Serum and testicular testosterone and androgen binding protein profiles following subchronic treatment with carbendazim

Lack of in vivo mutagenicity of carbendazim in the liver and glandular stomach of MutaMice

BACKGROUND

Carbendazim (methyl 2-benzimidazolecarbamate, CASRN: 10605-21-7) exhibits spindle poisoning effects and is widely used as a fungicide. With respect to genotoxicity, carbendazim is deemed to be non-mutagenic in vitro, but it causes indicative DNA damage in vivo and chromosome aberrations in vitro and in vivo. In this study, we examined the mutagenicity of carbendazim in vivo.

RESULTS

MutaMice were treated with carbendazim orally at doses of 0 (corn oil), 250, 500, and 1,000 mg/kg/day once a day for 28 days. A lacZ assay was used to determine the mutant frequency (MF) in the liver and glandular stomach of mice. MutaMice were administered up to the maximum dose recommended by the Organization for Economic Co-operation and Development Test Guidelines for Chemicals No. 488 (OECD TG488). The lacZ MFs in the liver and glandular stomach of carbendazim-treated animals were not significantly different from those in the negative control animals. In contrast, positive control animals exhibited a significant increase in MFs in both the liver and glandular stomach.

CONCLUSIONS

Carbendazim is non-mutagenic in the liver and glandular stomach of MutaMice following oral treatment.

Circulating microRNAs as promising testicular translatable safety biomarkers: current state and future perspectives

Drug-induced testicular injury (DITI) is one of the often-observed and challenging safety issues seen during drug development. Semen analysis and circulating hormones currently utilized have significant gaps in their ability to detect testicular damage accurately. In addition, no biomarkers enable a mechanistic understanding of the damage to the different regions of the testis, such as seminiferous tubules, Sertoli, and Leydig cells. MicroRNAs (miRNAs) are a class of non-coding RNAs that modulate gene expression post-transcriptionally and have been indicated to regulate a wide range of biological pathways. Circulating miRNAs can be measured in the body fluids due to tissue-specific cell injury/damage or toxicant exposure. Therefore, these circulating miRNAs have become attractive and promising non-invasive biomarkers for assessing drug-induced testicular injury, with several reports on their use as safety biomarkers for monitoring testicular damage in preclinical species. Leveraging emerging tools such as 'organs-on-chips' that can emulate the human organ's physiological environment and function is starting to enable biomarker discovery, validation, and clinical translation for regulatory qualification and implementation in drug development.

Food groups and nutrients consumption and risk of endometriosis: a systematic review and meta-analysis of observational studies

Dietary factors may play a role in the etiology of endometriosis and dietary intake of some food groups and nutrients could be associated with endometriosis risk. This systematic review and meta-analysis of observational studies was conducted to summarize the findings on the association between dietary intakes of selected food groups and nutrients (dairy, fats, fruits, vegetables, legumes, and animal-derived protein sources), and the risk of endometriosis among adult women. PubMed, Scopus, and ISI Web of Science were systematically searched up to September 2022. The inverse variance-weighted fixed-effect method was used to estimate the effect size and corresponding 95% CI. A total of 8 publications (4 studies) including 5 cohorts and 3 case-control with a sample size ranging from 156 to 116,607 were included in this study. A higher intake of total dairy [all low-fat and high-fat dairy foods] was associated with decreased risk of endometriosis (RR 0.90; 95% CI, 0.85 to 0.95; P < 0.001; I² = 37.0%), but these associations were not observed with intakes of low or high-fat dairy, cheese or milk. Increased risk of endometriosis was associated with higher consumption of red meat (RR 1.17; 95% CI, 1.08 to 1.26; P < 0.001; I² = 82.4%), trans fatty acids (TFA) (RR 1.12; 95% CI, 1.02 to 1.23; P = 0.019; I² = 73.0%), and saturated fatty acids (SFA) (RR 1.06; 95% CI, 1.04 to 1.09; P < 0.001; I² = 57.3%). The results of this meta-analysis suggest that there may be differing associations between dietary intake of dairy foods, red meat, SFAs, and TFAs and the risk of endometriosis. It may be useful to extend the analysis to other types of food groups and dietary patterns to obtain a complete picture. Additionally, further investigations are needed to clarify the role of diet in the incidence and progression of endometriosis.Trial registration: PROSPERO, CRD42020203939.

