use of Laboratory Animals.”
Experimental Design
The rats were allocated into four groups (eight rats each). The 1st group, the control group, received a normal basal diet and free access to water and the vehicle. The 2nd group, the candesartan group, received 5 mg/kg once daily for 14 days via oral gavage [26, 27]. The 3rd group, the Cd group, was injected with CdCl2 (in saline) at a dose of 1.2 mg/kg, i.p as a single dose [28,29,30] at the end of the 7th day. The 4th group, the Cd plus candesartan group, was administrated candesartan (5 mg/kg, P.O.) for 14 days. On the 7th day, Cd was injected (1.2 mg/kg, i.p).
At the end of the experiment, rats were anesthetized with ketamine (100 mg/kg), then euthanized. The blood was withdrawn from the left ventricle of the heart via cardiac puncture to prepare the serum. Then, the kidney and liver were immediately dissected and rinsed. Each of them was divided into three parts. The first part was used to prepare tissues homogenate for biochemical analyses. The second part was kept at − 80 °C for western blotting. The third part was flushed with phosphate buffer saline (PBS, pH 7.4) and fixed for 48 h in neutral buffer formalin for histological and immunohistochemical assessments.
Assessments of Hepatic and Renal Function Biomarkers
Assay kits for SGPT, SGOT, ALKP, albumin, creatinine, urea, and uric acid were used to measure the serum levels of these biomarkers quantitatively following the manufacturer’s instructions.
Assessments of Serum KIM-1, NGAL, IL-1β, TNF-α, IL-6, IL-10, Ang II, and Ang 1–7 Levels
The KIM-1, NGAL, IL-1β, TNF-α, IL-6, IL-10, Ang II, and Ang 1–7 levels were measured quantitatively using ELISA kits following the manufacturer’s instructions and as previously described [31].
Assessments of Hepatic and Renal Oxidative Stress
Hepatic and renal oxidative stress levels were estimated at the cellular level. Malondialdehyde (MDA) was measured in the liver and kidney of the rats using a spectrophotometric method described by Mihara and Uchiyama [32] at 535 and 520 nm, while the hepatic and renal GSH contents were also measured spectrophotometrically at 410 nm using Ellman’s method [33].
Histopathological Investigation
Histological evaluation of slides of liver and kidney samples stained with hematoxylin and eosin (H&E), Masson’s trichrome (MTC), and periodic acid–Schiff (PAS) was performed using a light microscope (Olympus, Optical Co. Ltd., Tokyo, Japan). The severity of histopathological findings was classified using scores from 0 to 3, where 0 means no alteration, 1 means slight alteration, 2 means moderate alteration, and 3 means severe alteration, as described by Hose et al. [34] modified from Poleksić et al. [35], and depicted by the following: 1, slight alteration, changes that do not destroy hepatic tissues and limited to restricted areas; 2, moderate alteration, more changes with pathological effects on tissues; and 3, severe alteration; marked irreversible histopathological alterations (Table 1). Regarding histopathological changes that occurred in renal tissues stained with H&E, we applied the method recorded by Derelanko [36]. The scoring system was designed as follows: ( −) normal appearance, ( +) mild changes, (+ +) moderate changes, and (+ + +) severe changes, and the results are tabulated (Table 2). Statistical analysis for histopathological scoring was carried out for different fields; each field was allocated a score regarding degenerative parenchymal changes, congestion of blood vessels, inflammatory cells infiltration, and tubular luminal acidophilic materials accumulation.
Immunohistochemical Studies
On the positively charged slides of the paraffin tissue sections, the standard horseradish peroxidase (HRP) immunohistochemistry technique was used. Rabbit anti-rat Bax, Bcl-2, Cyt-C, and Nrf2 were used in accordance with the manufacturer’s instructions. To block endogenous peroxidase activity, 5-µm-thick sections of the kidney and liver were dewaxed, rehydrated, and pretreated with 3 percent hydrogen peroxide (H2O2). Antigen retrieval was accomplished by microwaving slides in a 10 mM sodium citrate buffer for 10 min. After incubation with the primary antibody, the slides were rinsed with Tris-buffer saline and then incubated with the secondary antibody. Slides were counterstained with hematoxylin after being incubated with a 3, 3′-diaminobenzidine (DAB) substrate chromogen solution. At a magnification of 400, images of eight different fields were taken. The area of positive immune-staining proteins was measured and quantified using ImageJ® software [37].
Western Blotting Assay
According to our previously described method [38], hepatic and renal tissues were processed to determine NF-κB and IκB proteins. A total of 40 mg of liver tissue from various groups was homogenized in Tris lysis buffer containing protease and phosphatase inhibitor cocktail (China) for 30 min at 4 °C and centrifuged at 10,000 g for 15 min at 4 °C. Total protein was determined using the Bradford method [39]. Polyvinylidene difluoride (PVDF) membrane was used. The membrane was then blocked (5% non-fat milk) and probed overnight at 4 °C with anti-p-NF-κB-p65, anti-IκB, and anti-β-actin antibodies. After that, the membranes were washed with TBST and incubated with the secondary antibody for 1 h at room temperature. The membranes were then washed with TBST before being immersed in a premixed BCIP/NBT substrate (1:1) for 30 min. Using ImageJ software, the density of the obtained purple protein bands was quantified compared to β-actin as a control protein.
