Methotrexate-induced germ cell toxicity and the important role of zinc and SOD1: Investigation of molecular mechanisms

Combination treatment of zinc and selenium intervention ameliorated BPA-exposed germ cell damage in SD rats: elucidation of molecular mechanisms

Bisphenol A (BPA) is a commonly used environmental toxicant, is easily exposed to the human body and causes testicular damage, sperm abnormalities, DNA damage and apoptosis, and interferes in the process spermatogenesis and steroidal hormone production along with obstruction in testes and epididymis development. Zinc (Zn), a potent regulator of antioxidant balance, is responsible for cellular homeostasis, enzymes and proteins activities during spermatogenesis for cell defence mechanisms in the testes. Selenium (Se) is required for spermatogenesis, antioxidant action and in the activities of different selenoproteins. Both Zn and Se are essential simultaneously for the proper regulation of spermatogenesis and sperm maturation as well as protection against chemical and disease-associated germ cell toxicity. Thus, the study aimed to understand the importance and beneficial effect of Zn and Se co-treatment against BPA-exposed testicular damage in rats. BPA 100 and 200 mg/kg/day was exposed through an oral gavage. Zn (3 mg/kg/day) i.p. and Se (0.5 mg/kg/day) i.p. were injected for 8 weeks. The testicular toxicity was evaluated by measuring body and organs weight, biochemical investigations, sperm parameters, testicular and epididymal histopathology, quantification DNA damage by halo assay, DNA breaks (TUNEL assay), immunohistochemistry and western blot. Results revealed that Zn and Se co-treatment ameliorated BPA-associated male gonadal toxicity in rat as revealed by decreased SGPT, SGOT and BUN levels in serum, reduced testes and epididymis tissue injury, DNA breaks, apoptosis, expressions of 8-OHdG, γ-H2AX and NFκB with an increased serum testosterone and catalase levels. These findings suggest that Zn and Se co-treatment could be a beneficial and protective option against BPA-exposed testicular and epididymal toxicity.

Zinc Deficiency Exacerbates Bisphenol A-Induced Hepatic and Renal Damage: Delineation of Molecular Mechanisms

Zinc (Zn) plays an important role in the maintenance of redox status in the biological system. Zn deficiency has been found to be associated with negative effects on the functioning of many organ systems, including hepatic and renal systems. Bisphenol A (BPA) can alter Zn homeostasis and perturb the physiological system by provoking oxidative stress, which can lead to damage of different organs such as reproductive, immune, neuroendocrine, hepatic and renal systems. The present study aims to investigate the toxicity of BPA in Zn deficient condition in the liver and kidney of rat and to correlate its synergistic actions. Zn deficiency was induced by feeding Zn-deficient diet (ZDD), and BPA was administered orally (100 mg/kg/d). Male Sprague-Dawley rats were divided into four groups: NPD + Vehicle (normal feed and water), NPD + BPA (100 mg/kg/d), ZDD + Vehicle (fed with Zn-deficient diet only) and ZDD + BPA (Zn-deficient diet + BPA; 100 mg/kg/d) for 8 weeks. Biochemical, histopathological, TUNEL assay and protein expression profiles were determined to decipher the oxidative damage induced by ZDD and the toxicant BPA. Expression profile of nuclear factor erythroid 2-related factor 2, proliferating cell nuclear antigen, kelch-like ECH-associated protein 1, superoxide dismutase-1, metallothionein and apoptosis incidence showed that ZDD and BPA have a synergistic exacerbation effect on the liver and kidney of rat.

