Quercetin alleviates cadmium chloride-induced renal damage in rats by suppressing endoplasmic reticulum stress through SIRT1-dependent deacetylation of Xbp-1s and eIF2α

The role of SIRT1 in kidney diseases

SIRT1, a nicotinamide adenine dinucleotide (NAD +)-dependent class III histone deacetylase, exhibits a high level of expression within renal tissues. It has garnered considerable recognition for its pivotal role in modulating signaling pathways intricately linked with the aging process; however, it extends beyond this in the organism. The literature reports that SIRT1 regulates biological processes such as glucose metabolism, lipid metabolism, oxidative stress, inflammation, autophagy, endoplasmic reticulum stress, and apoptosis. Therefore, our study reviews the primary mechanisms by which SIRT1 induces kidney disease and the regulation of related signaling pathways in different models of renal disease. We also discuss commonly studied SIRT1-targeted interventional drugs reported in the literature, including inhibitors (e.g., Ex-527) and activators (e.g., resveratrol). This study aims to provide theoretical foundations and clinical insights for the development and screening of clinical drugs targeting SIRT1, aiming at enhanced scientific approaches for the prevention and treatment of kidney diseases.

BATF alleviates ox-LDL-induced HCAEC injury by regulating SIRT1 expression in coronary heart disease

BACKGROUND

Coronary heart disease (CHD) represents a significant global health concern, arising from an intricate interplay between genetic predisposition and environmental influences, with a pivotal involvement of oxidized low-density lipoprotein (ox-LDL) in the pathophysiology of it. We aimed to elucidate the synergistic dynamics of B cell activating transcription factor (BATF) and Sirtuin 1 (SIRT1) in cell injury caused by ox-LDL, reveal potential therapeutic strategies for CHD.

METHODS

The GSE42148 dataset was used to analyze Differentially expressed genes (DEGs) to construct a gene co-expression network. Then bioinformatics analysis was performed on key modules to select the BATF gene. In vitro experiments were conducted to investigate the protective impact of BATF against human coronary artery endothelial cells (HCAEC) injury induced by ox-LDL. Further investigations probed the synergistic impact of BATF and SIRT1 modulation on cellular apoptosis and damage in the presence of ox-LDL.

RESULTS

BATF was significantly down-regulated in the CHD sample of the GSE42148 dataset. In vitro assays have proven that BATF alleviates ox-LDL-induced HCAEC injury. Notably, BATF emerged as a pivotal regulator of SIRT1 expression post ox-LDL exposure. Subsequent experiments underscored the interplay between BATF and SIRT1 in mitigating ox-LDL-induced apoptosis and Lactate Dehydrogenase (LDH) activity elevation, highlighting their collaborative role in cellular protection.

CONCLUSION

The research findings suggested a prospective protective function of BATF in HCAEC injury induced by ox-LDL, likely through the mediation of SIRT1 regulation. These results could offer fresh perspectives on the etiology of CHD and possible treatment avenues.

Enhancing renal protection against cadmium toxicity: the role of herbal active ingredients

Background

Rapid industrialization globally has led to a notable increase in the production and utilization of metals, including cadmium (Cd), consequently escalating global metal pollution worldwide. Cd, characterized as a persistent environmental contaminant, poses significant health risks, particularly impacting human health, notably the functionality of the kidneys. The profound effects of Cd stem primarily from its limited excretion capabilities and extended half-life within the human body. Mechanisms underlying its toxicity encompass generating reactive oxygen species (ROS), disrupting calcium-signaling pathways and impairing cellular antioxidant defense mechanisms. This review focuses on the protective effects of various herbal active ingredients against Cd-induced nephrotoxicity.

Aim

This study aims to investigate the mechanisms of action of herbal active ingredients, including ant-oxidative, anti-inflammatory and anti-apoptotic pathways, to elucidate potential therapeutic strategies for reducing nephrotoxicity caused by Cd exposure.

Methods

A comprehensive search of scientific databases, including Web of Science, PubMed, Scopus and Google Scholar, used relevant keywords to identify studies published up to October 2024.

Results

Research illustrates that herbal active ingredients protect against Cd nephrotoxicity by reducing oxidative stress, enhancing antioxidant enzyme activity, inhibiting inflammation, preventing apoptosis, alleviating endoplasmic reticulum (ER) stress, enhancing autophagy and improving mitochondrial function in the kidney.

Conclusion

The present study indicates that an extensive understanding of the protective effects of herbal active ingredients holds promise for the development of innovative approaches to safeguard human health and environmental integrity against the detrimental effects of Cd exposure.

Natural products derived from traditional Chinese medicines targeting ER stress for the treatment of kidney diseases

Various factors, both internal and external, can disrupt endoplasmic reticulum (ER) homeostasis and increase the burden of protein folding, resulting in ER stress. While short periods of ER stress can help cells return to normal function, excessive or prolonged ER stress triggers a complex signaling network that negatively affects cells. Numerous studies have demonstrated the significant role of ER stress in various kidney diseases, such as immune-related kidney injury, diabetic kidney diseases, renal ischemia reperfusion injury, and renal fibrosis. To date, there is a severe shortage of medications for the treatment of acute and chronic kidney diseases of all causes. Natural products derived from various traditional Chinese medicines (TCM), which are a major source of new drugs, have garnered considerable attention. Recent research has revealed that many natural products have renoprotective effects by targeting ER stress-mediated events, such as apoptosis, oxidative stress, inflammation, autophagy, and epithelial-mesenchymal transition. This article provides a comprehensive review of the current research progress on natural products targeting ER stress for the treatment of kidney diseases.

Assessment of renal pathophysiological processes and protective effect of quercetin on contrast-induced acute kidney injury in type 1 diabetic mice using diffusion tensor imaging

Purpose: To investigate the renal pathophysiological processes and protective effect of quercetin on contrast-induced acute kidney injury (CI-AKI) in mice with type 1 diabetic mellitus(DM) using diffusion tensor imaging(DTI).Methods: Mice with DM were divided into two groups. In the diabetic + contrast medium(DCA) group, the changes of the mice kidneys were monitored at 1, 24, 48, and 72 h after the injection of iodixanol(4gI/kg). The mice in the diabetic + contrast medium + quercetin(DCA + QE) group were orally given different concentrations of quercetin for seven days before injection of iodixanol. In vitro experiments, renal tubular epithelial (HK-2) cells exposed to high glucose conditions were treated with various quercetin concentrations before treatment with iodixanol(250 mgI/mL).Results: DTI-derived mean diffusivity(MD) and fractional anisotropy(FA) values can be used to evaluate CI-AKI effectively. Quercetin significantly increased the expression of Sirt 1 and reduced oxidative stress by increasing Nrf 2/HO-1/SOD1. The antiapoptotic effect of quercetin on CI-AKI was revealed by decreasing proteins level and by reducing the number of apoptosis-positive cells. In addition, flow cytometry indicated quercetin-mediated inhibition of M1 macrophage polarization in the CI-AKI.Conclusions: DTI will be an effective noninvasive tool in diagnosing CI-AKI. Quercetin attenuates CI-AKI on the basis of DM through anti-oxidative stress, apoptosis, and inflammation.

