Assessment of female and male fertility in Sprague-Dawley rats administered vorinostat, a histone deacetylase inhibitor

How bad is brazilian ginseng extract for reproductive parameters in mice?

Properties attributed to the Panax ginseng are also attributed to the Brazilian ginseng, such as adaptogenic and aphrodisiac effects. There are studies demonstrating that the Brazilian ginseng (BGE) possibly increases the serum levels of testosterone and nitric oxide in mice and rats. The present study aimed to evaluate the effects of its extract on male fertility and sperm quality. Male Swiss mice (n = 60) were divided into six groups. The control animals were provided 0.5 mL of water, and 0.5 mL of water containing 7 mg/kg per day (d) sildenafil citrate. Other animals were treated with BGE at 100 mg/kg/d, 200 mg/kg/d, and 400 mg/kg/d by gavage for 42 days. Finally, animals from the last group received 200 mg/kg BGE every 3 days (3-3d) by gavage for 42 days. The results showed a reduction in the number of resistant spermatids in the testis and damage to daily sperm production, culminating in a reduction in the number of epididymal spermatozoa. Although the sperm quality decreased in all experimental animals, only males treated with BGE 100 mg/kg/d showed pre and post implantation embryo losses. We concluded that BGE alters sperm viability compromising the embryonic development after implantation.

Connectivity mapping of a chronic kidney disease progression signature identified lysine deacetylases as novel therapeutic targets

Tubulointerstitial injury is an important determinant of chronic kidney disease progression, yet treatment is limited. Accordingly, we derived a chronic kidney disease progression signature based on aging and disease in Col4a3^-/- mice, a model associated with proteinuria and progressive loss of kidney function. Computational drug repurposing with the Connectivity Map identified vorinostat, a lysine deacetylase inhibitor, as a candidate treatment to reverse progression signature gene expression. Vorinostat administration significantly increased the lifespan of Col4a3^-/- mice and attenuated tubulointerstitial fibrosis and JNK phosphorylation in the kidneys of Col4a3^-/- mice. In vitro, vorinostat reduced albumin- and angiotensin II-induced activation of canonical mitogen-activated protein kinases in kidney tubular epithelial cells. Finally, a subset of murine progression signature genes was differentially expressed across kidney transcriptomic data from patients with focal segmental glomerulosclerosis, IgA nephropathy, and diabetic nephropathy. Thus, our findings suggest that lysine deacetylase inhibition may be a novel treatment to chronic kidney disease associated with proteinuria and progressive tubulointerstitial injury.

Out of sight, out of mind? Germ cells and the potential impacts of epigenomic drugs

Epigenetic modifications, including DNA methylation and histone modifications, determine the way DNA is packaged within the nucleus and regulate cell-specific gene expression. The heritability of these modifications provides a memory of cell identity and function. Common dysregulation of epigenetic modifications in cancer has driven substantial interest in the development of epigenetic modifying drugs. Although these drugs have the potential to be highly beneficial for patients, they act systemically and may have “off-target” effects in other cells such as the patients’ sperm or eggs. This review discusses the potential for epigenomic drugs to impact on the germline epigenome and subsequent offspring and aims to foster further examination into the possible effects of these drugs on gametes. Ultimately, the information gained by further research may improve the clinical guidelines for the use of such drugs in patients of reproductive age.

Improvements in Clinical Trials Information Will Improve the Reproductive Health and Fertility of Cancer Patients

There are a number of barriers that result in cancer patients not being referred for oncofertility care, which include knowledge about reproductive risks of antineoplastic agents. Without this information, clinicians do not always make recommendations for oncofertility care. The objective of this study was to describe the level of reproductive information and recommendations that clinicians have available in clinical trial protocols regarding oncofertility management and follow-up, and the information that patients may receive in clinical trials patient information sheets or consent forms. A literature review of the 71 antineoplastic drugs included in the 68 clinical trial protocols showed that 68% of the antineoplastic drugs had gonadotoxic animal data, 32% had gonadotoxic human data, 83% had teratogenic animal data, and 32% had teratogenic human data. When the clinical trial protocols were reviewed, only 22% of the protocols reported the teratogenic risks and 32% of the protocols reported the gonadotoxic risk. Only 56% of phase 3 protocols had gonadotoxic information and 13% of phase 3 protocols had teratogenic information. Nine percent of the protocols provided fertility preservation recommendations and 4% provided reproductive information in the follow-up and survivorship period. Twenty-six percent had a section in the clinical trials protocol, which identified oncofertility information easily. When gonadotoxic and teratogenic effects of treatment were known, they were not consistently included in the clinical trial protocols and the lack of data for new drugs was not reported. Very few protocols gave recommendations for oncofertility management and follow-up following the completion of cancer treatment. The research team proposes a number of recommendations that should be required for clinicians and pharmaceutical companies developing new trials.