Antineoplastic drugs in environmentally relevant concentrations cause endocrine disruption and testicular dysfunction in experimental conditions

5-fluorouracil (5-FU) and methotrexate (MTX) are among the most widely consumed antineoplastic drugs worldwide. These drugs are known as emerging pollutants, once after consumption are excreted by feces and/or urine in a mixture of compounds and metabolites, entering the aquatic environment due to low efficiency in drug removal by effluent treatment plants. Considering that these substances may interact with the DNA, causing metabolic and morphological changes, leading to cell death, the present study aimed to investigate the potential impact of a long-term exposure to these antineoplastic drugs in environmentally relevant concentrations, on testicular morphophysiology of rats. Male Wistar rats (70 days old) were distributed into 4 groups (n = 10 / group): control, received only vehicle; MTX, received methotrexate at 10ngL-1 in drinking water; 5-FU received 5-fluorouracil at 10ngL-1 in drinking water; and MTX+ 5FU, received the combination of MTX and 5-FU at 10ngL-1 each. The treatment period was from postnatal day (PND)70 to PND160, when the animals were euthanized for evaluation of testicular toxicity and changes in endocrine signaling. In these experimental conditions, both drugs acted as endocrine disruptors causing cytotoxic effects in the testes of exposed rats, altering the structural pattern of seminiferous tubules and leading to oxidative stress even at environmental concentrations.

Impact of gervital against histopathological, ultrastructural, and biochemical alterations caused by methotrexate or azathioprine in albino rat testis

Methotrexate (MTX) and azathioprine (AZA) are chemotherapeutic, immunosuppressive, cytotoxic drugs with reported adverse effects, including oxidative damage to testis. This study aims to evaluate the potential effect of grape seed extract (GSE; gervital) to prevent testicular damage caused by MTX and AZA. Male albino rats were separated into six groups: group I, normal control group; group II, GSE (150 mg/kg/day); group III, MTX (8 mg/kg/week); group IV, AZA (15 mg/kg/day); group V, GSE (150 mg/kg/day) + MTX (8 mg/kg/week); group VI, GSE (150 mg/kg/day) + AZA (15 mg/kg/day). All rats were sacrificed, blood samples were obtained for testosterone analysis, and testis was removed for histological and ultrastructural studies and oxidation measurements. A reduction in relative body and testis weight, along with a significant decrease in testosterone levels, was observed. Histopathological and ultrastructural alterations induced by MTX or AZA included reduced spermatozoa, sloughing, marked reduction of spermatogenic cells, and pyknosis of some nuclei. Significant oxidative stress manifested as reduced glutathione (GSH) levels and catalase (CAT) and superoxide dismutase (SOD) activities, as well as increased malondialdehyde (MDA) levels. GSE administration showed an ameliorative effect on testosterone levels and histopathological and ultrastructural changes. GSE treatment also suppressed the increases in MDA levels and the decreases in GSH levels and CAT and SOD activities. In conclusion, these findings confirm that GSE is an effective antioxidant that protects testis from histopathological and ultrastructural damage induced by MTX and AZA. Therefore, GSE is a promising candidate for future use to minimize and alleviate MTX and AZA risks.

Regulation of Nucleotide Metabolism with Nutrient-Sensing Nanodrugs for Cancer Therapy

The continual growth of tumor cells requires considerable nutrient consumption. Methotrexate (MTX) is used to treat certain types of cancer by blocking the DNA and RNA productions through interfering one-carbon metabolism and de novo purine and pyrimidine synthesis. However, treatment of MTX may cause many serious adverse effects, which hamper its clinical application. Herein, the authors synthesize ferrous ions, histidine, and MTX assembled nanoparticles (FHM) to deliver MTX at tumor site and enhance the sensitivity of tumor cells to MTX with histidine catabolism. Furthermore, fasting-mimicking diet (FMD) is applied to intervene in the one-carbon metabolism and enhance the cytotoxicity of MTX. Meanwhile, FMD treatment can significantly augment the cellular uptake and tumor accumulation of FHM nanoparticles. Due to the triple inhibitions of the one-carbon metabolism, the proliferation of tumor cells is strongly disturbed, as which is highly replying on DNA and RNA production. Taken together, a 95% lower dose of MTX adopted in combined therapy significantly inhibits the growth of two types of murine tumors without evident systemic toxicity. This strategy may provide a promising nucleotide metabolism-based nanomedicine for cancer therapy.

