Sodium arsenite-induced cardiovascular and renal dysfunction in rat via oxidative stress and protein kinase B (Akt/PKB) signaling pathway

Betaine ameliorates arsenic-induced kidney injury in mice by mitigating oxidative stress-mediated inflammation

Arsenic, an environmental pollutant and poisonous metalloid, has adverse effects on different body organs, including the kidneys. Betaine is a natural nutrient that has many beneficial health effects. This research was conducted to examine the impact of betaine on nephrotoxicity caused by inorganic arsenic (NaAsO2) in mice. Mice were separated into following groups: control, NaAsO2 (50 ppm), NaAsO2 (50 ppm) + betaine (500 mg/kg), and betaine (500 mg/kg). Mice were received NaAsO2 via drinking water for 8 consecutive weeks and betaine was given to the animals via gavage once daily in the 7th and 8th weeks of the study. Upon completion of the study, the mice were euthanized and samples of serum and kidney were obtained for further evaluations. Administration of NaAsO2 increased the levels of blood urea nitrogen and creatinine in the serum. It enhanced the amounts of renal malondialdehyde and decreased the total thiol levels, as well as the activity of antioxidant enzymes (catalase, superoxide dismutase, and glutathione peroxidase). Furthermore, it enhanced the levels of renal inflammatory indicators (tumor necrosis factor-alpha and nitric oxide). Western blot results exhibited an increase in the protein expression of nuclear factor kappa B (NF-κB), and phosphorylated NF-κB in NaAsO2-treated mice. Histopathological results also confirmed kidney damage caused by NaAsO2. However, treatment with betaine improved NaAsO2-related kidney injuries in mice. The results of this work indicated that betaine can attenuate kidney damage caused by NaAsO2 by inhibiting oxidative stress and inflammation.

Transcriptomic profile of human iPSC-derived podocyte-like cells exposed to a panel of xenobiotics

Podocytes play a critical role in the formation and maintenance of the glomerular filtration barrier and injury to these cells can lead to a breakdown of the glomerular barrier causing permanent damage leading to progressive chronic kidney disease. Matured podocytes have little proliferative potential, which makes them critical cells from a health perspective, but also challenging cells to maintain in vitro. Differentiating podocyte-like cells from induced pluripotent stem cells (iPSC) provides a novel and continuous source of cells. Here, we investigated the effect of a 24-h exposure to eight compounds, including the known glomerular toxins doxorubicin and pamidronate, on transcriptomic alterations in iPSC derived podocytes. Doxorubicin (50 nM), pamidronate (50 μM), sodium arsenite (10 μM), and cyclosporine A (15 μM) had a strong impact on the transcriptome, gentamicin (450 μg/ml), lead chloride (15 μM) and valproic acid (500 μM) had a mild impact and busulfan (50 μM) exhibited no impact. Gene alterations and pathways analysis provided mechanistic insight for example, doxorubicin exposure affected the p53 pathway and dedifferentiation, pamidronate activated several pathways including HIF1alpha and sodium arsenite up-regulated oxidative stress and metal responses. The results demonstrate the applicability of iPSC derived podocytes for toxicological and mechanistic investigations.

Didactical approaches and insights into environmental processes and cardiovascular hazards of arsenic contaminants

Arsenic, as a metalloid, has the ability to move and transform in different environmental media. Its widespread contamination has become a significant environmental problem and public concern. Arsenic can jeopardize multiple organs through various pathways, influenced by environmental bioprocesses. This article provides a comprehensive overview of current research on the cardiovascular hazards of arsenic. A bibliometric analysis revealed that there are 376 papers published in 145 journals, involving 40 countries, 631 institutions, and 2093 authors, all focused on arsenic-related concerns regarding cardiovascular health. China and the U.S. have emerged as the central hubs of collaborative relationships and have the highest number of publications. Hypertension and atherosclerosis are the most extensively studied topics, with redox imbalance, apoptosis, and methylation being the primary mechanistic clues. Cardiovascular damage caused by arsenic includes arrhythmia, cardiac remodeling, vascular leakage, and abnormal angiogenesis. However, the current understanding is still inadequate over cardiovascular impairments, underlying mechanisms, and precautionary methods of arsenic, thus calling an urgent need for further studies to bridge the gap between environmental processes and arsenic hazards.

