Potential protective effect of etanercept and aminoguanidine in methotrexate-induced hepatotoxicity and nephrotoxicity in rats

Nobiletin alleviates methotrexate-induced hepatorenal toxicity in rats

We investigated the possible ameliorative effects of nobiletin (NBL) against methotrexate (MTX)-induced hepatorenal toxicity in rats. Twenty-eight Wistar albino rats were randomly divided into four groups, namely: Control; MTX (administered 20 mg/kg MTX); MTX+NBL (administered 20 mg/kg MTX and 10 mg/kg NBL per day); and NBL (administered 10 mg/kg/day NBL). Histopathological, immunohistochemical and biochemical analyses were performed on the kidney and liver tissues of rats at the end of the study. MTX caused renal toxicity, as indicated by increases in malondialdehyde (MDA) and caspase-3, as well as decreases in reduced glutathione (GSH), glucose-6-phosphate dehydrogenase (G6PD), glutathione peroxidase (GPx), catalase (CAT) and B-cell lymphoma-2 (Bcl-2). MTX also caused hepatotoxicity, as indicated by increases in 8-hydroxy-2'-deoxyguanosine (8-OHdG), tumor necrosis factor alpha (TNF-α), MDA and caspase-3 and decrease in interleukin 10 (IL-10), GSH, total antioxidant capacity, GPx, G6PD, CAT and Bcl-2. MTX caused histopathological changes in kidney and liver tissues indicating tissue and cellular damage. Administration of NBL concurrently with methotrexate reduced oxidative stress, inflammatory and apoptotic signs, and prevented kidney and liver damage caused by methotrexate. We consider NBL has attenuating and ameliorating effects on methotrexate-induced hepatorenal toxicity.

EphA2-specific microvesicles derived from tumor cells facilitate the targeted delivery of chemotherapeutic drugs for osteosarcoma therapy

Despite advances in surgery and chemotherapy, the survival of patients with osteosarcoma (OS) has not been fundamentally improved over the last two decades. Microvesicles (MVs) have a high cargo-loading capacity and are emerging as a promising drug delivery nanoplatform. The aim of this study was to develop MVs as specifically designed vehicles to enable OS-specific targeting and efficient treatment of OS. Herein, we designed and constructed a nanoplatform (YSA-SPION-MV/MTX) consisting of methotrexate (MTX)-loaded MVs coated with surface-carboxyl Fe3O4 superparamagnetic nanoparticles (SPIONs) conjugated with ephrin alpha 2 (EphA2)-targeted peptides (YSAYPDSVPMMS, YSA). YSA-SPION-MV/MTX showed an effective targeting effect on OS cells, which was depended on the binding of the YSA peptide to EphA2. In the orthotopic OS mouse model, YSA-SPION-MV/MTX effectively delivered drugs to tumor sites with specific targeting, resulting in superior anti-tumor activity compared to MTX or MV/MTX. And YSA-SPION-MV/MTX also reduced the side effects of high-dose MTX. Taken together, this strategy opens up a new avenue for OS therapy. And we expect this MV-based therapy to serve as a promising platform for the next generation of precision cancer nanomedicines.

Astaxanthin prevents nephrotoxicity through Nrf2/HO-1 pathway

Renal toxicity is one of the side effects of methotrexate (MTX). Therefore, this study explored the use of astaxanthin (AST), as a natural carotenoid, against MTX-induced nephrotoxicity emphasizing the changes in oxidative stress and the expression of nuclear factor erythroid 2-related factor 2/heme oxygenase 1 (Nrf2/HO-1). During the 10 days of the experiment, male Wistar rats in different groups received MTX (10 mg/kg) on days 6, 8, and 10 and three doses of AST (25, 50, and 75 mg/kg) during the entire course. Renal failure caused by MTX was observed in significant histopathological changes and a significant increase in serum levels of creatinine, urea, and uric acid (p < 0.05). Oxidative change induced by MTX injection was also observed by remarkably increasing the tissue level of malondialdehyde (MDA) and decreasing the activity of superoxide dismutase (SOD) and catalase (p < 0.001). AST decreases the adverse effects of MTX by upregulating the expression of Nrf2/HO-1 genes (p < 0.01) and decreasing the tissue level of MDA (p < 0.01). Also, AST significantly reduced the amount of creatinine, urea, and uric acid in the serum and improved the activity of SOD and catalase in the kidney tissue (p < 0.05). Thus, AST may protect the kidney against oxidative stress caused by MTX.

Andrographis paniculata (Burm.f.) Nees Alleviates Methotrexate-Induced Hepatotoxicity in Wistar Albino Rats

Andrographis paniculata is a herbal plant used in traditional medicinal approaches to treat various ailments and diseases. Methotrexate (MTX) is a clinically used immunosuppressant and anticancer drug. One of the increasing concerns with MTX use is liver toxicity. The aim of this study is to investigate the potential effect of aqueous leaf extract of Andrographis paniculata against methotrexate-induced hepatotoxicity. Wistar albino rats were grouped into five groups, and the drugs were administered. MTX (20 mg/kg b.w.) was intraperitoneally injected into rats on the ninth day alone. Aqueous leaf extract of Andrographis paniculata (500 mg/kg b.w./day) was orally administered for 10 days. We confirmed the beneficial effect of aqueous extracts of Andrographis paniculata on restoring the hepatic enzyme markers, lipid profile, antioxidant level, anti-inflammatory marker (IL-10), anti-apoptosis (bcl-2), significant suppression of inflammatory cytokines (TNF-α, and IL-6), apoptosis marker (caspase 3) and cellular tissue damage caused by MTX. Overall, we revealed that Andrographis paniculata reduces critical aspects of oxidative stress, inflammatory processes, and apoptosis, thus protecting against methotrexate-induced hepatotoxicity.

Cytokine modulation by etanercept ameliorates metabolic syndrome and its related complications induced in rats administered a high-fat high-fructose diet

The aim of the present study was to investigate the effect of etanercept (ETA)-an anti-tumor necrosis factor α (TNF-α) monoclonal antibody-on metabolic disorders such as obesity, hypertension, dyslipidemia, and insulin resistance associated with the metabolic syndrome (MS). MS was induced in rats via high-fat high-fructose (HFHF) administration for 8 weeks. Rats were divided into three groups: negative control, HFHF model, and ETA-treated groups [HFHF + ETA (0.8 mg/kg/twice weekly, subcutaneously) administered in the last 4 weeks]. ETA effectively diminished the prominent features of MS via a significant reduction in the percent body weight gain along with the modulation of adipokine levels, resulting in a significant elevation of serum adiponectin consistent with TNF-α and serum leptin level normalization. Moreover, ETA enhanced dyslipidemia and the elevated blood pressure. ETA managed the prominent features of MS and its associated complications via the downregulation of the hepatic inflammatory pathway that induces nonalcoholic steatohepatitis (NASH)-from the expression of Toll-like receptor 4, nuclear factor kappa B, and TNF-α until that of transforming growth factor-in addition to significant improvements in glucose utilization, insulin sensitivity, and liver function parameter activity and histopathological examination. ETA was effective for the treatment of all prominent features of MS and its associated complications, such as type II diabetes mellitus and NASH.

