Mechanism of diethylhexylphthalate (DEHP) induced testicular damage and of grape seed extract-induced protection in the rat

DEHP induces apoptosis and autophagy of the thyroid via Rap1 signaling pathway: In vivo and in vitro study

OBJECTIVE

DEHP has thyroid toxicity and affects thyroid function. However, the mechanism is unclear.

METHODS

The offspring of SD rats were gavaged with different doses of DEHP from in utero to 8 or 12 weeks old. We observed the thyroid morphology with HE and autophagosomes with TEM. The THs levels were tested with ELISA. The apoptosis level was tested by flow cytometry. The levels of apoptosis-related genes, autophagy-related genes and Rap1 pathway genes, were measured with qRT-PCR and Western blot. We established an MEHP-treated Nthy-ori 3-1 cell model and inhibited the Rap1 to verify the mechanism.

RESULTS

DEHP could cause pathological damage and ultrastructure damage of thyroids in offspring rats. After DEHP exposure, the THs levels were altered, the apoptosis levels increased, and autophagosomes appeared. DEHP significantly affected the levels of apoptosis-related genes and autophagy-related genes. DEHP also affected the levels of Rap1 pathway, which was correlated with the levels of apoptosis and autophagy. After inhibiting Rap1 in Nthy-ori 3-1 cells, the THs levels were altered. Rap1 pathway was inhibited and the levels of apoptosis and autophagy were down-regulated.

CONCLUSION

DEHP could induce the apoptosis and autophagy of the thyroid, and Rap1 signaling pathway may play a significant role.

Lactiplantibacillus plantarum RS20D Alleviates Male Reproductive Toxicity Induced by Pubertal Exposure to Di-n-butyl Phthalate and Mono-n-butyl Phthalate

Phthalate acid esters (PAEs) and their metabolites, such as di-n-butyl phthalate (DBP) and mono-n-butyl phthalate (MBP), are known to cause male reproductive damage. Lactiplantibacillus plantarum RS20D has demonstrated the ability to remove both DBP and MBP in vitro, suggesting its potential as a detoxifying agent against these compounds. This study aimed to investigate the protective effects of RS20D on DBP or MBP-induced male reproductive toxicity in adolescent rats. Oral administration of RS20D significantly mitigated the histological damage to the testes caused by MBP or DBP, restored sperm concentration, morphological abnormalities, and the proliferation index in MBP-exposed rats, and partially reversed spermatogenic damage in DBP-exposed rats. Furthermore, RS20D restored serum levels of estradiol (E2) and testosterone, and superoxide dismutase (SOD) activity in DBP-exposed rats, significantly increased testosterone levels in MBP-exposed rats, and restored copper (Cu) concentrations in the testes after exposure to DBP or MBP. Additionally, RS20D effectively modulated the intestinal microbiota in DBP-exposed rats and partially ameliorated dysbiosis induced by MBP, which may be associated with the alleviation of reproductive toxic effects induced by DBP or MBP. In conclusion, this study demonstrates that RS20D administration can alleviate male reproductive toxicity and gut dysbacteriosis induced by DBP or MBP exposure, providing a dietary strategy for the bioremediation of PAEs and their metabolites.

Oyster Peptide-Zinc Complex Ameliorates Di-(2-ethylhexyl) Phthalate-Induced Testis Injury in Male Mice and Improving Gut Microbiota

Di-(2-ethylhexyl) phthalate (DEHP) is a widely used plasticizer, which can cause damage to male reproductive organs, especially the atrophy of the testis. Meanwhile, DEHP can also lead to a decrease in testicular zinc content, but the role of zinc remains unclear. This study aims to prepare oyster peptide-zinc complex (OPZC) to alleviate DEHP-induced reproductive damage in mice. OPZC was successfully obtained through electron microscopy, X-ray diffraction, and thermogravimetric analysis, with stable structure and high water-solubility. Low dose oyster peptide-zinc complex (OPZCL) significantly reduced the reproductive damage caused by DEHP in mice. Further research had shown that OPZCL restored the content of serum hormones and the activity of oxidative stress kinases to normal, while also normalizing testicular zinc and selenium levels. In addition, it also recovered the disorder of gut microbiota, reduced the proportion of Bacteroides, increased the abundance of Ligilactobacillus, and restored the proportion of Acidobacteriota, Chloroflexi, and Proteobacteria. Therefore, OPZCL can relieve the reproductive damage caused by DEHP in mice by restoring testicular zinc homeostasis and the composition of intestinal microbiota, indicating that OPZCL has a potential protective effect on male reproductive health.