Reproductive and possible hormonal effects of carbendazim

This study aimed to better elucidate reproductive and possible hormonal effects of the fungicide carbendazim (CBZ) through a review of published toxicological studies as well as an evaluation of this fungicide in the Hershberger and uterotrophic assays, which are designed to detect in vivo effects of the sex hormones. The literature review indicates that CBZ induces reproductive and developmental toxicity through alteration of many key events which are important to spermatogenesis. The lower dose of CBZ (100mg/kg) evaluated in the Hershberger test increased prostate weight compared to control group but did not alter the weight of other testosterone-dependent tissues. In the uterotrophic assay, CBZ did not induce an estrogenic or an antiestrogenic effect. In the literature, it has been reported that CBZ may: (1) alter the levels of various hormones (testosterone, LH, FSH, GnRH); (2) negatively influence testicular steroidogenesis; (3) have androgenic effects acting directly in the androgenic receptors and/or increasing the expression of androgen receptors. Despite the contradictory results reported by the different studies that investigated a possible endocrine mode of action of CBZ, it seems that this fungicide may influence the hypothalamus-pituitary-gonad axis in addition to being a testicular toxicant.

Kolaviron prevents carbendazim-induced steroidogenic dysfunction and apoptosis in testes of rats

The study evaluated the protective role of kolaviron (an isolated biflavonoid from the seed of Garcinia kola) and vitamin E in carbendazim-induced reproductive dysfunction in male rats. Adult male Wistar rats were orally exposed to carbendazim (200mg/kg) singly or in combination with kolaviron (100 and 200mg/kg). Exposure to carbendazim significantly decreased the activities of superoxide dismutase and catalase but markedly increased sialic acid concentration and lipid peroxidation in the testes of rats. Western blot analysis revealed that carbendazim treatment decreased the expression of steroid acute regulatory (StAR) protein and androgen binding protein (ABP) with concomitant decrease in activities of steroidogenic enzymes. Germ cell apoptosis in carbendazim-treated rats was confirmed by TUNEL assay. However, pretreatment with kolaviron and vitamin E restored the testicular antioxidant status and steroidogenesis and decreased apoptotic nuclei to near control level in carbendazim-treated rats. Kolaviron may prove useful in combating carbendazim-induced reproductive toxicity.

Diet and risk of endometriosis in a population-based case-control study

Diet plausibly has a role in the aetiology of endometriosis through effects on steroid hormone levels; however, few published studies have examined the diet and endometriosis risk. We evaluated dietary risk factors for endometriosis in a population-based case-control study. Cases were 284 Group Health (GH) enrollees aged 18-49 years with newly diagnosed, surgically confirmed endometriosis between 1996 and 2001. Controls were 660 randomly selected age-matched female GH enrollees without a history of endometriosis. Nutrients and selected food groups were assessed using the Women's Health Initiative FFQ. OR of endometriosis risk associated with dietary exposures were estimated using unconditional logistic regression and adjusted for identified covariates. Increased total fat consumption was associated with decreased endometriosis risk (fourth quartile v. lowest: OR 0·5, 95% CI 0·2, 1·0, P-trend = 0·12). Increased β-carotene consumption and servings/d of fruit were associated with increased risk (β-carotene third quartile v. lowest: OR 1·7, 95% CI 1·1, 2·6; fourth quartile v. lowest: OR 1·6, 95% CI 1·0, 2·5, P-trend 0·16; fruit >2 servings/d v. < 1: OR 1·5, 95% CI 1·0, 2·3, P-trend = 0·04). We also found a suggestion of decreased endometriosis risk associated with the consumption of dairy products (2 servings/d v. ≤ 1: OR 0·6, >2 servings/d v. ≤ 1: OR 0·7), but this association was not statistically significant for the highest tertile. The present study suggests that specific dietary components may be associated with endometriosis risk.