Endoplasmic Reticulum Stress-Mediated Cell Death in Renal Fibrosis

The endoplasmic reticulum (ER) is indispensable for maintaining normal life activities. Dysregulation of the ER function results in the accumulation of harmful proteins and lipids and the disruption of intracellular signaling pathways, leading to cellular dysfunction and eventual death. Protein misfolding within the ER disrupts its delicate balance, resulting in the accumulation of misfolded or unfolded proteins, a condition known as endoplasmic reticulum stress (ERS). Renal fibrosis, characterized by the aberrant proliferation of fibrotic tissue in the renal interstitium, stands as a grave consequence of numerous kidney disorders, precipitating a gradual decline in renal function. Renal fibrosis is a serious complication of many kidney conditions and is characterized by the overgrowth of fibrotic tissue in the glomerular and tubular interstitium, leading to the progressive failure of renal function. Studies have shown that, during the onset and progression of kidney disease, ERS causes various problems in the kidneys, a process that can lead to kidney fibrosis. This article elucidates the underlying intracellular signaling pathways modulated by ERS, delineating its role in triggering diverse forms of cell death. Additionally, it comprehensively explores a spectrum of potential pharmacological agents and molecular interventions aimed at mitigating ERS, thereby charting novel research avenues and therapeutic advancements in the management of renal fibrosis.

New perspectives on the therapeutic potential of quercetin in non-communicable diseases: Targeting Nrf2 to counteract oxidative stress and inflammation

Non-communicable diseases (NCDs), including cardiovascular diseases, cancer, metabolic diseases, and skeletal diseases, pose significant challenges to public health worldwide. The complex pathogenesis of these diseases is closely linked to oxidative stress and inflammatory damage. Nuclear factor erythroid 2-related factor 2 (Nrf2), a critical transcription factor, plays an important role in regulating antioxidant and anti-inflammatory responses to protect the cells from oxidative damage and inflammation-mediated injury. Therefore, Nrf2-targeting therapies hold promise for preventing and treating NCDs. Quercetin (Que) is a widely available flavonoid that has significant antioxidant and anti-inflammatory properties. It modulates the Nrf2 signaling pathway to ameliorate oxidative stress and inflammation. Que modulates mitochondrial function, apoptosis, autophagy, and cell damage biomarkers to regulate oxidative stress and inflammation, highlighting its efficacy as a therapeutic agent against NCDs. Here, we discussed, for the first time, the close association between NCD pathogenesis and the Nrf2 signaling pathway, involved in neurodegenerative diseases (NDDs), cardiovascular disease, cancers, organ damage, and bone damage. Furthermore, we reviewed the availability, pharmacokinetics, pharmaceutics, and therapeutic applications of Que in treating NCDs. In addition, we focused on the challenges and prospects for its clinical use. Que represents a promising candidate for the treatment of NCDs due to its Nrf2-targeting properties.

Exploring the therapeutic potential of quercetin: A focus on its sirtuin-mediated benefits

As the global population ages, preventing lifestyle- and aging-related diseases is increasing, necessitating the search for safe and affordable therapeutic interventions. Among nutraceuticals, quercetin, a flavonoid ubiquitously present in various plants, has garnered considerable interest. This review aimed to collate and analyze existing literature on the therapeutic potentials of quercetin, especially its interactions with SIRTs and its clinical applicability based on its bioavailability and safety. This narrative review was based on a literature survey spanning from 2015 to 2023 using PUBMED. The keywords and MeSH terms used were: "quercetin" AND "bioavailability" OR "metabolism" OR "metabolites" as well as "quercetin" AND "SIRTuin" OR "SIRT*" AND "cellular effects" OR "pathway" OR "signaling" OR "neuroprotective" OR "cardioprotective" OR "nephroprotective" OR "antiatherosclerosis" OR "diabetes" OR "antidiabetic" OR "dyslipidemia" AND "mice" OR "rats". Quercetin demonstrates multiple therapeutic activities, including neuroprotective, cardioprotective, and anti-atherosclerotic effects. Its antioxidant, anti-inflammatory, antiviral, and immunomodulatory properties are well-established. At a molecular level, it majorly interacts with SIRTs, particularly SIRT1 and SIRT6, and modulates numerous signaling pathways, contributing to its therapeutic effects. These pathways play roles in reducing oxidative stress, inflammation, autophagy regulation, mitochondrial biogenesis, glucose utilization, fatty acid oxidation, and genome stability. However, clinical trials on quercetin's effectiveness in humans are scarce. Quercetin exhibits a wide range of SIRT-mediated therapeutic effects. Despite the compelling preclinical data, more standardized clinical trials are needed to fully understand its therapeutic potential. Future research should focus on addressing its bioavailability and safety concerns.

Fucoxanthin ameliorates endoplasmic reticulum stress and inhibits apoptosis and alleviates intervertebral disc degeneration in rats by upregulating Sirt1

Endoplasmic reticulum stress (ERS) and apoptosis of nucleus pulposus (NP) cells are considered to be the main pathological factors of intervertebral disc degeneration (IDD). Fucoxanthin (FX), a marine carotenoid extracted from microalgae, has antioxidant, anti-inflammatory, and anticancer properties. The aim of this study was to investigate the effect of FX on NP cells induced by oxidative stress and its molecular mechanism. Primary NP cells of the lumbar vertebrae of rats were extracted and tested in vitro. qRT-PCR, western blot, immunofluorescence, and TUNEL staining were used to detect apoptosis, ERS, extracellular matrix (ECM), and Sirt1-related pathways. In vivo experiments, the recovery of IDD rats was determined by X-ray, hematoxylin and eosin, Safranin-O/Fast Green, Alcian staining, and immunohistochemistry. Our study showed that oxidative stress induced ERS, apoptosis, and ECM degradation in NP cells. After the use of FX, the expression of Sirt1 was up-regulated, the activation of PERK-eIF2α-ATF4-CHOP was decreased, and apoptosis and ECM degradation were decreased. At the same time, FX improved the degree of disc degeneration in rats in vivo. Our study demonstrates the effect of FX on improving IDD in vivo and in vitro, suggesting that FX may be a potential drug for the treatment of IDD.

SIRT1 regulates endoplasmic reticulum stress-related organ damage

Endoplasmic reticulum (ER) stress plays a key role in the pathogenesis of several organ damages. Studies show that excessive ER stress (ERS) can destroy cellular homeostasis, causing cell damage and physiological dysfunction in various organs. In recent years, Sirtuin1 (SIRT1) has become a research hotspot on ERS. Increasing evidence suggests that SIRT1 plays a positive role in various ERS-induced organ damage via multiple mechanisms, including inhibiting cellular apoptosis and promoting autophagy. SIRT1 can also alleviate liver, heart, lung, kidney, and intestinal damage by inhibiting ERS. We discuss the possible mechanism of SIRT1, explore potential therapeutic targets of diseases, and provide a theoretical basis for treating ERS-related diseases.