Grape Seed Proanthocyanidins Improve the Quality of Fresh and Cryopreserved Semen in Bulls

Oxidative stress leads to a decrease in semen quality during semen cryopreservation and fresh semen production. Grape seed proanthocyanidins (GSPs) are endowed with well-recognized antioxidant, anti-inflammatory, anti-cancer, and anti-aging activities. Therefore, the objective of this experiment was to explore the effects of GSPs on the quality of fresh and cryopreserved semen to provide a basis for GSPs as a new dietary additive and semen diluent additive for males' reproduction. Fresh semen from three healthy bulls aged 3 to 5 years old were gathered and mixed with semen diluents dissolved with 0 µg/mL, 30 µg/mL, 40 µg/mL, 50 µg/mL, and 60 µg/mL GSPs respectively. The motility, physiological structures (acrosome integrity, membrane integrity, mitochondrial activity), and antioxidant capacity of frozen-thawed sperm were measured after storage in liquid nitrogen for 7 days (d). Bulls were fed with 20 mg/kg body weight (BW) GSPs in their diet for 60 days; the weight of the bull is about 600 kg. Then, the reproductive performance and antioxidant indexes of bulls were measured before and after feeding. The results demonstrated that GSPs supplementation significantly increased sperm motility, physiological structures, GSH-Px, and CAT enzyme activities and significantly decreased MDA content in sperm during semen cryopreservation. The optimal concentration of GSPs was 40 µg/mL (p < 0.05). After 20 mg/kg (body weight) GSP supplementation, sperm motility was significantly heightened (p < 0.05), the sperm deformity rate was significantly reduced (p < 0.05), and antioxidant enzyme activities (such as SOD, CAT, and GSH-Px) were significantly enhanced (p < 0.05), and the production of MDA was significantly suppressed (p < 0.05) in serum compared with that before feeding. In conclusion, these results reveal that a certain concentration of GSPs has a good protective effect on sperm damage caused by semen cryopreservation and the reproductive performance reduction caused by stress in bulls, which may be attributed to the antioxidant function of GSPs. In summary, GSPs are a useful cryoprotective adjuvant and dietary additive for bull sperm quality.

From oxidative imbalance to compromised standard sperm parameters: Toxicological aspect of phthalate esters on spermatozoa

The exponential rise in global male infertility and subfertility-related issues raises severe concern. One of the major contributors is phthalate esters, typical endocrine disruptors affecting millions of lives. The inevitable exposure to phthalates due to their universal application as plasticizers leaves the human population vulnerable to this silent threat. This review explicitly deals with the spermiotoxic effects of different phthalate esters on in vivo and in vitro models and on surveyed human populations to find the most plausible link between global usage of phthalates and poor sperm health. As the free radicals in spermatozoa are prerequisites for their standard structure and functioning, the precise regulation and phthalate-mediated impairment of pro-oxidant:anti-oxidant balance with subsequent loss of structural and functional integrity have also been critically discussed. Furthermore, we also provided future directives, which, if addressed, will fill the still-existing lacunae in phthalate-mediated male reproductive toxicity research.

The Protective Role of Grape Seed in Obesity and Lipid Profile: An Updated Narrative Overview of Preclinical and Clinical Studies

Obesity and dyslipidemia are common disorders universally. According to the acquired outcomes of recent studies, dietary supplementations which have great content of phenolic compounds exert protective effects against obesity and dyslipidemia. Grape [Vitis vinifera] seeds are considered attractive sources of phenolic compounds with anti-oxidative stress and anti-inflammatory effects. There are also various experimental studies describing hepatoprotective, neuroprotective, anti-aging, cardioprotective, and anti-carcinogenic effects of polyphenols isolated from grape seed, highlighting the therapeutic and biological aspects of proanthocyanidins. The present review article first discusses pharmacological, botanical, toxicological, and phytochemical characteristics of Vitis vinifera seeds and afterward designates the protective properties which are attributed to the intake of grape seeds in obesity and hyperlipidemia. Overall valuable and updated findings of this study display that polyphenol of grape seeds has meaningful impacts on the regulation of lipid profile levels and management of obesity.

