Melatonin Attenuates Cisplatin-Induced Acute Kidney Injury through Dual Suppression of Apoptosis and Necroptosis

Revealing Melatonin's Mysteries: Receptors, Signaling Pathways, and Therapeutics Applications

Melatonin (5-methoxy-acetyl tryptamine) is a sleep-inducing hormone, and the pineal gland produces it in response to the circadian clock of darkness. In the body, MT1 and MT2 receptors are mostly found, having an orthosteric pocket and ligand binding determinants. Melatonin acts by binding on melatonin receptors, intracellular proteins, and orphan nuclear receptors. It inhibits adenyl cyclase and activates phospholipase C, resulting in gene expression and an intracellular alteration environment. Melatonin signaling pathways are also associated with other intracellular signaling pathways, i. e., cAMP/PKA and MAPK/ERK pathways. Relative expression of different proteins depends on the coupling profile of G protein, accounting pharmacology of the melatonin receptor bias system, and mediates action in a Gi-dependent manner. It shows antioxidant, antitumor, antiproliferative, and neuroprotective activity. Different types of melatonin agonists have been synthesized for the treatment of sleeping disorders. Researchers have developed therapeutics that target melatonin signaling, which could benefit a wide range of medical conditions. This review focuses on melatonin receptors, pharmacology, and signaling cascades; it aims to provide basic mechanical aspects of the receptor's pharmacology, melatonin's functions in cancer and neurodegenerative diseases, and any treatments and drugs designed for these diseases. This will allow a basic comparison between the receptors in question, highlighting any parallels and differences that may exist and providing fundamental knowledge about these receptors to future researchers.

Necroptosis in Pneumonia: Therapeutic Strategies and Future Perspectives

Pneumonia remains a major global health challenge, necessitating the development of effective therapeutic approaches. Recently, necroptosis, a regulated form of cell death, has garnered attention in the fields of pharmacology and immunology for its role in the pathogenesis of pneumonia. Characterized by cell death and inflammatory responses, necroptosis is a key mechanism contributing to tissue damage and immune dysregulation in various diseases, including pneumonia. This review comprehensively analyzes the role of necroptosis in pneumonia and explores potential pharmacological interventions targeting this cell death pathway. Moreover, we highlight the intricate interplay between necroptosis and immune responses in pneumonia, revealing a bidirectional relationship between necrotic cell death and inflammatory signaling. Importantly, we assess current therapeutic strategies modulating necroptosis, encompassing synthetic inhibitors, natural products, and other drugs targeting key components of the programmed necrosis pathway. The article also discusses challenges and future directions in targeting programmed necrosis for pneumonia treatment, proposing novel therapeutic strategies that combine antibiotics with necroptosis inhibitors. This review underscores the importance of understanding necroptosis in pneumonia and highlights the potential of pharmacological interventions to mitigate tissue damage and restore immune homeostasis in this devastating respiratory infection.

Melatonin exhibits partial protective effects against gemcitabine- and cisplatin-induced kidney and reproductive injuries in mice

Cisplatin has the potential to cause kidney and reproductive organ injuries, prompting the search for protective agents against cisplatin-induced toxicity. Melatonin, an antioxidant hormone, has shown promise in mitigating oxidative stress in various organs. However, its protective effects on cisplatin-induced kidney and reproductive injuries have not been extensively investigated. The aim of this study was to explore the potential protective effects of melatonin on cisplatin-induced kidney and reproductive injuries when administered in combination with gemcitabine in mice. Male C57BL/6 mice were subjected to a seven-week treatment with gemcitabine plus cisplatin, with or without melatonin intervention. The testis, epididymis, and kidney were assessed through histological analysis and measurement of blood parameters. Treatment with cisplatin led to a significant reduction in testicular weight, histological abnormalities, and alterations in reproductive hormone levels. Melatonin exhibited a slight protective effect on the testis, with higher doses of melatonin yielding better outcomes. However, melatonin did not reverse the effects of cisplatin on the epididymis. Administration of melatonin before and during treatment with cisplatin plus gemcitabine in mice demonstrated a modest protective effect on testicular injuries, while showing limited effects on epididymal injuries. Serum creatinine levels in the group treated with gemcitabine plus cisplatin treatment and high-dose melatonin approached those of the control group, indicating a protective effect on the kidney. These findings underscore the potential of melatonin as a protective agent against cisplatin-induced kidney and reproductive injuries and emphasize the need for further research to optimize its dosage and evaluate its long-term effects.

Melatonin protected against kidney impairment induced by 5-fluorouracil in mice

The utility of 5-fluorouracil (5-FU) as a successful chemotherapeutic drug for several cancers is limited by the induction of kidney injury and dysfunction due to redox imbalance, inflammation, and apoptosis. Meanwhile, melatonin (MLT) is a potent antioxidant and anti-inflammatory natural compound with a wide safety range. The current study aimed to investigate MLT's protective effect against 5-FU-induced kidney impairment. Male mice were given multiple doses of 5-FU at 25 and 100 mg/kg, as well as MLT at 20 mg/kg. MLT treatment alleviated the toxic effect of 5-FU by normalizing blood urea and creatinine levels and preserving the histological structure, indicating MLT's nephroprotective ability. This is accompanied by body weight maintenance, an increase in survival percentage, and preserved hematological parameters in comparison to the 5-FU-treated mice. MLT's renoprotective effect was explained by improvements in C-reactive protein, IL-6, and caspase-3 in kidney tissue, indicating MLT's anti-inflammatory and antiapoptotic ability. Furthermore, MLT inhibited 5-FU-induced lipid peroxidation by maintaining the activity of superoxide dismutase and catalase, as well as glutathione levels in kidney tissue from mice treated with both doses of 5-FU. The current findings show that MLT has a novel protective effect against 5-FU-induced renal injury and renal impairment.