Prenatal arsenite exposure alters maternal cardiac remodeling during late pregnancy

Exposure to inorganic arsenic through drinking water is widespread and has been linked to many chronic diseases, including cardiovascular disease. Arsenic exposure has been shown to alter hypertrophic signaling in the adult heart, as well as in utero offspring development. However, the effect of arsenic on maternal cardiac remodeling during pregnancy has not been studied. As such, there is a need to understand how environmental exposure contributes to adverse pregnancy-related cardiovascular events. This study seeks to understand the impact of trivalent inorganic arsenic exposure during gestation on maternal cardiac remodeling in late pregnancy, as well as offspring outcomes. C57BL/6 J mice were exposed to 0 (control), 100 or 1000 μg/L sodium arsenite (NaAsO2) beginning at embryonic day (E) 2.5 and continuing through E17.5. Maternal heart function and size were assessed via transthoracic echocardiography, gravimetric measurement, and histology. Transcript levels of hypertrophic markers were probed via qRT-PCR and confirmed by western blot. Offspring outcomes were assessed through echocardiography and gravimetric measurement. We found that maternal heart size was smaller and transcript levels of Esr1 (estrogen receptor alpha), Pgrmc1 (progesterone receptor membrane component 1) and Pgrmc2 (progesterone receptor membrane component 2) reduced during late pregnancy with exposure to 1000 μg/L iAs vs. non-exposed pregnant controls. Both 100 and 1000 μg/L iAs also reduced transcription of Nppa (atrial natriuretic peptide). Akt protein expression was also significantly reduced after 1000 μg/L iAs exposure in the maternal heart with no change in activating phosphorylation. This significant abrogation of maternal cardiac hypertrophy suggests that arsenic exposure during pregnancy can potentially contribute to cardiovascular disease. Taken together, our findings further underscore the importance of reducing arsenic exposure during pregnancy and indicate that more research is needed to assess the impact of arsenic and other environmental exposures on the maternal heart and adverse pregnancy events.

Prenatal Arsenite Exposure Alters Maternal Cardiac Remodeling During Late Pregnancy

Exposure to inorganic arsenic through drinking water is widespread and has been linked to many chronic diseases, including cardiovascular disease. Arsenic exposure has been shown to alter hypertrophic signaling in the adult heart, as well as in-utero offspring development. However, the effect of arsenic on maternal cardiac remodeling during pregnancy has not been studied. As such, there is a need to understand how environmental exposure contributes to adverse pregnancy-related cardiovascular events. This study seeks to understand the impact of trivalent inorganic arsenic exposure during gestation on maternal cardiac remodeling in late pregnancy, as well as offspring outcomes. C57BL/6J mice were exposed to 0 (control), 100 or 1000 µg/L sodium arsenite (NaAsO 2 ) beginning at embryonic day (E) 2.5 and continuing through E17.5. Maternal heart function and size were assessed via transthoracic echocardiography, gravimetric measurement, and histology. Transcript levels of hypertrophic markers were probed via qRT-PCR and confirmed by western blot. Offspring outcomes were assessed through echocardiography and gravimetric measurement. We found that exposure to 1000 µg/L iAs abrogated normal physiologic growth of the maternal heart during late pregnancy and reduced transcript levels of estrogen receptor alpha (ERα), progesterone receptor membrane component 1 (Pgrmc1) and progesterone receptor membrane component 2 (Pgrmc2). Both 100 and 1000 µg/L iAs also reduced transcription of protein kinase B (Akt) and atrial natriuretic peptide (ANP). Akt protein expression was also significantly reduced after 1000 µg/L iAs exposure in the maternal heart with no change in activating phosphorylation. This significant abrogation of maternal cardiac hypertrophy suggests that arsenic exposure during pregnancy can potentially contribute to cardiovascular disease. Taken together, our findings further underscore the importance of reducing arsenic exposure during pregnancy and indicate that more research is needed to assess the impact of arsenic and other environmental exposures on the maternal heart and adverse pregnancy events.