Statistical Analysis
The results are expressed as the mean ± the standard error (SE). The data were analyzed using GraphPad Prism version 9 and one-way ANOVA with Tukey’s post hoc multiple range test. All significance declarations were based on a p-value of less than 0.05.
Results
Effect of Candesartan on Cd-Induced Hepatic and Renal Function Impairments
The hepatic and renal protective effect of candesartan against Cd-induced hepatorenal intoxication was determined by assessing hepatic function biomarkers; SGPT, SGOT, and ALKP, and renal function biomarkers; albumin, creatinine, urea, uric acid, KIM-1, and NGAL (Table 3). As expected, Cd injection resulted in liver and kidney impairments. The hepatic dysfunction pattern has appeared in the form of significant elevations in SGPT, SGOT, and ALKP compared to the control group (P < 0.05). In parallel, the renal injury has appeared in the form of significant elevation of creatinine, urea, uric acid, KIM-1, and NGAL compared to the control group (P < 0.05). At the same time, the level of albumin was significantly decreased. In contrast, oral administration of candesartan effectively alleviated Cd-induced serum marker alteration, evidenced by restoration of liver and kidney functions.
Effect of Candesartan on Cd-Induced Liver and Kidney Histological Changes
Liver Histopathological Examination
Examination of liver sections from control (Fig. 1A) as well as candesartan only (Fig. 1B) reported that the liver is formed of multiple hepatic lobules. Each lobule had a central vein from which the hepatic cords radiate; each cord was formed of hepatocytes and separated by hepatic sinusoids. On the other hand, Cd-treated rats (Fig. 1C) showed dilated and congested central veins, dilated hepatic sinusoids, and areas of inflammatory cell infiltration. In contrast, the treatment of Cd rats with candesartan (Fig. 1D) improved the appearance of central veins and minimized the inflammatory cell infiltration.
In highly magnified micrographs, liver sections from control (Fig. 2A) and candesartan-treated (Fig. 2B) rats showed normal morphology of the hepatic tissue. The hepatic cords radiated from the thin-walled central vein and formed hepatocytes with acidophilic cytoplasm and vesicular rounded nuclei. The hepatic sinusoids were separating the hepatic cords, with many Kupffer cells found in their walls. In contrast, liver sections from Cd-treated rats (Fig. 2C–E) showed dilated congested central veins, hepatic sinusoids, and many Kupffer cells. A restricted area of petechial hemorrhage was seen, but the inflammatory cell infiltration was marked. The hepatocytes lost their normal architecture where some had vacuolated cytoplasm, others showed pyknotic nuclei, and a few had completely destructed nuclei. However, in a few areas, hepatocytes still had rounded nuclei. Treating the Cd rats with candesartan (Fig. 2F) restored most of the normal morphology of the liver where hepatocytes had rounded vesicular nuclei, the central veins and hepatic sinusoids looked normal, but still few hepatic sinusoids were dilated. The severity of histopathological findings in liver tissues from all experimental groups was tabulated (Table 1) and reported a noticeable improvement in Cd plus candesartan–treated rats in contrast to Cd only–treated rats.
To demonstrate the amount of collagen deposition in the hepatic interstitium, we stained the liver sections with Masson’s trichrome. Sections from control (Fig. 3A) as well as the candesartan-treated group (Fig. 3B) showed scanty collagen fibers around the central veins and in between the liver cells. Administration of Cd (Fig. 3C) caused an increase in the deposition of collagen fibers around central veins and in between hepatocytes. Conversely, treatment of Cd rats with candesartan (Fig. 3D) nearly restored the distribution of collagen fibers to the normal.
To demonstrate glycogen stored in the cytoplasm of hepatocytes, we employed PAS histochemical reaction. Liver sections from control (Fig. 4A) and candesartan-treated (Fig. 4B) rats showed a strong PAS reaction for glycogen inclusions in the cytoplasm of hepatocytes. At the same time, Cd administration (Fig. 4C) depleted the intensity of the PAS reaction for glycogen. Interestingly, the administration of candesartan after Cd toxicity (Fig. 4D) restored the PAS reaction near the normal.
Kidney Histopathological Examination
Examination of kidney sections from control (Fig. 5A) and candesartan-treated (Fig. 5B) rats showed normal renal corpuscles and tubules while Cd toxicity (Fig. 5C) caused atrophy of glomeruli and widening of many renal tubules. In contrast, the renal morphology was improved after treating the Cd toxicity with candesartan (Fig. 5D).
