Influence of oil-related environmental pollutants on female reproduction

The microRNA miR-152 can mitigate and prevent the toxic effect of benzene on porcine ovarian cells

Epigenetic methods to prevent the reproductive toxicity of oil-related environmental contaminants are currently unavailable. The present study aimed to examine the ability of the microRNA miR-152 to mitigate the effects of benzene on ovarian cells. Porcine ovarian granulosa cells transfected or not transfected with miR-152 mimics were cultured with or without benzene (0, 10 and 100 ng/ml). The expression of miR-152; viability; proliferation (cell proliferation and expression of mRNAs and accumulation of PCNA and cyclin B1); apoptosis (expression of mRNAs and accumulation of bax and caspase 3; and the proportion of cells with fragmented DNA); and release of progesterone, estradiol and IGF-I were analyzed via RT-qPCR; the Trypan blue exclusion test; quantitative immunocytochemistry; BrdU; XTT; TUNEL assays; and ELISA. Administration of benzene promoted the expression of apoptosis markers and reduced cell viability, all measured markers of proliferation, the release of steroid hormones and IGF-I. Overexpression of miR-152 was associated with increased cell viability, proliferation, progesterone and IGF-I release and reduced apoptosis and estradiol output. Moreover, miR-152 mitigated or prevented the effects of benzene on all the measured parameters in addition to estradiol release. The present observations suggest the toxic effect of benzene and the stimulatory influence of miR-152 on ovarian cell functions. Moreover, this is the first demonstration of the ability of miRNAs to mitigate and prevent the reproductive toxicity of benzene.

Modulatory effects of quercetin on histological changes, biochemical and oxidative stress of rat placenta induced by inhalation exposure to crude oil vapor

The inhalation exposure to crude oil vapor (COV) has been shown to have adverse effects on the placenta and fetal development. The modulatory effects of quercetin (QUE) as a natural phenolic compound with antioxidant properties are promising for the protection of placental structure. This study aimed to investigate the modulatory role of QUE in mitigating histopathological damage, oxidative stress, and biochemical alteration in the placenta of COV-exposed pregnant rats. Forty-eight pregnant rats were divided into eight groups (days 15 and 20) as follows: 1-2) Control groups, 3-4) COV groups, 5-6) COV+QUE groups, and 7-8) QUE-treated groups (50 mg/kg). The inhalation method was used to expose pregnant rats to COV, and QUE was administered orally. On the 15th and 20th days of gestation, placental tissue was analyzed using PAS and H&E staining and immunohistochemistry. The expression of the caspase-3 gene and oxidative stress biomarkers including TAC, CAT, MDA, GPx, and SOD were investigated in the placental tissue. The COV significantly decreased the weight, diameter, and thickness of the placenta as well as the thickness of the junctional zone and labyrinth and the number of trophoblast giant cells in 15- and 20-day-old placentas (P<0.05). Also, COV significantly increased placental expression of caspase-3 and the oxidative stress biomarkers (P<0.05). The administration of QUE along with exposure to COV reduced morphometric and histological alteration, oxidative stress, and caspase-3 expression (P<0.05). Our findings indicated that QUE in COV-exposed pregnant rats can prevent placental histopathological alternations by increasing the activity of the antioxidant system.

Can some food/medicinal plants directly affect porcine ovarian granulosa cells and mitigate the toxic effect of toluene?

The action of buckwheat, rooibos and vitex on healthy female reproductive systems, as well as their ability to mitigate the reproductive toxicity of environmental contaminant toluene have not yet been examined. We analysed the influence of toluene (0, 10, 100 or 1000 ng/mL) with and without these plant extracts (10 μg/mL) on cultured porcine ovarian granulosa cells. Cell viability, proliferation (PCNA accumulation), apoptosis (accumulation of bax) and release of progesterone (P) and oestradiol (E) were measured. Toluene reduced ovarian cell viability and proliferation, increased apoptosis and suppressed E but not P release. Plant extracts, given alone, were also able to directly suppress some ovarian cell functions. The addition of buckwheat promoted toluene action on cell viability, proliferation and P release, but it did not modify other toluene effects. Rooibos mitigated toluene action on cell viability, proliferation and apoptosis but promoted its action on P and E. The addition of vitex mitigated all the tested toluene effects. These observations: (1) demonstrate the direct toxic influence of toluene on ovarian cells, (2) demonstrate the ability of food/medicinal plants to either promote or mitigate toluene effects and (3) suggest that vitex could be a natural protector against the suppressive effect of toluene on female reproduction.

Fennel affects porcine ovarian cell functions: The interrelationships with the environmental contaminant benzene

The objective of this study was to examine the direct effects of the medicinal plant fennel on basic functions of ovarian cells, including proliferation, apoptosis, and release of progesterone and insulin-like growth factor I (IGFI), as well as to prevent the influence of the environmental contaminant benzene on these cells. Porcine ovarian granulosa cells were cultured with or without fennel extract alone or in combination with benzene. The expression of the proliferation marker PCNA and the apoptosis marker bax was analyzed by quantitative immunocytochemistry and enzyme-linked immunosorbent assay (ELISA). Fennel was able to promote proliferation and IGF-I release, but to suppress apoptosis and progesterone release. Benzene promoted the accumulation of both the proliferation and apoptosis markers, as well as IGF-I release, but it inhibited progesterone secretion. The presence of fennel did not prevent the effects of benzene on any of the measured parameters, while benzene prevented the effects of fennel on cell proliferation, apoptosis, and IGF-I but not progesterone output. These observations demonstrate the direct influence of fennel and benzene on basic ovarian cell functions. Furthermore, they show the inability of fennel to prevent the effects of benzene on these cells. On the other hand, the environmental contaminant benzene can block the response of ovarian cells to the medicinal plant fennel.

Protective effect of quercetin on fetal development and congenital skeletal anomalies against exposure of pregnant Wistar rats to crude oil vapor

BACKGROUND

Epidemiological evidence indicates a relationship between maternal exposure to crude oil vapors (COV) during pregnancy and adverse pregnancy outcomes. Quercetin (QUE) is a plant flavonoid with purported antioxidant and anti-inflammatory effects, which has been shown to prevent birth defects. This study was aimed to investigate the protective role of QUE on fetal development and congenital skeletal anomalies caused by exposure of pregnant rats to COV.