Effects of subchronic exposure to carbendazim on spermatogenesis and fertility in male rats

The aim of this study is to investigate the effects of subchronic exposure to carbendazim on spermatogenesis and fertility in male rats. Ninety-eight healthy male rats were divided into four groups: three exposure groups and a control group. Carbendazim was administered orally to male rats at 0, 20, 100 and 200 mg/kg for 80 days prior to mating. Each male was cohabited with an unexposed female for a maximum of 5 days. In 100 and 200 mg/kg groups, the mating index was relatively increased, the fertility index was decreased, and the testis weight, the sperm counts and motility were also decreased. The levels of luteinizing hormone (LH) showed a decreasing tendency and there was a statistical difference between the 200 mg/kg group and the control group. There were no obvious effects on the levels of follicle stimulating hormone (FSH) and testosterone (T). Histopathological evaluation showed atrophic seminiferous tubules, decreased germ cells, and increased sloughing of germ cells. Flow cytometric analysis of the testicular tissue revealed that carbendazim inhibited meiotic transformation and interfered with the spermatogenic process. These results suggest that carbendazim has adverse effects on spermatogenesis, resulting in reduced fertility in male rats.

Endocrine-disrupting activity in carbendazim-induced reproductive and developmental toxicity in rats

This study was designed to investigate the endocrine-disrupting activity of carbendazim-induced reproductive and developmental toxicity in Sprague-Dawley rats treated orally with the fungicide. Cotreatment of male rats with 675 mg/kg carbendazim and 50 or 100 mg/kg flutamide, an androgen receptor antagonist, once daily for 28 d blocked decrease of testis weight induced by treatment with carbendazim alone. The cotreatment prevented losses of spermatozoa and cell morphology and decrease of sperm concentration induced by carbendazim. Premating treatment of male and female rats with 200 mg/kg carbendazim for 28 d produced androgenic effects including incomplete development of uterine horn, enlargement of uretha, absence of vagina, and induction of seminal vesicles in female offspring, without marked effects in male offspring. Premating treatment with 100mg/kg benomyl, the parent compound of carbendazim, resulted in incomplete development of uterine horn and absence of vagina in female offspring and produced testis and epidydimis atropy in male offspring. Treatment of male rats with 25, 50, 100, 200, 400, and 800 mg/kg carbendazim for 56 d produced dose-dependent increases of androgen receptor concentrations in testis and epididymis. Additions of 5, 50, and 500 microM carbendazim to testis extract from untreated rats replaced binding of [3H]-5 alpha-dihydrotestosterone to androgen receptor in a concentration-dependent manner. The present study demonstrates that reproductive toxicity induced by carbendazim is blocked by an androgen receptor antagonist in male rats and developmental toxicity of the fungicide shows androgenic properties in female offspring. These results suggest that androgen- and androgen receptor-dependent mechanisms are possibly involved in carbendazim-induced toxicity.

Pharmacokinetic comparison of intravenous carbendazim and remote loaded carbendazim liposomes in nude mice

Carbendazim is a novel anticancer agent. The aim of this study was to prepare and characterize a remote loaded liposome preparation of carbendazim, and compare its pharmacokinetic profile to that of unencapsulated carbendazim. Carbendazim was encapsulated in liposomes composed of sphingomyelin-cholesterol (3:1, w/w) by remote loading in response to a transmembrane pH gradient (pH 0.5 in/pH 4.0 out), which resulted in encapsulation of more than 95% of the available drug in preformed vesicles. High drug/lipid ratios were prepared which correspond to a molar ratio of up to 0.8. Physical isolation of the free drug and dialysis were used to determine the in vitro release of carbendazim from liposomes. The release was independent of the initial drug/lipid ratio and choice of internal buffer composition. Liposomal carbendazim (200 mg kg(-1)) was intravenously administered to athymic nude mice and the serum levels of free carbendazim were determined by HPLC analysis after a methanol-induced protein precipitation. Administration of liposomal carbendazim to mice resulted in significant alterations in the pharmacokinetics. Serum levels of free carbendazim were approximately 10-fold greater than those achieved for the same dose of unencapsulated drug. Liposomal carbendazim showed both high C(max), AUC and low clearance rate. Liposomal carbendazim and unencapsulated carbendazim displayed a similar terminal half-life (43-48 min). The relatively large volume of distribution of carbendazim suggests that the compound may partially enter cells or be bound to some extravascular structures. The results indicate that the liposomal formulation of carbendazim significantly increases its blood concentrations.