Antioxidant, Antiapoptotic, and Anti-Inflammatory Effects of Hesperetin in a Mouse Model of Lipopolysaccharide-Induced Acute Kidney Injury

Sepsis is a severe inflammatory condition that can cause organ dysfunction, including acute kidney injury (AKI). Hesperetin is a flavonoid aglycone that has potent antioxidant and anti-inflammatory properties. However, the effect of hesperetin on septic AKI has not yet been fully investigated. This study examined whether hesperetin has a renoprotective effect on lipopolysaccharide (LPS)-induced septic AKI. Hesperetin treatment ameliorated histological abnormalities and renal dysfunction in LPS-injected mice. Mechanistically, hesperetin attenuated LPS-induced oxidative stress, as evidenced by the suppression of lipid and DNA oxidation. This beneficial effect of hesperetin was accompanied by downregulation of the pro-oxidant NADPH oxidase 4, restoration of glutathione levels, and activation of antioxidant enzymes. This flavonoid compound also inhibited apoptotic cell death via suppression of p53-dependent caspase-3 pathway. Furthermore, hesperetin alleviated Toll-like receptor 4-mediated cytokine production and macrophage infiltration. Our findings suggest that hesperetin ameliorates LPS-induced renal structural and functional injury through suppressing oxidative stress, apoptosis, and inflammation.

Melatonin Treatment in Kidney Diseases

Melatonin is a neurohormone that is mainly secreted by the pineal gland. It coordinates the work of the superior biological clock and consequently affects many processes in the human body. Disorders of the waking and sleeping period result in nervous system imbalance and generate metabolic and endocrine derangements. The purpose of this review is to provide information regarding the potential benefits of melatonin use, particularly in kidney diseases. The impact on the cardiovascular system, diabetes, and homeostasis causes melatonin to be indirectly connected to kidney function and quality of life in people with chronic kidney disease. Moreover, there are numerous reports showing that melatonin plays a role as an antioxidant, free radical scavenger, and cytoprotective agent. This means that the supplementation of melatonin can be helpful in almost every type of kidney injury because inflammation, apoptosis, and oxidative stress occur, regardless of the mechanism. The administration of melatonin has a renoprotective effect and inhibits the progression of complications connected to renal failure. It is very important that exogenous melatonin supplementation is well tolerated and that the number of side effects caused by this type of treatment is low.

Autophagy and necroptosis in cisplatin-induced acute kidney injury: Recent advances regarding their role and therapeutic potential

Cisplatin (CP) is a broad-spectrum antineoplastic agent, used to treat many different types of malignancies due to its high efficacy and low cost. However, its use is largely limited by acute kidney injury (AKI), which, if left untreated, may progress to cause irreversible chronic renal dysfunction. Despite substantial research, the exact mechanisms of CP-induced AKI are still so far unclear and effective therapies are lacking and desperately needed. In recent years, necroptosis, a novel subtype of regulated necrosis, and autophagy, a form of homeostatic housekeeping mechanism have witnessed a burgeoning interest owing to their potential to regulate and alleviate CP-induced AKI. In this review, we elucidate in detail the molecular mechanisms and potential roles of both autophagy and necroptosis in CP-induced AKI. We also explore the potential of targeting these pathways to overcome CP-induced AKI according to recent advances.

Macrophage-derived exosomal miR-195a-5p impairs tubular epithelial cells mitochondria in acute kidney injury mice

Macrophages (Mφ) infiltration is a common characteristic of acute kidney injury (AKI). Exosomes-mediated cell communication between tubular epithelial cells (TECs) and Mφ has been suggested to be involved in AKI. Exosomes-derived from injured TECs could regulate Mφ polarization during AKI. However, little is known regarding how activated Mφ regulates kidney injury. To explore the role of activated Mφ in the AKI process, we revealed that Mφ-derived exosomes from AKI mice (Exos^AKI ) caused mitochondria damage and induced TECs injury. Then, we detected the global miRNA expression profiles of Mφ^NC and Mφ^AKI and found that among the upregulated miRNAs, miR-195a-5p, which regulates mitochondria metabolism in cancer, was significantly increased in Mφ^AKI . Due to the enrichment of miR-195a-5p in Exos^AKI , the miR-195a-5p level in the kidney was elevated in AKI mice. More interestingly, based on the high expression of pri-miR-195a-5p in kidney-infiltrated Mφ, and the reduction of miR-195a-5p in kidney after depletion of Mφ in AKI mice, we confirmed that miR-195a-5p may be produced in infiltrated Mφ, and shuttled into TECs via Exos^Mφ . Furthermore, in vitro inhibition of miR-195a-5p alleviated the effect of Exos^AKI induced mitochondrial dysfunction and cell injury. Consistently, antagonizing miR-195a-5p with a miR-195a-5p antagomir attenuated cisplatin-induced kidney injury and mitochondrial dysfunction in mice. These findings revealed that the Mφ exosomal miR-195a-5p derived from AKI mice played a critical pathologic role in AKI progression, representing a new therapeutic target for AKI.

Histopathological, ultrastructural, and biochemical traits of apoptosis induced by peroxisomicine A1 (toxin T-514) from Karwinskia parvifolia in kidney and lung

Peroxisomicine A1 (PA1) is a toxin isolated from the Karwinskia genus plants whose target organs are the liver, kidney, and lung. In vitro studies demonstrated the induction of apoptosis by PA1 in cancer cell lines, and in vivo in the liver. Apoptosis has a wide range of morphological features such as cell shrinkage, plasma membrane blistering, loss of microvilli, cytoplasm, and chromatin condensation, internucleosomal DNA fragmentation, and formation of apoptotic bodies that are phagocytized by resident macrophages or nearby cells. Early stages of apoptosis can be detected by mitochondrial alterations. We investigated the presence of apoptosis in vivo at the morphological, ultrastructural, and biochemical levels in two target organs of PA1: kidney and lung. Sixty CD-1 mice were divided into three groups (n = 20): untreated control (ST), vehicle control (VH), and PA1 intoxicated group (2LD50). Five animals of each group were sacrificed at 4, 8, 12, and 24 h post-intoxication. Kidney and lung were examined by morphometry, histopathology, ultrastructural, and DNA fragmentation analysis. Pre-apoptotic mitochondrial alterations were present at 4 h. Apoptotic bodies were observed at 8 h and increased over time. TUNEL positive cells were detected as early as 4 h, and the DNA ladder pattern was observed at 12 h and 24 h. The liver showed the highest value of fragmented DNA, followed by the kidney and the lung. We demonstrated the induction of apoptosis by a toxic dose of PA1 in the kidney and lung in vivo. These results could be useful in understanding the mechanism of action of this compound at toxic doses in vivo.