METHODS

Twenty-four pregnant Wistar rats were randomly categorized into four groups of control, COV, COV + QUE, and QUE (50 mg/kg). The inhalation method was used to expose pregnant rats to COV from day 0 to 20 of pregnancy, and QUE was administered orally during this period. On day 20 of gestation, the animals were anesthetized and a laparotomy was performed, and then the weight and crown rump length (CRL) of the fetuses were determined. Skeletal stereomicroscopic evaluations of fetuses were performed using Alcian blue/Alizarin red staining method, and the expression of osteogenesis-related genes (Runx2 and BMP-4) was evaluated using qPCR.

RESULTS

This study showed that prenatal exposure to COV significantly reduced fetal weight and CRL, and expression of Runx2 and BMP-4 genes. Moreover, COV significantly increased the incidence of congenital skeletal anomalies such as cleft palate, spina bifida and non-ossification of the fetal bones. However, administration of QUE with exposure to COV improved fetal bone development and reduced congenital skeletal anomalies.

CONCLUSION

QUE can ameliorate the teratogenic effects of prenatal exposure to COV by increasing the expression of osteogenesis-related genes.

Can flaxseed, chia or puncture vine affect mare ovarian cell functions and prevent the toxic effect of the environmental contaminant toluene?

The aim of this in vitro study was to examine the potential effect of functional food plant extracts, namely, extracts of flaxseed (Linum usitatissimum L.), chia (Salvia hispanica) and puncture vine (Tribulus terrestris L.), on basic mare ovarian cell functions and their response to the environmental contaminant toluene. Mare granulosa cells were incubated with and without toluene (0, 0.02, 0.2 or 2.0 μg/mL) in the presence or absence of flaxseed, chia and puncture vine extracts (10 μg/mL). Markers of cell proliferation (accumulation of proliferating cell nuclear antigen, PCNA) and apoptosis (accumulation of bax), viability (Trypan blue extrusion) and the release of progesterone (P), oxytocin (OT) and prostaglandin F 2 alpha (PGF) were measured. Toluene reduced all other measured parameters except OT release. All the tested plants were able to reduce cell viability and the release of P and PGF, but they did not influence other indexes. Moreover, flaxseed mitigated toluene action on ovarian cell proliferation, apoptosis, OT and PGF, whilst puncture vine prevented and inverted toluene action on P and PGF ourput. Chia extract did not modify toluene action on any parameter. On the other hand, toluene was able to promote the inhibitory action of flaxseed on cell viability and P release and to prevent the inhibitory action of all the plant extracts on PGF release. The present study (1) is the first demonstration, that flaxseed, chia and puncture vine can directly suppress mare ovarian cell functions, (2) shows that toluene can suppress basic ovarian cell functions and modify the reproductive effect of food plants and (3) demonstrates the ability of flaxseed and puncture vine, but not of chia, to prevent some toxic effect of toluene on mare ovarian cell functions.

Vitamin C supplementation modulates crude oil contaminated water induced gravid uterine impaired contractile mechanism and foetal outcomes in Wistar rats

OBJECTIVES

Crude oil is a common environmental contaminant that impacts the reproductive functions of women. Understanding the contractile mechanism of the gravid uterus and how it impacts fetal outcomes during crude oil-contaminated water (CCW) exposure is still evolving. This study investigates the effect of vitamin C supplementation during the ingestion of CCW from Bayelsa, Nigeria, on the contractile mechanism of the gravid uterus and fetal outcomes.

METHODS

Fifteen nulliparous pregnant rats were randomly divided into 3 groups of 5 rats each and treated with normal saline (control), CCW (2.5 mL), and CCW + vitamin C (10 mg/kg bwt), respectively. Treatments were via oral gavage from gestation days 1-19. Gas chromatography-mass spectrometry of CCW, uterine oxidative biomarkers, and in vitro contractile activity of excised uterine tissue to acetylcholine, oxytocin, magnesium, and potassium were determined. Furthermore, uterine responses to acetylcholine after incubation with nifedipine, indomethacin, and N-nitro-L-arginine methyl ester were also recorded using the Ugo Basile data capsule acquisition system. Fetal weights, morphometric indices, and anogenital distance were also determined.

RESULTS

Acetylcholine, oxytocin, magnesium, diclofenac, and indomethacin-mediated contractile mechanisms were significantly impaired with CCW exposure; however, vitamin C supplementation significantly attenuated the impaired uterine contractile activity. Maternal serum estrogen, weight, uterine superoxide dismutase, fetal weight, and anogenital distance were significantly reduced in the CCW group compared to the vitamin C supplemented group.

CONCLUSIONS

Ingestion of CCW impaired the uterine contractile mechanism, fetal developmental indices, oxidative biomarkers, and estrogen. Vitamin C supplementation modulated these by elevating uterine antioxidant enzymes and reducing free radicals.

Research progress in human biological monitoring of aromatic hydrocarbon with emphasis on the analytical technology of biomarkers

Aromatic hydrocarbons are unsaturated compounds containing carbon and hydrogen that form single aromatic ring, or double, triple, or multiple fused rings. This review focuses on the research progress of aromatic hydrocarbons represented by polycyclic aromatic hydrocarbons (including halogenated polycyclic aromatic hydrocarbons), benzene and its derivatives including toluene, ethylbenzene, xylenes (o-, m- and p-), styrene, nitrobenzene, and aniline. Due to the toxicity, widespread coexistence, and persistence of aromatic hydrocarbons in the environment, accurate assessment of exposure to aromatic hydrocarbons is essential to protect human health. The effects of aromatic hydrocarbons on human health are mainly derived from three aspects: different routes of exposure, the duration and relative toxicity of aromatic hydrocarbons, and the concentration of aromatic hydrocarbons which should be below the biological exposure limit. Therefore, this review discusses the primary exposure routes, toxic effects on humans, and key populations, in particular. This review briefly summarizes the different biomarker indicators of main aromatic hydrocarbons in urine, since most aromatic hydrocarbon metabolites are excreted via urine, which is more feasible, convenient, and non-invasive. In this review, the pretreatment and analytical techniques are compiled systematically for the qualitative and quantitative assessments of aromatic hydrocarbons metabolites such as gas chromatography and high-performance liquid chromatography with multiple detectors. This review aims to identify and monitor the co-exposure of aromatic hydrocarbons that provides a basis for the formulation of corresponding health risk control measures and guide the adjustment of the exposure dose of pollutants to the population.