Toxicity and endocrine-disrupting potential of PM2.5: Association with particulate polycyclic aromatic hydrocarbons, phthalate esters, and heavy metals

The adverse effects of fine atmospheric particulate matter with aerodynamic diameters of ≤2.5 μm (PM_2.5) are closely associated with particulate chemicals. In this study, PM_2.5 samples were collected from highway and industry sites in Hangzhou, China, during the autumn and winter, and their cytotoxicity and pulmonary toxicity and endocrine-disrupting potential (EDP) were evaluated in vitro and in vivo; the particulate polycyclic aromatic hydrocarbons (PAHs), phthalate esters (PAEs), and heavy metals were then characterized. The toxicological results suggested that the PM_2.5 from highway site induced higher cytotoxicity (cell viability inhibition, intracellular oxidative stress, and cell membrane injury) and pulmonary toxicity (inflammatory response (IR) and oxidative stress (OS)) than the samples from industry site, while the PM_2.5 from industry site exhibited higher EDP (estrogenic and anti-androgenic activity). The cytotoxicity and pulmonary toxicity of PM_2.5 in the winter were higher than those in the autumn, while no seasonal difference in the endocrine-disrupting potential was observed (p > 0.05). The Pearson correlation analysis between the biological effects and particulate chemicals revealed that the PM_2.5-induced inflammatory response and oxidative stress were closely associated with the particulate PAHs and heavy metals (Pearson correlation coefficients: r_{IR, PAHs} = 0.822-0.988, r_{IR, heavy metals} = 0.895-0.971, r_{OS, PAHs} = 0.843-0.986, and r_{OS, heavy metals} = 0.887-0.933), while particulate di (2-ethylhexyl)phthalate (DEHP) substantially contributed to the EDP of PM_2.5 (r_{EDP, DEHP} = 0.981). This study indicated that the toxicity and EDP of PM_2.5 could vary with the surrounding environment and season, which was closely associated with the variations of particulate chemicals. Further studies are needed to clarify the associations between the harmful effects of PM_2.5 and other contributing factors.

Grape Seed Proanthocyanidin Ameliorates FB1-Induced Meiotic Defects in Porcine Oocytes

Fumonisin B₁ (FB₁), as the most prevalent and toxic fumonisin, poses a health threat to humans and animals. The cytotoxicity of FB₁ is closely related to oxidative stress and apoptosis. The purpose of this study is to explore whether Grape seed proanthocyanidin (GSP), a natural antioxidant, could alleviate the meiotic maturation defects of oocytes caused by FB₁ exposure. Porcine cumulus oocyte complexes (COCs) were treated with 30 μM FB₁ alone or cotreated with 100, 200 and 300 μM GSP during in vitro maturation for 44 h. The results show that 200 μM GSP cotreatment observably ameliorated the toxic effects of FB₁ exposure, showing to be promoting first polar body extrusion and improving the subsequent cleavage rate and blastocyst development rate. Moreover, 200 μM GSP cotreatment restored cell cycle progression, reduced the proportion of aberrant spindles, improved actin distribution and protected mitochondrial function in FB₁-exposed oocytes. Furthermore, reactive oxygen species (ROS) generation was significantly decreased and the mRNA levels of CAT, SOD2 and GSH-PX were obviously increased in the 200 μM GSP cotreatment group. Notably, the incidence of early apoptosis and autophagy level were also significantly decreased after GSP cotreatment and the mRNA expression levels of BAX, CASPASE3, LC3 and ATG5 were markedly decreased, whereas BCL2 and mTOR were observably increased in the oocytes after GSP cotreatment. Together, these results indicate that GSP could exert significant preventive effects on FB₁-induced oocyte defects by ameliorating oxidative stress through repairing mitochondrial dysfunction.

Di-2-ethylhexyl phthalate induces heart looping disorders during zebrafish development

Di-2-ethylhexyl phthalate (DEHP) is a type of plasticizer widely used in industry. It is well-known for its toxic effects to endocrine and reproductive systems and has been detected in amniotic fluid and placenta. In the present study, we explored the effects of DEHP on heart development by using zebrafish as a model organism. DEHP (0.02 pg) was injected into the yolk sac of zebrafish embryos at the one-cell stage. No significant difference was found in embryonic lethality between control and DEHP groups at 1-day postfertilization (dpf), but mortality significantly increased in DEHP groups at 2 and 3 dpf. The average heart rate was significantly reduced in the surviving DEHP-treated zebrafish larvae at 3 and 4 dpf. In addition, massive pericardial edema was found in DEHP-treated zebrafish (12.6 ± 1.5%), which was significantly higher than that of the control group. Serious heart looping disorder was also observed in DEHP-treated larvae, mainly manifested with an elongated atrial-ventricular distance. Moreover, the expression of heart development transcription factors was affected by DEHP injection. Real-time polymerase chain reaction confirmed that five transcription factors (hand2, tp53, mef2c, esr1, and tbx18) were significantly downregulated in the DEHP group at 2 dpf, and three transcription factors (zic3, tcf21, and gata4) were significantly upregulated. Our results emphasize the need for the development of a nontoxic plasticizer to prevent possible deleterious effects on humans and other life-forms.