Methotrexate-Induced Alteration of Renal Aquaporins 1 and 2, Oxidative Stress and Tubular Apoptosis Can Be Attenuated by Omega-3 Fatty Acids Supplementation

Methotrexate (MTX) is a potent anti-cancer drug, commonly associated with nephrotoxicity via the induction of oxidative stress and apoptosis with alteration of renal water channel proteins, namely aquaporins (AQPs). Omega-3 long-chain polyunsaturated fatty acids (LC-PUFA) have shown cytoprotective effects through their anti-oxidant and antiapoptotic activities. The present study aims for the first time to explore the role of LC-PUFA against MTX-induced nephrotoxicity. Rats were divided into the following groups: saline control, LC-PUFA control, MTX, MTX + LC-PUFA (150 mg/kg), or MTX + LC-PUFA (300 mg/kg). Then, H&E staining and immunohistochemical staining for the anti-apoptosis marker B-cell lymphoma 2 (BCL-2), the apoptosis marker BCL2-Associated X Protein (BAX), the proinflammatory marker Nuclear factor kappa B (NF-kB), AQPs 1 and 2 were performed in kidney sections with an assessment of renal oxidative stress. The MTX caused a renal histopathological alteration, upregulated renal BAX and NF-kB, downregulated Bcl-2 and AQP1, altered the distribution of AQP2, and caused oxidative stress. The LC-PUFA attenuated the pathological changes and decreased renal BAX and NF-kB, increased BCL-2 and AQP1, restored the normal distribution of AQP2, and decreased the oxidative stress. Therefore, LC-PUFA is a good adjuvant to MTX to prevent its adverse effects on kidneys through its antiapoptotic, antioxidant, and anti-inflammatory effect and its role in the restoration of the expression of AQPs 1 and 2.

Protective effects of melatonin and L-carnitine against methotrexate-induced toxicity in isolated rat hepatocytes

The present study was designed to evaluate the possible protective effects of melatonin (MEL) and/or L-carnitine (L-CAR) against methotrexate (MTX)-induced toxicity in isolated rat hepatocytes. Hepatocytes were prepared using collagenase techniques of perfusion and digestion of rat liver. Trypan blue uptake, as well as, glutathione (GSH), lipid peroxidation (LPO), nitric oxide (NO), and tumor necrosis factor-alpha (TNF-α) levels were measured. Caspase-3 activity was also assessed. Pre-incubation of hepatocytes with MEL (1 mM) and/or L-CAR (10 mM) 30 min prior to intoxication with MTX, significantly protected hepatocytes against toxicity. In addition, LPO, NO, TNF-α levels, and caspase-3 activity were decreased in comparison to the MTX-intoxicated group. Furthermore, the two drugs increased the MTX-depleted GSH level. MEL and L-CAR prevented MTX-induced hepatocytotoxicity, at least partly, by their antioxidative, antiinflammatory, and antiapoptotic effects. Further studies are recommended on the clinical pharmacologic and toxicologic effects of MEL and L-CAR in patients receiving MTX.

Evaluation by different mechanisms of the protective effects of vitamin B12 on methotrexate nephrotoxicity

Methotrexate is used for cure of many cancer types. It has many side effects. For this reason, obtaining a nephroprotective agent is obligatory. In the study, our aim is to determine probable effects of Vitamin B12 on MTX caused kidney damages in rats. Rats were randomly divided into 4 groups, including 8 animals in each group. Control group, VitB12 group (3 μg-kg-ip B12 throughout 15 days), MTX group (at the 8th day of experiment, a single dose of 20 mg-kg-ip MTX), Vit B12 + MTX group (3 μg-kg-ip B12 throughout 15 days and at the 8th day of experiment, a single dose of 20 mg-kg-ip MTX) Animals were anesthetized and kidney tissues were removed to evaluate biochemically, immunohistochemically and histopathologycally. There were histopathological deteriorations, rises of apoptotic cells, expressions of heat shock proteins, endoplasmic reticulum stress and inflammation markers in the MTX group. In the MTX group, Superoxide Dismutase (SOD), Total Antioxidant Status (TAS) and Catalase (CAT) levels decreased, but Total Oxidant Status TOS, Malondialdehyde (MDA) and interleukin-6 (IL6) levels increased. In addition, there was amelioration in kidney tissue in Vit B12 + MTX group compared to the MTX group. We suggest that Vit B12 can be used to reduce the toxic effects of MTX.

Nephroprotective effect of naringin in methotrexate induced renal toxicity in male rats

The current work aims to study the nephroprotective potential of naringin (NG), a flavanone derived from citrus fruits, in methotrexate (MTX)-induced renal toxicity. Thirty male rats were divided into five groups; control group (IP saline), MTX group (IP single dose, 20 mg/kg), and three groups co-treated with MTX and naringin (IP daily dose; 20, 40, and 80 mg/kg, respectively). Kidney tissues were used to investigate renal function, oxidative stress, lipid peroxidation, and caspase-3 activity. Biochemical cytokine analysis was performed in addition to ultrastructural examinations of kidney tissue. When compared to the MTX-treated rats, MTX+NG significantly reduced the levels of urea, creatinine, MDA, NO, TNFα, IL-6, and caspase-3 activity. A significant increase in the levels of the antioxidant enzymes and GSH were also noted. Additionally, naringin ameliorated the apparent ultrastructural changes observed in the glomeruli and renal tubules of MTX-intoxicated rats. Noticeable structural improvements of glomerular lesions, proximal, and distal convoluted tubular epithelium were observed in MTX+NG treated animals, including podocytes with regular foot processes, perfectly organized filtration barrier, no signs of GBM thickening, organized brush border, and normal architecture of microvilli. Naringin (80 mg/kg) had the maximum amelioration effect. To the best of our knowledge, this is the first study to investigate the ultrastructural manifestations of naringin and/or MTX on the kidney of rats. Taken all, naringin has a potent therapeutic effect and can be used in adjuvant therapy to prevent MTX-induced nephrotoxicity. Nevertheless, the molecular mechanism underlying the nephroprotective capacity of naringin needs further investigation.