Ginkgo, fennel, and flaxseed can affect hormone release by porcine ovarian cells and modulate the effect of toluene

Experimental studies have documented the toxic effects of toluene on the mammalian female reproductive processes. The aim of this in vitro study was to examine the potential of functional food plant extracts, namely, of ginkgo, fennel, and flaxseed, in modifying the toluene-induced effects on ovarian hormone release. Porcine granulosa cells were incubated with ginkgo, fennel, or flaxseed extracts (0, 1, 10, or 100 µg/mL) and/or toluene (10 µg/mL). Enzyme immunoassays were used in order to measure the release of progesterone (P), oxytocin (OT), and prostaglandin F (PGF) in the culture media. Toluene suppressed the release of P and enhanced the release of OT and PGF. All tested plant extracts reduced P and increased OT release, while the PGF output was found inhibited by ginkgo and stimulated by fennel and flaxseed. When the cells were incubated with toluene and each one of the plant extracts, toluene was able to prevent their action on P release, as well as those of fennel and flaxseed on OT and PGF release. Moreover, ginkgo enhanced but fennel or flaxseed prevented the toluene-induced effects on OT and PGF release. These observations (i) document novel aspects of the toluene-induced toxicity; (ii) demonstrate the direct influence of ginkgo, fennel, and flaxseed extracts on the ovarian secretory activity; (iii) inform our understanding of the interrelationship between toluene and the tested plant extracts with regard to their effects on ovarian hormone release; (iiii) demonstrate the ability of fennel and flaxseed to prevent adverse effect of toluene on ovarian hormones.

Quercetin can affect porcine ovarian cell functions and to mitigate some of the effects of the environmental contaminant toluene

The present in vitro experiments aimed to examine the effects of the plant polyphenol quercetin and the environmental contaminant toluene on basic ovarian cell functions, including the ability of quercetin to be a natural protector against the adverse effects of toluene. The influence of toluene, quercetin, and their combination on proliferation (accumulation of PCNA), apoptosis (accumulation of bax) and release of progesterone, testosterone and insulin-like growth factor I (IGFI) by cultured porcine ovarian granulosa cells was investigated. Toluene stimulated cell proliferation and inhibited progesterone, IGF-I and testosterone release but did not affect apoptosis. Quercetin, when administered alone, inhibited cell proliferation, apoptosis, IGF-I and testosterone release and stimulated progesterone output. When administered in combination with toluene, quercetin mitigated toluene's effects on proliferation and on progesterone release and induced toluene to exhibit a pro-apoptotic effect. These observations demonstrate the direct effects of both quercetin and toluene on basic ovarian functions and a protective effect of quercetin against the effects of toluene. Therefore, quercetin-containing plants could be regulators of porcine reproduction and natural protectors against the adverse effects of the environmental contaminant toluene.

Volatilomics as an Emerging Strategy to Determine Potential Biomarkers of Female Infertility: A Pilot Study

Due to its high prevalence, infertility has become a prominent public health issue, posing a significant challenge to modern reproductive medicine. Some clinical conditions that lead to female infertility include polycystic ovary syndrome (PCOS), endometriosis, and premature ovarian failure (POF). Follicular fluid (FF) is the biological matrix that has the most contact with the oocyte and can, therefore, be used as a predictor of its quality. Volatilomics has emerged as a non-invasive, straightforward, affordable, and simple method for characterizing various diseases and determining the effectiveness of their current therapies. In order to find potential biomarkers of infertility, this study set out to determine the volatomic pattern of the follicular fluid from patients with PCOS, endometriosis, and POF. The chromatographic data integration was performed through solid-phase microextraction (SPME), followed by gas chromatography–mass spectrometry (GC-MS). The findings pointed to specific metabolite patterns as potential biomarkers for the studied diseases. These open the door for further research into the relevant metabolomic pathways to enhance infertility knowledge and diagnostic tools. An extended investigation may, however, produce a new mechanistic understanding of the pathophysiology of the diseases.

Benzene exposure causes structural and functional damage in rat ovaries: occurrence of apoptosis and autophagy

Studies to date have provided evidence for damage that can occur from hydrocarbon benzene on different tissues/organs. However, little is known regarding the possible influence of this hydrocarbon on female reproduction. In this study, female Wistar rats were treated with low (2000 ppm), middle (4000 ppm), and high (8000 ppm) doses of benzene by inhalation for 30 min daily for 28 days. Benzene exposure adversely affected ovarian function and structure by inducing histopathological changes and altering reproductive steroid hormone release. In addition, benzene-exposed ovaries exhibited increased TMR red fluorescent signals at middle and high doses, revealing significant apoptosis. Interestingly, the investigation of the autophagic protein marker LC3 showed that this protein significantly increased in all benzene-treated ovaries, indicating the occurrence of autophagy. Moreover, ovaries from benzene-treated groups exhibited differential regulation of several specific genes involved in ovarian folliculogenesis and steroidogenesis, including the INSL3, CCND1, IGF-1, CYP17a, LHR, ATG5, and GDF9 genes.

Effect of Xylene Oral Exposure on the Mouse Uterus – A Preliminary Study

Xylene is one of the environmental pollutants with a negative impact mainly on several organ systems. The aim of this study was to determine the effect of xylene on the uterus of mice. The study was performed on 12 adult female mice. Control mice (n = 6) were fed shredded pellets at a dose of 4 g per day. Xylene mice (n = 6) were fed the same diet at the same dose and orally administered xylene at 10 μl per day for 14 days. The mice were synchronized using the Whit-ten effect and introduced to males before the end of the procedure. Mice of both groups with no copulation plug were euthanized by cervical dislocation. The uteri were collected for routine histological and immunohistochemical analysis. The endometrial epithelium demonstrated vacuolar degeneration, mitotic cell activity, and the presence of leukocytes typical of metoestrus. Reductions of the endometrium, stroma, and myometrium were observed in the xylene mice. The xylene application did not have a significant effect on the superficial epithelium, or the size and number of uterine tubular glands. The immunohistochemical analysis of a proliferation marker PCNA revealed that the xylene increased its expression in the stroma, endometrial and myometrial cells, but did not significantly affect the superficial epithelial cells. The expression of an anti-apoptotic marker Bcl-xl in the xylene mice was stronger in the superficial epithelial, stromal, and endometrial cells. The Bcl-xl expression in the myometrial cells was similar to the controls. The results showed that the application of xylene stimulated the proliferation and exerted an anti-apoptotic effect on the uterine cells. However, the increased proliferation can lead to the malignant transformation of cells, resulting in their uncontrollable division.