Protective effect of pyrrolidine dithiocarbamate against methotrexate-induced testicular damage

The aim of the study was to investigate the protective effect of pyrrolidine dithiocarbamate (PDTC) against methotrexate (MTX)-induced testicular damage in rats. Forty Wistar albino male rats were divided into equally four groups: Control group (saline solution, IP), PDTC group (100 mg/kg PDTC,IP, 10 days), MTX group (20 mg/kg MTX, IP, single dose, on the 6th day) and MTX + PDTC group (100 mg/kg PDTC, IP, 10 days and 20 mg/kg MTX, IP, single dose, on the 6th day). After 10 days, testicular tissues were excised for morphometric, histological and immunohistochemical evaluations. Serum testosterone, follicle stimulating hormone (FSH), luteinizing hormone (LH) and prokineticin 2 (PK2) levels were determined. Body and testicular weights were measured. Testicular damage was assessed by histological evaluation. Nuclear factor kappa B (NFkB), nuclear factor erythroid 2 related factor 2 (Nrf2) and PK2 immunoreactivities were evaluated by HSCORE. Body and testicular weights, serum FSH, LH, testosterone levels, seminiferous tubule diameter and germinal epithelial thickness were significantly decreased in the MTX group. However, serum PK2 level, histologically damaged seminiferous tubules and interstitial field width were significantly increased. Additionally, there was an increase in NFkB and PK2 immunoreactivity, whereas there was a significant decrease in Nrf2 immunoreactivity. PDTC significantly improved hormonal, morphometric, histological and immunohistochemical findings. Taken together, we conclude that PDTC may reduce MTX-induced testicular damage via NFkB, Nrf2 and PK2 signaling pathways.

Protective effects of curcumin against methotrexate-induced testicular damage in rats by suppression of the p38-MAPK and nuclear factor-kappa B pathways

Objective

The present study aimed to investigate the possibility that curcumin (CMN) protects against methotrexate (MTX)-induced testicular damage by affecting the phospho-p38 (p-p38) mitogen-activated protein kinase (MAPK) and nuclear factor-kappa B (NF-κB) signaling pathways.

Methods

Eighteen male Wistar albino rats were randomly divided into three groups. The control group was given an intragastric administration of dimethyl sulfoxide (DMSO) daily for 14 days, the MTX group was given a single intraperitoneal dose of MTX (20 mg/kg) on the 11th day, and the MTX+CMN group was given intragastric CMN (100 mg/kg/day, dissolved in DMSO) for 14 days and a single intraperitoneal dose of MTX (20 mg/kg) on the 11th day. At the end of the experiment, all animals were sacrificed and the testicular tissues were removed for morphometry, histology, and immunohistochemistry. Body and testicular weights were measured.

Results

Body weights, seminiferous tubule diameter, and germinal epithelium height significantly decreased in the MTX group compared to the control group. Whereas, the number of histologically damaged seminiferous tubules and interstitial space width significantly increased in the MTX group. In addition, the number of p-p38 MAPK immunopositive cells and the immunoreactivity of NF-κB also increased in the MTX group compared to the control group. CMN improved loss of body weight, morphometric values, and histological damage due to MTX. CMN also reduced the number of p-p38 MAPK immunopositive cells and the NF-κB immunoreactivity.

Conclusion

CMN may reduce MTX-induced testicular damage by suppressing the p38 MAPK and NF-κB signaling pathways.