Cystathionine γ-lyase S-sulfhydrates SIRT1 to attenuate myocardial death in isoprenaline-induced heart failure

OBJECTIVE

Hydrogen sulfide (H₂S), the third gasotransmitter, plays a critical role in protecting against heart failure. Sirtuin-1 (SIRT1) is a highly conserved histone deacetylase that has a protective role in the treatment of heart failure by regulating the deacetylation of some functional proteins. This study investigates the interaction between SIRT1 and H₂S in heart failure and the underlying mechanisms.

METHODS AND RESULTS

Using endogenous H₂S-generating enzyme cystathionine γ-lyase (CSE) knockout mice, we found that CSE deficiency aggravated isoprenaline-induced cardiac injury. Treatment with H₂S attenuated atrial natriuretic peptide level, brain natriuretic peptide level, improved cardiac function. Moreover, H₂S treatment potentiated myocardial SIRT1 expression. Silencing CSE abolished intracellular SIRT1 expression. Furthermore, CSE/ H₂S S-sulfhydrated SIRT1 at its zinc finger domains and augmented its zinc ion binding activity to stabilize the alpha-helix structure.

DISCUSSION

In conclusion, these results uncover that a novel mechanism that CSE/H₂S S-sulfhydrated SIRT1 to prevent heart dysfunction through modulating its activity.

Quercetin alleviates cadmium-induced BRL-3A cell apoptosis by inhibiting oxidative stress and the PERK/IRE1α/ATF6 signaling pathway

Cadmium (Cd) is a highly toxic environmental pollutant. The liver is an important metabolic organ in the body and is susceptible to Cd toxicity attacks. Quercetin (Que) is a flavonoid compound with pharmacological activities of scavenging free radicals and antioxidant activity. Previous studies have shown that Que can alleviate Cd caused hepatocyte apoptosis in rats, but the specific mechanism remains unclear. To explore the specific mechanism, we established a model of Cd toxicity and Que rescue in BRL-3A cells and used 4-phenylbutyrate (4-PBA), an endoplasmic reticulum stress (ERS) inhibitor, as positive control. Set up a control group, Cd treatment group, Cd and Que co treatment group, Que treatment group, Cd and 4-PBA co treatment group, and 4-PBA treatment group. Cell Counting Kit-8 (CCK-8) method was employed to measure cell viability. Fluorescence staining was applied to observe cell apoptosis. Flow cytometry was performed to detect reactive oxygen species levels. Real-time quantitative polymerase chain reaction (qRT-PCR) and Western blot method was adopted to detect the mRNA and protein expression levels of ERS and apoptosis-related genes. The results showed that compared with the control group, the Cd treated group showed a significant decrease in cell viability (P < 0.01), an increase in intracellular ROS levels, and apoptosis. The mRNA and protein expression levels of ERS and apoptosis related factors such as GRP78, IRE1α, XBP1, ATF6, Caspase-12, Caspase-3 and Bax in the cells were significantly increased (P < 0.01), while the mRNA and protein expression levels of Bcl-2 were significantly reduced (P < 0.01). Compared with the Cd treatment group, the Cd and Que co treatment group and the Cd and 4-PBA co treatment group showed a significant increase in cell viability (P < 0.01), a decrease in intracellular ROS levels, a decrease in cell apoptosis, and a significant decrease in the expression levels of ERS and apoptosis related factors mRNA and protein (P < 0.01), as well as a significant increase in Bcl-2 mRNA and protein expression (P < 0.01). We confirmed that Que could alleviate the apoptosis caused by Cd in BRL-3A cells, and the effects of Que were similar to those of ERS inhibitor.

L-carnitine reverses methotrexate-induced nephrotoxicity in experimental rat model: Insight on SIRT1/PGC-1α/Nrf2/HO-1 axis

Methotrexate (MTX) is a chemotherapeutic agent used for treating several types of cancer as well as psoriasis and rheumatoid arthritis, but its use is limited due to its nephrotoxicity. The purpose of this research work was to observe ameliorative effects of L-carnitine (LC) toward renal toxicity caused by MTX and mechanisms responsible for these effects. Thirty-two male Sprague-Dawley rats were divided into four groups (eight rats/group), control group (received saline), MTX group (20 mg/kg/i.p. once), LC group (500 mg/kg/i.p. for 5 days), and MTX + LC group (received a single MTX dose 20 mg/kg/i.p. followed by LC 500 mg/kg/i.p. for 5 days). Histopathological examinations, lipid oxidation marker, malondialdehyde (MDA), and the antioxidant superoxide dismutase (SOD) as well as inflammatory (tumor necrosis factor-α [TNF-α] and interleukin-6 [IL-6]) and apoptotic markers (Bax, Bcl2, and caspase-3) were used to assess renal toxicity. Moreover, the protein levels of silent information regulator 1 (SIRT1) and its downstream signaling targets, peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α), and nuclear factor erythroid 2-related factor 2 (Nrf2) in addition to heme oxygenase-1 (HO-1) were measured. LC significantly protected against MTX-induced nephrotoxicity. It ameliorated MTX-induced renal histopathological changes and diminished MTX-induced renal oxidative stress, renal inflammation, and apoptosis. LC also upregulated the expression of SIRT1 and PGC-1 as well as Nrf2 and HO-1. By controlling the expression of renal SIRT1/PGC-1/Nrf2/HO-1, LC displayed antioxidant, anti-inflammatory, and anti-apoptotic activities. Hence, using LC supplements may help prevent negative MTX side effects.

Cadmium influence on lipid metabolism in Sprague-Dawley rats through linoleic acid and glycerophospholipid metabolism pathways

Cadmium (Cd) is widely distributed in the environment and easy adsorbed by living organisms with adverse effects. Exposure to Cd-contaminated food may disrupt lipid metabolism and increase human health risk. To study the perturbation effect of Cd on lipid metabolism in vivo, 24 male Sprague-Dawley (SD) rats were randomly assigned four groups and treated by Cd chloride solution (0, 1.375 mg/kg, 5.5 mg/kg, 22 mg/kg) for 14 days. The characteristic indexes of serum lipid metabolism were analyzed. Afterwards, untargeted metabolomics analysis was applied to explore the adverse effects of Cd on rats by liquid chromatography coupled with mass spectrometry (LC-MS). The results revealed that Cd exposure obviously decreased the average serum of triglycerides (TG) and low-density lipoprotein cholesterol (LDL-C) and caused an imbalance of endogenous compounds in the 22 mg/kg Cd-exposed group. Compared with the control group, 30 metabolites with significant differences were identified in the serum. Our results indicated that Cd caused lipid metabolic disorders in rats by disrupting linoleic acid and glycerophospholipid metabolism pathways. Furthermore, there were three kinds of remarkable differential metabolites-9Z,12Z-octadecadienoic acid, PC(20:4(8Z,11Z,14Z,17Z)/0:0), and PC(15:0/18:2(9Z,12Z)), which enriched the two significant metabolism pathways and could be the potential biomarkers.