Volatile organic compounds: A proinflammatory activator in autoimmune diseases

The etiopathogenesis of inflammatory and autoimmune diseases, including pulmonary disease, atherosclerosis, and rheumatoid arthritis, has been linked to human exposure to volatile organic compounds (VOC) present in the environment. Chronic inflammation due to immune breakdown and malfunctioning of the immune system has been projected to play a major role in the initiation and progression of autoimmune disorders. Macrophages, major phagocytes involved in the regulation of chronic inflammation, are a major target of VOC. Excessive and prolonged activation of immune cells (T and B lymphocytes) and overexpression of the master pro-inflammatory constituents [cytokine and tumor necrosis factor-alpha, together with other mediators (interleukin-6, interleukin-1, and interferon-gamma)] have been shown to play a central role in the pathogenesis of autoimmune inflammatory responses. The function and efficiency of the immune system resulting in immunostimulation and immunosuppression are a result of exogenous and endogenous factors. An autoimmune disorder is a by-product of the overproduction of these inflammatory mediators. Additionally, an excess of these toxicants helps in promoting autoimmunity through alterations in DNA methylation in CD4 T cells. The purpose of this review is to shed light on the possible role of VOC exposure in the onset and progression of autoimmune diseases.

Volatile organic compounds released in the mainstream smoke of flavor capsule cigarettes

In this study, the composition of mainstream smoke was investigated with an emphasis on a list of volatile organic compounds (VOCs: e.g., isoprene, acrylonitrile, methyl ethyl ketone, benzene, toluene, m-xylene and styrene) using the two types of flavor capsule cigarettes (FCCs, here coded as F1 and F2) in reference to one commercial, non-flavored (NF) and 3R4F cigarette. The concentrations of all the target compounds from FCCs were quantified under two contrasting conditions (i.e., with and without breaking the capsules). The effect of breaking the capsule was apparent in the FCC products with the enhancement of VOC levels, specifically between after and before breaking the capsules (e.g., 1.10-1.58 folds (benzene) and 1.30-1.53 folds (acetonitrile)). Such increases were apparent in both FCC samples if assessed in terms of the total amount of VOCs (TVOC): (1) F1 (from 2159 to 2530 μg cig-1 (p = 9.42 × 10-6)) and (2) F2 (from 1470 to 2014 μg cig-1 (p = 0.05)). In addition, these TVOC levels determined from the FCCs were 1.62- to 1.83- and 1.29- to 1.46-fold higher than those of the NF cigarette and the 3R4F cigarette, respectively. Thus, these FCC products are suspected to play a role as stronger sources of VOCs than the general cigarette products.

Toxicological Effects of Technical Xylene Mixtures on the Female Reproductive System: A Systematic Review

Technical xylene is a compound of massive production that is used in applications such as petrochemical and healthcare laboratories. Exposure to xylene can cause acute and chronic effects in humans and animals. Currently available studies regarding xylene’s adverse effects with credible designs were dated almost twenty years ago. This systematic review summarizes the findings regarding the detrimental effects of technical xylene from human, animal, and in vitro studies. It recapitulated available studies with respect to the effects of xylene on the female reproductive system to stress the need for updating the current data and guidelines. Based on pre-specified criteria, 22 studies from journal databases exploring the toxic effects of xylene on menstruation, endocrine endpoints, fetal development, and reproductive functions were included for the review. It was found that related studies with a specific focus on the effects of technical xylene on the female reproductive system were insufficient. Therefore, further studies are necessary to update the existing data, thus improving the quality and reliability of risk assessment of exposure to xylene in pregnant women

Potential Protective Effect of Puncture Vine (Tribulus terrestris, L.) Against Xylene Toxicity on Bovine Ovarian Cell Functions

The action of the medicinal plant Tribulus terrestris (TT) on bovine ovarian cell functions, as well as the protective potential of TT against xylene (X) action, remain unknown. The aim of the present in vitro study was to elucidate the influence of TT, X and their combination on basic bovine ovarian cell functions. For this purpose, we examined the effect of TT (at doses of 0, 1, 10, and 100 ng/ml), X (at 20 μg/ml) and the combination of TT + X (at these doses) on proliferation, apoptosis and hormone release by cultured bovine ovarian granulosa cells. Markers of proliferation (accumulation of PCNA), apoptosis (accumulation of Bax) and the release of hormones (progesterone, testosterone and insulin-like growth factor I, IGF-I) were analyzed by quantitative immunocytochemistry and RIA, respectively. TT addition was able to stimulate proliferation and testosterone release and inhibit apoptosis and progesterone output. The addition of X alone stimulated proliferation, apoptosis and IGF-I release and inhibited progesterone and testosterone release by ovarian cells. TT was able to modify X effects: it prevented the antiproliferative effect of X, induced the proapoptotic action of X, and promoted X action on progesterone but not testosterone or IGF-I release. Taken together, our observations represent the first demonstration that TT can be a promoter of ovarian cell functions (a stimulator of proliferation and a suppressor of apoptosis) and a regulator of ovarian steroidogenesis. X can increase ovarian cell proliferation and IGF-I release and inhibit ovarian steroidogenesis. These effects could explain its anti-reproductive and cancer actions. The ability of TT to modify X action on proliferation and apoptosis indicates that TT might be a natural protector against some ovarian cell disorders associated with X action on proliferation and apoptosis, but it can also promote its adverse effects on progesterone release.

Evaluation of the acute toxic effects of crude oil on intertidal mudskipper (Boleophthalmus pectinirostris) based on antioxidant enzyme activity and the integrated biomarker response

With the development of marine oil industry, oil spill accidents will inevitably occur, further polluting the intertidal zone and causing biological poisoning. The muddy intertidal zone and Boleophthalmus pectinirostris were selected as the research objects to conduct indoor acute exposure experiments within 48 h of crude oil pollution. Statistical analysis was used to reveal the activity changes of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione S-transferase (GST) in the gills and liver of mudskipper. Then, integrated biomarker response (IBR) indicators were established to comprehensively evaluate the biological toxicity. The results showed that the activities of SOD, CAT and GST in livers were higher than those in gills, and the maximum induction multipliers of SOD, CAT and GPx in livers appeared earlier than those in gills. Both SOD and GPx activities were induced at low pollutant concentrations and inhibited at high pollutant concentrations. For the dose-effect, the change trends of CAT and SOD were roughly inversed. There was substrate competition between GPx and CAT, with opposite trends over time. The activating mechanism of GST was similar to that of GPx, and the activation time was earlier than that of GPx. In terms of dose-effect trends, the IBR showed that the antioxidant enzymes activities in biological tissues were induced by low and inhibited by high pollutant concentrations. Overall, SOD and GPx in gills and CAT and GST in livers of the mudskippers were suitable as representative markers to comprehensively analyze and evaluate the biotoxicity effects of oil pollution in the intertidal zone. The star plots and IBR values obtained after data standardization were consistent with the enzyme activity differences, which can be used as valid supplementary indexes for biotoxicity evaluation. These research findings provide theoretical support for early indicators of biological toxicity after crude oil pollution in intertidal zones.