A systematic overview of the spermatotoxic and genotoxic effects of methotrexate, ganciclovir and mycophenolate mofetil

INTRODUCTION

Immunosuppressant drugs are increasingly being used in the reproductive years. Theoretically, such medications could affect fetal health either through changes in the sperm DNA or through fetal exposure caused by a presence in the seminal fluid. This systematic overview summarizes existing literature on the spermatotoxic and genotoxic potentials of methotrexate (MTX), a drug widely used to treat rheumatic and dermatologic diseases, and mycophenolate mofetil (MMF), which alone or supplemented with ganciclovir (GCV) may be crucial for the survival of organ transplants.

MATERIAL AND METHODS

The systematic overview was performed in accordance with the PRISMA guidelines: A systematic literature search of the MEDLINE and Embase databases was done using a combination of relevant terms to search for studies on spermatotoxic or genotoxic changes related to treatment with MTX, GCV or MMF. The search was restricted to English language literature, and to in vivo animal studies (mammalian species) and clinical human studies.

RESULTS

A total of 102 studies were identified, hereof 25 human and 77 animal studies. For MTX, human studies of immunosuppressive dosages show transient effect on sperm quality parameters, which return to reference values within 3 months. No human studies have investigated the sperm DNA damaging effect of MTX, but in other organs the genotoxic effects of immunosuppressive doses of MTX are fluctuating. In animals, immunosuppressive and cytotoxic doses of MTX adversely affect sperm quality parameters and show widespread genotoxic damages in various organs. Cytotoxic doses transiently change the DNA material in all cell stages of spermatogenesis in rodents. For GCV and MMF, data are limited and the results are indeterminate, for which reason spermatotoxic and genotoxic potentials cannot be excluded.

CONCLUSIONS

Data from human and animal studies indicate transient spermatotoxic and genotoxic potentials of immunosuppressive and cytotoxic doses of MTX. There are a limited number of studies investigating GCV and MMF.

Protective effects of apocynin on damaged testes of rats exposed to methotrexate

Background/aim

Methotrexate (MTX), widely used as a drug in cancer, has many adverse effects on tissues. Apocynin (APO) is a NADPH oxidase inhibitor and is known with many antioxidant properties. In this study, we aimed to evaluate the adverse effects of MTX on testicular tissue and the protective effects of APO at two different doses (20 mg/kg and 50 mg/kg) on MTX-induced testicular damage.

Materials and methods

Fifty adult male Wistar albino rats (8 weeks old and weighing 200–250 g) were divided into five groups of 10 rats each: 1. saline control, 2. dimethyl sulfoxide (DMSO) control, 3. MTX, 4. APO-20 + MTX, and 5. APO-50 + MTX. All injections were performed intraperitoneally. At the end of day 28, all rats were sacrificed under anesthesia. The testes were evaluated histologically and the blood samples were analyzed biochemically.

Results

According to histological and biochemical analyses, there was no significant difference between the DMSO and control groups. In terms of the histological findings, MTX group was significantly the worst affected group compared to the others, and in this group, apoptotic cell number (P = 0.011) was significantly increased in comparison with the control group. Except MTX, there was no significant difference in apoptotic cell number of the other groups compared to the control group. In the MTX group, malondialdehyde (MDA, P = 0.017) and myeloperoxidase (MPO, P < 0.001) levels were significantly increased in tissue and in blood (MDA P < 0.001, MPO P < 0.001), while tissue glutathione (GSH, P < 0.05) and serum testosterone levels (P < 0.01) were decreased compared with the control group. APO + MTX treatment groups exhibited better testis morphology, and apoptotic cells were also significantly decreased compared to MTX group (P < 0.001).

Conclusion

Our results suggest that MTX induced defects on testis via oxidative stress and APO reversed the effects of MTX with its antioxidant properties.

