Chronic cyclophosphamide treatment alters the expression of stress response genes in rat male germ cells

Integrative proteomics and metabolomics approach to identify the key roles of icariin-mediated protective effects against cyclophosphamide-induced spermatogenesis dysfunction in mice

The alkylating antineoplastic agent cyclophosphamide (CP) is known to be toxic to the male reproductive system, but there are no effective prevention or treatment options. The flavonoid icariin (ICA), which is used in Chinese medicine, has been shown to have a number of biological functions, including testicular protection. The current study looked into the protective effects of ICA in preventing CP-induced spermatogenesis dysfunction. The current study looked into the role of ICA in preventing testicular dysfunction caused by CP. For 5 days, healthy adult mice were given saline or a single dose of CP (50 mg/kg) intraperitoneally (i.p). For the next 30 days, mice were given ICA (80 mg/kg) by gavage. Animals were euthanized 12 h after receiving ICA, and testes were removed for biochemical, histopathological, sperm evaluation, and transmission electron microscope analysis (TEM). We also investigated the potential biological effects of ICA on CP-induced spermatogenesis dysfunction in mice using an integrated proteomic and metabolomic approach. The levels of 8309 proteins and 600 metabolites were measured. The majority of the differential proteins and metabolites were found to be enriched in a variety of metabolic pathways, including the PI3K-Akt signaling pathway, necroptosis, the mTOR signaling pathway, glycerophospholipid metabolism, and ABC transporters, implying that ICA may have molecular mechanisms that contribute to CP-induced spermatogenesis dysfunction in the testis. Taken together, these findings show that ICA effectively reduces testis injury, implying that ICA may have a role in male infertility preservation.

Phycobiliproteins Ameliorate Gonadal Toxicity in Male Mice Treated with Cyclophosphamide

Cyclophosphamide (CP)-which is used to treat autoimmune diseases and cancer-is related to gonadotoxicity attributed to oxidative stress. As phycobiliproteins (PBPs) are strong antioxidants that are unexplored as protective agents against male gonadotoxicity, our work aimed to investigate the effects of PBP crude extract on testicular damage and sperm parameter alterations caused by CP in mice. Three doses of PBP (50, 100, and 200 mg/kg) were tested in the experimental groups (n = 8 per group), administered concomitantly with 100 mg/kg CP. After 42 days receiving PBP daily and CP weekly, body and relative testicular weights, serum testosterone levels, testicular lipoperoxidation and antioxidant enzyme activity levels, and testicular histology and sperm parameter alterations were assessed. The results showed that PBP crude extract at 200 mg/kg prevented testosterone serum reduction, body weight loss, lipoperoxidation and enzyme activity increments, and sperm parameter alterations and partially ameliorated relative testicular weight reductions and histological damage in CP-treated mice. In conclusion, we showed that PBP crude extract (200 mg/kg) mitigated oxidative damage in the testes and ameliorated alterations in sperm parameters in mice treated with CP (100 mg/kg); therefore, PBP extract could be considered as a potential protective agent against CP toxicity.

Effects of Green cardamom (Elettaria cardamomum Maton) and its combination with cyclophosphamide on Ehrlich solid tumors

Background

Cardamom (Elettaria cardamomum) is a spice and exhibits potent antioxidant and biological activities through distinct molecular mechanisms. However, the anticancer effect of cardamom was not explored yet in Ehrlich solid tumor (EST)-bearing mice.

Objectives

This investigation was aimed to evaluate the anti-cancer effects of green cardamom (GCar) alone or combined with the anti-cancer drug cyclophosphamide in an in vivo model to explore its mechanistic role in tumor cell death in EST-bearing mice.

Methods

Ehrlich ascites tumor cells were injected in the mice and 5 days later the animals treated with GCar and/or cyclophosphamide for 10 days. Twenty-four hours from the last treatment, animals were sacrificed for the different measurements.

Results

Data recorded for tumor size, percentage of tumor growth inhibition, tumor growth delay and mean survival time of EST-bearing mice demonstrated the effective role of GCar alone or combined with CPO as a promising anti-cancer agent because it reduced tumor size. GCar elevated the mean survival time of EST-bearing mice compared to that of untreated EST and EST + CPO groups. Analysis of qPCR mRNA gene and protein expression revealed that GCar alone or combined with CPO were promising anticancer agents. After the treatment of EST with GCar, the apoptotic-related genes and proteins were significantly modulated. GCar induced markedly significant decreases in oxidative stress biomarkers and a significant increment in glutathione levels and that of antioxidant enzymes. With a marked diminish in liver and kidney function biomarkers.

Conclusion

The results revealed that GCar could serve as an apoptotic stimulator agent, presenting a novel and potentially curative approach for cancer treatment, inducing fewer side effects than those of the commercially used anti-cancer drugs, such as CPO.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-021-03305-2.