A review of how the saffron (Crocus sativus) petal and its main constituents interact with the Nrf2 and NF-κB signaling pathways

The primary by-product of saffron (Crocus sativus) processing is saffron petals, which are produced in large quantities but are discarded. The saffron petals contain a variety of substances, including alkaloids, anthocyanins, flavonoids, glycosides, kaempferol, and minerals. Pharmacological investigations revealed the antibacterial, antidepressant, antidiabetic, antihypertensive, antinociceptive, antispasmodic, antitussive, hepatoprotective, immunomodulatory, and renoprotective properties of saffron petals, which are based on their antioxidant, anti-inflammatory, and antiapoptotic effects. The nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway protects against oxidative stress, carcinogenesis, and inflammation. Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-ĸB) is a protein complex involved in approximately all animal cells and participates in different biological procedures such as apoptosis, cell growth, development, deoxyribonucleic acid (DNA) transcription, immune response, and inflammation. The pharmacological properties of saffron and its compounds are discussed in this review, along with their associated modes of action, particularly the Nrf2 and NF-ĸB signaling pathways. Without considering a time constraint, our team conducted this review using search engines or electronic databases like PubMed, Scopus, and Web of Science. Saffron petals and their main constituents may have protective effects in numerous organs such as the brain, colon, heart, joints, liver, lung, and pancreas through several mechanisms, including the Nrf2/heme oxygenase-1 (HO-1)/Kelch-like ECH-associated protein 1 (Keap1) signaling cascade, which would then result in its antioxidant, anti-inflammatory, antiapoptotic, and therapeutic effects.

Quercetin inhibits DNA damage responses to induce apoptosis via SIRT5/PI3K/AKT pathway in non-small cell lung cancer

SIRT5 is a mitochondrial NAD+ -dependent lysine deacylase. Downregulation of SIRT5 has been linked to several primary cancers and DNA damage. In clinical therapy for non-small cell lung cancer (NSCLC), the Feiyiliu Mixture (FYLM) is an experience and effective Chinese herb prescription. And we found that quercetin is an important ingredient in the FYLM. However, whether quercetin regulates DNA damage repair (DDR) and induces apoptosis through SIRT5 in NSCLC remains unknown. The present study revealed that quercetin directly binds to SIRT5 and inhibits the phosphorylation of PI3K/AKT through the interaction between SIRT5 and PI3K, thus inhibiting the repair process of homologous recombination (HR) and non-homologous end-joining (NHEJ) in NSCLC, which raise mitotic catastrophe and apoptosis. Our study provided a novel mechanism of action of quercetin in the treatment of NSCLC.

Tanshinone IIA ameliorates experimental diabetic cardiomyopathy by inhibiting endoplasmic reticulum stress in cardiomyocytes via SIRT1

Diabetic cardiomyopathy (DCM) is a common complication in patients with diabetes, and ultimately leads to heart failure. Endoplasmic reticulum stress (ERS) induced by abnormal glycolipid metabolism is a critical factor that affects the occurrence and development of DCM. Additionally, the upregulation/activation of silent information regulation 2 homolog-1 (SIRT1) has been shown to protect against DCM. Tanshinone II A (Tan IIA), the main active component of Salviae miltiorrhizae radix et rhizome (a valuable Chinese medicine), has protective effects against cardiovascular disease and diabetes. However, its role and mechanisms in diabetes-induced cardiac dysfunction remain unclear. Therefore, we explored whether Tan IIA alleviates ERS-mediated DCM via SIRT1 and elucidated the underlying mechanism. The results suggested that Tan IIA alleviated the pathological changes in the hearts of diabetic mice, ameliorated the cytopathological morphology of cardiomyocytes, reduced the cell death rate, and inhibited the expression of ERS-related proteins and mRNA. The SIRT1 agonist inhibited the activities of glucose-regulated protein 78 (GRP78). Furthermore, the opposite results under the SIRT1 inhibitor. SIRT1 knockdown was induced by siRNA-SIRT1 transfection, and the degree of GRP78 acetylation was increased. Cumulatively, Tan IIA ameliorated DCM by inhibiting ERS and upregulating SIRT1 expression.

Epigenetic regulation of mitochondrial-endoplasmic reticulum dynamics in kidney diseases

Kidney diseases are serious health problems affecting >800 million individuals worldwide. The high number of affected individuals and the severe consequences of kidney dysfunction demand an intensified effort toward more effective prevention and treatment. The pathophysiology of kidney diseases is complex and comprises diverse organelle dysfunctions including mitochondria and endoplasmic reticulum (ER). The recent findings prove interactions between the ER membrane and nearly all cell compartments and give new insights into molecular events involved in cellular mechanisms in health and disease. Interactions between the ER and mitochondrial membranes, known as the mitochondria-ER contacts regulate kidney physiology by interacting with each other via membrane contact sites (MCS). ER controls mitochondrial dynamics through ER stress sensor proteins or by direct communication via mitochondria-associated ER membrane to activate signaling pathways such as apoptosis, calcium transport, and autophagy. More importantly, these organelle dynamics are found to be regulated by several epigenetic mechanisms such as DNA methylation, histone modifications, and noncoding RNAs and can be a potential therapeutic target against kidney diseases. However, a thorough understanding of the role of epigenetic regulation of organelle dynamics and their functions is not well understood. Therefore, this review will unveil the role of epigenetic mechanisms in regulating organelle dynamics during various types of kidney diseases. Moreover, we will also shed light on different stress origins in organelles leading to kidney disease. Henceforth, by understanding this we can target epigenetic mechanisms to maintain/control organelle dynamics and serve them as a novel therapeutic approach against kidney diseases.

Hepatic Proteomics Analysis Reveals Attenuated Endoplasmic Reticulum Stress in Lactiplantibacillus plantarum-Treated Oxidatively Stressed Broilers

Endoplasmic reticulum (ER) stress plays important roles in oxidative stress (OS), contributing to liver injury. Lactiplantibacillus plantarum P8 (P8) was reported to regulate broiler OS and the gut microbiota in broilers, but its roles in hepatic ER stress remain unclear. In the present study, the role of P8 in liver OS and ER stress was evaluated, and proteomics was performed to determine the mechanism. Results revealed that P8 treatment decreased liver OS and ER stress in dexamethasone (DEX)-induced oxidatively stressed broilers. Proteomics showed that differentially expressed proteins (DEPs) induced by DEX cover the "cellular response to unfold protein" term. Moreover, the DEPs (GGT5, TXNDC12, and SRM) between DEX- and DEX + P8-treated broilers were related to OS and ER stress and enriched in the glutathione metabolism pathway. RT-qPCR further confirmed the results of proteomics. In conclusion, P8 attenuates hepatic OS and ER stress by regulating GGT5, TXNDC12, SRM, and glutathione metabolism in broilers.

Ginkgo biloba extract attenuates cisplatin-induced renal interstitial fibrosis by inhibiting the activation of renal fibroblasts through down-regulating the HIF-1α/STAT3/IL-6 pathway in renal tubular epithelial cells

BACKGROUND

Activation of renal fibroblasts into myofibroblasts plays an important role in promoting renal interstitial fibrosis (RIF). Ginkgo biloba extract (EGb) can alleviate RIF induced by cisplatin (CDDP).

PURPOSE

To elucidate the effect of EGb treatment on cisplatin-induced RIF and reveal its potential mechanism.