Biochemical and histopathological effects of carbendazim to rat male reproduction

The purpose of this study was to determine the effects of carbendazim (methyl 2-benzimidazole carbamate) on the some hormone levels and on testis tissue. Carbendazim in the doses of 0, 150, 300, and 600 mg/kg/day were administered (by gavage) to male rats, daily for 15 weeks. At the end of the experiment serum total testosterone and dihydrotestosterone (DHT) levels were analyzed and testis tissues were taken for light and electron microscopic examinations. A statistically significant decrease in total serum testosterone level in rats exposed to carbendazim (dose: 300 and 600 mg/kg/day), compared to the control, was observed. Also, dihydrotestosterone level was significantly decreased in all experimental groups. Histopathologically, carbendazim caused detrimental effects in testis tissues. These effects were vacuolization, disorganization and necrosis in germinal epithelium. In addition, multinucleated giant cells were observed in the lumen of the seminiferous tubules. These pathological findings were supported by electron microscopic examinations. These results suggest that carbendazim, in subchronic exposure, affects testis tissue and androgenic hormone levels.

Curative property of Withania somnifera Dunal root in the context of carbendazim-induced histopathological changes in the liver and kidney of rat

The liver and kidney of rat underwent severe histopathological lesions when treated with a single bolus dose of carbendazim, a fungicide, particularly affecting the hepatocytes and the renal corpuscles, respectively. The effects appear to be manifestations of the microtubule-disrupting activity of carbendazim. Treatment of carbendazim-treated rats with the powder of tuberous root of Withania somnifera (Ashwagandha) for 48 days resulted in complete cure of these organs. The results indicate that Withania somnifera would be an effective curative for carbendazim-induced histopathological changes in the liver and kidney.

Effect of inhaled methanol on pituitary and testicular hormones in chamber acclimated and non-acclimated rats

Two experiments were conducted in which the acute effects of inhaled methanol on serum hormones associated with reproductive function in the male rat were evaluated. In the first experiment, rats exposed to methanol (0, 200, 5000 and 10,000 ppm) for 6 h were killed at the end of the exposure period (6 h) or the following morning (24 h). Also, because the process of exposure itself could modify neuroendocrine function, the effect of the handling associated with placing the rat in the exposure chamber was evaluated further by dividing the exposed animals into acclimated (2 weeks of prior handling) and non-acclimated groups. At 6 h, an effect of prior handling was noted in the sham-exposed rats, with serum luteinizing hormone (LH) of the non-acclimated group being greater than that of the acclimated group. Serum LH concentrations were altered by methanol exposure, but the direction of change and the exposure level at which an effect was noted differed between the acclimated and non-acclimated rats. Methanol (5000 ppm) reduced serum LH in the non-acclimated animals, while 10,000 ppm increased LH in the acclimated rats. Follicle stimulating hormone (FSH) and testosterone were unchanged by methanol in rats killed at 6 h. Thus, this experiment did not confirm earlier reports that exposure to 200 ppm for 6 h reduced serum testosterone. At 24 h, an effect of prior handling was still present in the hormonal measures, with serum and interstitial fluid testosterone concentrations being greater in the non-acclimated rats. Also, there was a dose x handling interaction with methanol exposure inducing an increase in serum testosterone in the non-acclimated rats (up to 5000 ppm) and a decrease in the acclimated rats (up to 10,000 ppm). In the second experiment, groups of acclimated and non-acclimated rats were exposed to 0 or 5000 ppm methanol for 1, 2 and 6 h and killed immediately after removal from the chamber. Serum LH, testosterone and FSH values were not different in sham- vs methanol-exposed rats at any time point. As in experiment 1, an effect of prior handling was noted. In general, the concentrations of these hormones and serum prolactin in the non-acclimated rats were greater than those observed for acclimated rats. Methanol exposure resulted in increased prolactin concentrations under both handling conditions.(ABSTRACT TRUNCATED AT 400 WORDS)