Evaluation of the Biological Efficiency of Silver Nanoparticles Biosynthesized Using Croton tiglium L. Seeds Extract against Azoxymethane Induced Colon Cancer in Rats

BACKGROUND

Colorectal cancer (CRC) is considered as the most common type of gastrointestinal cancers. Chemotherapy became limited due to the adverse side effects. Therefore, the most effective Croton tiglium extract was selected to be incorporated by silver nanoparticles (Ag-NPs) then evaluated against colon cancer induced by azoxymethane (AOM) in rats.

METHODS

Different hematological and biochemical measurements were quantified in addition to markers of oxidative stress. Specific tumor and inflammatory markers were assayed. Colonic tissues were examined histopathologically in addition to immunohistochemistry (IHC). Native proteins and isoenzymes patterns were electrophoretically assayed beside expression of Tumor Protein P53 (TP53) and Adenomatous Polyposis Coli (APC) genes in colonic tissues.

RESULTS

It was found that AOM caused significant (P≤0.05) elevation in the hematological and biochemical measurements. C. tiglium nano-extract restored these measurements to normalcy. Tumor and inflammatory markers elevated significantly (P≤0.05) in sera of AOM induced colon cancer group in addition to increasing peroxidation products with decline in antioxidant enzymes activities in colon tissues. Nano-extract restored these measurements to normalcy in post-treated group. Histopathological study revealed that nano-extract minimized severity of inflammatory reactions in all nano-extract treated groups and prevented  anti-Keratin 20 antibody expression in post-treated group. The lowest similarity index (SI%) values were noticed with electrophoretic protein (SI=71.43%), lipid (SI=0.00%) and calcium (SI=75.00%) moieties of protein patterns, catalase (SI=85.71%), peroxidase (SI=85.71%), α-esterase (SI=50.00%) and β-esterase (SI=50.00%) isoenzymes in colon cancer group. Furthermore, AOM altered the relative quantities of total native bands. The nano-extract prevented the alterations that occurred qualitatively in nano-extract post-treated group and quantitatively in all nano-extract treated groups. Levels of TP53 and APC gene expression increased in AOM injected group and nano-extract restored their levels to normalcy in the post-treated group.

CONCLUSION

C. tiglium nano-extract exhibited ameliorative effect against the biochemical and molecular alterations induced by AOM in nano-extract post-treated group.

Non-oncologic Indications for Male Fertility Preservation

PURPOSE OF REVIEW

To explore non-oncologic indications for male fertility preservation.

RECENT FINDINGS

Common scenarios in which male fertility could be irreversibly compromised include autoimmune conditions requiring treatment with cyclophosphamide, gender dysphoria prior to starting hormone therapy, military deployment, and critical illness. Fertility preservation should be considered with particular attention to the timing and logistics specific to each scenario. Recognition and familiarity with such situations will help physicians provide better counseling to patients and their families, improve the quality of decision-making, and ultimately reduce missed opportunities and regret.

Evaluating of β-carotene role in ameliorating of favism-induced disturbances in blood and testis

Background

Favism is an acute hemolytic anemia occurs in glucose 6-phosphate dehydrogenase (G6-PD) deficient individuals. β-Carotene occurs in vegetables such as carrots. This study aimed to establish the therapeutic effect of β-carotene to rebalance the testicular and blood proteins disturbances in favism.

Methods

Forty-eight male rats were divided into six equal groups; Groups 1, 2 and 3: normal rats were daily oral administrated with 1 ml saline, 1 ml corn oil and β-carotene (60 mg/kg dissolved in 1 ml corn oil), respectively, once a day over 15 days period. Group 4 (favism-induced group): normal rats injected intraperitoneal (ip) with diethyl maleate (5 μl/rat) and after 1 h injected ip with 1/3 LD50 of faba beans ethanolic extract for 15 day to induce favism. Groups 5 and 6: favism-induced rats were daily oral administered with 30 and 60 mg/kg β-carotene dissolved in 1 ml corn oil, respectively, once a day over 15 days.

Results

The results revealed that oral administration of corn oil or β-carotene into normal rats over 15 days period did not induce any change. In favism-induced groups, hematological parameters, liver function, serum glucose, G6-PD, luteinizing and follicle-stimulating hormones and sex-hormone binding globulin showed significant increase. Moreover, serum testosterone and dehydroepiandrosterone sulfate, testicular G6-PD, 3β-hydroxy steroid dehydrogenase, cholesterol and total protein were decreased. Treatment with both doses of β-carotene into favism groups restored all the abovementioned parameters to approach normal values. Favism inhibited blood proteins while β-carotene treatment into favism group stopped blood cells damage and blood proteins inhibition. These results were supported by histological studies.