Zinc and selenium combination treatment protected diabetes-induced testicular and epididymal damage in rat

Diabetes increases the possibility of germ cell damage, hypogonadism, and male infertility. Diabetic condition negatively impacts zinc (Zn) and selenium (Se) levels in the body. Zn and Se are among the most important trace elements involved in the regulation of redox reaction, antioxidants enzymes activities, and DNA expression in a germ cell. The present study aimed to elucidate the combined effects of Zn and Se treatment on diabetes-induced germ cell damage in male Sprague Dawley rats. Type 1 diabetes was induced by the single intraperitoneal (i.p.) injection of streptozotocin (55 mg/kg). Zn (3 mg/kg, i.p.) and Se (0.5 mg/kg, i.p.) were administered daily for 8 consecutive weeks. All the animals were provided with normal feed and water throughout the study. The effects on germ cell damage were evaluated by body weight, feed-water intake, organ weight, sperm count, motility, sperm head morphology, biochemical analysis, histology, immunohistochemistry, halo assay, germ cell comet assay, testes terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick end-labeling (TUNEL) assay, sperm TUNEL assay, serum protein pattern analysis, and subcellular analysis using transmission electron microscopy. Further, the expressions of nuclear erythroid-derived related factor 2, catalase, glutathione peroxidase 4, and glutathione peroxidase 5 were carried out to ascertain the mechanism of protection. The present results demonstrated that 8 weeks combined treatment of Zn (3 mg/kg, i.p.) and Se (0.5 mg/kg, i.p.) reduced diabetes-induced germ cell damage. This study further highlighted that Zn and Se combination treatment might be a better strategy for the germ cell protection in diabetes and deserve further investigation.

Zinc abrogates anticancer drug tamoxifen-induced hepatotoxicity by suppressing redox imbalance, NO/iNOS/NF-ĸB signaling, and caspase-3-dependent apoptosis in female rats

Tamoxifen (TAM) is used in breast cancer chemotherapy since its approval by the Food and Drug Administration in 1977. However, TAM therapy is accompanied with hepatotoxicity - a source of worry to clinicians. Oxidative stress and inflammation are the major implicated mechanisms contributing to TAM hepatotoxicity. In this study, we explored whether zinc (Zn) supplementation could prevent TAM-induced hepatotoxicity in female Wistar rats. Rats were subjected to oral pretreatment of Zn (100 mg/kg body weight (b.w.)/day) for 14 days against hepatic toxicity induced by single intraperitoneal administration of TAM (50 mg/kg b.w.) on day 13. TAM markedly elevated serum liver enzymes, whereas total protein and albumin considerably reduced. TAM caused prominent depletion of hepatic-reduced glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) activity. Also, TAM significantly increased malondialdehyde (MDA) level. Further, it raised liver levels of tumor necrosis factor-α (TNF-α), interleukin-1β, (IL-1β), interleukin-6 (IL-6), and nitric oxide (NO) confirmed by the liver histopathological alterations. The mechanistic inflammatory expression of inducible nitric oxide synthase (iNOS) and nuclear factor-kappa B (NF-ĸB), and expression of caspase-3 protein prominently increased. Zinc supplementation significantly modulated serum liver function markers, antioxidant enzymes, and GSH and MDA levels. Zinc downregulated the expression of cytokines, NO, iNOS, NF-ĸB and caspase-3, and ameliorated histopathological changes. Zinc protects against TAM-induced hepatotoxicity; it may serve as an adjuvant supplement for female patients undergoing TAM chemotherapy.

Boar semen improvement through sperm capacitation management, with emphasis on zinc ion homeostasis

Critical to fertilization success, sperm capacitation within the female oviductal sperm reservoir endows mammalian spermatozoa with hyperactivated motility and capacity to fertilize. An elaborate cascade of signaling events during capacitation guides the redistribution of sperm plasma membrane seminolipid and cholesterol, Ca-influx and increases tyrosine phosphorylation to promote hyperactivated motility. Such events result in the remodeling of the sperm acrosome, increased fluidity and fusability of the plasma membrane, shedding of surface-adsorbed seminal plasma proteins that glue sperm heads to the oviductal epithelium and ultimately the release of hyperactivated spermatozoa from the oviductal sperm reservoir. Discovered recently, the capacitation-induced sperm zinc ion efflux and resultant zinc signatures are reflective of sperm capacitation status and fertilizing ability, inspiring the retrospection of zinc ion functions in the physiology and fertility of boar sperm and that of other species. This review also highlights the merit of the domestic boar as a biomedical model for spermatology and fertilization research. Relevant to the quest for better fertility management in the livestock industries, the benefits of zinc ion supplementation through nutrition and direct addition to extended semen are discussed in the context of artificial insemination (AI). Ideas are shared on future technologies for zinc management in AI doses and research on the sperm zinc-interacting proteome.