Ameliorative role of inducible nitric oxide synthase inhibitors against sodium arsenite-induced renal and hepatic dysfunction in rats

Arsenic exposure causes immense health distress by increasing risk of cardiovascular abnormalities, diabetes mellitus, neurotoxicity, and nephrotoxicity. The present study explored the role of inducible nitric oxide synthase (iNOS) inhibitors against sodium arsenite-induced renal and hepatic dysfunction in rats. Female Sprague Dawley rats were subjected to arsenic toxicity by administering sodium arsenite (5 mg/kg/day, oral) for 4 weeks. The iNOS inhibitors, S-methylisothiourea (10 mg/kg, i.p.) and aminoguanidine (100 mg/kg, i.p.) were given one hour before sodium arsenite administration in rats for 4 weeks. Sodium arsenite led rise in serum creatinine, urea, uric acid, electrolytes (potassium, fractional excretion of sodium), microproteinuria, and decreased creatinine clearance (p < 0.001) indicated renal dysfunction in rats. Arsenic-intoxication resulted in significant oxidative stress in rat kidneys, which was measured in terms of increase in lipid peroxides, superoxide anion generation and decrease in reduced glutathione (p < 0.001) levels. A threefold increase in renal hydroxyproline level in arsenic intoxicated rats indicated fibrosis. Hematoxylin-eosin staining indicated tubular damage, whereas picrosirius red staining highlighted collagen deposition in rat kidneys. S-methylisothiourea and aminoguanidine improved renal function and attenuated arsenic led renal oxidative stress, fibrosis, and decreased the kidney injury score. Additionally, arsenite-intoxication resulted in significant rise in hepatic parameters (serum aspartate aminotransferase, alanine transferase, alkaline phosphatase, and bilirubin (p < 0.001) along with multi-fold increase in oxidative stress, fibrosis and liver injury score in rats, which was significantly (p < 0.001) attenuated by concurrent administration of iNOS inhibitors). Hence, it is concluded that iNOS inhibitors attenuate sodium arsenite-induced renal and hepatic dysfunction in rats.

New Avenues for Treatment and Prevention of Drug-Induced Steatosis and Steatohepatitis: Much More Than Antioxidants

Drug-induced lipid accumulation in the liver may induce two clinically relevant conditions, drug-induced steatosis (DIS) and drug-induced steatohepatitis (DISH). The list of drugs that may cause DIS or DISH is long and heterogeneous and includes therapeutically relevant molecules that cannot be easily replaced by less hepatotoxic medicines, therefore making specific strategies necessary for DIS/DISH prevention or treatment. For years, the only available tools to achieve these goals have been antioxidant drugs and free radical scavengers, which counteract drug-induced mitochondrial dysfunction but, unfortunately, have only limited efficacy. In the present review we illustrate how in vitro preclinical research unraveled new key players in the pathogenesis of specific forms of DISH, and how, in a few cases, proof of concept of the beneficial effects of their pharmacological modulation has been obtained in vivo in animal models of this condition. The key issue emerging from these studies is that, in selected cases, liver toxicity depends on mechanisms unrelated to those responsible for the desired, primary pharmacological effects of the toxic drug and, therefore, specific strategies can be designed to overcome steatogenicity without making the drug ineffective. In particular, the hepatotoxic drug could be given in combination with a second molecule intended to selectively antagonize its liver toxicity whilst, ideally, potentiating its desired pharmacological activity. Although most of the evidence that we discuss is from in vitro or animal models and will need to be further explored and validated in humans, it highlights new avenues to be pursued in order to improve the safety of steatogenic drugs.

Naringin alleviates methotrexate-induced liver injury in male albino rats and enhances its antitumor efficacy in HepG2 cells

Methotrexate (MTX) is an efficient chemotherapeutic and immunosuppressant drug, but the hepatotoxicity of MTX limits its clinical use. Naringin (Nar) is a flavonoid derived from Citrus paradise, and has been shown to possess several pharmacological activities, including free-radical scavenging and antioxidant properties. In the present study, we first tested the possible protective effects of multiple doses of Nar against MTX-induced acute hepatotoxicity in rats, and then we investigated the growth inhibition and apoptotic effects of MTX and/or Nar against the HepG2 hepatocarcinoma cell line. Our in vivo results showed that Nar significantly reduced MTX-induced increases in serum alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase and total bilirubin levels. Nar also reduced MTX-induced oxidative stress by significantly reducing liver malondialdehyde (MDA) and nitric oxide (NO) content and increasing superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), and glutathione (GSH). In addition, Nar significantly counteracted MTX-induced increases in hepatic interleukin-6 and tumor necrosis factor-α (TNF-α). Further, Nar greatly protected hepatocyte ultrastructure against MTX-induced injury. In contrast, in vitro MTX and/or Nar treatment of HepG2 cells for 48 h exhibited a cytotoxic effect and induced apoptosis in a dose-dependent manner mediated by a significant increase in the Bax/Bcl-2 protein expression ratio. Noticeably, Nar potentiated the MTX effect on the Bax/Bcl-2 ratio. In conclusion, Nar decreased MTX-induced functional and ultrastructural liver damage in a tumor-free animal model. Also, our data introduce MTX and Nar as promising antiproliferative agents with a distinctive mode of action, inducing apoptosis in HepG2 tumor cells through activation of Bax and down-regulation of Bcl-2 protein expression.

Protective effects of apigenin on altered lipid peroxidation, inflammation, and antioxidant factors in methotrexate-induced hepatotoxicity

Methotrexate (MTX) is used as an effective chemotherapeutic agent against autoimmune diseases and tumors. Oxidative stress and inflammation are involved in the pathogenesis of MTX-induced damage. This study aimed at examining the ameliorating effects of apigenin (API) as a natural antioxidant on MTX-induced hepatotoxicity. The rats were classified into four groups: group I: normal saline-treated, group II: MTX-treated (20 mg/kg, ip, single dose at day 7), group III: MTX + API-treated (20 mg/kg, po), and group IV: API-treated. API was administrated for 9 days. Alanine aminotransferase (ALT), alkaline phosphatase (ALP), and aspartate aminotransferase (AST) were used as biochemical factors of MTX-induced hepatic injury. In hepatic tissues, the levels of malondialdehyde (MDA), nitric oxide (NO), glutathione (GSH), and activities of antioxidant enzymes such as catalase (CAT), glutathione peroxidase (GPx), and superoxide dismutase (SOD) as oxidative stress markers along with inflammatory factors such as tumor necrosis factor-alpha (TNF-α) and interleukin 1 beta (IL-1β) were assessed. Our results showed that MTX administration significantly increased ALP, ASP, ALT, MDA, NO, TNF-α, and IL-1β levels and significantly decreased antioxidant factors such as GSH, CAT, GPx, and SOD. The API pretreatment group showed a significant rise in hepatic antioxidant markers, besides significant reductions in the serum levels of AST, ALT, and ALP and hepatic content of MDA, TNF-α, NO, and IL-1β. In addition, the hepatoprotective effect of API was confirmed by histological evaluation of the liver. API can prevent MTX-induced hepatotoxicity through mitigation of oxidative stress and inflammation.