Conclusions

In conclusion, taken β-carotene into favism group abolished testicular and blood proteins disturbances and this effect was dose dependent.

Fertaric Acid Protects from Octylphenol-Related Hepatotoxicity in Rats: Biochemical, Molecular, and Histopathological Studies

The endocrine-disrupting chemical 4-tert-octylphenol (OP) can mimic estrogen and testosterone hormones and threaten health; fertaric acid (FA) is a hydroxycinnamic acid found in grapefruit. This study aimed to investigate whether FA has a protective effect on 4-tert-octylphenol-related hepatotoxicity. Thirty male albino rats were divided into 5 equal groups of 6 rats each as follows: control group-administrated orally with 1 ml saline 3 days/week for 4 weeks; corn oil group-administrated orally with 1 ml corn oil 3 days/week for 4 weeks; FA-treated group-administrated orally with FA (45 mg /kg body weight) dissolved in saline 3 days/week for 4 weeks; OP-treated group-administrated orally with OP (40 mg /kg body weight) dissolved in corn oil 3 days/week for 4 weeks; FA + OP-treated group-administrated orally with FA (45 mg /kg body weight) dissolved in saline 3 days/week for 4 weeks then administrated orally with OP (40 mg/kg body weight) dissolved in corn oil 3 days/week for another 4 weeks. The results obtained showed that OP-exposed rats had significant increase in serum aspartate aminotransferase, alanine aminotransferase, γ-glutamyl transferase, lactate dehydrogenase, bilirubin, serum and liver tumor necrosis factor-α, interleukin-1β and malondialdehyde, serum interleukin-6 and interleukin-10 and significant decrease in serum alkaline phosphatase, acid phosphatase, serum and liver superoxide dismutase, glutathione peroxidase, and catalase. OP caused an inhibitory action on the gene expression of liver proteins. Rats treated with FA before OP exposure had near-normal values. In addition, FA prevented the degradation of liver deoxyribonucleic acid (DNA), and DNA reformation occurred. In conclusion, FA protects from dangerous OP-related hepatic effects, and these results were supported by molecular and histological investigations.

Doxorubicin and vincristine affect undifferentiated rat spermatogonia

Anticancer drugs, such as alkylating agents, can affect male fertility by targeting the DNA of proliferative spermatogonial stem cells (SSC). Therefore, to reduce such side effects, other chemotherapeutics are used. However, less is known about their potential genotoxicity on SSC. Moreover, DNA repair mechanisms in SSC are poorly understood. To model treatments deprived of alkylating agents that are commonly used in cancer treatment, we tested the impact of exposure to doxorubicin and vincristine, alone or in combination (MIX), on a rat spermatogonial cell line with SSC characteristics (GC-6spg). Vincristine alone induced a cell cycle arrest and cell death without genotoxic impact. On the other hand, doxorubicin and the MIX induced a dose-dependent cell death. More importantly, doxorubicin and the MIX induced DNA breaks, measured by the COMET assay, at a non-cytotoxic dose. To elucidate which DNA repair pathway is activated in spermatogonia after exposure to doxorubicin, we screened the expression of 75 genes implicated in DNA repair. Interestingly, all were expressed constitutively in GC-6spg, suggesting great potential to respond to genotoxic stress. Doxorubicin treatments affected the expression of 16 genes (>1.5 fold change;P < 0.05) involved in cell cycle, base/nucleotide excision repair, homologous recombination and non-homologous end joining (NHEJ). The significant increase in CDKN1A and XRCC1 suggest a cell cycle arrest and implies an alternative NHEJ pathway in response to doxorubicin-induced DNA breaks. Together, our results support the idea that undifferentiated spermatogonia have the ability to respond to DNA injury from chemotherapeutic compounds and escape DNA break accumulation.