Direct but no transgenerational effects of decitabine and vorinostat on male fertility

Establishment and maintenance of the correct epigenetic code is essential for a plethora of physiological pathways and disturbed epigenetic patterns can provoke severe consequences, e.g. tumour formation. In recent years, epigenetic drugs altering the epigenome of tumours actively have been developed for anti-cancer therapies. However, such drugs could potentially also affect other physiological pathways and systems in which intact epigenetic patterns are essential. Amongst those, male fertility is one of the most prominent. Consequently, we addressed possible direct effects of two epigenetic drugs, decitabine and vorinostat, on both, the male germ line and fertility. In addition, we checked for putative transgenerational epigenetic effects on the germ line of subsequent generations (F1-F3). Parental adult male C57Bl/6 mice were treated with either decitabine or vorinostat and analysed as well as three subsequent untreated generations derived from these males. Treatment directly affected several reproductive parameters as testis (decitabine & vorinostat) and epididymis weight, size of accessory sex glands (vorinostat), the height of the seminiferous epithelium and sperm concentration and morphology (decitabine). Furthermore, after decitabine administration, DNA methylation of a number of loci was altered in sperm. However, when analysing fertility of treated mice (fertilisation, litter size and sex ratio), no major effect of the selected epigenetic drugs on male fertility was detected. In subsequent generations (F1-F3 generations) only subtle changes on reproductive organs, sperm parameters and DNA methylation but no overall effect on fertility was observed. Consequently, in mice, decitabine and vorinostat neither affected male fertility per se nor caused marked transgenerational effects. We therefore suggest that both drugs do not induce major adverse effects-in terms of male fertility and transgenerational epigenetic inheritance-when used in anti-cancer-therapies.

Effects of chemotherapy and radiotherapy on spermatogenesis in humans

Treatment of cancer with chemo- or radiotherapy causes reduction of sperm counts often to azoospermic levels that may persist for several years or be permanent. The time course of declines in sperm count can be predicted by the sensitivity of germ cells, with differentiating spermatogonia being most sensitive, and the known kinetics of recovery. Recovery from oligo- or azoospermia is more variable and depends on whether there is killing of stem cells and alteration of the somatic environment that normally supports differentiation of stem cells. Of the cytotoxic therapeutic agents, radiation and most alkylating drugs are the most potent at producing long-term azoospermia. Most of the newer biologic targeted therapies, except those used to target radioisotopes or toxins to cells, seem to have only modest effects, mostly on the endocrine aspects of the male reproductive system; however, their effects when used in combination with cytotoxic agents have not been well studied.

Regulatory assessment of reproductive toxicology data

This chapter outlines a regulator's personal approach to the assessment of reproductive toxicology data in the context of the assessment of the overall nonclinical data package for pharmaceutical agents. Using as a framework the International Conference on Harmonisation Common Technical Document headings, guidance is provided on the expectations of regulators for the presentation and discussion of the data by the applicant to facilitate the risk assessment process. Consideration is given to the use of reproductive toxicology data in the assessment process for both clinical trial applications (CTAs) and marketing authorization applications (MAAs). Suggestions for some guiding principles in drafting of the various product information documents (for example the Investigator's Brochure (IB) for CTAs and the Nonclinical Overview and Summary of Product Characteristics for MAAs) are included.

Antifibrotic activity of an inhibitor of histone deacetylases in DOCA-salt hypertensive rats

BACKGROUND AND PURPOSE

Histone deacetylases (HDACs) silence genes by deacetylating lysine residues in histones and other proteins. HDAC inhibitors represent a new class of compounds with anti-inflammatory activity. This study investigated whether treatment with a broad spectrum HDAC inhibitor, suberoylanilide hydroxamic acid (SAHA), would prevent cardiac fibrosis, part of the cardiovascular remodelling in deoxycorticosterone acetate (DOCA)-salt rats.