Methotrexate-induced toxic effects and the ameliorating effects of astaxanthin on genitourinary tissues in a female rat model

PURPOSE

The purpose of the study was to explore the possible deleterious effects of Methotrexate (MTX) treatment on the urogenital tissues and the potential protective effects of Astaxanthin (AXA).

METHODS

Twenty-four female Wistar Albino rats (12 months old) were divided into 3 groups as follows: Group I (Control group): rats received a single dose of 0.1 ml saline by gavage and intraperitoneal injection. Group II (MTX group): rats received a single dose of 20 mg/kg MTX, i.p, on the 2nd day. Group III (MTX + AXA group): rats received 100 mg/kg AXA orally for 7 days in addition to a single dose of MTX. The levels of total oxidant status (TOS), total antioxidant status (TAS), oxidative stress index (OSI), and histopathological and immunohistochemical markers (Caspase-3, iNOS, CRP, G-CSF) were evaluated in urogenital tissues.

RESULTS

In ovarian tissues, a statistically significant increase in TOS levels (p = 0.001) and OSI index (p = 0.028) were observed in Group II compared to Group I. TAS level was significantly higher in Group III compared to Group II and I (p = 0.009 and 0.002, respectively). However, a significant decrease in OSI level was observed in Group III compared to Group II (p = 0.035). In fallopian tube tissues, TAS level was significantly decreased in Group II compared to Group I (p = 0.047). Histopathologically, marked hyperemia was observed in MTX group. AXA treatment ameliorated all the pathological findings. Immunohistochemically, all the studied markers were considerably increased in Group II, however, they were decreased by AXA.

CONCLUSION

These findings revealed that MTX treatment caused oxidative stress, apoptosis, and inflammation in the urogenital tissue. We found that AXA significantly ameliorated the damage caused by MTX in the urogenital tissue. The results of the study have indicated that AXA may be a promising nutritional support substance against the damage caused by chemotherapeutic and cytotoxic agents, such as MTX, to the urogenital tissue.

Evaluation of the effect of methotrexate on the hippocampus, cerebellum, liver, and kidneys of adult male albino rat: Histopathological, immunohistochemical and biochemical studies

Methotrexate (MTX) has been used for treatment of autoimmune diseases, inflammatory disorders as rheumatic arthritis, and different types of cancers. However, it has shown adverse effects on vital organs. The current study was conducted to investigate the toxic effect of MTX on the hippocampus, cerebellum, liver and kidneys of adult male albino rats. MTX was injected weekly at 5 mg/kg body weight via I/P injection for 6 weeks. At the end of the experiment, histopathological, immunohistochemical and biochemical evaluation were performed on the hippocampus, cerebellum, liver, and kidney tissues of the sacrificed rats. We observed that methotrexate induced neural tissue damage in the hippocampus and cerebellum, degeneration of hepatocytes, congestion of the central vein and blood sinusoids of the liver, distortion in the renal corpuscles and necrosis of the renal tubule. Immunohistochemical findings revealed strong positive expression of Caspase-3, PCNA and GFAP. Biochemical studies revealed significant elevation in the serum levels of AST and ALT, in addition to high serum concentrations of creatinine and urea. Also, MTX injection increased MDA, while it decreased GSH, SOD and AChE levels. We conclude the ability of MTX to induce oxidative stress that results into apoptosis and tissue injury, leading to neurotoxicity, hepatotoxicity, and nephrotoxicity.

Protective effects of Glycyrrhiza glabra supplementation against methotrexate-induced hepato-renal damage in rats: An experimental approach

ETHNOPHARMACOLOGICAL RELEVANCE

In traditional medicine, Glycyrrhiza glabra, commonly known as liquorice, is known to possess promising pharmacological properties including anti-oxidative, anti-inflammatory, gastro, hepato and nephro-protective activities.

AIM

The present study investigated the protective effects of Glycyrrhiza glabra rhizome extract (GGE) on MTX-induced hepato-renal damage in Wistar albino rats.

MATERIALS AND METHODS

Rats were pre-treated with GGE (100, 200 or 400 mg/kg) from day 1 to 15 and administered MTX (20 mg/kg) on day 4. Methotrexate-induced hepato-renal damage was assessed by serum toxicity biomarkers (AST, ALT, BUN and creatinine), oxidative stress estimation (MDA, GSH, SOD, CAT, peroxidase and glutathione reductase), interleukins profiling (TNF-α, IL-1β, IL-6 and IL-12), tissue histopathology and immunohistochemical (caspase-3 and NFkB) examination.

RESULTS

MTX induced hepato-renal damage resulted in elevated serum levels of AST, ALT, BUN and creatinine, increased pro-inflammatory cytokines concentration and accumulation of MDA and reduced levels of GSH, SOD, CAT, peroxidase and glutathione reductase. Conversely, co-treatment with GGE dose-dependently ameliorated oxidative stress, serum interleukins, hepato-renal toxicity biomarkers (p < 0.001), preserved tissue architecture and downregulated both caspase-3 and NFkB expression in hepato-renal tissue.

CONCLUSION

The above results suggested that GGE can alleviate MTX-induced hepato-renal damage by decreasing oxidative stress and suppressing the ensuing activation of pro-apoptotic and pro-inflammatory pathways.

Zingerone protects liver and kidney tissues by preventing oxidative stress, inflammation, and apoptosis in methotrexate-treated rats

The clinical use of drugs used in the treatment of diseases is limited due to the toxic side effects, and many studies have been conducted to benefit from herbal adjuvant therapies recently to eliminate these effects. In this study, the protective effect of zingerone against liver and kidney damage generated in rats through methotrexate (MTX). Histopathological investigations were performed to determine tissue damage caused by MTX and the healing effect of zingone and liver function markers such as serum alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP), and renal function markers such as urea, creatine, and aquaporin-1 (AQP-1) were measured. The effects of MTX and protective properties of zingerone on oxidative stress were investigated through the measurement of malondialdehyde and reduced glutathione (GSH) levels, catalase (CAT), and glutathione peroxidase (GPx) enzyme activities. The anti-inflammatory effect of zingerone was determined by measuring the cytokine levels causing inflammation such as nuclear factor-kappa B (NF-κB), tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β), and its effects on apoptosis were determined by immunohistochemical analysis of caspase-3 and B-cell lymphoma-2 (Bcl-2) expression levels. According to the results obtained within the scope of the study, it was determined that zingerone treatment prevented the increase in MTX-induced liver and kidney function markers, showed healing effects on antioxidant parameters degraded in both tissues, and decreased the inflammation parameters. It was determined that it also prevented apoptosis and possessed a protective effect on disrupted tissue architecture by decreasing the increased caspase-3 expression and increasing the decreased Bcl-2 level.