Immunosuppressants and Male Reproduction

Prolonged use of immunosuppressant medications is occasionally seen in infertile men with chronic inflammatory conditions; autoimmune disorders; or an organ or hematopoietic stem cell transplant. Chronic inflammation impacts negatively on male reproductive endpoints, so immunosuppressant therapy can produce improvements. Corticosteroids have been used to treat antisperm antibodies and even as an empirical treatment for male infertility in general. Trials of these methods have provided mixed results on semen quality and fertility, with improvement, no change and negative effects reported by different investigators. In a substantial number of observational studies, patients on long-term therapy with prednisone for chronic inflammatory disease, testosterone levels were lower compared to untreated controls, though randomized controlled trials have not been conducted. Similarly decreases in testosterone have been reported in men receiving corticosteroids to minimize transplant rejection; however, most were treated with multiple immunosuppressive medications that may have contributed to this effect. A large number of trials of healthy men treated with corticosteroids have shown some disruption in reproductive hormone levels, but other studies reported no effect. Studies in monkeys, rats (at human equivalent dose), cattle, sheep, and horses have shown endocrine disruption, including low testosterone with dexamethasone treatment. Of the cytostatic immunosuppressives, which have high potential for cellular damage, cyclophosphamide has received the most attention, sometimes lowering sperm counts significantly. Methotrexate may decrease sperm numbers in humans and has significant negative impacts in rodents. Other chemotherapeutic drugs used as immunosuppressants are likely to impact negatively on male fertility endpoints, but few data have been collected. The TNF-α Inhibitors have also received little experimental attention. There is some evidence that the immunophilin modulators: cyclosporine, sirolimus, and everolimus cause endocrine disruption and semen quality impairment. As we review in this chapter, results in experimental species are concerning, and well-designed studies are lacking for the effects of these medications on reproductive endpoints in men.

The mechanisms of cyclophosphamide-induced testicular toxicity and the protective agents

INTRODUCTION

Cyclophosphamide (CP) is an alkylating antineoplastic agent with known toxicity to the male reproductive system. Areas covered: This review summarizes the known mechanisms by which CP exerts its toxic effects on the male reproductive system and the methods utilized to prevent such effects so that it could be further investigated and applied in clinical use. Keywords including ['Cyclophosphamide' AND 'male reproductive' OR' sperm toxicity' OR 'spermatotoxicity' OR 'infertility] were searched through Google Scholar, PubMed and Scopus databases based on PRISMA guidelines. After removing duplicates and irrelevant data, 76 papers were reviewed concerning the outcomes of treatment of male mice, rats, and humans with CP and the effects of co-administration of various natural and synthetic compounds on male reproductive system. Expert opinion: CP exerts its effect mainly by inducing oxidative stress and changing gene expression in spermatocytes variably during different stages of development. These effects could be either restored or prevented by the administration of compounds with antioxidant properties and those which target the biochemical alterations induced by CP.

Transcriptome research on spermatogenic molecular drive in mammals

It is known that spermatogenic disorders are associated with genetic deficiency, although the primary mechanism is still unclear. It is difficult to demonstrate the molecular events occurring in testis, which contains germ cells at different developmental stages. However, transcriptomic methods can help us reveal the molecular drive of male gamete generation. Many transcriptomic studies have been performed on rodents by utilizing the timing of the first wave of spermatogenesis, which is not a suitable strategy for research in fertile men. With the development of separation methods for male germ cells, transcriptome research on the molecular drive of spermatogenesis in fertile men has seen great progress, and the results could be ultimately applied to improve the diagnosis and treatment for male infertility.

Melatonin controlled apoptosis and protected the testes and sperm quality against bisphenol A-induced oxidative toxicity

Epidemiological reports have indicated a correlation between the increasing bisphenol A (BPA) levels in the environment and the incidence of male infertility. In this study, the protective effects of melatonin on BPA-induced oxidative stress and apoptosis were investigated in the rat testes and epididymal sperm. Melatonin (10 mg/kg body weight (bw)) was injected concurrently with BPA (50 mg/kg bw) for 3 and 6 weeks. The administration of BPA significantly increased oxidative stress in the testes and epididymal sperm. This was associated with a decrease in the serum testosterone level as well as sperm quality, chromatin condensation/de-condensation level, and the percentage of haploid germ cells in the semen. BPA administration caused a significant increase in apoptosis accompanied by a decrease in the expression of the antiapoptotic proteins Bcl-2 in the testes and epididymal sperm. The concurrent administration of melatonin decreased oxidative stress by modulating the levels of glutathione, superoxide dismutase, and catalase as well as the malondialdehyde and hydrogen peroxide concentrations in the testes and sperm. Melatonin sustained Bcl-2 expression and controlled apoptosis. Furthermore, melatonin maintained the testosterone levels, ameliorated histopathological changes, increased the percentages of seminal haploid germ cells, and protected sperm chromatin condensation process, indicating appropriate spermatogenesis with production of functional sperm. In conclusion, melatonin protected against BPA-induced apoptosis by controlling Bcl-2 expression and ameliorating oxidative stress in the testes and sperm. Thus, melatonin is a promising pharmacological agent for preventing the potential reproductive toxicity of BPA following occupational or environmental exposures.