Highly magnified photomicrographs of the renal cortex from control (Fig. 6A), as well as candesartan-treated (Fig. 6B), rats demonstrated normally looking renal corpuscles formed of glomerular tuft that is separated from the Bowman’s capsule by urinary space. The proximal convoluted tubules had narrow lumens while the distal tubules had wider lumens and the nuclei of the lining epithelium of both types of tubules were rounded and vesicular. Kidney sections from Cd-treated rats (Fig. 6C–E) showed distortion of the normal structure of the kidney where the glomerular tuft was atrophied with a widening of the urinary space and disruption of Bowman’s capsule. In addition, kidney tubules displayed structural changes, including vacuolation of the cytoplasm of many lining cells, nuclear pyknosis, complete disintegration of the cytoplasm of few cells, and deposition of acidophilic material in the tubular lumens. Few scattered inflammatory cells were observed in the renal interstistium with many areas of petechial hemorrhage and congested blood vessels. In comparison, kidney tissue from Cd plus candesartan rats (Fig. 6F) showed an improvement in renal corpuscles and tubules, but few scattered tubular cells had mildly vacuolated cytoplasm darkly stained nuclei. The severity of histopathological findings in kidney tissues of all experimental groups was tabulated (Table 2) and reported considerable improvement in Cd plus candesartan–treated rats compared to Cd only–treated rats.
To portray the collagen fiber deposition in the renal interstitium, we employed Masson’s trichrome staining. Sections from control (Fig. 7A) and candesartan-treated (Fig. 7B) rats showed minimal amounts of collagen fibers in between the kidney tubules. Interestingly, Cd toxicity (Fig. 7C) caused increased deposition of collagen fibers around the tubules. In contrast, rats treated with Cd and candesartan (Fig. 7D) showed a decrease in deposition of collagen fibers around kidney tubules in comparison to Cd-treated rats.
Periodic acid–Schiff–stained renal sections from control (Fig. 8A) as well as candesartan-treated (Fig. 8B) animals showed kidney tubules with intact brush border and resting on a continuous basement membrane. In contrast, Cd-treated rats (Fig. 8C) showed breakdown of the basement membrane and brush border loss, while treating the Cd toxicity with candesartan (Fig. 8D) was found to restore the integrity of the basement membrane and brush border.
Effect of Candesartan on Cd-Induced Hepatic and Renal Oxidative Injury
Cd-intoxicated rats exhibited a disturbance in the oxidant/antioxidant status evidenced by marked elevation in MDA content and significant reduction of GSH content in both the liver and kidney of these rats compared to normal control rats (P < 0.05). Conversely, candesartan administration remarkably decreased the hepatic and renal contents of MDA and raised the GSH contents when compared to Cd-intoxicated rats (Fig. 9F–G and Fig. 10F–G, respectively). Besides, we applied the immunohistochemical technique to explore the effects of candesartan treatment on Cd-induced alterations in the expression of Nrf2 in hepatic and renal tissues. In hepatic and renal tissues, Nrf2 was intensely expressed in the hepatocytes as well as renal tissues of rats from both control and candesartan-treated groups. On the other hand, Cd toxicity induced marked depletion of Nrf2 immunostaining in hepatocytes as well as in the renal tubules and glomeruli. Surprisingly, treatment of Cd toxicity with candesartan showed a marked increase in the expression of Nrf2 immunostaining in hepatic and renal tissues compared to treatment with Cd alone (Figs. 9 and 10).
Effect of Candesartan on Cd-Induced Hepatic and Renal Inflammation
Besides oxidative stress, hepatic, and renal levels of NF-κB, IκB, IL-1β, TNF-α, IL-6, and IL-10 were assessed. Our data revealed that Cd injection resulted in a significant inflammation in the rats’ liver and kidney, evidenced by downregulation of IκB and IL-10 levels associated with significant upregulation in the strategic controller of inflammation; NF-κB and its downstream IL-1β, TNF-α, and IL-6 as compared to normal rats. On the contrary, oral administration of candesartan counteracted these effects effectively compared to Cd-intoxicated rats (Fig. 11).
Effect of Candesartan on Cd-Induced Hepatic and Renal Apoptosis
To explore the effects of candesartan on Cd-induced apoptosis, we employed the immunohistochemical technique to localize the expression of apoptotic proteins Bax, Cyt-C, and the anti-apoptotic protein Bcl-2 in hepatic and renal tissues. In the present study, Bax and Cyt-C proteins were weakly expressed in the kidney and liver of rats from control and candesartan-treated groups, while Bcl-2 expression was intense in the rats of control and candesartan-treated rats. Cd toxicity induced an increase in Bax and Cyt-C immunostaining expression and a decrease in the expression of Bcl-2 in hepatic and renal tissues. In contrast, treatment of Cd-intoxicated rats with candesartan reversed the Cd-induced effects. It decreased the expression of Bax and Cyt-C and increased the expression of Bcl-2 compared to Cd-intoxicated rats (Figs. 12 and 13).
Effect of Candesartan on Ang II and Ang 1–7 in Cd-Intoxicated Rats
Our data showed that Cd intoxication caused a significant increase in the Ang II level, while the level of Ang 1–7 markedly decreased compared to normal animals. Conversely, candesartan administration resulted in a marked downregulation of Ang II while restoring the Ang 1–7 potency with respect to Cd-intoxicated rats (Fig. 14).