Grape seed extract protects against amiodarone - induced nephrotoxicity and ultrastructural alterations associated with the inhibition of biomarkers of inflammation and oxidative stress in rats

Amiodarone (AMD) is one of the highly effective antiarrhythmic agents used for treating refractory arrhythmias. It is well known to have long-term administration side effects such as nephrotoxicity. The possible ameliorative effects of antioxidant grape seed extract; on the extent of tissue damage in AMD-induced nephrotoxicity has not been investigated before. Twenty-four albino rats were used in this study and divided into four groups (n = 6). The 1^st group served as an untreated control group, under the same laboratory conditions, the 2^nd group received (100 mg/kg/day) of grape seed extract (GSE), the 3rd group, AMD-treated group, received AMD (40 mg/kg/day) and the 4th group received both AMD and GSE in the same doses as the previous groups. AMD-treated group showed abnormal glomerular capillaries with wrinkling basement membranes damaged mesangial cells and distorted proximal tubules with plenty of lysosomes. Ultrastructural alterations were also observed in this group. This was also associated with a significant increase in biomarkers of kidney injury (creatinine), oxidative stress ((Decreased SOD and increased MDA) and biomarkers of inflammation IL-6) in comparison to the control group. Supplementation of GSE to AMD group for eight weeks counteracted these effects. It caused an improvement in histological and t ultrastructure changes of the renal tissues associated with decreased creatinine and biomarkers of oxidative stress and inflammation in comparison to AMD-treated group. We conclude that GSE protects against AMD-induced kidney injuries in rats, which is associated with the inhibition of biomarkers of inflammation and oxidative stress.

Di-2-ethylhexyl phthalate (DEHP) induces apoptosis and autophagy of mouse GC-1 spg cells

As a widely used plasticizer in industry, di-2-ethylhexylphthalate (DEHP) can cause testicular toxicity, yet little is known about the potential mechanism. In this study, DEHP exposure dramatically inhibited cellviability and induced apoptosis of mouse GC-1 spg cells. Furthermore, DEHP significantly increased the levels of autophagy proteins LC3-II, Beclin1 and Atg5, as well as the ratio ofLC3-II/LC3-I. Transmission electron microscopy (TEM) further confirmed that DEHP induced autophagy of mouse GC-1 spg cells. DEHP was also shown to induceoxidative stress; while inhibition of oxidative stress with NAC could increase cell viability and inhibit DEHP-induced apoptosis and autophagy. These results suggested that DEHP induced apoptosis and autophagy of mouse GC-1 spg cells via oxidative stress. 3-MA, an inhibitor of autophagy, could rescue DEHP-induced apoptosis. In summary, DEHP induced apoptosis and autophagy of mouse GC-1 spg cells via oxidative stress, and autophagy might exert a cytotoxic effect on DEHP-induced apoptosis.

Di(2-ethylhexyl) phthalate inhibits glutathione regeneration and dehydrogenases of the pentose phosphate pathway on human colon carcinoma cells

Phthalates, particularly di(2-ethylhexyl) phthalate (DEHP), are compounds widely used as plasticizers and have become serious global contaminants. Because of the bioaccumulation of such substances, the food chain is at risk. The food contamination by some phthalates has been linked to different side effects in experimental animals. That is why we have chosen the intestinal system's cells which represent the primary targets of these compounds to test their toxic effects. Human colon carcinoma cells (HCT 116) were chosen to elucidate whether DEHP triggers oxidative stress and apoptosis. Our results indicated that DEHP is cytotoxic; it induces the overexpression of Hsp70 protein and causes oxidative damage through the generation of free radicals leading to lipid peroxidation induction and the increase of superoxide dismutase (SOD) and catalase (CAT) activities. In addition, cell treatment with DEHP resulted in a glutathione (GSH) content decrease and a decrease in the glutathione reductase (GR) activity. As new evidence provided in this study, we demonstrated that the DEHP affected the two enzymes' activities of the oxidative phase of the pentose phosphate pathway: Glucose-6-phosphate dehydrogenase (G6PD) and 6-phosphogluconate dehydrogenase (6PGD). This leads to a decrease in the level of NADPH used by the GR to maintain the regeneration of the reduced GSH. We also demonstrated that such effects can be responsible for DEHP-induced apoptosis.