Zingerone reduces sodium arsenite-induced nephrotoxicity by regulating oxidative stress, inflammation, apoptosis and histopathological changes

Arsenic is widely available in the environment and arsenic toxicity is a public health problem of serious concern worldwide. Zingerone is a promising phytochemical with various pharmacological effects. In this study, the potential protective effect of zingerone against sodium arsenite (NaAsO₂, SA) induced nephrotoxicity was investigated. Thirty-five male Sprague-Dawley rats were divided into five different groups as control, zingerone, SA, SA + zingerone 25, SA + zingerone 50. SA was administered alone at a dose of 10 mg/kg for 14 days or given 30 min before zingerone (25 mg/kg or 50 mg/kg) treatment. At the end of the experiment, the kidney tissues was examined biochemically, molecularly and microscopically. SA toxicity was associated with increased malondialdehyde level, whereas glutathione, superoxide dismutase, catalase, and glutathione peroxidase were decreased. Administration of SA caused inflammation in the kidney tissue by upregulation of NF-κB and IL-1β, TNF-α, IL-6, iNOS, COX-2, MAPK14, MAPK15, JNK. SA administration caused apoptosis in the kidney by upregulating caspase-3 and Bax levels and downregulating Bcl-2, and autophagy by activating beclin-1. Also, SA administration showed a suppressive effect on AKT2 and FOXO1 mRNA transcript levels. All these factors impair kidney function and increase creatinine and urea levels, resulting in pathological changes and a decrease in nephrin. Treatment with zingerone at doses of 25 and 50 mg/kg significantly reduced oxidative stress, inflammation, apoptosis and autophagy in kidney tissue. In addition, it was confirmed by histological evaluation as well as serum urea and creatinine levels that kidney damage due to SA toxicity can be modulated by zingerone administration.

Quercetin Zinc and Iron Metal Complexes Protect against Sodium Arsenite Intoxication in the Hepato-Renal System of Wistar Rats via the Oxidative Stress Pathway

BACKGROUND

Chronic exposure to arsenic is a major health concern consequent upon generation of excessive reactive oxygen species. The safety of treatment with chelating agents has not been well established; therefore, there is a need for a paradigm shift in the approach to management of arsenic toxicity. Bioflavonoids are known to influence redox homeostasis in cells; the study therefore investigates the efficacy of quercetin and its zinc and iron metal complexes on sodium arsenite (NaAr)-intoxication in rats.

METHODS

Spectroscopic study of quercetin hydrate and its metal complexes was performed using UV-Vis and FT-IR spectrometer. Furthermore, twenty male Wistar rats were obtained and equally divided into four groups, treated orally and daily for 28 days with 10 mg/kg NaAr, 30 mg/kg quercetin, quercetin-zinc, and quercetin-iron separately. Five more rats were used as control. Plasmatic aspartate transferase (AST), alanine transferase (ALT), creatinine (CREA), and total protein (TP) were estimated. Levels of kidney and liver lipid peroxidation (LPO), glutathione (GSH), catalase (CAT), and glutathione-S-transferase (GST) were determined. Histology was used to view the lesions.

RESULTS

Treatment of arsenic-toxicity with quercetin and its complexes decreased the activities of ALT, AST, CREA, TP, CAT, and GST and concentration of LPO and GSH. Quercetin-zn treatment showed a better result than quercetin-iron in the liver. Histology results showed absence of lesions in quercetin zinc and iron treatment in both the kidney and the liver.

CONCLUSION

Quercetin zinc and iron increased the bioavailability of quercetin and therefore could be relevant as adjuvants in arsenic poisoning.