Protective Effects of Orexin A in a Murine Model of Cisplatin-Induced Acute Kidney Injury

Cisplatin is a chemotherapeutic agent widely used in the treatment of various cancers, but its application is often limited due to complications such as acute kidney injury (AKI). Orexins are hypothalamic neuropeptides that modulate the sleep-wake cycle, neuroendocrine function, and the autonomic nervous system. Emerging evidence suggests that orexin A (OXA) has anti-inflammatory and neuroprotective effects in animal models of neuroinflammatory diseases of the central nervous system. However, the effect of OXA on kidney diseases has not been examined. Here, we investigated whether OXA has a protective effect in a murine model of cisplatin-induced AKI. Intraperitoneal administration of OXA ameliorated renal dysfunction, and histological abnormalities in mice injected with cisplatin. OXA inhibited cisplatin-induced oxidative stress through the modulation of prooxidant and antioxidant enzymes. This peptide reduced apoptotic cell death by inhibiting the p53-mediated pathway in mice injected with cisplatin. OXA also alleviated cisplatin-induced cytokine production and macrophage infiltration into injured kidneys. Taken together, these results showed that OXA ameliorates cisplatin-induced AKI via antioxidant, anti-apoptotic, and anti-inflammatory actions. This peptide could be a potential therapeutic agent for cisplatin-induced AKI.

Protective Effects of Carnosol on Renal Interstitial Fibrosis in a Murine Model of Unilateral Ureteral Obstruction

Renal fibrosis is a common feature of chronic kidney disease and is a promising therapeutic target. However, there is still limited treatment for renal fibrosis, so the development of new anti-fibrotic agents is urgently needed. Accumulating evidence suggest that oxidative stress and endoplasmic reticulum (ER) stress play a critical role in renal fibrosis. Carnosol (CS) is a bioactive diterpene compound present in rosemary plants and has potent antioxidant and anti-inflammatory properties. In this study, we investigated the potential effects of CS on renal injury and fibrosis in a murine model of unilateral ureteral obstruction (UUO). Male C57BL/6J mice underwent sham or UUO surgery and received intraperitoneal injections of CS (50 mg/kg) daily for 8 consecutive days. CS improved renal function and ameliorated renal tubular injury and interstitial fibrosis in UUO mice. It suppressed oxidative injury by inhibiting pro-oxidant enzymes and activating antioxidant enzymes. Activation of ER stress was also attenuated by CS. In addition, CS inhibited apoptotic and necroptotic cell death in kidneys of UUO mice. Furthermore, cytokine production and immune cell infiltration were alleviated by CS. Taken together, these findings indicate that CS can attenuate renal injury and fibrosis in the UUO model.

Melatonin administration alleviates 2,2,4,4-tetra-brominated diphenyl ether (PBDE-47)-induced necroptosis and secretion of inflammatory factors via miR-140-5p/TLR4/NF-κB axis in fish kidney cells

2,2,4,4-tetra-brominated diphenyl ether (PBDE-47)-the dominant homologue of polybrominated diphenyl ethers-is a toxic environmental pollutant in the aquatic environment that continuously exists and bioaccumulates in the aquatic food chain. In experimental disease models, melatonin (MEL) has been reported to attenuate necroptosis and inflammatory responses. To further explore the mechanism underlying PBDE-47 toxicity and the mitigative impact of MEL detoxification, in this study, fish kidney cell models of PBDE-47 poisoning and/or MEL treatment were developed. The Ctenopharyngodon idellus kidney (CIK) cell line was treated with PBDE-47 (100 μM) and/or MEL (60 μM) for 24 h. Experimental data suggest that PBDE-47 exposure resulted in the enhancement of cytoplasmic Ca²⁺ concentration, induction of calcium dysmetabolism, decrease in the miR-140-5p miRNA level, upregulation of Toll-like Receptor 4 (TLR4) and nuclear factor-kappaB (NF-κB), triggering of receptor interacting serine/threonine kinase-induced necroptosis, and NF-κB pathway mediated secretion of inflammatory factors in CIK cells. PBDE-47-induced CIK cell damage could be mitigated by MEL through the regulation of calcium channels and the restoration of disorders of the miR-140-5p/TLR4/NF-κB axis. Overall, MEL relieved PBDE-47-induced necroptosis and the secretion of inflammatory factors through the miR-140-5p/TLR4/NF-κB axis. These findings enrich the current understanding of the toxicological molecular mechanisms of the PBDE-47 as well as the detoxification mechanisms of the MEL.

Melatonin Attenuates Cisplatin-Induced Ototoxicity via Regulating the Cell Apoptosis of the Inner Ear

Objective

The mechanism of ototoxicity caused by cisplatin is currently unclear, and the induced apoptosis may play an important role in inner ear injury. Melatonin has high antioxidant and antiapoptotic effects. This study is aimed at clarifying the protective effect on the inner ear and the underlying mechanism of melatonin.

Design

The mice and HEI-OC1 cells were randomly separated into four groups: control group, cisplatin group, melatonin group, and cisplatin exposure after melatonin pretreatment group. Place and Duration of the Study. From September 2018 to September 2021, all experiments were completed at the Second Hospital of Shandong University. And the study was approved by the Ethics Committee of the Second Hospital of Shandong University (KYLL-2020 (KJ) A-0191). Methodology. Mice were pretreated with peritoneal injection of melatonin prior to the application of cisplatin. Auditory Brainstem Response (ABR) test was performed before and after treatment, then the temporal bones were collected for histology investigation. HEI-OC1 cells were pretreated with melatonin before adding cisplatin. The apoptosis of HEI-OC1 cells was observed by MTS, TUNEL, and flow cytometry, respectively. Moreover, the mRNA expression of apoptosis-related factors was detected by qRT-PCR.

Results

ABR and morphological analysis showed that cisplatin caused damage to the function and structure of the inner ear. MTS, TUNEL, and flow cytometry showed that the application of cisplatin caused a significant increase in the apoptosis level of HEI-OC1 cells, and melatonin pretreatment reduced this damage. Moreover, melatonin pretreatment reversed the mRNA expression changes of apoptosis-related factors induced by cisplatin.

Conclusions

Apoptosis is involved in the inner ear dysfunction caused by cisplatin. Melatonin reduces the ototoxicity of cisplatin by regulating the induced apoptosis response.