Zinc Transport Differs in Rat Spermatogenic Cell Types and Is Affected by Treatment with Cyclophosphamide

Adequate zinc levels are required for proper cellular functions and for male germ cell development. Zinc transport is accomplished by two families of zinc transporters, the ZIPs and the ZnTs, that increase and decrease cytosolic zinc levels, respectively. However, very little is known about zinc transport in the testis. Furthermore, whether cytotoxic agents such as cyclophosphamide (CPA), a known male germ cell toxicant, can affect zinc transport and homeostasis is unknown. We examined zinc transporter expression and zinc transport in pachytene spermatocytes (PS) and round spermatids (RS) in a normal state and after exposure to CPA. We observed differences in the expression of members of the ZnT and ZIP families in purified populations of PS and RS. We also observed that RS accumulate more zinc over time than PS. The expression of many zinc binding genes was altered after CPA treatment. Interestingly, we found that the expression levels of ZIP5 and ZIP14 were increased in PS from animals treated daily with 6 mg/kg CPA for 4 wk but not in RS. This up-regulation led to an increase in zinc uptake in PS but not in RS from treated animals compared to controls. These data suggest that CPA treatment may alter zinc homeostasis in male germ cells leading to an increased need for zinc. Altered zinc homeostasis may disrupt proper germ cell development and contribute to infertility and effects on progeny.

Neuroprotective effect of Decalepis hamiltonii on cyclophosphamide-induced oxidative stress in the mouse brain

BACKGROUND

Cyclophosphamide (CP), one of the most widely used antineoplastic drugs, causes toxic side effects on vital organs including brain. In this study, we have investigated neuroprotective potential of the aqueous extract of the roots of Decalepis hamiltonii (DHA) against CP-induced oxidative stress in the mouse brain.

METHODS

Swiss albino male mice were pre-treated with DHA (50 and 100 mg/kg b.w.) for 10 consecutive days followed by an injection with CP intraperitoneally (25 mg/kg b.w.) for 10 days 1 h after DHA treatment; 16 h later, they were euthanized, their brains were immediately removed, and biochemical and molecular analyses were conducted.

RESULTS

The results indicated that injection of CP induced oxidative stress in the mouse brain as evident from the increased lipid peroxidation, reactive oxygen species, depletion of glutathione and reduced activities of the antioxidant enzymes such as superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, and glutathione-S-transferase. Treatment with DHA significantly mitigated the CP-induced oxidative stress. Moreover, expression of genes for the antioxidant enzymes was downregulated by CP treatment which was reversed by DHA.

CONCLUSIONS

In conclusion, DHA protected the brain from oxidative stress induced by CP, and therefore, it could be a promising nutraceutical as a supplement in cancer chemotherapy in order to ameliorate the toxic side effects of cancer drugs.

Amelioration of cyclophosphamide-induced hepatotoxicity by the root extract of Decalepis hamiltonii in mice

Hepatoprotective potential of the aqueous extract of the roots of Decalepis hamiltonii (DHA) against cyclophosphamide (CP)-induced oxidative stress has been investigated in mice. Administration of CP (25mg/kg b.w., i.p) for 10 days induced hepatic damage as indicated by the serum marker enzymes aspartate and alanine transaminases (AST, ALT), alkaline phosphatase (ALP) and lactate dehydrogenase (LDH). Parallel to these changes CP induced oxidative stress in the liver as evident from the increased lipid peroxidation (LPO), reactive oxygen species (ROS), depletion of glutathione (GSH), and reduced activities of the antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), and glutathione-S-transferase (GST). Treatment with DHA (50 and 100 mg/kg b.w., po) mitigated the CP-induced oxidative stress. Moreover, expression of genes for the antioxidant enzymes, were down-regulated by CP treatment which was reversed by DHA. Our study shows the DHA protected the liver from toxicity induced by CP and therefore, it could be serve as a safe medicinal supplement during cyclophosphamide chemotherapy.

Alfa-lipoic acid protects testosterone secretion pathway and sperm quality against 4-tert-octylphenol induced reproductive toxicity

The protective effect of α-lipoic acid (LA) (50 mg/kg bw) against 4-tert-octylphenol (OP) (50 mg/kg bw) induced reproductive toxicity in male rats was studied. LA was injected 1h prior to OP administration three times a week. OP caused significant increase in oxidative stress in hypothalamus and epididymal sperm, disturbed hormonal levels in serum, decreased sperm quality, increased DNA fragmentation and loss of 35 and 95 kDa proteins in sperm, as well as elevated proliferating index in testis. LA protected against oxidative stress through promoting the levels of glutathione and glutathione-S-transferase in hypothalamus and sperm. In addition, LA prevented the decrease in testosterone, dehydroepiandrosterone sulfate, 3β-hydroxysteroid dehydrogenase, and inhibited the elevations in sex-hormone-binding globulin levels and showed normal sperm quality. LA modulated proliferation of germ cell, protected against DNA fragmentation and maintained membrane protein organization in the sperm. In conclusion, LA normalized oxidative stress and protected testosterone synthesis pathway across hypothalamus-testicular axis and sperm quality indicating its defensive influence against OP-induced oxidative reproductive dysfunction in male rats.