Network pharmacology and experimental analysis to reveal the mechanism of Dan-Shen-Yin against endothelial to mesenchymal transition in atherosclerosis

Atherosclerosis is a chronic inflammatory disease characterized by the formation of plaque and endothelial dysfunction. Under pro-inflammatory conditions, endothelial cells adopt a mesenchymal phenotype by a process called endothelial-to-mesenchymal transition (EndMT) which plays an important role in the pathogenesis of atherosclerosis. Dan-Shen-Yin (DSY) is a well-known traditional Chinese medicine used in the treatment of cardiovascular disease. However, the molecular mechanism whereby DSY mitigates atherosclerosis remains unknown. Therefore, we employed a network pharmacology-based strategy in this study to determine the therapeutic targets of DSY, and in vitro experiments to understand the molecular pharmacology mechanism. The targets of the active ingredients of DSY related to EndMT and atherosclerosis were obtained and used to construct a protein-protein interaction (PPI) network followed by network topology and functional enrichment analysis. Network pharmacology analysis revealed that the PI3K/AKT pathway was the principal signaling pathway of DSY against EndMT in atherosclerosis. Molecular docking simulations indicated strong binding capabilities of DSY’s bioactive ingredients toward PI3K/AKT pathway molecules. Experimentally, DSY could efficiently modify expression of signature EndMT genes and decrease expression of PI3K/AKT pathway signals including integrin αV, integrin β1, PI3K, and AKT1 in TGF-β2-treated HUVECs. LASP1, which is upstream of the PI3K/AKT pathway, had strong binding affinity to the majority of DSY’s bioactive ingredients, was induced by EndMT-promoting stimuli involving IL-1β, TGF-β2, and hypoxia, and was downregulated by DSY. Knock-down of LASP1 attenuated the expression of integrin αV, integrin β1, PI3K, AKT1 and EndMT-related genes induced by TGF-β2, and minimized the effect of DSY. Thus, our study showed that DSY potentially exerted anti-EndMT activity through the LASP1/PI3K/AKT pathway, providing a possible new therapeutic intervention for atherosclerosis.

Distribution of arsenic species and pathological characteristics of tissues of the mice fed with arsenic-supplemented food simulating rice

The exposure and harm of arsenic have attracted wide attention. Rice is an arsenic-rich crop. The purpose of this study was to learn the distribution of arsenic species and the pathological changes in tissues of mice exposed to arsenic-supplemented food simulating rice. Test groups of mice were orally exposed with prepared arsenic feeds supplemented with four arsenic species (arsenite iAs^III, arsenate iAs^V, monomethylarsonate MMA, and dimethylarsinate DMA) at three doses (total As concentration: 0.91, 9.1 and 30 μg/g), which simulated the arsenic species ratio in rice. After 112 days, the concentrations of the arsenic species in the spleen, thymus, heart, skin and hair were detected, and histopathology of the spleen, heart and skin was observed. Each arsenic species was detected and their total concentration increased in a dose-dependent manner with a few exceptions. One interesting phenomenon is that ratio of the organic arsenic to inorganic arsenic also increased in a dose-dependent manner. For the other, the order of tissues from high to low arsenic concentration was the same in the medium- and high-dose groups. The histopathological sections of the spleen, heart and skin showed dose-dependent debilitating alterations in tissue architecture. Hyperplasia, hyaline degeneration and sclerosis of fibrous connective tissue occurred in the spleen. Myocardial cell atrophy and interstitial edema occurred in the heart. Hyperpigmentation, hyperkeratosis and atypia of basal cells occurred in the skin. In summary, the long-term intake of high arsenic rice has a health risk. Further studies are needed to assess it.

Attenuation of sodium arsenite-induced cardiotoxicity and neurotoxicity with the antioxidant, anti-inflammatory, and antiapoptotic effects of hesperidin