Melatonin Ameliorates Cisplatin-Induced Renal Tubular Epithelial Cell Damage through PPARα/FAO Regulation

Previous studies revealed that melatonin ameliorated acute renal injury induced by cisplatin, but the mechanisms remain unclear. Peroxidase proliferative receptor α (PPARα) is considered the major regulator of fatty acid oxidation (FAO), which is an important source of energy for renal tubular epithelial cells. In this study, the aim was to investigate the role of melatonin in cisplatin-induced NRK-52E (rat renal tubular epithelial cell line) cell damage and the underlying mechanisms. We established a cisplatin-stimulated NRK-52E model in vitro. We assessed the levels of apoptotic proteins, including caspase-3, caspase-9, and B-cell lymphoma 2-associated X protein (Bax), as well as PPARα and FAO-related genes (Acadm, Acat1, Acsm2, Acsm3, PGC-1α, Pecr, Bdh2, and Echs1). Furthermore, we detected the effects of miR-21 and PPARα antagonist on the above indicators. We found that melatonin reduced the protein expression levels of caspase-3, caspase-9, and Bax, and increased the expression levels of the PPARα gene and protein and PPARα activity, as well as FAO-related genes, in NRK-52E cells. However, miR-21 mimics and PPARα antagonists partially antagonized the above effects of melatonin. Our data indicated that melatonin could alleviate cisplatin-induced cell damage through the upregulation of PPARα/FAO.

Melatonin Alleviates Acute Kidney Injury by Inhibiting NRF2/Slc7a11 Axis-Mediated Ferroptosis

Acute kidney injury (AKI) is still a puzzling clinical problem; its pathophysiology is not completely understood. Up to now, an effective treatment for AKI is lacking. Ferroptosis is a novel form of regulated cell death characterized by the lethal accumulation of lipid hydroperoxides that are dependent on iron and reactive oxygen species and mitochondrial dysfunction. Recently, ferroptosis was shown to play a vital role in AKI such as ischemia-reperfusion kidney injury and folic acid-induced AKI. Melatonin (MT) is an antioxidant that regulates the sleep-wake cycle. While the therapeutic effect of melatonin on AKI has been reported, its mechanism for the treatment of renal ferroptosis remains unclear. We found that melatonin treatment significantly alleviated the serum biochemistry index and histopathological alterations in vivo AKI models induced by bilateral renal artery ischemia reperfusion and folic acid in mice. Ferroptosis induced by hypoxia and reoxygenation or erastin (Era) in mouse tubular epithelial cells (MTEC) was also rescued by melatonin treatment. RNA sequence analysis of ferroptosis-related genes showed that melatonin affects oxidative stress responses by inhibiting hypoxia and reoxygenation- (HR-) mediated downregulation of NRF2 and upregulation of Slc7a11 in MTEC. Specific knockdown of NRF2 increased the sensitivity of cells to ferroptosis, and melatonin failed to protect against ferroptosis in the HR condition. Together, our data indicate that melatonin prevents ferroptosis in AKI by acting on the NRF2/Slc7a11 axis.

Histological Effect of Gemcitabine on the Liver and Kidney of Male Rat with and without Melatonin

Background: the aim of this study is to identify the toxic effect of gemcitabine on the kidney and liver tissues of rat and whether melatonin has any protective effect on these tissues. MATERIALS AND METHODS: 32 adults male Wistar rats were selected and divided into four groups. Group A was the control group that received normal saline. Group B received gemcitabine alone in a dose of 25mg/kg body weight intraperitoneally once per week for four successive weeks. Group C received gemcitabine intraperitoneally in a dose of 25mg/ kg and melatonin orally in a dose of 10mg/kg once per week for four successive weeks. Group D received only melatonin 10mg/kg once per week for four weeks. RESULTS: The histological changes of liver of group B showed disorganization of hepatic tissue with congestion in the portal area and chronic inflammatory cells infiltration in the periportal area. Nuclei of some hepatocytes were vesicular with steatosis. In group C liver sections showed inflammatory cell infiltration with mild pyknosis of some hepatocytes. Liver sections of group D were limited to degeneration of some hepatocyte. Renal sections of group B showed degeneration and necrosis of epithelial cells with thickening of blood vessel wall, congestion and thrombus formation with cystic appearance in the interstitial tissue were detected. While in group C the histological sections showed swelling of epithelial cells lining renal tubules with congestion of blood vessels. Renal sections of group D were more or less normal. CONCLUSION:   the present study concluded that gemcitabine induced toxic effect on liver and kidney of male rats and melatonin may play protective effect on the tissue of these organs. Key wards: gemcitabine, melatonin, liver, kidney, rat

Oridonin Attenuates Cisplatin-Induced Acute Kidney Injury via Inhibiting Oxidative Stress, Apoptosis, and Inflammation in Mice

The use of cisplatin, a chemotherapy drug, is often limited due to its renal side effects such as acute kidney injury (AKI). However, there are no validated medications to prevent or treat cisplatin-induced AKI. Oridonin is the major bioactive component of Isodon rubescens (Rabdosia rubescens) and exhibits anticancer, antioxidative, and anti-inflammatory effects. Recent studies have shown that oridonin alleviated a variety of inflammatory diseases, including renal diseases, in rodents. This study was aimed at investigating the potential renoprotective effect of oridonin on cisplatin-induced AKI. Male C57BL/6 mice were administered with cisplatin (20 mg/kg) with or without oridonin (15 mg/kg). Oridonin administration to mice after cisplatin injection attenuated renal dysfunction and histopathological changes. Upregulation of tubular injury markers was also suppressed by oridonin. Mechanistically, oridonin suppressed lipid peroxidation and reversed the decreased ratio of reduced to oxidized glutathione in cisplatin-injected mice. The increase in cisplatin-induced apoptosis was also alleviated by the compound. Moreover, oridonin inhibited cytokine overproduction and attenuated immune cell infiltration in cisplatin-injected mice. Altogether, these data demonstrated that oridonin alleviates cisplatin-induced kidney injury via inhibiting oxidative stress, apoptosis, and inflammation.

Protective Effects of Carnosic Acid on Lipopolysaccharide-Induced Acute Kidney Injury in Mice

Septic acute kidney injury (AKI) is an important medical problem worldwide, but current treatments are limited. During sepsis, lipopolysaccharide (LPS) activates various signaling pathways involved in multiorgan failure. Carnosic acid is a natural phenolic diterpene and has multiple bioactivities, such as anti-tumor, anti-inflammatory, and anti-oxidative effects. However, the effect of carnosic acid on septic AKI has not been explored. Therefore, this study aimed to determine whether carnosic acid has a therapeutic effect on LPS-induced kidney injury. Administration of carnosic acid after LPS injection ameliorated histological abnormalities and renal dysfunction. Cytokine production, immune cell infiltration, and nuclear factor-κB activation after LPS injection were also alleviated by carnosic acid. The compound suppressed oxidative stress with the modulation of pro-oxidant and antioxidant enzymes. Tubular cell apoptosis and caspase-3 activation were also inhibited by carnosic acid. These data suggest that carnosic acid ameliorates LPS-induced AKI via inhibition of inflammation, oxidative stress, and apoptosis and could serve as a useful treatment agent for septic AKI.