Discussion
Hepatic and renal intoxication by Cd is a severe health problem associated with inflammation, oxidative stress, and apoptosis perturbations and requires therapeutic attention. Meanwhile, candesartan is an FDA-approved drug for cardiovascular problems with promising anti-inflammatory and antioxidant effects. Thus, we examined the potential protective impacts of candesartan against Cd-induced hepatorenal intoxication.
Herein, Cd injection resulted in hepatic impairments evidenced by the significant elevations in serum hepatic function biomarkers SGPT, SGOT, and ALKP. In parallel, we observed that Cd exposure caused severe hepatic degenerative and necrotic changes with distortion of the normal histoarchitecture, inflammatory cell infiltrates, and increased deposition of fibrous tissue. This result was in concordance with the results obtained by El-Boshy and coworkers [40], who explained these damaging effects because of exposure to Cd.
Regarded renal intoxication by Cd, a group of rats injected with Cd injection exhibited a renal impairment evidenced by an increase in creatinine, urea, uric acid, KIM-1, and NGAL, while the level of albumin was significantly decreased [11]. In parallel to kidney biomarker investigation, we observed injurious effects, including degeneration, necrosis, inflammatory infiltrates, and increased fibrous tissue amount in histopathologically examined kidney tissues. In consistency with other studies, degenerative effects and distortion of renal histoarchitecture were observed by other authors [17, 41]. On the other side, we found that candesartan potently ameliorated injurious effects on the liver and the kidney caused by Cd toxicity. In line with these obtained data, Moinuddin et al. [42] reported the protective effects of candesartan on the liver and kidney injury in pressure overload rats. Also, Xie et al. [43] reported the improvement of kidney tissues with candesartan treatment. Of MTC staining, previous studies similarly documented a marked reduction of damage and fibrosis in injured hepatic tissues [44, 45] and renal tissues [46] after treatment with candesartan. Additionally, we found that candesartan decreased the deposition of collagen fibers in kidney tissues. Similarly, Gross et al. [47] reported that candesartan diminished fibrosis of the kidneys. They attributed this effect to antagonizing angiotensin II chemotactic effect to macrophages, and other pro-inflammatory effects. Higashi et al. [46] also reported significant amelioration of renal fibrosis with candesartan treatment.
Oxidative injury has a key role in mediating the hepatic and renal detrimental effects of Cd [11, 48]. Cd-intoxicated rats exhibited a disturbance in the oxidant/antioxidant status. In contrast, candesartan administration remarkably restored the antioxidant balance. Sherif and Sarhan [49] reported that candesartan antagonizes the oxidative stress damage elicited by Ang II in cisplatin-induced testicular damage. Furthermore, we found that Cd toxicity caused a marked decrease in Nrf2 levels in hepatic and renal tissues. A recent study was done by Chen et al. [12] who reported that Nrf2 deficiency aggravates the kidney injury induced by subacute Cd exposure in mice. They attributed the tissue damage effect of Cd toxicity to the ablation of the fundamental role of Nrf2 in maintaining cellular homeostasis and antagonizing oxidative stress [12].
Furthermore, hepatic and renal inflammation induced by Cd was assessed via the determination of hepatic and renal levels of NF-κB, IκB, IL-1β, TNF-α, IL-6, and IL-10 proteins. Notably, IκBα has a critical role in the deactivation process of NF-κB by inhibiting its translocation to the nucleus [50]. In turn, this process prevents NF-κB attachment to responsive elements and consequently production of down streaming pro-inflammatory genes [51]. Our data revealed that Cd exposure resulted in hepatic and renal inflammation. Similar findings were observed with Cd in rodent models [11, 52]. Alternatively, treatment with candesartan counteracted hepatorenal inflammation in Cd-intoxicated rats. Like our results, Yu and coworkers [53] reported that candesartan had reduced renal inflammation and fibrosis, but they proved that this effect of candesartan was dose-dependent.
Another point of view is the impact of apoptosis in the liver and kidney of rats in hepatorenal intoxication by Cd. Flora et al. [54] reported that increased ROS led to an increased cellular expression of Bax and decreased Bcl-2, which induce mitochondrial Cyt-C release and hence activation of apoptosis terminal pathways. Liu and coworkers [55] suggested that exposure to Cd leads to apoptosis of the kidney cells in a dose-dependent manner. They concluded that exposure to Cd disrupts apoptosis and causes renal damage [55]. Interestingly, we found that Cd toxicity induced hepatic and renal apoptosis. These results are like the previous studies [41, 56]. On the other hand, candesartan treatment attenuated Cd hepatorenal apoptosis as indicated by an increase in the expression of anti-apoptotic protein Bcl-2. At the same time, it decreased the expression of the pro-apoptotic Bax and Cyt-C. These findings are consistent with previous studies that found candesartan could attenuate apoptosis via modulating apoptotic and anti-apoptotic proteins [49, 57].