In the scope of the study, the protective effect of hesperidin (HES), a flavanone glycoside, was investigated against sodium arsenite (NaAsO₂, SA) induced heart and brain toxicity. For this purpose, 35 Sprague-Dawley male rats were divided into 5 different groups, 7 in each group. Physiological saline was given to the first group. Dose of 200 mg/kg of HES to the second group, 10 mg/kg dose of SA to the 3rd group, 100 mg/kg HES and 10 mg/kg SA to the 4th group, 200 mg/kg HES, and 10 mg/kg SA to the 5th group were given orally for 15 days. At the end of the study, biochemical, histopathological, and immunohistochemical examinations were performed on the heart and brain tissues of the rats. According to the results, SA increased malondialdehyde (MDA) and 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels and decreased glutathione (reduced, GSH) level and superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) activities in both tissues. Also, it increased cardiac lactate dehydrogenase (LDH) and creatine kinase isoenzyme-MB (CK-MB) activities and cardiac troponin-I level (cTn-I), cerebral acetylcholine esterase activity, nuclear factor kappa-B (NF-κB), tumor necrosis factor-alpha (TNF-α), interleukin-one beta (IL-1β), and cysteine aspartate-specific protease-3 (caspase-3) levels. In addition, as a result of histopathological examination, it was determined that SA damaged tissue architecture, and as a result of immunohistochemical examination, it increased cardiac Bcl-2-associated X protein (Bax) and cerebral glial fibrillary acidic protein (GFAP) expression. The results have also shown that HES co-treatment has an antioxidant, anti-inflammatory, antiapoptotic effect on SA-induced toxicity and aids to protect tissue architecture by showing a regulatory effect on all values. Consequently, it was determined that HES co-treatment had a protective effect on SA-induced heart and brain toxicity in rats.

Methanol extract of Caesalpinia benthamiana normalizes blood pressure and attenuates oxidative stress in uninephrectomized hypertensive rats

OBJECTIVES

Hypertension is the number one risk factor and primary contributor of cardiovascular diseases. Caesalpinia benthamiana is a valuable medicinal plant with unvalidated anti-hypertensive activity. This study was carried out to explore the antihypertensive effect of C. benthamiana on uninephrectomized hypertensive rats.

METHODS

Fifty rats were grouped into five groups, each containing 10 animals: Group A-normal control (normotensive); B-uninephrectomized control; C-uninephrectomized treated with 50 mg/kg C. benthamiana extract; D-uninephrectomized treated with 100 mg/kg C. benthamiana; and E- uninephrectomized treated with 10 mg/kg of Lisinopril.

RESULTS

Significant increases were observed in systolic, diastolic and mean blood pressure of uninephrectomized control rats. Furthermore, markers of oxidative stress (malondialdehyde, hydrogen peroxide, protein carbonyl, myeloperoxidase and the advanced oxidative protein products) increased significantly while antioxidant status (reduced glutathione, glutathione peroxidase, glutathione S-transferase and superoxide dismutase), reduced significantly in uninephrectomized hypertensive rats. Histopathology revealed thrombosis and occlusion of coronary vessels in the heart, and congestion in the kidney. However, the observed high blood pressure parameters were remarkably normalized together with reduction in markers of oxidative stress and improvement in antioxidant defence system of uninephrectomized hypertensive rats treated with C. benthamiana extract similar to normotensive rats.

CONCLUSIONS

C. benthamiana extract exhibited antihypertensive action, strong antioxidant ability, attenuated oxidative stress-mediated hypertension and lessened the development of cardiac and renal damage associated with hypertension induced by uninephrectomy and high dietary intake of salt. Together, C. benthamiana extract might be useful in the management of hypertension due to volume overload in the cardiovascular system.

Puerarin attenuates the endothelial-mesenchymal transition induced by oxidative stress in human coronary artery endothelial cells through PI3K/AKT pathway