Protective Effects of 6-Shogaol, an Active Compound of Ginger, in a Murine Model of Cisplatin-Induced Acute Kidney Injury

Acute kidney injury (AKI) is a dose-limiting side effect of cisplatin therapy in cancer patients. However, effective therapies for cisplatin-induced AKI are not available. Oxidative stress, tubular cell death, and inflammation are known to be the major pathological processes of the disease. 6-Shogaol is a major component of ginger and exhibits anti-oxidative and anti-inflammatory effects. Accumulating evidence suggest that 6-shogaol may serve as a potential therapeutic agent for various inflammatory diseases. However, whether 6-shogaol exerts a protective effect on cisplatin-induced renal side effect has not yet been determined. The aim of this study was to evaluate the effect of 6-shogaol on cisplatin-induced AKI and to investigate its underlying mechanisms. An administration of 6-shogaol after cisplatin treatment ameliorated renal dysfunction and tubular injury, as shown by a reduction in serum levels of creatinine and blood urea nitrogen and an improvement in histological abnormalities. Mechanistically, 6-shogaol attenuated cisplatin-induced oxidative stress and modulated the renal expression of prooxidant and antioxidant enzymes. Apoptosis and necroptosis induced by cisplatin were also suppressed by 6-shogaol. Moreover, 6-shogaol inhibited cisplatin-induced cytokine production and immune cell infiltration. These results suggest that 6-shogaol exhibits therapeutic effects against cisplatin-induced AKI via the suppression of oxidative stress, tubular cell death, and inflammation.

Melatonin Alleviates Renal Injury in Mouse Model of Sepsis

Melatonin (N-acetyl-5-methoxytryptamine; MLT) has been shown to have a renal-protective effect against kidney injury. However, the mechanisms underlying the protective role of MLT in sepsis-induced renal injury are yet to be revealed. In this study, MLT alleviated renal dysfunction with the increase of BUN (blood urea nitrogen) and SCR (serum creatinine) and reduction of fibrosis in the CLP (cecal ligation puncture) model. RNA-seq analysis showed that MLT repressed the oxidant stress in response to kidney injury. Our in vitro study showed that MLT suppresses LPS-induced accumulation of ROS (reactive oxygen species) production via SOD2 downregulation and Nox4 upregulation in HK-2 cells. Furthermore, we found that MLT alleviated the inflammatory response, with the mRNA-level reduction of Il-1α, Il-1β, Mcp-1, and Tgf-β1. Taken together, in evaluating the therapeutic effect of MLT on sepsis-induced acute kidney injury, the results showed that MLT alleviated renal damage by regulating the production of ROS.

Protective prospects of eco-friendly synthesized selenium nanoparticles using Moringa oleifera or Moringa oleifera leaf extract against melamine induced nephrotoxicity in male rats

Nanotechnology is used in a wide range of applications, including medical therapies that precisely target disease prevention and treatment. The current study aimed firstly, to synthesize selenium nanoparticles (SeNPs) in an eco-friendly manner using Moringa oleifera leaf extract (MOLE). Secondly, to compare the protective effects of green-synthesized MOLE-SeNPs conjugate and MOLE ethanolic extract as remedies for melamine (MEL) induced nephrotoxicity in male rats. One hundred and five male Sprague Dawley rats were divided into seven groups (n = 15), including 1st control, 2nd MOLE (800 mg/kg BW), 3rd SeNPs (0.5 mg/kg BW), 4th MOLE-SeNPs (200 μg/kg BW), 5th MEL (700 mg/kg BW), 6th MEL+MOLE, and 7th MEL+MOLE SeNPs. All groups were orally gavaged day after day for 28 days. SeNPs and the colloidal SeNPs were characterized by TEM, SEM, and DLS particle size. SeNPs showed an absorption peak at a wavelength of 530 nm, spherical shape, and an average size between 3.2 and 20 nm. Colloidal SeNPs absorption spectra were recorded between 400 and 700 nm with an average size of 3.3-17 nm. MEL-induced nephropathic alterations represented by a significant increase in serum creatinine, urea, blood urea nitrogen (BUN), renal TNFα, oxidative stress-related indices, and altered the relative mRNA expression of apoptosis-related genes Bax, Caspase-3, Bcl2, Fas, and FasL. MEL-induced array of nephrotoxic morphological changes, and up-regulated immune-expression of proliferating cell nuclear antigen (PCNA) and proliferation-associated nuclear antigen Ki-67. Administration of MOLE or MOLE-SeNPs significantly reversed MEL-induced renal function impairments, oxidative stress, histological alterations, modulation in the relative mRNA expression of apoptosis-related genes, and the immune-expression of renal PCNA and Ki-67. Conclusively, the green-synthesized MOLE-SeNPs and MOLE display nephron-protective properties against MEL-induced murine nephropathy. This study is the first to report these effects which were more pronounced in the MOLE group than the green biosynthesized MOLE-SeNPs conjugate group.

Possible benefits of exogenous melatonin for individuals on dialysis: a narrative review on potential mechanisms and clinical implications

Prevention of oxidative stress and inflammation in chronic kidney disease patients (CKD) on dialysis may reduce dialysis-associated complications. Administration of powerful antioxidants may improve the consequences of peritoneal dialysis (PD) and hemodialysis (HD). This narrative review aimed to show the potential therapeutic effects of melatonin (MLT) on the consequences of CKD patients receiving HD or PD. The results of preclinical and clinical studies have proven that CKD and dialysis are accompanied by reduced endogenous MLT levels and related complications such as sleep disorders. Enhanced oxidative stress, inflammation, cellular damages, and renal fibrosis, along with dysregulation of the renin-angiotensin system (RAS), have been observed in CKD and patients on dialysis. Results of studies have revealed that the restoration of MLT via the exogenous source may regulate oxidative stress, inflammation, and RAS functions, inhibit fibrosis, and improve complications in patients with long-term dialysis patients. In summary, treatment of patients with CKD and dialysis with exogenous MLT is suggested as a practical approach in reducing the outcomes and improving the quality of life in patients via antioxidant, anti-inflammatory, and anti-fibrotic signaling pathways. Therefore, this hormone can be considered in clinical practice to manage dialysis-related complications.