Levels of urinary metabolites of benzene compounds, trichloroethylene, and polycyclic aromatic hydrocarbons and their correlations with socioeconomic, demographic, dietary factors among pregnant women in six cities of China

Maternal exposure to benzene and related compounds, trichloroethylene, and polycyclic aromatic hydrocarbons has been suggested as risk factors for reproductive and developmental problem. In different countries and groups, there are differences in socioeconomic circumstances, consumer products, dietary habits, lifestyles, and so on, resulting in different exposure risks from these chemicals. This study investigated the correlation between their metabolite concentrations and socioeconomic, demographic, and dietary factors to explore the possible exposure source of the concerned pollutants in pregnant women. We conducted biological monitoring to assess the exposure of these chemicals using urine samples from 590 to 639 pregnant women during 2nd or 3rd trimester of pregnancy in six cities of China. Socioeconomic and demographic characteristics and dietary habits were collected from questionnaires. The detection rate was over 74% of the urine samples for all metabolites. Compared with the Fourth National Report on Human Exposure to Environmental Chemical concentrations for females (FNRHEEC, the US Centers for Disease Control and Prevention), the metabolite concentrations of benzene compounds and trichloroethylene, excluding MA reported here, were higher. Principal component analysis results showed that SBMA and MHA could be proxy of the principal sources of metabolites for benzene compounds. The concentrations of SBMA and MA were higher in Fuzhou and Wuhan, respectively. The concentration of DCVMA was higher in Shenzhen, Xi'an, and Nanning, and the concentration of PGA was higher in Fuzhou, Wuhan, and Xi'an. Also, the 1-OHPG concentration in Wuhan is higher than that in Fuzhou and Shenzhen. Unhealthy dietary habits, using cosmetics and indoor exposure, contacting chemical solvent during pregnancy were associated with increased benzene compounds, trichloroethylene, and PAH exposure. There were significant positive associations between 1-OHPG level and maternal BMI, low education status, and cooking without a range hood. Pregnant women in China may be at a greater risk of exposure to most of the target compounds than US females, and their exposure levels varied in different regions. Some adverse environmental and behavioral factors may increase the exposure of environmental toxins, which can urge people to take measures to reduce the health risk to pregnant women during pregnancy.

Toluene Can Disrupt Rat Ovarian Follicullogenesis and Steroidogenesis and Induce Both Autophagy and Apoptosis

Toluene has been shown to be highly toxic to humans and animals and can cause damage to various tissues. However, studies reporting its effects on ovarian function are still limited. In this study, we investigated the in vivo effect of toluene using female Wistar rats. We found that toluene exposure decreased ovarian weight and affected ovarian structure by increasing the number of abnormally growing follicles. Moreover, it significantly increased progesterone and testosterone levels. We also showed that toluene exposure decreased GDF-9 protein and its encoding gene. In addition, it inhibited the expression of most of the genes involved in granulosa cell proliferation and differentiation, such as Insl3, ccnd2 and actb. The TUNEL assay showed that apoptosis occurred at the middle and high doses only (4000 and 8000 ppm, respectively), whereas no effect was observed at the low dose (2000 ppm). Interestingly, we showed that toluene exposure induced autophagy as LC3 protein and its encoding gene significantly increased for all doses of treatment. These results may suggest that the activation of autophagy at a low dose of exposure was to protect ovarian cells against death by inhibiting apoptosis, whereas its activation at high doses of exposure triggered apoptosis leading to cell death.

Buckwheat, rooibos, and vitex extracts can mitigate adverse effects of xylene on ovarian cells in vitro

This study examines whether selected functional food and medicinal plants can mitigate the adverse effects of xylene on ovarian cells. The influences of xylene (0, 10, 100, or 1000 ng/mL), buckwheat (Fagopyrum esculentum), rooibos (Aspalathus linearis), vitex (Vitex agnus-castus), extracts (10 μg/mL each), and a combination of xylene with these plant additives on cultured porcine ovarian granulosa cells are compared. Cell viability, proliferation (PCNA accumulation), apoptosis (accumulation of bax), and release of progesterone (P4) and estradiol (E2) were analyzed by the trypan blue tests, quantitative immunocytochemistry, and enzyme-linked immunosorbent assays, respectively. Xylene suppressed all measures of ovarian cell function. Rooibos prevented all of xylene's effects, whereas buckwheat and vitex prevented four of five of the analyzed effects (buckwheat prevented xylene influence on viability, PCNA, bax, and E2; vitex prevented xylene action on viability, PCNA, and P4 and E2). These observations show that xylene has the potential to suppress ovarian cell functions, and that buckwheat, rooibos, and vitex can mitigate those effects, making them natural protectors against the adverse effects of xylene on ovarian cells.

Effects of the occupational exposure on health status among petroleum station workers, Khartoum State, Sudan

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Mean blood lead level for exposed group of non-smokers was 0.58 mg/l.

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Mean blood lead level for exposed group of smokers was 1.49 mg/l.

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Mean value of lead in urine of smokers were 1.59 mg/L & 1.16 mg/L in both groups.

Objective

The hazards of petroleum station activities are greatly emphasized due to their negative impact on workers’ health and safety concerns. This study aims to assess the effect of occupational exposure among the workers in various petroleum station at the Khartoum State, Sudan.

Methods

An analytical and experimental study design is followed where 60 participants were selected through purposive sampling technique. The participants were recruited from the petroleum workstation and were considered as the lead exposed group whereas the participants who lived faraway from the petroleum station and had no exposure to lead were considered as un-exposed group. To avoid the effects of smoking on lead concentration we further divided these groups into smokers and non-smokers. IBM, SPSS was used for the statistical analysis of the collected data.