Endothelial-mesenchymal transition (EndMT) is a process in which endothelial cells lose their specific morphology/markers and undergo a dramatic remodeling of the cytoskeleton. It has been implicated in the progression of cardiovascular diseases such as cardiac fibrosis and cardiac dysfunction. Recent study indicated that puerarin could inhibit EndMT against cardiac fibrosis. However, the precise role of puerarin in EndMT and the underlying molecular mechanisms remain unclear. EndMT was induced by H₂O₂ (150 μM) in human coronary artery endothelial cells (HCAECs). HCAECs were exposed to H₂O₂ for six days with or without puerarin pretreated 2 h. The protein changes of EndMT markers (CD31, VE-cadherin, FSP1 and α-SMA) in HCAECs were detected. The levels of phosphoinositide-3-kinase (PI3K) and protein kinase B (AKT) proteins were analyzed by Western Blot. Wound healing and transwell assay were carried out to examine cell chemotaxis. Puerarin mitigated H₂O₂-induced EndMT as indicated by alleviating the reduced expression of CD31 and VE-cadherin and inhibiting the upregulation of α-SMA and FSP1. Furthermore, the mechanisms study showed that puerarin activated the PI3K/AKT pathway by inhibiting reactive oxygen species and further attenuated EndMT. On the other hand, PI3K inhibitor LY294002 reversed this effect imposed by puerarin. Puerarin alleviated the migration of mesenchymal-like cells through reducing MMPs protein expression. These results implicated that puerarin exhibited cytoprotective effects against H₂O₂-induced EndMT in HCAECs through alleviating oxidative stress, activating the PI3K/AKT pathway and limiting cell migration.

Sevoflurane preconditioning inhibits cardiomyocyte injury induced by oxygen‑glucose deprivation by modulating TXNIP

The thioredoxin interaction protein (TXNIP) has been reported to be closely related to cell oxidative stress, apoptosis and inflammation. TXNIP is involved in the regulation of oxidative stress in lung and renal injury. However, it is unclear as to whether it participates in the protective effects of sevoflurane preconditioning in cardiomyocyte injury caused by oxidative stress in ischemia. In the present study, H9c2 cardiomyocytes were cultured with 0, 1.5, 2, 3.5, 5 or 6% sevoflurane for 3 h, followed by exposure to oxygen and glucose deprivation. The results demonstrated that oxygen and glucose deprivation induced an increase in TXNIP expression, lactate dehydrogenase (LDH) release, caspase‑3 activity, reactive oxygen species and malondialdehyde production. Preconditioning of the H9c2 cells with 3.5% sevoflurane suppressed TXNIP expression, LDH leakage, caspase‑3 activity, reactive oxygen species and malondialdehyde production, and it promoted cell viability. TXNIP overexpression reversed the effects of 3.5% sevoflurane preconditioning on caspase‑3 activity, reactive oxygen production and cell viability. Furthermore, TXNIP modulated p27 expression via PKB (protein kinase B/AKT) phosphorylation following preconditioning with 3.5% sevoflurane, and oxygen and glucose deprivation. On the whole these findings indicated that sevoflurane preconditioning protected the H9c2 cells against injury induced by oxygen and glucose deprivation by modulating TXNIP, AKT activation and p27 signaling.

Cobalt chloride toxicity elicited hypertension and cardiac complication via induction of oxidative stress and upregulation of COX-2/Bax signaling pathway

Cobalt is a ferromagnetic metal with extensive industrial and biological applications. To assess the toxic effects of, and mechanisms involved in cobalt chloride (CoCl₂)-induced cardio-renal dysfunctions. Male Wistar rats were exposed orally, daily through drinking water to 0 ppm (control), 150 ppm, 300 ppm, and 600 ppm of CoCl₂, respectively. Following exposure, results revealed significant ( p < 0.05) rise in markers of oxidative stress, but decreased activities of catalase, glutathione peroxidase, glutathione-S-transferase, and reduced glutathione content in cardiac and renal tissues. There were significant increases in systolic, diastolic, and mean arterial blood pressure at the 300- and 600-ppm level of CoCl₂-exposed rats relative to the control. Prolongation of QT and QTc intervals was observed in CoCl₂ alone treated rats. Also, there were significant increases in the heart rates, and reduction in P wave, and PR duration of rats administered CoCl₂. Histopathology of the kidney revealed peritubular and periglomerular inflammation, focal glomerular necrosis following CoCl₂ exposure. Further, cyclooxygenase-2 and B-cell associated protein X expressions were upregulated in the cardiac and renal tissues of CoCl₂-exposed rats relative to the control. Combining all, results from this study implicated oxidative stress, inflammation, and apoptosis as pathologic mechanisms in CoCl₂-induced hypertension and cardiovascular complications of rats.