Given the role of RAAS particularly, Ang II/Ag 1–7 signal in the hepatic and renal oxidative stress and/or inflammation [58], and the main mechanism of candesartan as Ang II receptor blocker, the serum levels of Ang II and Ang 1–7 were determined. Notably, RAAS system components have previously been recognized in most organs, including the kidney, heart, and liver [59]. In the present investigation, candesartan administration resulted in a marked downregulation of Ang II while restoring the Ang 1–7 potency with respect to Cd-intoxicated rats. As a result, the current findings support the hypothesis that candesartan affects Ang II/Ang (1–7), providing hepatorenal protective, antioxidant, and anti-inflammatory effects.
Conclusions
Candesartan effectively attenuated hepatorenal intoxication induced by Cd. Candesartan administration remarkably decreased hepatic and renal oxidative stress–mediated by Nrf2 activation. Moreover, candesartan counteracted renal and hepatic inflammation by upregulating IκB and IL-10 levels and downregulating NF-κB and its downstream IL-1β. Additionally, candesartan treatment attenuated Cd-induced hepatorenal apoptosis by regulating Bax/Bcl-2/Cyt-C signal. Finally, candesartan modulates Ang II/Ang 1–7 signal. Overall, our findings revealed that candesartan with promising antioxidant, anti-inflammatory, and anti-apoptotic properties could attenuate Cd-induced hepatic and renal intoxication.
Change history
15 August 2024
This article has been retracted. Please see the Retraction Notice for more detail: https://doi.org/10.1007/s12011-024-04347-6
References
Genchi G, Sinicropi MS, Lauria G, Carocci A, Catalano A (2020) The effects of cadmium toxicity. Int J Environ Res Public Health. 17(11). https://doi.org/10.3390/ijerph17113782
Satarug S, Garrett SH, Sens MA, Sens DA (2010) Cadmium, environmental exposure, and health outcomes. Environ Health Perspect 118(2):182–190. https://doi.org/10.1289/ehp.0901234
Buchet JP, Lauwerys R, Roels H, Bernard A, Bruaux P, Claeys F et al (1990) Renal effects of cadmium body burden of the general population. Lancet (London England) 336(8717):699–702. https://doi.org/10.1016/0140-6736(90)92201-r
Stohs SJ, Bagchi D (1995) Oxidative mechanisms in the toxicity of metal ions. Free Radical Biol Med 18(2):321–336. https://doi.org/10.1016/0891-5849(94)00159-h
Rani A, Kumar A, Lal A, Pant M (2014) Cellular mechanisms of cadmium-induced toxicity: a review. Int J Environ Health Res 24(4):378–399. https://doi.org/10.1080/09603123.2013.835032
Kandemir FM, Caglayan C, Darendelioğlu E, Küçükler S, İzol E, Kandemir Ö (2021) Modulatory effects of carvacrol against cadmium-induced hepatotoxicity and nephrotoxicity by molecular targeting regulation. Life Sci 277:119610. https://doi.org/10.1016/j.lfs.2021.119610
Zhang J, Zheng S, Wang S, Liu Q, Xu S (2020) Cadmium-induced oxidative stress promotes apoptosis and necrosis through the regulation of the miR-216a-PI3K/AKT axis in common carp lymphocytes and antagonized by selenium. Chemosphere 258:127341. https://doi.org/10.1016/j.chemosphere.2020.127341
Zhuang J, Nie G, Yang F, Dai X, Cao H, Xing C et al (2019) Cadmium induces cytotoxicity through oxidative stress-mediated apoptosis pathway in duck renal tubular epithelial cells. Toxicol Vitro Int J Published Assoc BIBRA 61:104625. https://doi.org/10.1016/j.tiv.2019.104625
Liu H, Colavitti R, Rovira II, Finkel T (2005) Redox-dependent transcriptional regulation. Circ Res 97(10):967–974. https://doi.org/10.1161/01.Res.0000188210.72062.10
Himmelfarb J (2004) Linking oxidative stress and inflammation in kidney disease: which is the chicken and which is the egg? Semin Dial 17(6):449–454. https://doi.org/10.1111/j.0894-0959.2004.17605.x