Toxic effects of different doses of cyclophosphamide on the reproductive parameters of male mice

The cyclophosphamide is used in cancer treatment. The aim of this study was evaluating the effect of different doses of this drug on male mice reproductive parameters. The cyclophosphamide was administered in the doses 100, 150, 200 e 250 mg.kg-1, intraperitoneal route, for six weeks. As a result, it was observed a decrease in body mass and a decrease in testicles and kidney's weight, in all animals treated with cyclophosphamide. Only the groups that received the doses 100, 150 mg.kg-1 of cyclophosphamide were able to fertilize their females. There was higher incidence of post- implantation losses, reabsorptions and decrease in fetal viability in the group that received the dose of 150 mg.kg-1. It was observed a reduction in epididymis and liver's weight of the animals treated with the doses 150, 200 e 250 mg.kg-1. Abnormal spermatozoa were found in the doses 200 e 250 mg.kg-1. Based on the methodology used and results obtained, it was concluded that the cyclophosphamide was toxic, considering the decrease in animal's body mass and testicle's weight; promoted hepatotoxicity and nephrotoxic effect; influenced in the animals spermatogenesis taking them to infertility and/or subfertility; decreased fetal viability, despite it didn't cause significant malformations in the offspring.

Protection of cyclophosphamide-induced toxicity in reproductive tract histology, sperm characteristics, and DNA damage by an herbal source; evidence for role of free-radical toxic stress

Cyclophosphamide (CP) as an anticancer alkylating agent has been known as a male reproductive tract toxicant. The aim of this study was to examine whether Satureja khuzestanica essential oil (SKEO) as an established herbal antioxidant, might protect tract rat reproductive system from toxicity of CP. To reach this aim, total antioxidant power (TAP) and lipid peroxidation (LPO) in testis and plasma, blood levels of sex hormones, sperm characteristics, DNA integrity and chromatin quality, and fertility in male rats were tested. Histopathological analysis of testes and epididymides and staining of mast cells were performed for assessment of spermatogenic disorders. CP (6 mg/kg/day) and SKEO (225 mg/kg/day) were administered alone or in combination by gavage for 28 days. In the CP-exposed rats, testicular and plasma LPO increased, TAP decreased, plasma testosterone diminished, and both spermatogenesis and fertility were impaired. In CP-treated rats, a decrease in sperm quality was associated with increased DNA damage and decreased chromatin quality. Coadministration of SKEO significantly improved CP-induced changes in plasma testosterone, sperm quality, spermatogenesis and fertility, toxic stress, and DNA damage. It is concluded that CP-induced toxic effects on androgenesis and spermatogenesis is mediated by free radicals. SKEO protects reproductive system from toxicity of CP through its antioxidant potential and androgenic activity.

Impact of the chemotherapy cocktail used to treat testicular cancer on the gene expression profile of germ cells from male Brown-Norway rats

Advances in treatment for testicular cancer that include the coadministration of bleomycin, etoposide, and cisplatin (BEP) have brought the cure rate to higher than 90%%. The goal of this study was to elucidate the impact of BEP treatment on gene expression in male germ cells. Brown-Norway rats were treated for 9 wk with vehicle (0x) or BEP at doses equivalent to 0.3x and 0.6x the human dose. At the end of treatment, spermatogenesis was affected, showing altered histology and a decreased sperm count; spermatozoa had a higher number of DNA breaks. After 9 wk of treatment, round spermatids were isolated, and RNA was extracted and probed on Rat230-2.0 Affymetrix arrays. Of the 31 099 probe sets present on the array, 59%% were expressed in control round spermatids. BEP treatment significantly altered the expression of 221 probe sets, with at least a 1.5-fold change compared with controls; 80% were upregulated. We observed a dose-dependent increase in the expression of oxidative stress response genes and no change in the expression of genes involved in DNA repair. BEP upregulated genes were implicated in pathways related to Jun and Junb protooncogenes. Increased mRNA levels of Jun and Junb were confirmed by quantitative RT-PCR; furthermore, JUN protein was increased in elongating spermatids. Thus, BEP exposure triggers an oxidative stress response in round spermatids and induces many pathways that may lead to the survival of damaged cells and production of abnormal sperm.