Aminoguanidine inhibits IL-1β-induced protein expression of iNOS and COX-2 by blocking the NF-κB signaling pathway in rat articular chondrocytes

Osteoarthritis is a chronic joint disease which has a serious impact on the health and quality of life of affected humans and animals. As an inhibitor of inducible nitric oxide synthase (iNOS), aminoguanidine (AG) displays anti-inflammatory effects. The purpose of the present study was to investigate the effect of AG on the expression of iNOS and cyclooxygenase-2 (COX-2), and the activity of the NF-κB signaling pathway in rat chondrocytes stimulated by interleukin-1β (IL-1β). The viability of chondrocytes treated with AG (0.3, 1 or 3 mM) alone was determined using a Cell Counting Kit-8 assay. Subsequently, the chondrocytes were treated with either 10 ng/ml IL-1β alone, or co-treated with increasing concentrations of AG (0.3, 1 or 3 mM) and 10 ng/ml IL-1β. The protein levels of COX-2, iNOS, phosphorylated (p)-p65, p65, p-NF-κβ inhibitor α (IκBα), IκBα, p-inhibitor of NF-κβ-β (IKKβ) and IKKβ were evaluated by western blotting. NF-κB translocation was determined by immunofluorescence analysis. Western blotting and reverse transcription-quantitative PCR were used to detect expression levels of relevant proteins/genes. The results suggested that the inhibitory effect of AG on the protein and gene expression levels of iNOS and COX-2 in IL-1β-treated chondrocytes was dose-dependent. In addition, AG decreased the level of phosphorylation of IKKβ, IκBα and NF-κB p65, the degradation of IKKβ, IκBα and p65, and the translocation of NF-κB in IL-1β-stimulated chondrocytes. The most significant inhibitory effect of AG was observed at a concentration of 1 mM. Therefore, the present study suggested that AG may serve as a potential agent to reduce the inflammatory response of chondrocytes stimulated by IL-1β.

Role of Nrf2/HO-1 and PI3K/Akt Genes in the Hepatoprotective Effect of Cilostazol

BACKGROUND

Cilostazol, a phosphodiesterase 3 inhibitor (PDE3I), is a platelet aggregation inhibitor and vasodilator that is useful for treating intermittent claudication. Experimental studies have shown that cilostazol has potent anti-inflammatory, anti-oxidant effects effects.

OBJECTIVES

Although the hepatoprotective effect cilostazol has been studied, the molecular mechanisms of such protection, including: the nuclear factor-erythroid 2-related factor 2 (Nrf2) / hemoxygenase (HO-1) and the phosphoinositide 3-kinase (PI3K) /serine/threonine kinase (Akt) pathways are not fully explored, which is the aim of this study.

METHODS

To achieve the aim of this study, 35 rats were grouped into: control groups, liver injury group (model- non treated: injected with thioacetamide (TAA), 150 mg/kg, i.p.), and two cilostazoltreated groups (treated with cilostazol 10 and 50 mg/kg, p.o.). The rats were treated for 8 days and injected with TAA on the 7th day of the experiment and sacrificed 48 hours after TAA injection.

RESULTS

The model group showed evidence of liver injury as indicated by the elevation of liver enzymes and confirmed by histopathological findings. TAA-induced liver injury was accompanied by down-regulation of the cytoprotective pathways: PI3K/Akt and Nrf2/HO-1 mRNAs. Cilostazol administration ameliorated TAA-induced liver injury, where it caused a significant improvement in the activity of liver enzymes as well as in the histopathological changes. Such an effect was associated with a significant increase in the expression of PI3K/Akt and Nrf2/HO-1 mRNAs as detected by Real-time reverse transcription polymerase chain reaction (RT-PCR).

CONCLUSION

Cilostazol protected rats against TAA hepatotoxicity through up-regulation of PI3K/Akt and Nrf2/HO-1 gene expression.

Protective effects of benfotiamine on irisin activity in methotrexate-induced liver injury in rats

INTRODUCTION

Methotrexate (MTX) causes hepatotoxicity by producing oxidative stress. Benfotiamine and irisin have protective effects against oxidative stress. The aim of this study was to investigate the changes in irisin activity in the liver as a result of toxicity produced by MTX and the protective role of benfotiamine in the hepatotoxicity.

MATERIAL AND METHODS

Rats were divided into 4 groups as follows: control, benfotiamine (50 mg/kg, oral gavage (o.g.), for 14 days), MTX (MTX 20 mg/kg intraperitoneally (i.p.) on day 1), MTX + benfotiamine (MTX 20 mg/kg (i.p.) on day 1, then 50 mg/kg (o.g.) benfotiamine for 14 days). Liver tissue was used to examine histopathological and immunohistochemical changes. Serum was used to look for oxidative stress markers (total antioxidant status (TAS) and total oxidant status (TOS)).

RESULTS

Administration of MTX caused a significant TOS increase and TAS decrease in the serum as compared to the control group. Immunohistochemically, irisin was significantly increased in immunoreactivity in the MTX group as compared to the control group (p < 0.05). Significant histopathological improvement and decrease in serum TOS levels were observed in the MTX + benfotiamine group compared to the MTX group (p < 0.05). In addition, an increase in TAS level and a decrease in irisin immunoreactivity were observed but they were not statistically significant (p > 0.05).

CONCLUSIONS

Our results showed that MTX caused an increase in the activity of irisin after producing toxicity in the liver. In addition, we found that benfotiamine was effective in preventing damage caused by MTX in the liver.

Genetic Polymorphisms in Antioxidant Enzymes Modulate the Susceptibility of Idiosyncratic Antituberculous Drug-Induced Liver Injury and Treatment Outcomes in Patients with Tuberculosis

BACKGROUND

The pathogenic mechanism of antituberculous drug-induced liver injury (ATDILI) is associated with antioxidant enzymes. The objective of the present study was to investigate the associations of ATDILI susceptibility with genetic polymorphisms of antioxidant enzyme genes including nitric oxide synthase 2 (NOS2), thioredoxin reductase 1 (TXNRD1), superoxide dismutase 2 (SOD2), BTB domain and CNC homolog 1 (BACH1), and MAF bZIP transcription factor K (MAFK).

METHODS

Thirty tag single nucleotide polymorphisms (tag-SNPs) from the all candidate genes were genotyped in a 2-stage cohort study including an initial discovery stage with 461 ATDILI patients and 466 controls and a replication stage with 216 ATDILI patients and 432 controls. The frequencies and distributions of genotypes and haplotypes were compared between the case and control groups. Three different genetic models including dominant, recessive, and additive models were used to determine the associations with susceptibility to ATDILI.