El-Boshy ME, Risha EF, Abdelhamid FM, Mubarak MS, Hadda TB (2015) Protective effects of selenium against cadmium induced hematological disturbances, immunosuppressive, oxidative stress and hepatorenal damage in rats. J Trace Elem Med Biol Organ Soc Miner Trace Elem (GMS) 29:104–110. https://doi.org/10.1016/j.jtemb.2014.05.009
Chen C, Han X, Wang G, Liu D, Bao L, Jiao C et al (2021) Nrf2 deficiency aggravates the kidney injury induced by subacute cadmium exposure in mice. Arch Toxicol 95(3):883–893. https://doi.org/10.1007/s00204-020-02964-3
Wu KC, Liu JJ, Klaassen CD (2012) Nrf2 activation prevents cadmium-induced acute liver injury. Toxicol Appl Pharmacol 263(1):14–20. https://doi.org/10.1016/j.taap.2012.05.017
Zhang Y, Jiang N, Liu Q, Zhu Y, Huang X (2020) Role of mitochondrial damage in cadmium-induced cell apoptosis and DNA damage of hepatocytes. Wei sheng yan jiu = J Hyg Res. 49(2):290–7. https://doi.org/10.19813/j.cnki.weishengyanjiu.2020.02.021
Zheng J, Zhuo L, Ran D, Ma Y, Luo T, Zhao H et al (2020) Cadmium induces apoptosis via generating reactive oxygen species to activate mitochondrial p53 pathway in primary rat osteoblasts. Toxicology 446:152611. https://doi.org/10.1016/j.tox.2020.152611
Zamzami N, Susin SA, Marchetti P, Hirsch T, Gómez-Monterrey I, Castedo M et al (1996) Mitochondrial control of nuclear apoptosis. J Exp Med 183(4):1533–1544. https://doi.org/10.1084/jem.183.4.1533
Albasher G, Albrahim T, Aljarba N, Alharbi RI, Alsultan N, Alsaiari J et al (2020) Involvement of redox status and the nuclear-related factor 2 in protecting against cadmium-induced renal injury with Sana Makki (Cassia senna L.) pre-treatment in male rats. Anais da Academia Brasileira de Ciencias 92(2):20191237. https://doi.org/10.1590/0001-3765202020191237
Wang X, Wang T, Pan T, Huang M, Ren W, Xu G et al (2020) Senna alexandrina extract supplementation reverses hepatic oxidative, inflammatory, and apoptotic effects of cadmium chloride administration in rats. Environ Sci Pollut Res Int 27(6):5981–5992. https://doi.org/10.1007/s11356-019-07117-3
Hitomi H, Kiyomoto H, Nishiyama A (2007) Angiotensin II and oxidative stress. Curr Opin Cardiol 22(4):311–315. https://doi.org/10.1097/HCO.0b013e3281532b53
Husain K, Hernandez W, Ansari RA, Ferder L (2015) Inflammation, oxidative stress and renin angiotensin system in atherosclerosis. World J Biol Chem 6(3):209–217. https://doi.org/10.4331/wjbc.v6.i3.209
Gleiter CH, Jägle C, Gresser U, Mörike K (2004) Candesartan. Cardiovasc Drug Rev 22(4):263–284. https://doi.org/10.1111/j.1527-3466.2004.tb00146.x
See S, Stirling AL (2000) Candesartan cilexetil: an angiotensin II-receptor blocker. Am J Health Syst Pharm 57(8):739–746. https://doi.org/10.1093/ajhp/57.8.739
Chen S, Ge Y, Si J, Rifai A, Dworkin LD, Gong R (2008) Candesartan suppresses chronic renal inflammation by a novel antioxidant action independent of AT1R blockade. Kidney Int 74(9):1128–1138. https://doi.org/10.1038/ki.2008.380
Ahmed HI, Mohamed EA (2019) Candesartan and epigallocatechin-3-gallate ameliorate gentamicin-induced renal damage in rats through p38-MAPK and NF-κB pathways. J Biochem Mol Toxicol 33(3):e22254. https://doi.org/10.1002/jbt.22254
Cediel E, Sanz-Rosa D, Oubina MP, de las Heras N, González Pacheco FR, Vegazo O et al (2003) Effect of AT1 receptor blockade on hepatic redox status in SHR: possible relevance for endothelial function? Am J Physiol Regul Integr Comp Physiol 285(3):R674-81. https://doi.org/10.1152/ajpregu.00643.2002
Thakur KS, Prakash A, Bisht R, Bansal PK (2015) Beneficial effect of candesartan and lisinopril against haloperidol-induced tardive dyskinesia in rat. J Renin Angiotensin Aldosterone Syst JRAAS 16(4):917–29. https://doi.org/10.1177/1470320313515038
Sugimoto K, Tsuruoka S, Matsushita K, Fujimura A (1999) Effects of candesartan cilexetil on oxidative state and renal function in 5/6 nephrectomized rats. J Human Hypertension. 13 Suppl 1:S63–70; discussion S81. https://doi.org/10.1038/sj.jhh.1000743.