Astaxanthin inhibits cytotoxic and genotoxic effects of cyclophosphamide in mice germ cells

Cyclophosphamide (CP), an alkylating agent used in the treatment of several cancers as well as an immunosuppressant in rheumatoid arthritis. It is used against several cancers due to its broad spectrum efficacy, but at the same time possesses unwanted risks for occupational exposure as well as therapy related toxicities to patients. The present study was aimed to investigate the protective effect of astaxanthin (AST) a red carotenoid pigment on CP induced germ cell toxicity in male mice. CP was administered intraperitoneally (i.p.) at the dose of 50, 100 and 200mg/kg body weight to mice (20-25 g) once in a week for a period of five weeks. AST was given at the dose of 25mg/kg per oral (p.o.) for five consecutive days in a week for five weeks. The animals were sacrificed one week after the last injection of CP. The protective effect of AST against CP induced male germ cell toxicity was evaluated using body weight, testes and epididymis weight, sperm count, sperm head morphology, sperm comet assay, histology of testes and TUNEL assay. AST treatment significantly improved the testes weight, sperm count and sperm head morphology as compared to only CP treated animals. The result of comet assay showed that AST treatment significantly restored the sperm DNA damage induced by CP. Further, AST treatment showed protection against CP induced testicular toxicity as evident from testes histology and TUNEL assay. The present results indicate the chemoprotective potential of AST against CP induced germ cell toxicity in mice.

Chronic cyclophosphamide exposure alters the profile of rat sperm nuclear matrix proteins

Chronic exposure of male rats to the alkylating agent cyclophosphamide, a well-known male-mediated developmental toxicant, alters gene expression in male germ cells as well as in early preimplantation embryos sired by cyclophosphamide-exposed males. Sperm DNA is organized by the nuclear matrix into loop-domains in a sequence-specific manner. In somatic cells, loop-domain organization is involved in gene regulation. Various structural and functional components of the nuclear matrix are targets for chemotherapeutic agents. Consequently, we hypothesized that cyclophosphamide treatment would alter the expression of sperm nuclear matrix proteins. Adult male rats were treated for 4 wk with saline or cyclophosphamide (6.0 mg kg(-1) day(-1)), and the nuclear matrix was extracted from cauda epididymal sperm. Proteins were analyzed by two-dimensional gel electrophoresis. Identified proteins within the nuclear matrix proteome were mainly involved in cell structure, transcription, translation, DNA binding, protein processing, signal transduction, metabolism, cell defense, or detoxification. Interestingly, cyclophosphamide selectively induced numerous changes in cell defense and detoxification proteins, most notably, in all known forms of the antioxidant enzyme glutathione peroxidase 4, in addition to an uncharacterized 54-kDa form; an overall increase in glutathione peroxidase 4 immunoreactivity was observed in the nuclear matrix extracts from cyclophosphamide-exposed spermatozoa. An increase in glutathione peroxidase 4 expression suggests a role for this enzyme in maintaining nuclear matrix stability and function. These results led us to propose that a change in composition of the nuclear matrix in response to drug exposure was a factor in altered sperm function and embryo development.

Exposure of male rats to cyclophosphamide alters the chromatin structure and basic proteome in spermatozoa

BACKGROUND

The formation of mature sperm involves the expression of numerous proteins during spermiogenesis and the replacement of histones with protamines to package the genome. Exposure to cyclophosphamide (CPA), an anticancer alkylating agent, during spermiogenesis may disrupt chromatin condensation with adverse consequences to the offspring.

METHODS

Adult male rats were given CPA in one of two schedules: (i) subchronic, 4 days - day 1 (100 mg kg(-1)) and days 2-4 (50 mg kg(-1) per day) or (ii) chronic - daily (6.0 mg kg(-1) per day). Animals were euthanized on days 14, 21 or 28.

RESULTS

The effects of CPA on epididymal sperm chromatin structure were germ-cell-phase specific; mid-spermiogenic spermatids were most sensitive. The acridine orange DNA denaturation assay showed significant increases in susceptibility to denaturation (P < 0.01). Chromatin packaging assessment revealed 1,4-dithiothreitol-dependent chromomycin A3 DNA binding and less condensed, protamine-deficient sperm; the total thiol (P < 0.001) and protamine contents (P < 0.01), measured using monobromobimane and the HUP1N protamine 1 antibody, respectively, were reduced. The sperm basic proteome was also altered; proteins that were identified are involved in events during spermiogenesis and fertilization.

CONCLUSIONS

Paternal exposure to CPA alters sperm chromatin structure, as well as the composition of sperm head basic proteins. We speculate that these changes underlie effects on fertilization and embryo development.