RESULTS

The SNPs rs9906835, rs944725, and rs3794764 of the NOS2 gene were significantly associated with an increased risk of ATDILI. The MAFK rs3735656 SNP was significantly associated with a decreased risk for ATDILI. The AAA haplotype of the NOS2 gene was associated with susceptibility to ATDILI. The treatment outcomes of patients with tuberculosis were further affected by genetic variants of the NOS2 and MAFK genes.

CONCLUSIONS

Genetic polymorphisms of NOS2 and MAFK are associated with ATDILI susceptibility in Chinese patients with tuberculosis. The variants in NOS2 and MAFK affect treatment outcomes of tuberculosis patients. Further studies are needed to better understand the molecular mechanisms of ATDILI susceptibility via regulation of the expression of ATDILI-susceptibility genes and proteins.

Activation of pCREB/Nrf-2 signaling mediates re-positioning of liraglutide as hepato-protective for methotrexate -induced liver injury (MILI)

Methotrexate (MTX) is commonly used to treat several types of cancer and autoimmune diseases. However, there is increasing concern over its organs toxicities particularly liver toxicity. Liraglutide, a glucagon like peptide-1 agonist, possesses antioxidant and anti-inflammatory features. This study aimed to explore the potential protective effect of liraglutide pre-treatment in ameliorating MTX-induced hepatotoxicity and to further investigate the underlying mechanisms. Rats received 1.2 mg/kg liraglutide intraperitoneal twice daily for 7 days before MTX. Results revealed that liraglutide significantly decreased activities of liver enzymes and oxidative stress in hepatocytes. Furthermore, NF-kB expression and related inflammatory markers (TNF-α, COX-2 and IL-6) were reduced in the pre-treatment group of liraglutide. These data validate the advantageous effects of liraglutide in MTX hepatotoxic animals. In addition, liraglutide increased the expression of the antioxidant transcription factor nuclear factor-erythroid 2-related factor 2 (Nrf-2), along with the transcription of downstream phosphorylated cAMP response element-binding protein (pCREB) which increases the activity of Nrf-2. Additionally, caspase-3 expression/activity and BAX/Bcl-2 ratio were decreased following liraglutide pre-treatment. In conclusion, it was confirmed that liraglutide enhanced the antioxidant activity of liver cells by activating the Nrf-2 and pCREB signaling, thereby, reducing liver cell inflammation and apoptosis induced by MTX.

Etanercept protects ovarian reserve against ischemia/reperfusion injury in a rat model

INTRODUCTION

Etanercept has been widely used in autoimmune diseases for blocking tumor necrosis factor α (TNF-α), which is an inflammatory cytokine. The anti-apoptotic and anti-inflammatory effects of etanercept against ischemia/reperfusion (I/R) injury have been shown for several tissues in rat studies, but to the best of our knowledge, there are no reports on its protective effects following similar injury in ovarian tissue. The aim of this study was to investigate whether etanercept has beneficial effects on ovarian I/R injury, as well as on ovarian reserve.

MATERIAL AND METHODS

Twenty-four rats were randomly divided into four groups (n = 6/group): sham (laparotomy only); sham + etanercept; I/R; and I/R + etanercept. Ischemia was induced for 3 h by twisting the ovary, and 24 h after detorsion the ovarian tissues were collected to evaluate histopathologic changes, glutathione (GSH), malondialdehyde (MDA), myeloperoxidase (MPO), and superoxide dismutase (SOD) concentrations for oxidative stress, 8-hydroxy-2'-deoxyguanosine (8-OHdG) for DNA damage, caspase-3 activity for apoptosis and ovarian follicle counts. To measure anti-Mullerian hormone (AMH), serum samples were drawn before and after surgery.

RESULTS

Tissue GSH and SOD levels were significantly higher, while MDA and MPO levels were significantly lower in the I/R + etanercept group than in the I/R group (p < 0.05, p < 0.01, respectively). Tissue 8-OHdG and caspase-3 activity were significantly lower in the I/R+etanercept group than in the I/R group (p < 0.05, p < 0.01, respectively). Preoperative and postoperative AMH levels were compared and there was a significant reduction in the I/R and I/R + etanercept groups (p < 0.001, p < 0.001). The reduction of AMH in the I/R + etanercept group was significantly lower than in the I/R group. The primordial, preantral and small antral follicle numbers were also significantly higher in the I/R + etanercept group compared to the I/R group (p < 0.001, p < 0.001, p < 0.005, respectively).

CONCLUSIONS

Etanercept attenuated inflammation and related oxidative stress and also helped to preserve ovarian reserve following ovarian I/R damage.

The adaptogenic anti-ageing potential of resveratrol against heat stress-mediated liver injury in aged rats: Role of HSP70 and NF-kB signalling

Heat stress (HS) is a major international problem which has attracted a considerable attention due to its oxidative tissue effects and high morbidity and mortality rates, especially among elderly people. Discovering an effective antioxidant is pivotal for overcoming HS-induced injury. Therefore, the aim of this study was to estimate the hepatic protective effects of orally supplemented resveratrol (RES) against HS-mediated liver injury in young and old male Wistar albino rats. Compared to control rats, RES administered orally at a dose of 20 mg/kg BW for 21 successive days efficiently ameliorated HS-induced oxidative damage by significantly increasing (P ≤ 0.05) the level of reduced glutathione and glutathione peroxidase, and decreasing the levels of malondialdehyde and TNF-α in hepatic tissue of both young and aged rats. However, level of NF-κB was downregulated significantly in aged rats rather than young rats. Moreover, RES significantly decreased (P ≤ 0.05) the serum levels of aspartate transaminase and alkaline phosphatase in both ages of rats compared to their corresponding HS-stressed rats. Furthermore, RES upregulated the immunohistochemical expression of caspase 3 and heat shock protein 70 in young and aged rats, however it was more pronounced in young one. In addition, RES administration moderately normalized (P ≤ 0.0001) the harmful effects of HS on the hepatic architecture of both young and aged rats. In conclusion, this study reveals for the first time that RES exerts promising hepato-ameliorative effects against HS-induced oxidative stress in the young and aged rats via its antioxidant, anti-inflammatory, and anti-apoptotic effect, as well as via its inhibitory effect against the NF-κB signalling in a cellular system.

Allopurinol potentiates the hepatoprotective effect of metformin and vitamin E in fructose-induced fatty liver in rats

Aim of the study

Non-alcoholic fatty liver disease (NAFLD) is a challenging health problem. Hyperuricemia is a key player in the pathogenesis of NAFLD. This study investigated the effect of allopurinol (uric acid synthesis inhibitor) in combination with metformin and vitamin E in prevention of fructose induced-fatty liver in rats.