METHODS

The two main active components in EGb were determined by high-performance liquid chromatography (HPLC) analysis. Rats were induced by CDDP and then treated with EGb, 2ME2 (HIF-1α inhibitor) or amifostine. After HK-2 cells and HIF-1α siRNA HK-2 cells were treated with CDDP, EGb or amifostine, the conditioned medium from each group was cultured with NRK-49F cells. The renal function of rats was detected. The renal damage and fibrosis were evaluated by H&E and Masson trichrome staining. The IL-6 content in the cell medium was detected by ELISA. The expression levels of indicators related to renal fibrosis and signaling pathway were examined by western blotting and qRT-PCR.

RESULTS

HPLC analysis showed that the contents of quercetin and kaempferol in EGb were 36.0 μg/ml and 45.7 μg/ml, respectively. In vivo, EGb and 2ME2 alleviated renal damage and fibrosis, as well as significantly decreased the levels of α-SMA, HIF-1α, STAT3 and IL-6 in rat tissues induced by CDDP. In vitro, the levels of HIF-1α, STAT3 and IL-6 were significantly increased in HK-2 cells and HIF-1α siRNA HK-2 cells induced by CDDP. Notably, HIF-1α siRNA significantly decreased the levels of HIF-1α, STAT3 and IL-6 in HK-2 cells, as well as the IL-6 level in medium from HK-2 cells. Additionally, the α-SMA level in NRK-49F cells was significantly increased after being cultured with conditioned medium from HK-2 cells or HIF-1α siRNA HK-2 cells exposed to CDDP. Furthermore, exogenous IL-6 increased the α-SMA level in NRK-49F cells. Importantly, the expression levels of the above-mentioned indicators were significantly decreased after the HK-2 cells and HIF-1α siRNA HK-2 cells were treated with EGb.

CONCLUSION

This study revealed that EGb improves CDDP-induced RIF, and the mechanism may be related to its inhibition of the renal fibroblast activation by down-regulating the HIF-1α/STAT3/IL-6 pathway in renal tubular epithelial cells.

Carvacrol protects against λ-Cyhalothrin-induced hepatotoxicity and nephrotoxicity by modulating oxidative stress, inflammation, apoptosis, endoplasmic reticulum stress, and autophagy

λ-Cyhalothrin, a type II synthetic pyrethroid, has been widely used in households, agriculture, public health, and gardening to control insect pests. Despite its widespread usage, it is known to induce a variety of adverse effects, including hepatotoxicity and nephrotoxicity. The goal of this study was to investigate the protective effect of carvacrol, which has antioxidant, anti-inflammatory, anti-apoptotic, and some other properties, on λ-Cyhalothrin-induced hepatotoxicity and nephrotoxicity 35 male Sprague-Dawley rats were randomly divided into five groups for this purpose: I-Control group: II-CRV group (50 mg/kg carvacrol), III-LCT group (6.23 mg/kg LCT), IV-LCT + CRV 25 group (6.23 mg/kg LCT + 25 mg/kg carvacrol), and V-LCT + CRV 50 group (6.23 mg/kg LCT + 50 mg/kg carvacrol). Using biochemical, real-time PCR, and western blotting methods, the collected tissues were analyzed. While λ-Cyhalothrin treatment increased MDA levels, which are indicated of lipid peroxidation, but reduced SOD, CAT, GPx activities, and GSH levels. After receiving carvacrol therapy, the degree of oxidative stress reduced as the values of these parameters approached those of the control group. Increased inflammation, apoptosis, endoplasmic reticulum stress, and autophagy with λ-Cyhalothrin administration reduced with carvacrol co-administration, and liver and kidney tissues were protected from damage, depending on the degree of oxidative stress. After considering all of these data, it was discovered that λ-Cyhalothrin-induced oxidative stress, inflammation, apoptosis, endoplasmic reticulum stress, and autophagy in the liver and kidneys; however, carvacrol protected the tissues from damage. Our findings indicate that carvacrol may be a promising protective agent in λ-Cyhalothrin-induced hepatotoxicity and nephrotoxicity.

Selenium alleviates cadmium-induced oxidative stress, endoplasmic reticulum stress and programmed necrosis in chicken testes

Cadmium (Cd) is a common heavy metal pollutant, and one of the important target organs of its toxicity is the testis. Selenium (Se) has the ability to antagonize the toxicity of Cd. However, the mechanism of the alleviating effects of Se on Cd in chicken testis injury through oxidative stress, endoplasmic reticulum stress (ERS), and programmed necrosis remained unclear. To explore this, 80 7-day-old chickens were divided into the Control group, the Se group (1.00 mg/kg Se), the Cd group (150.00 mg/kg Cd), and the CdSe group. On the 30th and 60th days, serum and chicken testis tissue samples were collected for testing. The results showed that Cd exposure resulted in swelling and deformation of seminiferous tubules, and thinning of the seminiferous epithelium. The ROS and MDA increased, and the SOD, CAT, GSH, GSH-Px decreased. The expression of GRP78, PERK, IRE1, ATF6, CHOP, and JNK in the Cd group increased. The expression of TNF-α, TNFR1, RIP1, RIP3, MLKL, and PARP1 increased, while the expression of Caspase-8 decreased. Histopathological changes, oxidative stress, ERS, and programmed necrosis were improved after CdSe treatment. In conclusion, Se antagonized the toxicity of Cd, and Se could alleviate Cd-induced oxidative stress, ERS, and programmed necrosis in chicken testis.

Molecular and biochemical investigation of the protective effects of rutin against liver and kidney toxicity caused by malathion administration in a rat model

Widely used malathion (MLT) causes environmental pollution, leading to toxicity in many living things, including humans. Rutin (RUT) is a flavonoid with various biological properties. In the present study, the protective effects of rutin against liver and kidney toxicity caused by malathion were investigated. In the study, MLT (100 mg/kg) and RUT (50 or 100 mg/kg) were administered to rats alone or in combination for 28 days. Then, oxidative stress, inflammation, endoplasmic reticulum stress (ERS), apoptosis, and autophagy markers in liver and kidney tissues were analyzed by biochemical and molecular methods. The results showed that MLT caused oxidative stress in both tissues, while RUT showed antioxidant properties and protected these tissues from oxidative damage. Moreover, MLT upregulated the expressions of ATF-6, PERK, IRE1, GRP78, and CHOP, leading to ERS. However, RUT alleviated ER stress and suppressed these markers. The study also found that MLT increased inflammatory, apoptotic, and autophagic markers. All these factors affected liver and kidney functions and caused an increase in plasma ALT, AST, urea, and creatinine levels. On the other hand, it has been observed that RUT may protect liver and kidney tissues from the destructive effect of MLT by showing anti-inflammatory, anti-apoptotic, and anti-autophagic properties. Thus, it was determined that ALT, AST, urea, and creatinine levels decreased after RUT treatment. As a result, it was observed that MLT had a toxic effect on the liver and kidney tissues of rats, and it was determined that this toxicity could be alleviated by RUT treatment.