de Lima EC, de Moura CFG, Silva MJD, Vilegas W, Santamarina AB, Pisani LP et al (2020) Therapeutical properties of Mimosa caesalpiniifolia in rat liver intoxicated with cadmium. Environ Sci Pollut Res Int 27(10):10981–10989. https://doi.org/10.1007/s11356-019-07455-2
Handan BA, De Moura CFG, Cardoso CM, Santamarina AB, Pisani LP, Ribeiro DA (2020) Protective effect of grape and apple juices against cadmium intoxication in the kidney of rats. Drug Res 70(11):503–511. https://doi.org/10.1055/a-1221-4733
de Souza PF, Diamante MA, Dolder H (2010) Testis response to low doses of cadmium in Wistar rats. Int J Exp Pathol 91(2):125–131. https://doi.org/10.1111/j.1365-2613.2009.00692.x
Van Weemen B, Schuurs A (1971) Immunoassay using antigen—enzyme conjugates. FEBS Lett 15(3):232–236
Mihara M, Uchiyama M (1978) Determination of malonaldehyde precursor in tissues by thiobarbituric acid test. Anal Biochem 86(1):271–278. https://doi.org/10.1016/0003-2697(78)90342-1
Ellman GL (1959) Tissue sulfhydryl groups. Arch Biochem Biophys 82(1):70–77. https://doi.org/10.1016/0003-9861(59)90090-6
Hose JE, McGurk MD, Marty GD, Hinton DE, Brown ED, Baker TTJCJoF, et al (1996) Sublethal effects of the (Exxon Valdez) oil spill on herring embryos and larvae: morphological, cytogenetic, and histopathological assessments, 1989 1991. 53(10):2355–65
Poleksić V, Mitrović-Tutundžić VJS, Books ceopoffOFN (1994) Fish gills as a monitor of sublethal and chronic effects of pollution. 339–52
Derelanko MJ (2017) Risk assesment. The Toxicologist's Pocket Handbook. CRC Press. p. 215–50
Abdel-Wahab BA, Ali FEM, Alkahtani SA, Alshabi AM, Mahnashi MH, Hassanein EHM (2020) Hepatoprotective effect of rebamipide against methotrexate-induced hepatic intoxication: role of Nrf2/GSK-3β, NF-κβ-p65/JAK1/STAT3, and PUMA/Bax/Bcl-2 signaling pathways. Immunopharmacol Immunotoxicol 42(5):493–503. https://doi.org/10.1080/08923973.2020.1811307
Ali FEM, Bakr AG, Abo-Youssef AM, Azouz AA, Hemeida RAM (2018) Targeting Keap-1/Nrf-2 pathway and cytoglobin as a potential protective mechanism of diosmin and pentoxifylline against cholestatic liver cirrhosis. Life Sci 207:50–60. https://doi.org/10.1016/j.lfs.2018.05.048
Bradford MM (1976) A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. Anal Biochem 72:248–254. https://doi.org/10.1006/abio.1976.9999
El-Boshy M, Refaat B, Almaimani RA, Abdelghany AH, Ahmad J, Idris S et al (2020) Vitamin D(3) and calcium cosupplementation alleviates cadmium hepatotoxicity in the rat: Enhanced antioxidative and anti-inflammatory actions by remodeling cellular calcium pathways. J Biochem Mol Toxicol 34(3):e22440. https://doi.org/10.1002/jbt.22440
Almeer RS, AlBasher GI, Alarifi S, Alkahtani S, Ali D, Abdel Moneim AE (2019) Royal jelly attenuates cadmium-induced nephrotoxicity in male mice. Sci Rep 9(1):5825. https://doi.org/10.1038/s41598-019-42368-7
Moinuddin G, Inamdar MN, Kulkarni KS, Kulkarni C (2013) Modulation of haemodynamics, endogeneous antioxidant enzymes, and pathophysiological changes by selective inhibition of angiotensin II type 1 receptors in pressureoverload rats. Cardiovasc J Afr 24(3):58–65. https://doi.org/10.5830/cvja-2012-080
Xie HH, Miao CY, Liu JG, Su DF (2003) Effects of long-term treatment with candesartan on organ damages in sinoaortic denervated rats. J Cardiovasc Pharmacol 41(2):325–331. https://doi.org/10.1097/00005344-200302000-00023
Tuncer I, Ozbek H, Ugras S, Bayram I (2003) Anti-fibrogenic effects of captopril and candesartan cilexetil on the hepatic fibrosis development in rat The effect of AT1-R blocker on the hepatic fibrosis. Exp Toxicol Pathol Off J Gesellschaft fur Toxikologische Pathologie 55(2–3):159–66. https://doi.org/10.1078/0940-2993-00309
Yoshiji H, Kuriyama S, Yoshii J, Ikenaka Y, Noguchi R, Nakatani T et al (2001) Angiotensin-II type 1 receptor interaction is a major regulator for liver fibrosis development in rats. Hepatology (Baltimore MD) 34(4 Pt 1):745–750. https://doi.org/10.1053/jhep.2001.28231
Higashi K, Oda T, Kushiyama T, Hyodo T, Yamada M, Suzuki S et al (2010) Additive antifibrotic effects of pioglitazone and candesartan on experimental renal fibrosis in mice. Nephrology (Carlton) 15(3):327–335. https://doi.org/10.1111/j.1440-1797.2009.01253.x
Gross O, Schulze-Lohoff E, Koepke ML, Beirowski B, Addicks K, Bloch W et al (2004) Antifibrotic, nephroprotective potential of ACE inhibitor vs AT1 antagonist in a murine model of renal fibrosis. Nephrol Dial Transplant Off Publ Eur Dial Transplant Assoc Eur Renal Assoc 19(7):1716–1723. https://doi.org/10.1093/ndt/gfh219