Results

The results show that there is no significant difference in white blood cells (WBCs) count between exposed and unexposed lead group. We also did not find significant difference in Red blood cells (RBCs) count. Participant from both groups had normal range of haemoglobin (Hb). However, haematocrit (Hct) levels were elevated in both of these groups. We also tested the platelet count in these groups and found that platelet count was slightly lower in lead exposed group as compared to the unexposed group but average count was found within the normal range. Finally, the lead concentration in serum and urine was detected of the participants. Results reveal that the serum lead concentration of non-smokers (0.58 mg/l) in the exposed group was higher than in non-smokers of unexposed group (0.49 mg/l). The lead concentration in serum of smokers in exposed group was also high (1.49 mg/l) than the lead concentration detected in serum of smokers in unexposed group (1.14 mg/l). Urine lead levels of exposed group was also high than the unexposed group in smokers and non-smokers. Mean value of lead in urine among non-smokers of the exposed and unexposed group were 0.76 mg/L and 0.19 mg/L respectively. In the case of smokers, 1.59 mg/L and 1.16 mg/L were the mean value of lead in urine for both exposed and unexposed groups respectively.

Conclusion

From the given results it can be concluded that health safety measures for workers must be implemented to maintain good health status of workers at petroleum stations.

Effects of benzene on gilts ovarian cell functions alone and in combination with buckwheat, rooibos, and vitex

We aimed to examine the influence of benzene and of three dimethyl sulfoxide (DMSO) plant extracts-buckwheat (Fagopyrum Esculentum), rooibos (Aspalathus linearis), and vitex, (Vitex Agnus-Castus), and the combination of benzene with these three plant extracts on basic ovarian cell functions. Specifically, the study investigated the influence of benzene (0, 10, 100, or 1000 ng/mL) with and without these three plant additives on porcine ovarian granulosa cells cultured during 2 days with and without these additives. Cell viability, proliferation (accumulation of proliferating cell nuclear antigen, PCNA), apoptosis (accumulation of Bcl-2-associated X protein , bax), and the release of progesterone (P) and estradiol (E) were analyzed by the Trypan blue test, quantitative immunocytochemistry, and enzyme-linked immunosorbent assay, respectively. Benzene reduced cell viability, as well as P and E release. Plant extracts, given alone, were able directly promote or suppress ovarian cell functions. Furthermore, buckwheat and rooibos, but not vitex prevented the inhibitory action of benzene on cell viability. Buckwheat induced the stimulatory action of benzene on proliferation. Rooibos and vitex promoted benzene effect on cell apoptosis. All these plant additives were able to promote suppressive action of benzene on ovarian steroidogenesis.These observations show that benzene may directly suppress ovarian cell viability, P, and E release and that buckwheat, rooibos, and vitex can directly influence ovarian cell functions and modify the effects of benzene-prevent toxic influence of benzene on cell viability and induce stimulatory action of benzene on ovarian cell proliferation, apoptosis, and steroidogenesis. The observed direct effects of benzene and these plants on ovarian cells functions, as well as the functional interrelationships of benzene and these plants, should be taken into account in their future applications.

Plant polyphenols can directly affect ovarian cell functions and modify toluene effects

The influence of toluene alone and in combination with plant polyphenols apigenin, daidzein or rutin on viability, proliferation (proliferating cell nuclear antigen accumulation), apoptosis (Bax accumulation) and release of progesterone (P), testosterone (T) and estradiol (E) in cultured porcine ovarian granulosa cells was evaluated. Toluene reduced ovarian cell viability, proliferation and E release; it promoted P release, demonstrating no effect on apoptosis or T output. Apigenin alone failed to affect cell viability, proliferation, apoptosis and P and T release, but stimulated E release, promoting the inhibitory action of toluene on proliferation, preventing and even reversing the stimulatory effect of toluene on apoptosis and P. Daidzein alone reduced cell viability and promoted T release, preventing and reversing the stimulatory effect of toluene on cell proliferation. Rutin administration reduced cell viability and E output, promoting the inhibitory action of toluene on cell viability and stimulatory effect on P release, and preventing the inhibitory action of toluene on E release. Toluene reduced apigenin- and rutin-induced E release, promoting action of daidzein on cell viability. These observations suggest the action of toluene and plant polyphenols on ovarian cell functions and the functional interrelationships between these molecules in the ovary.

The inhibitory influence of toluene on mare ovarian granulosa cells can be prevented by fennel

The influence of environmental contaminant toluene and of plant fennel (Foeniculum vulgare Mill.) on reproduction are reported, but the mechanisms of their action and the protective effect of fennel on contaminant influence remain to be elucidated. In this study, we hypothesized that toluene and fennel directly affects basic ovarian cell functions, and that fennel can be used as an appropriate natural protective agent against the potential adverse effects of toluene. This study aimed to examine the action of toluene (20 μg/mL) and fennel extract (0, 1, 10, 100 μg/mL), and assess their combination on viability, proliferation, apoptosis, and hormone release by cultured healthy mare ovarian granulosa cells. Viability, proliferation (percentage of PCNA-positive cells), apoptosis and release of progesterone, oxytocin and prostaglandin F were evaluated by using Trypan blue exclusion tests, immunocytochemistry and enzyme immunoassays, respectively. Toluene, when given alone, inhibited viability, proliferation, apoptosis, progesterone, prostaglandin F and IGF-I. However, it did not affect oxytocin release. Moreover, Fennel, when given alone, inhibited viability, progesterone, and prostaglandin F release, as well as stimulating proliferation and oxytocin release. In addition, Fennel did not affect apoptosis. When given in combination with toluene, fennel was able to suppress, and even invert, the effects of toluene on viability, proliferation, apoptosis, prostaglandin F, and IGF-I. However, it did not alter its effect on progesterone release. Moreover, fennel induced the inhibitory effect of toluene on oxytocin output. The findings of our study suggest direct adverse effects of toluene on the basic ovarian functions of mares. Lastly, we also observed the direct influence of fennel on these functions, as well as its ability to be a natural protector against the action of toluene on the ovarian functions of mares.