DEHP induces immunosuppression through disturbing inflammatory factors and CYPs system homeostasis in common carp neutrophils

Di-(2-ethylhexyl) phthalate (DEHP), a common pollutant in the water environment, has been reported to be associated with immune functions, especially aquatic organisms. However, whether DEHP exposure causes neutrophils toxicity in common carp is still unclear. To investigate the toxic effect of DEHP on immune functions, common carp neutrophils were exposed to DEHP (40 μmol/L and 200 μmol/L) for 2 h. The common carp neutrophils exposed to DEHP showed a decrease in neutrophil phagocytosis rate compared with control group. DEHP exposure induced a significant decrease in mRNA expression levels of inflammatory cytokines-related genes (Interleukin-6, Interleukin-8, transforming growth factor, tumor necrosis factor (TNF)-α, TNF-R1, TNF-T1, Interferon (IFN)-2a, IFN-g2b, IFN-g1) in common carp neutrophils, while the expression levels of IL-1β and IL-10 were increased compared with control group (P < 0.05). Furthermore, the detection of cytochrome P450 enzyme related genes showed that the mRNA expression levels of CYP (cytochrome P450 proteins)-1A, CYP-1B1, CYP-C1, CYP-2K were significantly decreased, and the mRNA expression level of CYP-3A was significantly reduced (P < 0.05). The results indicated that DEHP could affect the phagocytic ability of neutrophils by regulating the expression of inflammatory cytokines and disrupting cytochrome P450 homeostasis, which caused the immunosuppression in common carp.

Effects of α-ethinyl estradiol (EE2) and diethylhexyl phthalate (DEHP) on growth performance, antioxidant status and immune response of juvenile yellow catfish Pelteobagrus fulvidraco

The four experimental groups were carried out to test the response of yellow catfish to EE2 and DEHP: control group was exposed to DMSO; EE2 group was exposed to 1.0 μg/L EE2; DEHP group was exposed to 1.0 mg/L DEHP; mix group was exposed to 1.0 μg/L EE2 and 1.0 mg/L DEHP. The experiment continued for 56 days. Fish survival rate was not different among experimental groups. Fish in DEHP and mix groups had the highest weight gain, and lowest value appeared in control group. The highest hepatosomatic index was found in DEHP and mix groups. Serum alanine transaminase of fish in control group was lower than other groups, but the alkaline phosphatase value was the highest. Serum total anti-oxidation capacity, superoxide dismutase and catalase activities of fish in control group were higher than other groups, but malondialdehyde content is opposite. Respiratory burst and phagocytic indices of fish in EE2 group were the lowest. After 96 h of ammonia stress, the survival rate of fish in mix group was significantly lower than control group. This study indicates that EE2 and DEHP exposure can lead to gain weight of yellow catfish, which is related to liver damage and fat accumulation; EE2 and DEHP exerts its toxic effects by inducing ROS generation, leading to lipid peroxidation and immunosuppression.

Early life exposure to di(2-ethylhexyl)phthalate causes age-related declines associated with insulin/IGF-1-like signaling pathway and SKN-1 in Caenorhabditis elegans

Di(2-ethylhexyl)phthalate (DEHP) is an ubiquitous and emerging contaminant that is widely present in food, agricultural crop, and the environment, posing a potential risk to human health. This study utilized the nematode Caenorhabditis elegans to decipher the toxic effects of early life exposure to DEHP on aging and its underlying mechanisms. The results showed that exposure to DEHP at 0.1 and 1.5 mg/L inhibited locomotive behaviors. In addition, DEHP exposure significantly shortened the mean lifespan of the worms and further adversely affected pharyngeal pumping rate and defecation cycle in aged worms. Moreover, DEHP exposure also further enhanced accumulation of age-related biomarkers including lipofuscin, lipid peroxidation, and intracellular reactive oxygen species in aged worms. In addition, exposure to DEHP significantly suppressed gene expression of hsp-16.1, hsp-16.49, and hsp-70 in aged worms. Further evidences showed that mutation of genes involved in insulin/IGF-1-like signaling (IIS) pathway (daf-2, age-1, pdk-1, akt-1, akt-2, and daf-16) restored lipid peroxidation accumulation upon DEHP exposure in aged worms, whereas skn-1 mutation resulted in enhanced lipid peroxidation accumulation. Therefore, IIS and SKN-1 may serve as an important molecular basis for DEHP-induced age-related declines in C. elegans. Since IIS and SKN-1 are highly conserved among species, the age-related declines caused by DEHP exposure may not be exclusive in C. elegans, leading to adverse human health consequences due to widespread and persistent DEHP contamination in the environment.