Combined Melatonin and Extracorporeal Shock Wave Therapy Enhances Podocyte Protection and Ameliorates Kidney Function in a Diabetic Nephropathy Rat Model

(1) Background: Diabetic nephropathy (DN) is common complication of diabetes. Current therapy for DN does not include promotion of podocyte protection. Therefore, we investigated the therapeutic effect of melatonin (Mel) combined extracorporeal shock wave (SW) therapy on a DN rat model. (2) Methods: The DN rats were treated with Mel (5 mg/kg) twice a week for 6 weeks and SW treatment once a week (0.13 mJ/mm²) for 6 weeks. We assessed urine microalbumin, albumin to creatinine ratio (ACR), glomerular hypertrophy, glomerular fibrosis, podocyte markers (Wilm’s tumor protein-1, synaptopodin and nephrin), cell proliferation, cell survival, cell apoptosis, renal inflammation and renal oxidative stress. (3) Results: The Mel combined SW therapy regimen significantly reduced urine microalbumin excretion (3.3 ± 0.5 mg/dL, p < 0.001), ACR (65.2 ± 8.3 mg/g, p < 0.001), glomerular hypertrophy (3.1 ± 0.1 × 10⁶ μm³, p < 0.01) and glomerular fibrosis (0.9 ± 0.4 relative mRNA fold, p < 0.05). Moreover, the Mel combined SW therapy regimen significantly increased podocyte number (44.1 ± 5.0% area of synaptopodin, p < 0.001) in the Mel combined SW group. This is likely primarily because Mel combined with SW therapy significantly reduced renal inflammation (753 ± 46 pg/mg, p < 0.01), renal oxidative stress (0.6 ± 0.04 relative density, p < 0.05), and apoptosis (0.3 ± 0.03 relative density, p < 0.001), and also significantly increased cell proliferation (2.0 ± 0.2% area proliferating cell nuclear antigen (PCNA), p < 0.01), cell survival, and nephrin level (4.2 ± 0.4 ng/mL, p < 0.001). (4) Conclusions: Mel combined SW therapy enhances podocyte protection and ameliorates kidney function in a DN rat model. Mel combined SW therapy may serve as a novel noninvasive and effective treatment of DN.

Regulated cell death in cisplatin-induced AKI: relevance of myo-inositol metabolism

Regulated cell death (RCD), distinct from accidental cell death, refers to a process of well-controlled programmed cell death with well-defined pathological mechanisms. In the past few decades, various terms for RCDs were coined, and some of them have been implicated in the pathogenesis of various types of acute kidney injury (AKI). Cisplatin is widely used as a chemotherapeutic drug for a broad spectrum of cancers, but its usage was hampered because of being highly nephrotoxic. Cisplatin-induced AKI is commonly seen clinically, and it also serves as a well-established prototypic model for laboratory investigations relevant to acute nephropathy affecting especially the tubular compartment. Literature reports over a period of three decades have indicated that there are multiple types of RCDs, including apoptosis, necroptosis, pyroptosis, ferroptosis, and mitochondrial permeability transition-mediated necrosis, and some of them are pertinent to the pathogenesis of cisplatin-induced AKI. Interestingly, myo-inositol metabolism, a vital biological process that is largely restricted to the kidney, seems to be relevant to the pathogenesis of certain forms of RCDs. A comprehensive understanding of RCDs in cisplatin-induced AKI and their relevance to myo-inositol homeostasis may yield novel therapeutic targets for the amelioration of cisplatin-related nephropathy.

PGC-1α alleviates mitochondrial dysfunction via TFEB-mediated autophagy in cisplatin-induced acute kidney injury

Because of the key role of impaired mitochondria in the progression of acute kidney injury (AKI), it is striking that peroxisome proliferator γ coactivator 1-α (PGC-1α), a transcriptional coactivator of genes involved in mitochondrial biogenesis and autophagy, protects from kidney injury. However, the specific mechanism involved in PGC-1α-mediated autophagy remains elusive. In vivo, along with the severe kidney damage, the expression of PGC-1α was decreased in cisplatin-induced AKI mice. Conversely, PGC-1α activator (ZLN005) administration could alleviate kidney injury. Consistently, in vitro overexpression of PGC-1α or ZLN005 treatment inhibited cell apoptosis and mitochondrial dysfunction induced by cisplatin. Moreover, ZLN005 treatment increased the expression of LC3-II and co-localization between LC3 and mitochondria, suggesting that the mitophagy was activated. Furthermore, PGC-1α-mediated the activation of mitophagy was reliant on the increased expression of TFEB, and the protective effects were abrogated in TFEB-knockdown cells. These data suggest that the activation of PGC-1α could alleviate mitochondrial dysfunction and kidney injury in AKI mice via TFEB-mediated autophagy.

Melatonin Improves Endoplasmic Reticulum Stress-Mediated IRE1α Pathway in Zücker Diabetic Fatty Rat

Obesity and diabetes are linked to an increased prevalence of kidney disease. Endoplasmic reticulum stress has recently gained growing importance in the pathogenesis of obesity and diabetes-related kidney disease. Melatonin, is an important anti-obesogenic natural bioactive compound. Previously, our research group showed that the renoprotective effect of melatonin administration was associated with restoring mitochondrial fission/fusion balance and function in a rat model of diabesity-induced kidney injury. This study was carried out to further investigate whether melatonin could suppress renal endoplasmic reticulum (ER) stress response and the downstream unfolded protein response activation under obese and diabetic conditions. Zücker diabetic fatty (ZDF) rats and lean littermates (ZL) were orally supplemented either with melatonin (10 mg/kg body weight (BW)/day) (M-ZDF and M-ZL) or vehicle (C-ZDF and C-ZL) for 17 weeks. Western blot analysis of ER stress-related markers and renal morphology were assessed. Compared to C-ZL rats, higher ER stress response associated with impaired renal morphology was observed in C-ZDF rats. Melatonin supplementation alleviated renal ER stress response in ZDF rats, by decreasing glucose-regulated protein 78 (GRP78), phosphoinositol-requiring enzyme1α (IRE1α), and ATF6 levels but had no effect on phospho-protein kinase RNA-like endoplasmic reticulum kinase (PERK) level. In addition, melatonin supplementation also restrained the ER stress-mediated apoptotic pathway, as indicated by decreased pro-apoptotic proteins phospho-c-jun amino terminal kinase (JNK), Bax, and cleaved caspase-3, as well as by upregulation of B cell lymphoma (Bcl)-2 protein. These improvements were associated with renal structural recovery. Taken together, our findings revealed that melatonin play a renoprotective role, at least in part, by suppressing ER stress and related pro-apoptotic IRE1α/JNK signaling pathway.