Untargeted metabolomics reveals the preventive effect of quercetin on nephrotoxicity induced by four organophosphorus pesticide mixtures

This research aimed to explore the protective effect of quercetin against nephrotoxicity induced by four organophosphate pesticide mixtures (PM) using untargeted metabolomics technology in rat kidneys. Sixty male Wistar rats were randomly divided into six groups: control, low-dose quercetin treated (10 mg/kg. bw), high-dose quercetin treated (50 mg/kg. bw), PM-treated, and two dosages of quercetin + PM-treated. Metabolomics results showed that 17 differential metabolites were identified in the PM-treated group, and pathway analysis revealed that renal metabolic disorders include purine metabolism, glycerophospholipid metabolism, and vitamin B6 metabolism. When high-dose quercetin and PM-treated were administered to rats concurrently, the intensities of differential metabolites were substantially restored (p < 0.01), suggesting that quercetin can improve renal metabolic disorders caused by organophosphate pesticides (OPs). Mechanistically, quercetin could regulate the purine metabolism disorder and endoplasmic reticulum stress (ERS)-mediated autophagy induced by OPs by inhibiting XOD activity. Moreover, quercetin inhibits PLA2 activity to regulate glycerophospholipid metabolism and it could also exert antioxidant and anti-inflammatory effects to correct vitamin B6 metabolism in rat kidneys. Taken together, the high dose of quercetin (50 mg/kg.bw) has a certain protective effect on OPs-induced nephrotoxicity in rats, which provides a theoretical basis for quercetin against nephrotoxicity caused by OPs.

The involvement of oxidative stress mediated endoplasmic reticulum pathway in apoptosis of Golden Pompano (Trachinotus blochii) liver under PS-MPs stress

Globally, microplastics (MPs) are highly prevalent, especially in coastal areas. Unfortunately, golden pompano as a major marine fish in China is typically raised in floating marine cages near coasts, facing these MPs sources. However, toxicological studies on Golden Pompano which farm in coastal areas and face actual microplastic exposure are rare. Therefore, golden pompano were exposed to 10.0 μg/L, 100.0 μg/L, and 1000.0 μg/L polystyrene MPs (PS-MPs) for 14 days to study the potential impact of the microplastics on the Golden Pompano. Fish show slowed growth after 14 days of exposure. Histopathology shows irregular shaped nuclei and nuclear and cytoplasmic vacuolation traits in liver. Oxidative stress-related enzyme activity and gene expression data show that oxidative damage occurs in the high-concentrations (100.0 μg/L and 1000.0 μg/L) of PS-MPs exposures. Up-regulation of Grp78, Xbp-1, Eif-2α and chop gene expression indicates the occurrence of endoplasmic reticulum stress, and the western blot results also confirmed this. Severe oxidative stress also caused ERS, which ultimately increased BAX/Bcl-2 ratios and induces apoptosis. Furthermore, up-regulated anaerobic respiration, altered lipid metabolism, and immune disturbance were exhibited during PS-MPs stress. Therefore, oxidative stress appeared to be the main toxicity issue caused by MPs, while ERS-mediated apoptosis, metabolic alterations, and immune responses were induced by this stress. Notably, endoplasmic reticulum stress and apoptosis are a self-protective mechanism, which may be an intermediate link in the toxicity of microplastics. This study highlights the role of endoplasmic reticulum stress in MPs toxicology and assesses the adverse effects of microplastics on Golden Pompano.

Cinobufagin induces acute promyelocytic leukaemia cell apoptosis and PML-RARA degradation in a caspase-dependent manner by inhibiting the β-catenin signalling pathway

CONTEXT

Acute promyelocytic leukaemia (APL) is a malignant hematological tumour characterized by the presence of promyelocytic leukaemia-retinoic acid receptor A (PML-RARA) fusion protein. Cinobufagin (CBG) is one of the main effective components of toad venom with antitumor properties. However, only a few reports regarding the CBG treatment of APL are available.

OBJECTIVE

We explored the effect and mechanism of action of CBG on NB4 and NB4-R1 cells.

MATERIALS AND METHODS

We evaluated the viability of NB4 and NB4-R1 cells treated with 0, 20, 40, and 60 nM CBG for 12, 24, and 48 h. After treatment with CBG for 24 h, Bcl-2 associated X (Bax), B-cell lymphoma 2 (Bcl-2), β-catenin, cyclin D1, and c-myc expression was detected using western blotting and real-time polymerase chain reaction. Caspase-3 and PML-RARA expression levels were detected using western blotting.

RESULTS

CBG inhibited the viability of NB4 and NB4-R1 cells. The IC₅₀ values of NB4 and NB4-R1 cells treated with CBG for 24 h were 45.2 nM and 37.9 nM, respectively. CBG induced NB4 and NB4-R1 cell apoptosis and PML-RARA degradation in a caspase-dependent manner and inhibited the β-catenin signalling pathway.

DISCUSSION AND CONCLUSION

CBG induced NB4 and NB4-R1 cell apoptosis and PML-RARA degradation in a caspase-dependent manner by inhibiting the β-catenin signalling pathway. This study proposes a novel treatment strategy for patients with APL, particularly those with ATRA-resistant APL.

Plant Flavonoids on Oxidative Stress-Mediated Kidney Inflammation

The kidney is susceptible to reactive oxygen species-mediated cellular injury resulting in glomerulosclerosis, tubulointerstitial fibrosis, tubular cell apoptosis, and senescence, leading to renal failure, and is a significant cause of death worldwide. Oxidative stress-mediated inflammation is a key player in the pathophysiology of various renal injuries and diseases. Recently, flavonoids' role in alleviating kidney diseases has been reported with an inverse correlation between dietary flavonoids and kidney injuries. Flavonoids are plant polyphenols possessing several health benefits and are distributed in plants from roots to leaves, flowers, and fruits. Dietary flavonoids have potent antioxidant and free-radical scavenging properties and play essential roles in disease prevention. Flavonoids exert a nephroprotective effect by improving antioxidant status, ameliorating excessive reactive oxygen species (ROS) levels, and reducing oxidative stress, by acting as Nrf2 antioxidant response mediators. Moreover, flavonoids play essential roles in reducing chemical toxicity. Several studies have demonstrated the effects of flavonoids in reducing oxidative stress, preventing DNA damage, reducing inflammatory cytokines, and inhibiting apoptosis-mediated cell death, thereby preventing or improving kidney injuries/diseases. This review covers the recent nephroprotective effects of flavonoids against oxidative stress-mediated inflammation in the kidney and their clinical advancements in renal therapy.

Effective dose/duration of natural flavonoid quercetin for treatment of diabetic nephropathy: A systematic review and meta-analysis of rodent data

BACKGROUND

Given the challenges on diabetic nephropathy (DN) treatment, research has been carried out progressively focusing on dietary nutrition and natural products as a novel option with the objective of enhancing curative effect and avoiding adverse reactions. As a representative, Quercetin (Qu) has proved to be of great value in current data.

PURPOSE

We aimed to synthetize the evidence regarding the therapeutic effect and specific mechanism of quercetin on DN via systematically reviewing and performing meta-analysis.

METHODS

Preclinical literature published prior to August 2021, was systematical retrieval and manually filtrated across four major databases including PubMed, Web of Science, EMBASE and Cochrane library. Pooled overall effect sizes of results were generated by STATA 16.0, and underlying mechanisms were summarized. Three-dimensional dose/time-effect analyses and radar maps were conducted to examine the dosage/time-response relations between Qu and DN.