Plant isoflavones can prevent adverse effects of benzene on porcine ovarian activity: an in vitro study

We evaluated the influence of the oil-related environmental contaminant benzene (0, 10, 100, or 1000 ng/mL) alone and in combination with apigenin, daidzein, or rutin (10 μg/mL each) on viability; proliferation (accumulation of proliferating cell nuclear antigen); apoptosis (accumulation of Bax); and release of progesterone (P), testosterone (T), and estradiol (E) in cultured porcine ovarian granulosa cells. Cell viability; proliferation; apoptosis; and release of P, T, and E have been analyzed by the trypan blue test, quantitative immunocytochemistry, and ELISA, respectively. Benzene did not affect apoptosis, but reduced ovarian cell viability and P and E release, and promoted proliferation and T output. Apigenin did not affect cell viability, but stimulated proliferation and T and E release, and inhibited apoptosis and P secretion. It prevented and reversed the action of benzene on proliferation and P and T release, and induced the inhibitory action of benzene on apoptosis. Daidzein promoted cell viability, proliferation, P release, but not apoptosis and T or E release. Daidzein induced the stimulatory effect of benzene on T, without modifying other effects. Rutin administered alone reduced cell viability and apoptosis, and promoted cell proliferation. Furthermore, rutin prevented and reversed the effect of benzene on proliferation and P and E release. These observations suggest the direct action of benzene and plant polyphenols on basic ovarian cell functions, and the ability of apigenin and rutin, but not of daidzein, to prevent benzene effects on the ovary.

Relationship between body conditions and environmental contaminants in bovine ovarian cells

The effect of body condition and environmental contaminants on reproductive processes is known; however, it is not known whether basic ovarian cell functions and their response to these contaminants depend on body condition. This study aimed to understand the interrelationships between body conditions and environmental contaminants on ovarian cells. For this purpose, we compared ovarian granulosa cells isolated from cows with an emaciation tendency (body condition score, BCS2 on a scale from 1 to 5) and cows with average body condition (BCS3); proliferation, apoptosis, secretory activity and the response to environmental contaminants were all assessed in the cells. In the 1st series of experiments, ovarian granulosa cells isolated from BCS2 and BCS3 cows were cultured with and without benzene, xylene, and toluene (0.1%). The accumulation of nuclear and cytoplasmic markers of apoptosis (p53 and bax, respectively), a proliferation marker (PCNA), progesterone (P4), and insulin-like growth factor I (IGF-I) was evaluated by Western blot and radioimmunoassay (RIA) experiments. In the 2nd series of experiments, the groups of granulosa cells were cultured with and without mycotoxine deoxynivalenol (DON, 0, 10, 100, or 1000 ng/ml). The secretion of P4 and testosterone (T) was measured by RIA. In comparison to cells from BCS2 animals, ovarian cells isolated from BCS3 cows accumulated higher levels of bax and PCNA but not p53, and they secreted higher amounts of IGF-I but not P4 or T. In cells from BCS2 animals, benzene and xylene promoted p53 accumulation, and toluene reduced the accumulation. In the BCS2 group, all treatments promoted bax and PCNA expression. However, in cells from BCS3 animals, all environmental pollutants inhibited p53, toluene inhibited PCNA but not bax, and xylene did not affect the expression of proliferation or apoptosis markers. In the BCS2 group, P4 was inhibited by xylene, and IGF-I was stimulated by xylene but not by benzene or toluene. Low-dose exposure to DON (10 ng/ml) promoted P4 release from cells from both BCS2 and BCS3 animals, but high-dose exposure to DON (1000 ng/ml) reduced P4 secretion from the cells from BCS2 animals but not from the cells from BCS3 animals. The release of T was inhibited by high-dose exposure to DON (1000 ng/ml), irrespective of the BCS. An emaciation tendency reduces proliferation, apoptosis, and IGF-I release, and it induces or reverses the action of environmental contaminants on ovarian functions. Taken together, these observations demonstrate the effect of body condition and the direct influence of environmental contaminants on basic bovine ovarian functions. Furthermore, they demonstrate for the first time that the response of ovarian cells to environmental contaminants can be regulated by cow body condition.

Interrelationships between metabolic hormones, leptin and ghrelin, and oil-related contaminants in control of oxytocin and prostaglandin F release by feline ovaries

We examined the effects of metabolic hormones leptin and ghrelin, and the oil-related environmental contaminants toluene and xylene on the release of ovarian hormones by gravid and non-gravid cats, as well as the functional interrelationships between metabolic hormones and contaminants. Ovarian fragments of non-gravid cats were cultured with and without leptin and toluene. Next, ovarian fragments of either non-gravid or gravid animals were cultured with and without ghrelin and xylene. Oxytocin (OT) and prostaglandin F (PGF) release was measured using ELISA. We confirm ovarian OT and PGF production by feline ovary, demonstrate the involvement of leptin and ghrelin in controlling OT and PGF release, show the direct influence of toluene and xylene on feline ovarian secretory activity, indicate the ability of leptin and ghrelin to mimic and promote the main contaminant effects, demonstrate that oil-related contaminants can prevent and even invert the effects of leptin and ghrelin on the ovary, and suggest the gravidity-associated changes in ability of ghrelin to promote xylene action on PGF (but not to OT), but not in basic ovarian OT and PGF release and their response to ghrelin or xylene.

Mechanisms of the direct effects of oil-related contaminants on ovarian cells

We studied the influence of oil-related environmental contaminants (OREC) on the viability, hormone secretion, and protein expression using cultured porcine ovarian granulosa cells. Addition of benzene and xylene promoted proliferation and apoptosis and reduced ovarian cell viability whereas toluene induced apoptosis only. The release of progesterone (P4) and oxytocin (OT) was promoted by benzene and xylene, and suppressed by toluene while prostaglandin F (PGF) output was stimulated by benzene and toluene, but not xylene. The addition of FSH to the culture medium increased ovarian cell proliferation and hormone release, but did not affect apoptosis. However, this FSH's proliferative effect has been prevented in presence of benzene. On the other hand and in the presence of FSH, toluene prevented P4 release and decreased PGF release, while xylene prevented PGF release. We concluded that OREC can affect reproductive processes by directly influencing ovarian cell proliferation, apoptosis, viability, hormone release, and response to gonadotropins.