Material and methods

Rats were divided into 7 groups: control group, fructose group (model group of NAFLD), allopurinol-treated group, metformin-treated group, vitamin E-treated group, metformin plus vitamin E-treated group and a combination group (received allopurinol plus metformin plus vitamin E). Development of NAFLD was assessed biochemically by serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) as well as by histopathological examination. Oxidative stress parameters [reduced glutathione (GSH), superoxide dismutase (SOD), malondialdehyde (MDA)], and the inflammatory mediators tumor necrosis factor α (TNF-α) and inducible nitric oxide synthase (iNOS) were assessed, along with serum levels of uric acid and triglyceride (TG).

Results

Combination of allopurinol plus metformin plus vitamin E significantly attenuated fatty changes compared to their respective monotherapy. Interestingly, though all treated groups showed significant attenuation in the oxidative stress markers, TNF-α level and iNOS immunostaining in hepatic tissue, along with a significant decrease in the levels of uric acid and TG, the combination group showed a further significant decrease in the serum level of uric acid and iNOS immunostaining compared to other treated regimens.

Conclusions

Allopurinol synergistically increases the protective effect of metformin and vitamin E in treatment of NAFLD, namely via reduction of uric acid synthesis and iNOS expression.

Protective effect of aminoguanidine against lipopolysaccharide-induced hepatotoxicity and liver dysfunction in rat

Lipopolysaccharide (LPS) as the major component of the outer membrane of Gram-negative bacteria activates macrophages to produce a high level of pro-inflammatory cytokines which is considered as a cause of liver dysfunction. Overproduction of nitric oxide (NO) has been suggested to have a role in hepatic injury. The aim of the present study was to explore the protective effects of aminoguanidine (AG) as inducible nitric oxide synthase (iNOS) inhibitor against LPS -induced liver dysfunction in rat. The animals were divided into five groups: (1) control (2) LPS (3) LPS-AG50, (4) LPS-AG100 and (5) LPS-AG150. LPS (1 mg/kg) was injected for 5 weeks and AG (50, 100 and 150 mg/kg) was administered 30 min before LPS. Drugs were injected intraperitoneally. LPS induced liver dysfunction presented by increasing the serum level of alkaline phosphatase (ALK-P), alanine aminotransferase (ALT), aspartate aminotransferase (AST). Pretreatment with AG restored harmful effects of LPS on liver function. In addition, LPS resulted in hepatotoxicity, accompanied by enhancing the level of interleukin (IL)-6, malondialdehyde (MDA) and nitric oxide (NO) metabolites and decreasing the content of total thiol groups and superoxide dismutase (SOD) and catalase (CAT) activity. Injection of AG before LPS attenuated LPS-induced hepatotoxicity through decreasing the level of IL-6, MDA and NO metabolites and increasing total thiols and SOD and CAT activity. Considering the protective effect of AG which was seen in the present study, it seems that increased levels of NO due to activation of iNOS has a role in LPS-induced hepatic injury.

The effects of casticin and myricetin on liver damage induced by methotrexate in rats

OBJECTIVES

In this study, we evaluated the therapeutic effects of casticin and myricetin on liver damage induced by methotrexate in rats.

MATERIALS AND METHODS

Thirty-six male rats were used for the study and divided into 6 groups: control, methotrexate, casticin, myricetin, casticin+methotrexate, and myricetin+methotrexate. It was performed by methotrexate (20 mg/kg single dose, IP) in methotrexate, casticin+methotrexate and myricetin+methotrexate groups. Casticin 200 mg/kg dose was given to casticin and casticin+methotrexate groups. Myricetin 50 mg/kg dose was given to myricetin and myriceytin+methotrexate groups. At the end of the experiment, liver tissues were removed for the purpose of histopathological, biochemical and immunohistochemical assessments.

RESULTS

In our study, we have detected that MDA levels increased and activities of antioxidant enzymes SOD, CAT, and GPX decreased in the methotrexate group compared to the other groups, but the level of MDA decreased and activities of these enzymes increased in casticin+methotrexate and myricetin+methotrexate groups compared to the methotrexate group. In immunohistochemical examinations of control, casticin and myricetin groups in liver tissues no caspase-3 and 8-OHdG expressions were observed. In the MTX group, caspase-3 and 8-OHdG expressions were seen at the severe levels. Caspase-3 and 8-OHdG expressions were mild in hepatocytes in the casticin+methotrexate and myricetin+methotrexate groups. When the liver tissues of the rats in the methotrexate group were examined, severe pathological damage was detected both in the parietal region and in the portal region.

CONCLUSION

By looking at these results, we can say that casticin and myricetin are effective against liver damage induced by methotrexate.

TAT-mediated intracellular delivery of carboxypeptidase G2 protects against methotrexate-induced cell death in HepG2 cells

Side effects of methotrexate (MTX) especially hepatotoxicity limits clinical applications of this anticancer agent. Carboxypeptidase G2 (CPG2) is administrated for the treatment of elevated plasma concentrations of MTX. In this study, we have investigated the intracellular delivery of CPG2 fused to the transactivator transduction domain (TAT) and its protective effects against MTX-induced cell death of HepG2 cells. We have observed that both native and denatured forms of the enzyme transduced into the HepG2 cells efficiently in a concentration and time-dependent manner. The denatured protein transduced with higher efficiency than the native form and was functional inside the cells. MTX exposure significantly decreased HepG2 cell viability in a dose- and time-dependent manner. The cell viability after 24 and 48 h of incubation with 100 μM MTX was reduced to 44.37% and 17.69%, respectively. In cells pretreated with native and denatured TAT-CPG2 protein the cell viability was 98.63% and 86.31% after 24 and 48 h, respectively. Treatment with MTX increased the number of apoptotic HepG2 cells to 90.23% after 48 h. However, the apoptosis percentage in cells pretreated with native and denatured TAT-CPG2 was 21.49% and 22.28%, respectively. Our results showed that TAT-CPG2 significantly prevents MTX-induced oxidative stress by decreasing the formation of ROS and increasing the content of glutathione (GSH) and catalase activity. Our finding indicates that both native and denatured TAT-CPG2 strongly protect HepG2 cells against MTX-induced oxidative stress and apoptosis. Hence, intracellular delivery of CPG2 might provide a new therapeutic strategy for protecting against MTX mediated cytotoxicity.