Lactobacillus plantarum TW1-1 Alleviates Diethylhexylphthalate-Induced Testicular Damage in Mice by Modulating Gut Microbiota and Decreasing Inflammation

Diethylhexylphthalate (DEHP), acting as an endocrine disruptor, disturbed reproductive health. Here, we evaluated the effects of Lactobacillus plantarum TW1-1 (L. plantarum TW1-1) on DEHP-induced testicular damage in adult male mice. Results showed that oral supplementation of L. plantarum TW1-1 significantly increased the serum testosterone concentration, enhanced the semen quality, and attenuated gonad development defects in DEHP-exposed mice. L. plantarum TW1-1 also alleviated DEHP-induced oxidative stress and inflammatory responses by decreasing the mRNA expression and serum protein concentration of different inflammatory factors [tumor necrosis factor-α, interleukin (IL)-1β and IL-6]. Furthermore, L. plantarum TW1-1 significantly reduced DEHP-induced intestinal hyper-permeability and the increase in the serum lipopolysaccharide level. Gut microbiota diversity analysis revealed that L. plantarum TW1-1 shifted the DEHP-disrupted gut microbiota to that of the control mice. At phylum level, L. plantarum TW1-1 reversed DEHP-induced Bacteroidetes increase and Firmicutes decrease, and restored Deferribacteres in DEHP-exposed mice. Spearman's correlation analysis showed that Bacteroidetes, Deferribacteres, and Firmicutes were associated with DEHP-induced testicular damage. In addition, the ratio of Firmicutes to Bacteroidetes (Firm/Bac ratio) significantly decreased from 0.28 (control group) to 0.13 (DEHP-exposed group), which was restored by L. plantarum TW1-1 treatment. Correlation analysis showed that the Firm/Bac ratio was negatively correlated with testicular damage and inflammation. These findings suggest that L. plantarum TW1-1 prevents DEHP-induced testicular damage via modulating gut microbiota and decreasing inflammation.

Sex hormones and oxidative stress mediated phthalate-induced effects in prostatic enlargement

Prostatic enlargement might affect up to 30% of men and can cause signs and symptoms in the lower urinary tract in the elderly. Imbalanced estrogen and androgen secretions are important in prostatic physiopathology. Phthalates-environmental endocrine disruptors-affect androgen secretion and disrupt sexual organs, including testes and the prostate, but the underlying mechanisms are unclear. Using European Association of Urology (EAU) guidelines, we recruited from urology clinics in southern Taiwan 207 elderly men diagnosed with benign prostatic hyperplasia (BPH) and prostatic enlargement between 2015 and 2017. We took blood and urine samples from all patients on the same day. We used multivariate linear regression, associations, and potential interactions after we had measured and analyzed oxidative stress (OS) markers, steroidal hormones, and 11 urinary phthalate metabolites, and then we adjusted for confounders. Di(2-ethylhexyl) phthalate (DEHP) metabolite levels, particularly urinary mono-(2-ethylhexyl) phthalate, were positively associated with androgen, estrogen, hormone ratios, inducible nitric oxide synthetase (iNOS), 8-hydroxy-2'-deoxyguanosine (8-OHdG), prostate specific antigen (PSA), and prostate volume (PV) (p < 0.05). PV and PSA were positively associated with androgen, estrogen, hormone ratios and OS markers (p < 0.05). The estimated percentages of exposure to phthalates in prostatic enlargement mediated by androgen, estrogen, and OS markers ranged from 3.5% to 63.1%. Exposure to DEHP promoted the progress of BPH by increasing dihydrotestosterone (DHT), estradiol (E₂), the converted enzymes aromatase and 5α reductase, and reactive oxygen species (ROS) (8-OHdG and iNOS) production. Sex hormones and OS might be important hyperplasia-promoters after a patient has been exposed to phthalates, especially to DEHP.

Effects of perinatal di (2-ethylhexyl) phthalate exposure on thyroid function in rat offspring