RESULTS

This paper pools all current available evidence in a comprehensive way, and shows the therapeutic benefits as well as potential action mechanisms of Qu in protecting the kidney against damage. A total of 304 potentially relevant citations were identified, of which 18 studies were enrolled into analysis. Methodological quality was calculated, resulting in an average score of 7.06/10. This paper provided the preliminary evidence that consumption of Qu could induce a statistical reduction in mesangial index, Scr, BUN, 24-h urinary protein, serum urea, BG, kidney index, TC, TG, LDL-C, AST, MDA, AGE, TNF-α, TGF-β1, TGF-β1 mRNA, CTGF and IL-1β, whereas HDL-C, SOD, GSH, GSH-Px, CAT and smad-7 were significantly increased. Furthermore, Qu could remarkably improve the renal pathology. In terms of the mechanisms underlying therapy of DN, Qu exerts anti-diabetic nephropathy properties possibly through PI3K/PKB, AMPK-P38 MAPK, SCAP/SREBP2/LDLr, mtROS-TRX/TXNIP/NLRP3/IL-1β, TGF-β1/Smad, Nrf2/HO-1, Hippo, mTORC1/p70S6K and SHH pathways. Dose/time-response images predicted a modest association between Qu dosage consumption/administration length and therapeutic efficacy, with the optimal dosage at 90-150 mg/kg/d and administration length ranging from 8 weeks to 12 weeks.

CONCLUSIONS

Quercetin exhibit highly pleiotropic actions, which simultaneously contributes to prevent fundamental progression of DN, such as hyperglycemia, dyslipidemia, inflammation, fibrotic lesions and oxidative stress. The therapeutic effect becomes stronger when Qu administration at higher dosages lasts for longer durations. Taken together, quercetin could be used in patients with DN as a promising agent, which has well-established safety profiles and nontoxicity according to existing literature.

Deep learning approach identified a gene signature predictive of the severity of renal damage caused by chronic cadmium accumulation

Epidemiology studies have indicated that environmental cadmium exposure, even at low levels, will result in chronic cadmium accumulation in the kidney with profound adverse consequences and that the diabetic population is more susceptible. However, the underlying mechanisms are yet not fully understood. In the present study, we applied an animal model to study chronic cadmium exposure-induced renal injury and performed whole transcriptome profiling studies. Repetitive CdCl₂ exposure resulted in cadmium accumulation and remarkable renal injuries in the animals. The diabetic ob/ob mice manifested increased severity of renal injury compared with the wild type C57BL/6 J littermate controls. RNA-Seq data showed that cadmium treatment induced dramatic gene expression changes in a dose-dependent manner. Among the differentially expressed genes include the apoptosis hallmark genes which significantly demarcated the treatment effects. Pathway enrichment and network analyses revealed biological oxidation (mainly glucuronidation) as one of the major stress responses induced by cadmium treatment. We next implemented a deep learning algorithm in conjunction with cloud computing and discovered a gene signature that can predict the degree of renal injury induced by cadmium treatment. The present study provided, for the first time, a comprehensive mechanistic understanding of chronic cadmium-induced nephrotoxicity in normal and diabetic populations at the whole genome level.

Fenugreek Seed Galactomannan Aqueous and Extract Protects against Diabetic Nephropathy and Liver Damage by Targeting NF-κB and Keap1/Nrf2 Axis

This investigation was conducted to test the potential of the galactomannan (F-GAL) and aqueous extract (FS-AE) of the Fenugreek seed aqueous to prevent liver and kidney damage extracts in streptozotocin (STZ)-induced T1DM in rats. Non-diabetic and diabetic rats received the normal saline as a vehicle or were treated with FS-EA or F-GAL at a final concentration of 500 mg/kg/each. Treatments with both drugs reduced fasting hyperglycemia and improved serum and hepatic lipid profiles in the control and diabetic rats. Additionally, F-GAL and FS-AE attenuated the associated reduction in the mass and structure of the islets of Langerhans in diabetic rats and improved the structure of the kidneys and livers. In association, they also reduced the generation of reactive oxygen species (ROS), lipid peroxides, factor (TNF-α), interleukin-6 (IL-6), and nuclear levels of NF-κB p65, and improved serum levels of ALT, AST, albumin, and creatinine. However, both treatments increased hepatic and renal superoxide dismutase (SOD) in the livers and kidneys of both the control and diabetic-treated rats, which coincided with a significant increase in transcription, translation, and nuclear localization of Nrf2. In conclusion, FS-AE and F-GAL are effective therapeutic options that may afford a possible treatment for T1DM by attenuating pancreatic damage, hyperglycemia, hyperlipidemia, and hepatic and renal damage.

Early life PCB138 exposure induces kidney injury secondary to hyperuricemia in male mice

Polychlorinated biphenyls (PCBs) are a class of persistent organic pollutants (POPs) that have adverse effects on human health. However, the long-term health effects and potential mechanism of neonatal exposure to PCBs are still unclear. In this study, nursing male mice exposed to PCB138 at 0.5, 5, and 50 μg/kg body weight (bw) from postnatal day (PND) 3 to PND 21 exhibited increased serum uric acid levels and liver uric acid synthase activity at 210 days of age. We also found an increased kidney somatic index in the 50 μg/kg group and kidney fibrosis in the 5 and 50 μg/kg groups. Mechanistically, PCB138 induced mitochondrial dysfunction and endoplasmic reticulum (ER) stress, which might have led to inflammatory responses, such as activation of the NF-κB (nuclear factor kappa-B) and NLRP3 (NOD-like receptor protein 3) pathways. The inflammatory response might regulate renal fibrosis and hypertrophy. In summary, this study reports a long-term effect of neonatal PCB exposure on uric acid metabolism and secondary nephrotoxicity and clarifies the underlying mechanism. Our work also indicates that early life pollutant exposure may be an important cause of diseases later in life.

Cold Exposure Induces Intestinal Barrier Damage and Endoplasmic Reticulum Stress in the Colon via the SIRT1/Nrf2 Signaling Pathway

Ambient air temperature is a key factor affecting human health. Long-term exposure to a cold environment can cause various diseases, while the impact on the intestine, the organ which has the largest contact area with the external environment, cannot be ignored. In this study, we investigated the effect of chronic cold exposure on the colon and its preliminary mechanism of action. Mice were exposed to 4°C for 3 hours a day for 10 days. We found that cold exposure damaged the morphology and structure of the colon, destroyed the tight junctions of the colonic epithelial tissue, and promoted inflammation of the colon. At the same time, cold exposure also activated the unfolded protein response (UPR) in the colon and promoted apoptosis in intestinal epithelial cells. Chronic cold exposure induced oxidative stress in vivo, but also significantly enhanced the response of the Nrf2 pathway that promotes an anti-oxidant effect. Furthermore, we demonstrated that chronic cold exposure promoted p65 acetylation to aggravate the inflammatory response by inhibiting SIRT1. Similar results were observed following SIRT1 knock-down by shRNA in Caco-2 cells treated with Thapsigargin (Tg). Knock-down of SIRT1 promoted nuclear localization of Nrf2, and increased the level of Nrf2 acetylation. Taken together, our study indicates that cold exposure may aggravate endoplasmic reticulum stress and damage epithelial tight junctions in the colon by inhibiting SIRT1, which promotes nuclear localization of Nrf2 and induces an anti-oxidant response to maintain intestinal homeostasis. These findings suggest that SIRT1 is a potential target for regulating intestinal health under cold exposure conditions.