Owumi SE, Dim UJ, Najophe ES (2019) Diethylnitrosamine aggravates cadmium-induced hepatorenal oxidative damage in prepubertal rats. Toxicol Ind Health 35(8):537–547. https://doi.org/10.1177/0748233719863287
Sherif IO, Sarhan OM (2019) Candesartan in a rat model of testicular toxicity: new insight on its protective mechanism. Exp Biol Med (Maywood) 244(7):593–601. https://doi.org/10.1177/1535370219842149
Liu T, Zhang L, Joo D, Sun S-C (2017) NF-κB signaling in inflammation. Signal Transduct Target Ther 2:17023. https://doi.org/10.1038/sigtrans.2017.23
Lawrence T (2009) The nuclear factor NF-kappaB pathway in inflammation. Cold Spring Harb Perspect Biol 1(6):a001651. https://doi.org/10.1101/cshperspect.a001651
Tian X, Ding Y, Kong Y, Wang G, Wang S, Cheng D (2021) Purslane (Portulacae oleracea L.) attenuates cadmium-induced hepatorenal and colonic damage in mice: role of chelation, antioxidant and intestinal microecological regulation. Phytomedicine : Int J Phytother Phytopharmacol. 92:153716. https://doi.org/10.1016/j.phymed.2021.153716
Yu C, Gong R, Rifai A, Tolbert EM, Dworkin LD (2007) Long-term, high-dosage candesartan suppresses inflammation and injury in chronic kidney disease: nonhemodynamic renal protection. J Am Soc Nephrol 18(3):750–759. https://doi.org/10.1681/asn.2006070770
Flora SJ, Saxena G, Mehta A (2007) Reversal of lead-induced neuronal apoptosis by chelation treatment in rats: role of reactive oxygen species and intracellular Ca(2+). J Pharmacol Exp Ther 322(1):108–116. https://doi.org/10.1124/jpet.107.121996
Liu Q, Zhang R, Wang X, Shen X, Wang P, Sun N et al (2019) Effects of sub-chronic, low-dose cadmium exposure on kidney damage and potential mechanisms. Ann Transl Med 7(8):177. https://doi.org/10.21037/atm.2019.03.66
Wang C, Nie G, Yang F, Chen J, Zhuang Y, Dai X et al (2020) Molybdenum and cadmium co-induce oxidative stress and apoptosis through mitochondria-mediated pathway in duck renal tubular epithelial cells. J Hazard Mater 383:121157. https://doi.org/10.1016/j.jhazmat.2019.121157
Lv J, Jia R, Yang D, Zhu J, Ding G (2009) Candesartan attenuates angiotensin II-induced mesangial cell apoptosis via TLR4/MyD88 pathway. Biochem Biophys Res Commun 380(1):81–86. https://doi.org/10.1016/j.bbrc.2009.01.035
Lakshmanan AP, Watanabe K, Thandavarayan RA, Sari FR, Harima M, Giridharan VV et al (2011) Telmisartan attenuates oxidative stress and renal fibrosis in streptozotocin induced diabetic mice with the alteration of angiotensin-(1–7) mas receptor expression associated with its PPAR-gamma agonist action. Free Radic Res 45(5):575–584. https://doi.org/10.3109/10715762.2011.560149
Garg M, Angus PW, Burrell LM, Herath C, Gibson PR, Lubel JS (2012) Review article: the pathophysiological roles of the renin-angiotensin system in the gastrointestinal tract. Aliment Pharmacol Ther 35(4):414–428. https://doi.org/10.1111/j.1365-2036.2011.04971.x
Funding
Open access funding provided by The Science, Technology & Innovation Funding Authority (STDF) in cooperation with The Egyptian Knowledge Bank (EKB).
Author information
Authors and Affiliations
Contributions
Esam Kamel: methodology, visualization, reviewing and editing, investigation, resources. Wail Gad-Elrab: validation, investigation, resources, reviewing and editing. Mohammed Ahmed: validation, investigation, resources, reviewing and editing. Zuhair Mohammedsaleh: reviewing and editing, data curation, resources. Emad Hassanein: conceptualization; data curation; writing—original draft preparation; formal analysis. Fares Ali: conceptualization, data curation, methodology, reviewing and editing.
Corresponding author
Ethics declarations
Ethics Approval
The Faculty of Medicine Ethics Committee of Assiut University, Egypt, approved our experimental study following the “NIH Guide for the Care and Use of Laboratory Animals.”
Conflict of Interest
The authors declare no competing interests.
Additional information
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
This article has been retracted. Please see the retraction notice for more detail:https://doi.org/10.1007/s12011-024-04347-6
Rights and permissions
Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.
About this article
Cite this article
Kamel, E.O., Gad-Elrab, W.M., Ahmed, M.A. et al. RETRACTED ARTICLE: Candesartan Protects Against Cadmium-Induced Hepatorenal Syndrome by Affecting Nrf2, NF-κB, Bax/Bcl-2/Cyt-C, and Ang II/Ang 1–7 Signals. Biol Trace Elem Res 201, 1846–1863 (2023). https://doi.org/10.1007/s12011-022-03286-4
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s12011-022-03286-4