Vanillin mitigates the adverse impact of cisplatin and methotrexate on rat kidneys

The present study investigated the probable protective effect of vanillin (VLN) against kidney injury induced by cisplatin (CSN) and methotrexate (MTX) in rats. The rats received a single injection of either CSN (7.5 mg/kg, i.p.) or MTX (20 mg/kg, i.p.). VLN treatment (150 mg/kg/day, i.p.) was started 1 day before administration of the nephrotoxic agents and continued for 7 days. Both CSN and MTX significantly increased serum creatinine, cystatin C, and neutrophil gelatinase–associated lipocalin and kidney tissue renal malondialdehyde, inducible nitric oxide synthase, tumor necrosis factor-α, interleukin-18, nuclear factor-κB p65, cytosolic cytochrome C, and caspase-3 and significantly decreased renal total antioxidant capacity and Bcl-2/Bax ratio in rats. VLN significantly ameliorated the changes of biochemical parameters induced by CSN and MTX. VLN also significantly reduced CSN- and MTX-induced histopathological injury and the expression of Fas ligand in rat kidneys. In conclusion, VLN significantly protected against CSN- and MTX-induced kidney injury in rats by inhibiting oxidative/nitrosative stress, inflammation, and apoptosis.

Recombinant human erythropoietin prevents etoposide- and methotrexate-induced toxicity in kidney and liver tissues via the regulation of oxidative damage and genotoxicity in Wistar rats

Etoposide (ETO) and methotrexate (MTX) are two effective chemotherapeutic drugs. However, the clinical use of these drugs is limited by its toxicity in normal tissues, especially in kidney and in liver tissues. Recombinant human erythropoietin (rhEPO), erythropoietin hormone, has also been shown to exert tissue protective effects. The purpose of this study was to explore the protective effect of rhEPO against oxidative stress and genotoxicity induced by ETO and MTX in vivo. Adult male Wistar rats were divided into 10 groups (6 animals each): control group, rhEPO alone group, ETO alone group, MTX alone group and rhEPO + ETO/MTX groups. In rhEPO + ETO/MTX groups, three doses of pretreatment with rhEPO were performed: 1000, 3000 and 6000 IU/kg. Our results showed that rhEPO pretreatment protects liver and kidney tissues against oxidative stress induced by the anticancer drugs. The glycoprotein decreased malondialdehyde (MDA) levels, reduced catalase activity and ameliorated glutathione depletion. Furthermore, we showed that rhEPO administration prevented drug-induced DNA damage accessed by comet test. Altogether, our results suggested a protective role of rhEPO, especially at 3000 IU/kg, against ETO- and MTX-induced oxidative stress and genotoxicity in vivo.

Aminoguanidine pretreatment prevents methotrexate-induced small intestinal injury in the rat by attenuating nitrosative stress and restoring the activities of vital mitochondrial enzymes

BACKGROUND

One of the major toxic side effects of methotrexate (MTX) is enterocolitis, for which there is no efficient standard treatment. Nitric oxide overproduction has been reported to play an important role in MTX-induced mucositis. This study was designed to investigate whether pretreatment with aminoguanidine (AG) - a selective iNOS inhibitor - prevents MTX-induced mucositis in rats.

METHODS

Rats were pretreated with AG (30 and 50 mg/kg body weight) i.p. daily 1 h before MTX (7 mg/kg body weight) administration for 3 consecutive days. After the final dose of MTX, the rats were killed, and the small intestines were used for analysis.

RESULTS

The small intestines of MTX-treated rats showed moderate to severe injury. Pretreatment with AG had a dose-dependent protective effect on MTX-induced mucositis. AG pretreatment reduced iNOS protein levels, mucosal nitric oxide levels, and protein tyrosine nitration. AG pretreatment also restored the activities of electron transport chain (ETC) complexes, vital tricarboxylic acid (TCA cycle) enzymes, and mitochondrial antioxidant enzymes.

CONCLUSIONS

These findings suggest that AG is beneficial in ameliorating MTX-induced enteritis in rats.

Hepatoprotective effect of sitagliptin against methotrexate induced liver toxicity

Sitagliptin is selective dipeptidyl peptidase-4 inhibitor (DPP4-I), used clinically as a new oral anti-diabetic agent. This study explored the underlying mechanisms of the hepatoprotective role of sitagliptin pretreatment against methotrexate (MTX) induced hepatotoxicity in mice. Forty mice were divided into four groups (10 mice each); control, MTX, and two sitagliptin groups (pretreated with sitagliptin 10 and 20 mg/kg/day, respectively) for five consecutive days prior to MTX injection. Results showed that MTX induced marked hepatic injury in the form of cloudy swelling, hydropic degeneration, apoptosis and focal necrosis in all hepatic zones. Biochemical analysis revealed significant increase in the serum transaminases, alkaline phosphatase and lactate dehydrogenase in MTX group. Oxidative stress and depressed antioxidant system of the hepatic tissues were evident in MTX group. MTX down-regulated nuclear factor erythroid 2-related factor 2 (Nrf2) expression and reduced its binding capacity. Additionally, MTX increased the activation and the expression of nuclear factor kappa-B (NF-κB) and downstream inflammatory mediators. MTX induced the activation of inducible nitric oxide synthase (iNOS) and increased nitrite/nitrate level. Finally, hepatic cellular apoptosis was clearly obvious in MTX-intoxicated animals using TUNEL staining. Also, there was increase in the immunoexpression of pro-apoptotic protein Bax, increase in Bax and caspase-3 levels and decrease in the level of anti-apoptotic Bcl2 in liver. On the other hand, sitagliptin pretreatment significantly ameliorated all of the above mentioned biochemical, histopathological, immunohistochemical changes induced by MTX. These results provide new evidences that the hepatoprotective effect of sitagliptin is possibly mediated through modulation of Nrf2 and NF-κB signaling pathways with subsequent suppression of inflammatory and apoptotic processes.

Aminoguanidine treatment increased NOX2 response in diabetic rats: Improved phagocytosis and killing of Candida albicans by neutrophils

In this study, we show that aminoguanidine (AMG), an inhibitor of protein glycation, increases the NOX2 (phagocyte NADPH oxidase) response and microbicidal activity by neutrophils, regardless of diabetic status. The non-enzymatic glycation of proteins, yielding irreversible advanced glycation end products (AGEs), is involved in the development of diabetes complications, including alterations of signaling pathways and the generation of reactive oxygen species by phagocytes. The phagocytes produce ROS (reactive oxygen species) through activation of the NOX2 complex, which generates superoxide. The purpose of this study was to evaluate the effect of hyperglycemia and the glycation of proteins on the NOX2 activity of neutrophils and its implications for cellular physiology, with a focus on the microbicidal activity of these cells. We treated diabetic rats with AMG and evaluated neutrophil ROS generation and Candida albicans killing ability. We observed a large increase in the microbicidal activity of peritoneal neutrophils from AMG-treated rats. The increase was independent of diabetic status and myeloperoxidase activity. Collectively, our results suggest that AMG has an immunomodulator role that triggers an increase in the microbicidal response of neutrophils mainly related to reactive oxygen species production by NOX2.