Potential ameliorative effect of dietary quercetin against lead-induced oxidative stress, biochemical changes, and apoptosis in laying Japanese quails

Lead (Pb) is a widespread environmental pollutant which is a toxic threat to human and animal health. The present study was designed to evaluate the ameliorative role of quercetin in laying quails exposed to Pb. A total of 112 birds were randomly divided into four groups. The control group was fed with basal diet, the Pb group was fed with ration supplemented with Pb at the dose of 100 mg/kg (as Pb (II) acetate trihydrate), the Quercetin group was fed with ration supplemented with quercetin at the dose of 400 mg/kg, and the Pb+ Quercetin group was fed with ration supplemented with Pb at the dose of 100 mg/kg and quercetin at dose of 400 mg/kg. Results showed that serum total protein, glucose, albumin, and blood urea nitrogen (BUN) values of the Pb + Quercetin group partially improved with quercetin supplementation. Meanwhile, serum creatinine values of the Pb + Quercetin group was found to be significantly lower than that of the Pb group. Aspartate aminotransferase (AST) and alanine transaminase (ALT) enzyme activities in the Quercetin and Pb + Quercetin groups were similar to those of the Control group, unlike the Pb group. Moreover, alkaline phosphatase (ALP) enzyme activity of the Pb + Quercetin group significantly improved with the addition of quercetin. We also found that malondialdehyde (MDA) levels of the kidney, liver, and heart were significantly reduced by quercetin supplementation. The glutathione, catalase, and glutathione peroxidase activities of the kidney, liver, and heart tissue were increased by quercetin supplementation. These results were in line with the observed apoptotic markers. The expression of caspase-3 and caspase-9 were significantly decreased by quercetin supplementation. It may be concluded that dietary supplementation with quercetin ameliorates the toxic effects of Pb exposure by alleviating oxidative stress, biochemical changes, and apoptosis in quails.

Arctigenin alleviates cadmium-induced nephrotoxicity: Targeting endoplasmic reticulum stress, Nrf2 signaling, and the associated inflammatory response

AIM

Nephrotoxicity is a critical consequence of cadmium toxicity. Cadmium induces nephrotoxicity through disruption of cellular redox balance and induction of endoplasmic reticulum stress (ERS) and inflammatory responses. The present study investigated the renoprotective effects of the naturally occurring arctigenin against the cadmium-induced nephrotoxicity.

MAIN METHODS

Male Wistar rats were randomized into normal control, arctigenin control, cadmium, and cadmium/arctigenin groups. Cadmium and arctigenin were administered daily over a seven-day period. On the eighth day, blood and kidney tissue specimens were collected and subjected to spectrophotometric, ELISA, and immunoblotting analysis.

KEY FINDINGS

Arctigenin significantly improved renal functions and reduced renal tubular injury in the cadmium-intoxicated rats as reflected by increased GFR and reduced levels of serum creatinine, BUN, urinary albumin-to-creatinine ratio, and protein expression of KIM-1. Arctigenin alleviated the cadmium-induced oxidative DNA damage and lipid peroxidation while boosted reduced glutathione level and antioxidant enzymes activity. Mechanistically, arctigenin enhanced nuclear translocation of the antioxidant transcription factor Nrf2 and up-regulated its downstream redox-regulating enzymes HO-1 and NQO1. Importantly, arctigenin ameliorated the cadmium-evoked ERS as demonstrated by reduced protein expression of the key molecules Bip, PERK, IRE1α, CHOP, phspho-eIF2α, and caspase-12 and diminished activity of caspase-12. Additionally, arctigenin down-regulated the cadmium-induced NF-κB nuclear translocation and decreased its downstream pro-inflammatory cytokines TNF-α and IL-1β.

SIGNIFICANCE

The current work underlines the alleviating activity of arctigenin against cadmium-evoked nephrotoxicity potentially through mitigating ERS and targeting Nrf2 and NF-κB signaling. The current findings support possible therapeutic application of arctigenin in controlling cadmium-induced nephrotoxicity although clinical investigations are necessary.

Cadmium-Induced Kidney Injury in Mice Is Counteracted by a Flavonoid-Rich Extract of Bergamot Juice, Alone or in Association with Curcumin and Resveratrol, via the Enhancement of Different Defense Mechanisms

Cadmium (Cd) represents a public health risk due to its non-biodegradability and long biological half-life. The main target of Cd is considered the kidney, where it accumulates. No effective treatment for Cd poisoning is available so that several therapeutic approaches were proposed to prevent damages after Cd exposure. We evaluated the effects of a flavonoid-rich extract of bergamot juice (BJe), alone or in association with curcumin (Cur) and resveratrol (Re), in the kidney of mice exposed to cadmium chloride (CdCl₂). Male mice were administered with CdCl₂ and treated with Cur, Re, or BJe alone or in combination for 14 days. The kidneys were processed for biochemical, structural and morphometric evaluation. Cd treatment significantly increased urea nitrogen and creatinine levels, along with tp53, Bax, Nos2 and Il1b mRNA, while reduced that of Bcl2, as well as glutathione (GSH) content and glutathione peroxidase (GPx) activity. Moreover, Cd caused damages to glomeruli and tubules, and increased Nrf2, Nqo1 and Hmox1 gene expression. Cur, Re and BJe at 40 mg/kg significantly improved all parameters, while BJe at 20 mg/kg showed a lower protective effect. After treatment with the associations of the three nutraceuticals, all parameters were close to normal, thus suggesting a new potential strategy in the protection of renal functions in subjects exposed to environmental toxicants.

Cadmium-Induced Kidney Injury: Oxidative Damage as a Unifying Mechanism

Cadmium is a nonessential metal that has heavily polluted the environment due to human activities. It can be absorbed into the human body via the gastrointestinal tract, respiratory tract, and the skin, and can cause chronic damage to the kidneys. The main site where cadmium accumulates and causes damage within the nephrons is the proximal tubule. This accumulation can induce dysfunction of the mitochondrial electron transport chain, leading to electron leakage and production of reactive oxygen species (ROS). Cadmium may also impair the function of NADPH oxidase, resulting in another source of ROS. These ROS together can cause oxidative damage to DNA, proteins, and lipids, triggering epithelial cell death and a decline in kidney function. In this article, we also reviewed evidence that the antioxidant power of plant extracts, herbal medicines, and pharmacological agents could ameliorate cadmium-induced kidney injury. Finally, a model of cadmium-induced kidney injury, centering on the notion that oxidative damage is a unifying mechanism of cadmium renal toxicity, is also presented. Given that cadmium exposure is inevitable, further studies using animal models are warranted for a detailed understanding of the mechanism underlying cadmium induced ROS production, and for the identification of more therapeutic targets.