EXPERIMENTAL APPROACH

Control and DOCA-salt rats were treated with SAHA (25 mg x kg(-1) x day(-1) s.c.) for 32 days. Changes in cardiovascular structure and function were assessed by blood pressure in vivo and in Langendorff perfused hearts, ventricular papillary muscle and in aortic rings in vitro. Left ventricular collagen deposition was assessed by histology.

KEY RESULTS

Administration of SAHA to DOCA-salt rats attenuated the following parameters: the increased concentration of over 20 pro-inflammatory cytokines in plasma, increased inflammatory cell infiltration and interstitial collagen deposition, increased passive diastolic stiffness in perfused hearts, prolongation of action potential duration at 20% and 90% of repolarization in papillary muscle, development of left ventricular hypertrophy, systolic hypertension and changes in vascular dysfunction.

CONCLUSIONS AND IMPLICATIONS

The HDAC inhibitor, SAHA, attenuated the cardiovascular remodelling associated with DOCA-salt hypertensive rats and improved cardiovascular structure and function, especially fibrosis, in the heart and blood vessels, possibly by suppressing inflammation. Control of cardiac histone or non-histone protein acetylation is a potential therapeutic approach to preventing cardiac remodelling, especially cardiac fibrosis.

Nonclinical safety assessment of the histone deacetylase inhibitor vorinostat

Vorinostat (SAHA, Zolinza), a histone deacetylase inhibitor, is assessed in nonclinical studies to support its approval for cutaneous T-cell lymphoma. Vorinostat is weakly mutagenic in the Ames assay; is clastogenic in rodent (ie, CHO) cells but not in normal human lymphocytes; and is weakly positive in an in vivo mouse micronucleus assay. No effects are observed on potassium ion currents in the hERG assay up to 300 microM (safety margin approximately 300-fold the approximately 1 microM serum concentration associated with the 400 mg/d maximum recommended human dose. No rat respiratory or central nervous system effects are found at 150 mg/kg (>2-fold maximum recommended human dose). No cardiovascular effects, including effects on QTc interval, are observed after a single oral dose (150 mg/kg) in dogs. Vorinostat is orally dosed daily in rats (controls, 20, 50, or 150 mg/kg/d) and dogs (controls, 60, 80, or 100/125/160 mg/kg/d) for 26 weeks with a 4-week recovery. Rat vorinostat-related adverse findings are decreased food consumption, weight loss, and hematologic changes; a no observed adverse effects level is not established. In dogs, adverse effects are primarily gastrointestinal; the no observed adverse effects level is 60 mg/kg/d (approximately 6-fold maximum recommended human dose). Toxicities are reversible and can be monitored in the clinic.

Collaborative work on evaluation of ovarian toxicity. 7) Effects of 2- or 4- week repeated dose studies and fertility study of cyclophosphamide in female rats

The main focus of this study was to determine the optimal administration period concerning the toxic effects on ovarian morphological changes in the repeated dose toxicity study. In order to assess the morphological and functional changes induced in the ovary by cyclophosphamide (CP), the compound was administrated to female rats at dose levels of 0, 5, 10 and 20 mg/kg for the repeated dose toxicity study for 2 or 4 weeks, and at 0, 5, 10, and 20 mg/kg for the female fertility study from 2 weeks prior to mating to Day 7 of pregnancy. In the repeated dose toxicity study, increases in large sized atretic follicles, atrophy of corpora lutea were observed in the 20 mg/kg group in the 4-week study by the histopathological examination of the ovaries. There were no drug-related changes in the ovary in the 2-week study. In the female fertility study, the numbers of implantation were slightly decreased and the corpora lutea of pregnancy was not observed in the 20 mg/kg group. The dose-dependent increase in the incidence of post-implantation loss was observed, and no abnormalities were observed in the estrus cycle and mating in all treated groups. From these findings, the histopathological changes in the ovary are important endpoints for the evaluation of drug-induced ovarian damage as well as caesarean section. In conclusion, a 4-week administration period is sufficient to detect the ovarian toxicity of CP in the repeated dose toxicity study.