Determining the endocrine disruption potential of industrial chemicals using an integrative approach: Public databases, in vitro exposure, and modeling receptor interactions

Environmental and occupational exposure to industrial chemicals has been linked to toxic and carcinogenic effects in animal models and human studies. However, current toxicology testing does not thoroughly explore the endocrine disrupting effects of industrial chemicals, which may have low dose effects not predicted when determining the limit of toxicity. The objective of this study was to evaluate the endocrine disrupting potential of a broad range of chemicals used in the petrochemical sector. Therefore, 139 chemicals were classified for reproductive toxicity based on the United Nations Globally Harmonized System for hazard classification. These chemicals were evaluated in PubMed for reported endocrine disrupting activity, and their endocrine disrupting potential was estimated by identifying chemicals with active nuclear receptor endpoints publicly available databases. Evaluation of ToxCast data suggested that these chemicals preferentially alter the activity of the estrogen receptor (ER). Four chemicals were prioritized for in vitro testing using the ER-positive, immortalized human uterine Ishikawa cell line and a range of concentrations below the reported limit of toxicity in humans. We found that 2,6-di-tert-butyl-p-cresol (BHT) and diethanolamine (DEA) repressed the basal expression of estrogen-responsive genes PGR, NPPC, and GREB1 in Ishikawa cells, while tetrachloroethylene (PCE) and 2,2'-methyliminodiethanol (MDEA) induced the expression of these genes. Furthermore, low-dose combinations of PCE and MDEA produced additive effects. All four chemicals interfered with estradiol-mediated induction of PGR, NPPC, and GREB1. Molecular docking demonstrated that these chemicals could bind to the ligand binding site of ERα, suggesting the potential for direct stimulatory or inhibitory effects. We found that these chemicals altered rates of proliferation and regulated the expression of cell proliferation associated genes. These findings demonstrate previously unappreciated endocrine disrupting effects and underscore the importance of testing the endocrine disrupting potential of chemicals in the future to better understand their potential to impact public health.

DNA Damage and Perturbed Topoisomerase IIα as a Target of 1,4-Benzoquinone Toxicity in Murine Fetal Liver Cells

Benzene is a ubiquitous environmental pollutant. Recent studies have shown a link between the development of childhood leukemias and maternal benzene exposure, suggesting that these leukemias may be initiated in utero. Benzene crosses the placental barrier however the mechanisms behind in utero benzene toxicity have not been well elucidated. This study is the first to show that the benzene metabolite, benzoquinone (BQ), perturbs fetal topoisomerase IIα (Topo IIα), an enzyme essential for DNA repair. Using cultured murine CD-1 fetal liver cells, this study shows that Topo IIα activity decreases following 24 hours of exposure to BQ (12.5 and 15.625 µM), with the 12.5 µM confirmed to disrupt the c-kit+Lin-Sca-1-Il7rα- population of cells in culture. Pre-treatment with the antioxidant, N-acetylcysteine did not prevent the inhibtion of Topo IIα by BQ. An increase in Topo IIα-DNA covalent adducts was detected following 24-hour exposures to BQ (12.5 and 50 µM). Interestingly, BQ (12.5 µM) exposure did not significantly increase levels of 4-hydroxynonenal (4-HNE), a marker of oxidative stress after 24 hours. However, increased levels of the double-stranded DNA break marker γH2AX were detected following 24 hours of BQ exposure, confirming that Topo IIα-induced breaks are increased in BQ treated cells. This study shows that fetal Topo IIα is perturbed by BQ and suggests that this protein is a target of benzene and may be implicated with in utero benzene toxicity.

Sanitary pads and diapers contain higher phthalate contents than those in common commercial plastic products

Sanitary pads and diapers are made of synthetic plastic materials that can potentially be released while being used. This study measured the amounts of volatile organic compounds (VOCs) (methylene chloride, toluene, and xylene) and phthalates (DBP, DEHP, DEP, and BBP) contained in sanitary pads and diapers. In sanitary pads, 5,900- and 130-fold differences of VOC and phthalate concentrations were seen among the brands. In the diapers, 3- and 63-fold differences of VOC and phthalate concentrations were detected among the brands. VOC concentrations from the sanitary pads and diapers were similar to that of the residential air. However, phthalate concentrations of sanitary pads and diapers were significantly higher than those found in common commercial plastic products. As sanitary pads and diapers are in direct contact with external genitalia for an extended period, there is a probability that a considerable amount of VOCs or phthalates could be absorbed into the reproductive system.

Fluorescence-Based Detection of Benzene, Toluene, Ethylbenzene, Xylene, and Cumene (BTEXC) Compounds in Fuel-Contaminated Snow Environments

Reported herein is the sensitive and selective cyclodextrin-promoted fluorescence detection of benzene, toluene, ethylbenzene, xylene, and cumene (BTEXC) fuel components in contaminated snow samples collected from several locations in the state of Rhode Island. This detection method uses cyclodextrin as a supramolecular scaffold to promote analyte-specific, proximity-induced fluorescence modulation of a high-quantum-yield fluorophore, which leads to unique fluorescence responses for each cyclodextrin-analyte-fluorophore combination investigated and enables unique pattern identifiers for each analyte using linear discriminant analysis (LDA). This detection method operates with high levels of sensitivity (sub-micromolar detection limits), selectivity (100% differentiation between structurally similar compounds, such as ortho-, meta-, and para-xylene isomers), and broad applicability (for different snow samples with varying chemical composition, pH, and electrical conductivity). The high selectivity, sensitivity, and broad applicability of this method indicate significant potential in the development of practical detection devices for aromatic toxicants in complex environments.

Metabolic state can define the ovarian response to environmental contaminants and medicinal plants

Environmental contaminants and medicinal plants can affect reproductive processes. The aim of this study was to investigate the effect of maternal metabolic status on the response of mouse ovaries to the environmental contaminants benzene and xylene, as well as to extracts of the medicinal plant yucca. Ovaries isolated from normal-lean and slightly obese mice were cultured with or without 0.1% benzene or xylene for 24 h. Similarly, ovaries isolated from normal-lean, slightly obese, and significantly obese mice were cultured for 24 h with or without an extract of Yucca shidigera (YS, 10 μ g/mL). We found that the metabolic status did not influence the release of basal progesterone (P4), testosterone (T), or insulin-like growth factor I (IGF-I), but obesity influenced the effects of the environmental contaminants and YS. Benzene reduced P4 output in ovaries from obese but not normal-lean mice; it also reduced IGF-I (but not T) release from ovaries irrespective of the metabolic status. Xylene dramatically increased P4 and T (but not IGF-I) release by ovaries from normal-lean mice, but there were no changes in P4 and only small increases in T output in obese mice. YS increased P4 (but not T or IGF-I) release in normal-lean and slightly obese animal ovaries, whilst significant obesity was associated with a lack of P4 response to YS. Obesity might affect the basal ovarian release of T or IGF-I and increases the sensitivity of ovaries to the action of benzene but decreases their responsiveness to xylene and YS.