Di (2-ethylhexyl) phthalate (DEHP) is a commonly used plasticizer in industry and displays the characteristics of an endocrine disruptor. Disorders of the maternal thyroid hormone (TH) during pregnancy can cause adverse effects on the fetus. We investigated the effects and possible mechanism of perinatal DEHP exposure on the thyroid function of pups. Pregnant female Wistar rats were randomly divided into four groups and received doses of DEHP of 0, 30, 300, 750 mg/kg/day by gavage at from gestational day (GD) 0 to postnatal day (PN) 21. The concentration of serum THs and the ultrastructure of thyroid follicular cells in the offspring were examined. Related protein level and gene expression of thyroid proteins in pups were analyzed by western blotting and real-time PCR. We found that DEHP significantly reduced total thyroxine (TT₄) and increased thyroid stimulating hormone (TSH) in pups, while total triiodothyronine (TT₃) showed no change. Thyroid follicular cells ultrastructure was damaged in DEHP exposed pups as viewed by electron microscopy. Furthermore, exposure to DEHP significantly increased protein and mRNA levels of thyroid transcription factor 1 (TTF-1), paired box 8 (PAX8), sodium iodide symporter (NIS) and thyroid peroxidase (TPO) in pups. In addition, levels of deiodinases of pups were also affected. These findings indicated that DEHP can disrupt thyroid function by damaging thyroid follicles and affecting TTF-1, PAX8, NIS, TPO and the deiodinase protein family.

Androgenic/antiandrogenic activities of PAEs determined by a novel AR-mediated reporter gene assay based on LLC-MK2 cells

Recent reports have concentrated on some androgens/antiandrogens and confirmed that certain chemicals have demonstrated androgenic/antiandrogenic activities in vitro. However, it is still unknown whether more chemicals in the human environment possess endocrine toxicity. 58A novel AR-mediated reporter gene assay based on LLC-MK2 cells was established by transiently co-transfecting with pARE-sv40-Luc, hAR-pcDNA3.1 and pRL-tk. pARE-sv40-Luc was constructed using a pGL3-promoter plasmid with three repeated androgen responsive elements. hAR-pcDNA3.1 was constructed using pcDNA3.1 with a hAR sequence. After transfection for 12 h, the culture medium was exposed to various concentrations of dihydrotestosterone (DHT) and other test chemicals (phthalic acid esters and dexamethasone) in order to measure the androgenic/antiandrogenic activity. The assay possessed a concentration-dependent response to DHT from 10^-12 M to 10^-6 M. Nilutamide concentrations of over 10^-7 M completely blocked the luciferase expression induced by 10^-9 M DHT. Other data showed that DBP, DEHP and MEHP possessed weak androgenic activity for certain concentration ranges, while DMP, DINP and DIBP did not show any androgenic activity. Moreover, five PAEs (DBP, DEHP, DINP, DIBP and MEHP) showed corresponding antiandrogenic activities for certain concentrations with an approximate tendency (MEHP > DBP > DEHP > DIBP > DINP). The assay is high-throughput, specific, and sensitive for the detection of androgenic/antiandrogenic chemicals. In addition, PAEs (especially transitional PAEs) exhibited corresponding androgenic/antiandrogenic activities for certain concentration ranges.

Lactobacillus plantarum TW1-1 Alleviates Diethylhexylphthalate-Induced Testicular Damage in Mice by Modulating Gut Microbiota and Decreasing Inflammation

Diethylhexylphthalate (DEHP), acting as an endocrine disruptor, disturbed reproductive health. Here, we evaluated the effects of Lactobacillus plantarum TW1-1 (L. plantarum TW1-1) on DEHP-induced testicular damage in adult male mice. Results showed that oral supplementation of L. plantarum TW1-1 significantly increased the serum testosterone concentration, enhanced the semen quality, and attenuated gonad development defects in DEHP-exposed mice. L. plantarum TW1-1 also alleviated DEHP-induced oxidative stress and inflammatory responses by decreasing the mRNA expression and serum protein concentration of different inflammatory factors [tumor necrosis factor-α, interleukin (IL)-1β and IL-6]. Furthermore, L. plantarum TW1-1 significantly reduced DEHP-induced intestinal hyper-permeability and the increase in the serum lipopolysaccharide level. Gut microbiota diversity analysis revealed that L. plantarum TW1-1 shifted the DEHP-disrupted gut microbiota to that of the control mice. At phylum level, L. plantarum TW1-1 reversed DEHP-induced Bacteroidetes increase and Firmicutes decrease, and restored Deferribacteres in DEHP-exposed mice. Spearman's correlation analysis showed that Bacteroidetes, Deferribacteres, and Firmicutes were associated with DEHP-induced testicular damage. In addition, the ratio of Firmicutes to Bacteroidetes (Firm/Bac ratio) significantly decreased from 0.28 (control group) to 0.13 (DEHP-exposed group), which was restored by L. plantarum TW1-1 treatment. Correlation analysis showed that the Firm/Bac ratio was negatively correlated with testicular damage and inflammation. These findings suggest that L. plantarum TW1-1 prevents DEHP-induced testicular damage via modulating gut microbiota and decreasing inflammation.