Melittin Ameliorates Endotoxin-Induced Acute Kidney Injury by Inhibiting Inflammation, Oxidative Stress, and Cell Death in Mice

Sepsis-related acute kidney injury (AKI) is a worldwide health problem, and its pathogenesis involves multiple pathways. Lipopolysaccharide (LPS) is an endotoxin that induces systemic inflammatory responses. Melittin, a main constituent of bee venom, exerts several biological activities such as antioxidant, anti-inflammatory, and antiapoptotic actions. However, whether melittin protects against endotoxin-induced AKI remains undetermined. Here, we aimed to examine the potential action of melittin on LPS-induced renal injury and explore the mechanisms. We showed that acute renal failure and structural damage after injection of LPS were markedly attenuated by administration of melittin. The peptide also suppressed expression of markers of direct tubular damage in kidneys of the LPS-treated mice. Mechanistically, melittin reduced systemic and renal levels of cytokines and inhibited renal accumulation of immune cells with concomitant suppression of nuclear factor kappa-B pathway. Increased amounts of lipid peroxidation products after LPS treatment were largely decreased by melittin. Additionally, the peptide decreased expression of nicotinamide adenine dinucleotide phosphate oxidase 4 and enhanced nuclear factor erythroid-2-related factor 2-mediated antioxidant defenses. Moreover, melittin inhibited apoptotic and necroptotic cell death after LPS treatment. Lastly, we showed that melittin improved the survival rate of LPS-injected mice. These results suggest that melittin ameliorates endotoxin-induced AKI and mortality through inhibiting inflammation, oxidative injury, and apoptotic and necroptotic death of tubular epithelial cells.

Isoquercitrin Ameliorates Cisplatin-Induced Nephrotoxicity Via the Inhibition of Apoptosis, Inflammation, and Oxidative Stress

Cisplatin is extensively used and is highly effective in clinical oncology; nevertheless, nephrotoxicity has severely limited its widespread utility. Isoquercitrin (IQC), a natural flavonoid widely found in herbage, is well known and recognized for its antioxidant, anti-inflammatory, and anti-apoptotic properties. However, the potential effects and mechanism of IQC in cisplatin-induced acute kidney diseases remain unknown. In this study, we postulated the potential effects and mechanism of IQC upon cisplatin exposure in vivo and in vitro. For the in vivo study, C57BL/6J mice were pretreated with IQC or saline (50 mg/kg/day) by gavage for 3 days before cisplatin single injection (25 mg/kg). Renal function, apoptosis, inflammation, oxidative stress and p-ERK were measured to evaluate kidney injury. In vitro, mouse proximal tubular cells (mPTCs) and human proximal tubule epithelial cell line (HK2) were pretreated with or without IQC (80 μM for mPTCs and 120 μM for HK2) for 2 h and then co-administrated with cisplatin for another 24 h. Apoptosis, inflammation, ROS and p-ERK of cells were also measured. In vivo, IQC administration strikingly reduced cisplatin-induced nephrotoxicity as evidenced by the improvement in renal function (serum creatinine and blood urea nitrogen), kidney histology (PAS staining), apoptotic molecules (cleaved caspase-3, caspase-8, Bax and Bcl-2), inflammatory cytokines (IL-1β, IL-6, TNF-α, and COX-2), oxidative stress (MDA and total glutathione) and p-ERK. In line with in vivo findings, IQC markedly protected against cisplatin-induced cell injury in mPTCs and HK2 cells. Collectively, these findings demonstrated that IQC administration could significantly protect against cisplatin nephrotoxicity possibly through ameliorating apoptosis, inflammation and oxidative stress accompanied by cross talk with p-ERK. Furthermore, IQC may have potential therapeutic uses in the treatment of cisplatin-induced acute kidney injury.

Inhibition of p300 by Garcinol Protects against Cisplatin-Induced Acute Kidney Injury through Suppression of Oxidative Stress, Inflammation, and Tubular Cell Death in Mice

Emerging evidence suggests that epigenetic mechanisms such as histone modification are crucially involved in the pathophysiology of acute kidney injury (AKI). The histone acetyltransferase p300 regulates several biological processes through the acetylation of histones or transcription factors. However, the role of p300 in cisplatin-induced AKI remains poorly understood. Therefore, we investigated the effects of garcinol, a potent p300 inhibitor, on cisplatin-induced AKI and explored the mechanisms. Administration of garcinol significantly reversed the upregulation of p300 and increased acetylation of histone H3, along with amelioration of renal dysfunction and histopathological injury in the kidneys of cisplatin-injected mice. Garcinol also attenuated oxidative stress and reduced expression of pro-oxidant enzymes. In addition, garcinol reduced the elevated production of cytokines and chemokines and suppressed immune cell accumulation together with downregulation of vascular adhesion molecules. These beneficial effects of garcinol were associated with a reduction in acetylation of the p65 subunit of nuclear factor kappa-B. Further, garcinol significantly inhibited apoptosis and caspase-3 activation, with a decrease in p53 acetylation in cisplatin-injected mice. Taken together, we demonstrated that the inhibition of p300 by garcinol ameliorated cisplatin-induced renal injury, presumably through epigenetic mechanisms. These results suggest that garcinol might be a potential preventive agent for cisplatin-induced AKI.

Kahweol Ameliorates Cisplatin-Induced Acute Kidney Injury through Pleiotropic Effects in Mice

Cisplatin is an effective chemotherapeutic agent, but its clinical use is frequently limited by its nephrotoxicity. The pathogenesis of cisplatin-induced acute kidney injury (AKI) remains incompletely understood, but oxidative stress, tubular cell death, and inflammation are considered important contributors to cisplatin-induced renal injury. Kahweol is a natural diterpene extracted from coffee beans and has been shown to possess anti-oxidative and anti-inflammatory properties. However, its role in cisplatin-induced nephrotoxicity remains undetermined. Therefore, we investigated whether kahweol exerts a protective effect against cisplatin-induced renal injury. Additionally, its mechanisms were also examined. Administration of kahweol attenuated renal dysfunction and histopathological damage together with inhibition of oxidative stress in cisplatin-injected mice. Increased expression of nicotinamide adenine dinucleotide phosphate oxidase 4 and decreased expression of manganese superoxide dismutase and catalase after cisplatin treatment were significantly reversed by kahweol. Moreover, kahweol inhibited cisplatin-induced apoptosis and necroptosis in the kidneys. Finally, kahweol reduced inflammatory cytokine production and immune cell accumulation together with suppression of nuclear factor kappa-B pathway and downregulation of vascular adhesion molecules. Together, these results suggest that kahweol ameliorates cisplatin-induced renal injury via its pleiotropic effects and might be a potential preventive option against cisplatin-induced nephrotoxicity.