Effects of Acute and Chronic Cyclophosphamide Treatment on Meiotic Progression and the Induction of DNA Double-Strand Breaks in Rat Spermatocytes1

Male rats treated with cyclophosphamide, an alkylating agent commonly used clinically in both acute and chronic regimens, present with damaged male germ cells and abnormal progeny outcome. The extent and type of damage induced by cyclophosphamide largely depend on the germ cell type exposed to the drug and its ability to respond to insult. In the present study, the response of pachytene spermatocytes to damage was evaluated by assessing their ability to undergo meiotic G2/MI transition following exposure to acute or chronic cyclophosphamide. Male rats were given an acute high dose (70 mg/kg, once) or chronic low doses (6 mg/kg, daily for 5-6 wk) of cyclophosphamide. Pachytene spermatocytes were isolated, cultured, and induced to undergo G2/MI transition with okadaic acid. To determine the effect of DNA damage on meiotic progression, induction of DNA double-strand breaks was detected after each treatment regimen by the formation of foci of phosphorylated histone H2AX. The transition from G2 to MI was impaired after acute cyclophosphamide treatment; this impairment in the progression of pachytene spermatocytes was correlated with extensive DNA double-strand breaks. In contrast, despite the presence of significant levels of DNA damage, meiotic progression was not impaired in spermatocytes after chronic cyclophosphamide exposure. We suggest that the cell cycle impairment induced after acute cyclophosphamide treatment could be mediated by a G2/M checkpoint activated in response to DNA damage. The absence of impairment after chronic treatment raises concern about the functionality of defense mechanisms in male germ cells after repeated exposure to low doses of genotoxic agents.

Prenatal estrogen exposure differentially affects estrogen receptor-associated proteins in rat testis gonocytes

We previously reported that gonocytes from 3-day-old rat testes proliferate in response to estradiol. In the present study, we found that purified gonocytes contained the mRNAs of estrogen receptor beta (ERbeta) and the chaperones Hsp90, p23, and Cyp40, but no inducible Hsp70. Immunoblot analysis showed high levels of ERbeta, Hsp90, p23, Cyp40, and the constitutive Hsc70 in gonocytes. Prenatal exposure to the estrogenic compounds diethylstilbestrol, bisphenol A, genistein, and coumestrol led to significantly increased Hsp90 mRNA levels in testis, but not p23 and Cyp40. In situ hybridization analysis indicated that Hsp90 mRNA was prominent in gonocytes, where it was increased following phytoestrogen exposure, whereas bisphenol A induced a more generalized increase throughout the testis. Immunoblot analysis of testicular extracts demonstrated that Hsp90 protein levels were significantly increased following estrogen exposure, and immunohistochemical analysis indicated that this increase occurred predominantly in gonocytes. By contrast, no change was observed in the expression of Cyp40, p23, and ERbeta, whereas Hsc70 was increased by bisphenol A only. Using an antibody and reverse transcriptase-polymerase chain reaction probes specific for Hsp90alpha, we subsequently confirmed that Hsp90alpha was primarily expressed in gonocytes, and that it was increased following estrogen exposure. Hsp90 immunolocalization in fetal and prepubertal testes showed an increased expression in fetal gonocytes upon estrogen exposure, but no difference in the subsets of Hsp90-positive germ cells in prepubertal testes. These results demonstrate that prenatal estrogen exposure specifically affects Hsp90 expression in gonocytes. Considering the interaction of Hsp90 with several signaling molecules, changes in its expression levels may lead to subsequent changes in gonocyte development.

Numerical chromosomal abnormalities in rat epididymal spermatozoa following chronic cyclophosphamide exposure

Chronic, low-dose treatment of male rats with cyclophosphamide, a chemotherapeutic agent, is known to affect progeny outcome adversely in a dose-dependent and time-specific manner, resulting in increased pre- and postimplantation loss as well as malformations. Concern exists regarding the genetic quality of mature gametes exposed to cyclophosphamide during mitosis and meiosis. The goal of the present study was to determine the effect of chronic cyclophosphamide treatment during spermatogenesis on the frequency of numerical chromosomal anomalies in epididymal spermatozoa. Male rats were treated with either saline or cyclophosphamide (6 mg kg-1 day-1) for 6 or 9 wk, and cauda epididymal spermatozoa were collected. The rat sperm Y-4 fluorescence in situ hybridization assay was used to assess the induction of spermatozoal disomy, nullisomy, and diploidy involving chromosomes Y and 4. The overall frequency of numerically abnormal spermatozoa was elevated approximately 2-fold (P < 0.001) after 9 wk of cyclophosphamide treatment. Exposure for 9 wk, but not for 6 wk, significantly increased the frequency of spermatozoa with chromosome 4 disomy (P < 0.02) and nullisomy (P < 0.05), but disomy Y and diploidy were not significantly increased with treatment compared to corresponding controls. Independent of treatment, only 27% of aneuploid spermatozoa presented with morphological abnormalities, but all diploid spermatozoa were approximately twice the size of normal cells. Thus, cyclophosphamide disrupts meiotic events before pachynema during spermatogenesis, emphasizing the potential for adverse progeny outcomes following genotoxic damage.