Effect of diethyldithiocarbamate in cyclophosphamide-induced nephrotoxicity: Immunohistochemical study of superoxide dismutase 1 in rat

OBJECTIVES:

To investigate the role of diethyldithiocarbamate (DEDTC) in cyclophosphamide (CP)-induced nephrotoxicity in Sprague–Dawley rat. DEDTC is a known chelating agent for copper and zinc. It is also used as a thiol protecting agent, as nuclear factor kappa-light-chain-enhancer of activated B-cells inhibitor and nitric oxide synthase inhibitor. It is also reported to inhibit superoxide dismutase (SOD) both in vitro and in vivo conditions. Considering this wide range of actions, current study investigated the role of DEDTC in CP-induced nephrotoxicity in experimental rat model.

MATERIALS AND METHODS:

Thirty-two male rats were randomized into four groups. Group 1, control received only saline ip; Group 2 and 4, received CP at the dose of 150 mg/kg body weight ip on the 4^th day, while Group 3 and 4, received DEDTC at the dose of 250 mg/kg alternatively (fractionated dose of 1000 mg/kg). All the experimental animals were sacrificed on the 7^th day and organs of interest were collected for biochemical, histopathological, DNA damage, and immunohistochemical assessments.

RESULTS:

DEDTC administration was found to further exacerbate the condition of CP-induced kidney damage as assessed by several biochemical and histological parameters. Further, the damage was also significantly reflected in the bladder in DEDTC-treated animals as compared to controls. SOD1 (Cu/Zn- dependent enzyme) expression was found to be decreased and this might be due to the action of DEDTC on SOD and other antioxidants.

CONCLUSION:

The present study indicates that DEDTC administration further exacerbated the CP-induced kidney damage in rat.

Protective effects of sea cucumber (Holothuria atra) extract on testicular dysfunction induced by immune suppressant drugs in Wistar rats

The current study was aimed to evaluate the protective effect of Holothurian atra (HA) extract; naturally occurring marine resource, against methotrexate (MTX) induced testicular dysfunction. Mature rats received either MTX (20 mg/kg, intraperitoneally) or saline on the 7th day of experiment al design. Seven days prior and after MTX-injection, rats received HA at dose of 300 mg/kg intragastrically (HA + MTX group; HA group alone). Serum was extracted and testicular tissues were examined for the changes in serum biochemistry (liver & kidney biomarkers, testicular hormones and antioxidants), molecular and histopthological alterations using RT-PCR and immunohistochemistry. MTX-injected rats induced alteration in all testicular parameters. Prior administration of HA ameliorated the MTX-induced oxidative stress. HA administration normalised MTX-induced decrease in serum levels of interleukin-6 (IL-6), tumour necrosis factor alpha (TNF-α), interferon-gamma (IFN-γ), reproductive hormones (FSH, LH and testosterone) and antioxidants GST, SOD and catalase. MTX-injected rats down-regulated mRNA expression of GST, SOD, steroidogenesis associated genes, IFN-γ, Bcl2 and NFKB. MTX up-regulated BAX expression and caspase 9 immunoreactivity that were ameliorated in HA + MTX group. Collectively, HA ameliorated and restored all altered genes. In conclusion, HA is a promising supplement that is helpful in protection against testicular cytotoxicity and dysfunction induced by methotrexate.