Oxidative stress and mitochondrial dysfunction involved in ammonia-induced nephrocyte necroptosis in chickens

Ammonia (NH₃), an environmental pollutant, poses a serious threat to human and avian health. Although previous studies have showed that NH₃ caused kidney injury, the molecular mechanisms of nephrotoxicity induced by NH₃ remain unclear. To explore the mechanisms of NH₃ nephrotoxicity, a total of 36 broiler chicks at one day of age were exposed to NH₃. After 42 days of exposure, blood samples were collected to determine creatinine and uric acid; and kidney samples were weighted and then collected to detect ultrastructural changes, oxidative stress parameters, ATPases, necroptosis- and mitochondrial dynamics-related genes. The results showed that chickens exposed to NH₃ showed lower relative kidney weight and an increase concentration in serum creatinine and uric acid. NH₃ exposure caused nephrocyte necrosis and increased the expression of necroptosis-related genes (TNF-α, RIPK1, RIPK3, MLKL, and JNK). Besides, the activities of antioxidant systems (SOD, CAT, GSH-Px, and T-AOC) were reduced, whereas the concentrations of H₂O₂ and MDA were elevated. Lower activities of ATPases were obtained in NH₃ treatment groups. Furthermore, the mitochondrial fission-related genes drp1 and mff were activated, and mitochondrial fusion-related genes opa1, mfn1 and mfn2 were suppressed after NH₃ exposure. Based on the above results, we conclude that NH₃ caused-oxidative stress and mitochondrial dysfunction mediated nephrocyte necroptosis in chickens. This study may provide new insight into NH₃ nephrotoxicity.

Protective Effects of Bee Venom against Endotoxemia-Related Acute Kidney Injury in Mice

Sepsis-associated acute kidney injury (AKI) is a leading cause of death in hospitalized patients worldwide. Despite decades of effort, there is no effective treatment for preventing the serious medical condition. Bee venom has long been used to treat a variety of inflammatory diseases. However, whether bee venom has protective effects against lipopolysaccharide (LPS)-induced AKI has not been explored. The aim of this study was to evaluate the effects of bee venom on LPS-induced AKI. The administration of bee venom alleviated renal dysfunction and structural injury in LPS-treated mice. Increased renal levels of tubular injury markers after LPS treatment were also suppressed by bee venom. Mechanistically, bee venom significantly reduced plasma and tissue levels of inflammatory cytokines and immune cell infiltration into damaged kidneys. In addition, mice treated with bee venom exhibited reduced renal expression of lipid peroxidation markers after LPS injection. Moreover, bee venom attenuated tubular cell apoptosis in the kidneys of LPS-treated mice. In conclusion, these results suggest that bee venom attenuates LPS-induced renal dysfunction and structural injury via the suppression of inflammation, oxidative stress, and tubular cell apoptosis, and might be a useful therapeutic option for preventing endotoxemia-related AKI.

Protective Effects of SPA0355, a Thiourea Analogue, Against Lipopolysaccharide-Induced Acute Kidney Injury in Mice

Inflammation and oxidative stress plays an essential role in the pathophysiology of sepsis-associated acute kidney injury (AKI). SPA0355, a thiourea analogue, has been shown to display beneficial effects against a variety of inflammatory diseases arising from its anti-inflammatory and anti-oxidant properties. However, the potential protective effects of SPA0355 against lipopolysaccharide (LPS)-induced AKI have not been explored. The aim of this study was to evaluate the effects of SPA0355 on LPS-induced AKI and investigate its underlying mechanisms. We found that renal dysfunction and histological abnormalities after LPS injection were significantly ameliorated by SPA0355. The compound also reduced renal expression of tubular injury markers. Mechanistically, SPA0355 significantly suppressed plasma and tissue levels of inflammatory cytokines and immune cell infiltration with inhibition of nuclear factor kappa-B p65 signaling. In addition, elevated levels of 4-hydroxynonenal and malondialdehyde after LPS injection were significantly decreased by SPA0355. The compound also regulated expression of pro-oxidant and antioxidant enzymes after LPS injection. Moreover, SPA0355 attenuated LPS-induced tubular cell apoptosis via inhibition of p53 signaling pathway. Altogether, these results suggest that SPA0355 protects against LPS-induced AKI through suppressing inflammation, oxidative stress, and tubular cell apoptosis and might be a potential preventive option for the disease.

Protective Effects of Melatonin Against Aristolochic Acid-Induced Nephropathy in Mice

Melatonin, a pineal hormone, is well known to regulate the sleep–wake cycle. Besides, the hormone has been shown to display pleiotropic effects arising from its powerful anti-oxidant and anti-inflammatory activities. Recent studies have reported that melatonin exerts protective effects in animal models of kidney disease. However, the potential effects of melatonin on aristolochic acid (AA)-induced nephropathy (AAN) have not yet been investigated. Here, we found that the administration of melatonin ameliorated AA-induced renal dysfunction, as evidenced by decreased plasma levels of blood urea nitrogen and creatinine and histopathological abnormalities such as tubular dilatation and cast formation. The upregulation of tubular injury markers after AA injection was reversed by melatonin. Melatonin also suppressed AA-induced oxidative stress, as evidenced by the downregulation of 4-hydroxynonenal and reduced level of malondialdehyde, and modulated expression of pro-oxidant and antioxidant enzymes. In addition, p53-dependent apoptosis of tubular epithelial cells, infiltration of macrophages and CD4⁺ T cells into damaged kidneys, and renal expression of cytokines and chemokines were inhibited by melatonin. Moreover, melatonin attenuated AA-induced tubulointerstitial fibrosis through suppression of the tumor growth factor-β/Smad signaling pathway. These results suggest that melatonin might be a potential therapeutic agent for AAN.