Role of autophagy in di-2-ethylhexyl phthalate (DEHP)-induced apoptosis in mouse Leydig cells

Di-2-ethylhexyl phthalate (DEHP) has been widely used as a plasticizer in industry. DEHP can cause testicular atrophy, yet the exact mechanism remains unclear. In this study, male mice were intragastrically (i.g.) administered with 0, 100, 200 or 400 mg DEHP/kg/day for 21 days. We found that DEHP caused disintegration of the germinal epithelium and decreased sperm density in the epididymis. Furthermore, there was a significant increase in the levels of cleaved Caspase-8, cleaved Caspase-3 and Bax proteins and a decrease in Bcl2 protein. The results indicated that DEHP could induce apoptosis of the testis tissue. Meanwhile, DEHP significantly induced autophagy in the testis tissues with increases in LC3-II, Atg5 and Beclin-1 proteins. The serum testosterone concentration decreased in the DEHP-treated group, implying that DEHP might lead to Leydig cell damage. Furthermore, oxidative stress was induced by DEHP in the testis. To further investigate the potential mechanism, mouse TM3 Leydig cells were treated with 0-80 μM DEHP for 48 h. DEHP significantly inhibited cell viability and induced cell apoptosis. Oxidative stress was involved in DEHP-induced apoptosis as N-Acetyl-L-cysteine (NAC), an inhibitor of oxidative stress, could rescue the inhibition of cell viability and induction of apoptosis by DEHP. Similar to the in vivo findings, DEHP could also induce cell autophagy. However, inhibition of autophagy by 3-Methyladenine (3-MA) significantly increased cell viability and inhibited apoptosis. Taken together, oxidative stress was involved in DEHP-induced apoptosis and autophagy of mouse TM3 Leydig cells, and autophagy might play a cytotoxic role in DEHP-induced cell apoptosis.

Involvement of oxidative stress in di-2-ethylhexyl phthalate (DEHP)-induced apoptosis of mouse NE-4C neural stem cells

Di-2-ethylhexyl phthalate (DEHP) has been widely used as a plasticizer in industry and can cause neurotoxicity; however, the underlying mechanism remains unclear. In the study, we found that DEHP significantly inhibited viability of mouse NE-4C neural stem cells and caused lactate dehydrogenase (LDH) release from the cells. DEHP dramatically increased the levels of apoptosis-related proteins such as cleaved Caspase-8, cleaved Caspase-3 and Bax, as well as decreased Bcl-2 protein level. DEHP could also significantly increase the total numbers of AnnexinV-positive/PI-negative and AnnexinV-positive/PI-positive staining cells. Hoechst 33342 staining showed that marked DNA condensation and apoptotic bodies could be found in the ZnO NPs-treated cells. These results indicated that DEHP could induce apoptosis of NE-4C cells. Meanwhile, DEHP could significantly increase malondialdehyde (MDA) level, and decrease the content of glutathione (GSH) and activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX), respectively, implying that DEHP could induce oxidative stress of NE-4C cells. Furthermore, N-Acetyl-l-cysteine (NAC), an inhibitor of oxidative stress, could rescue the inhibition of cell viability and induction of apoptosis by DEHP. Taken together, our results showed that oxidative stress was involved in DEHP-induced apoptosis of mouse NE-4C cells.

Nesfatin-1 ameliorates testicular injury and supports gonadal function in rats induced with testis torsion

Testicular torsion causes ischemia-reperfusion injury and an increased risk of infertility. Nesfatin-1 is a novel peptide with antioxidant, anti-inflammatory and anti-apoptotic properties. In the present study, we aimed to investigate the putative beneficial effects of nesfatin-1 on oxidative injury and impaired testicular function induced by testis torsion. Under anesthesia, male Sprague-Dawley rats (180-230 g; n = 24) had sham-operation or they underwent testicular torsion by rotating the left testis 720° and fixing it for 2 h, followed by a 2-h detorsion. Rats in each group were treated intraperitoneally with either nesfatin-1 (0.3 μg/kg) or saline prior to the torsion or sham-torsion. At the end of the 4-h experimental period, tissue samples were removed for evaluation of spermatozoa, molecular and histochemical analyses. In saline-treated torsion/detorsion group, a high percentage of abnormal spermatozoa with head defects was observed, which was abolished in nesfatin-1-treated torsion/detorsion group. The levels of 8-OHdG, tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, caspase-3 were increased in the saline-treated torsion/detorsion group as compared to sham-operated group, while nesfatin-1 pre-treatment significantly decreased the expressions of the pro-inflammatory cytokines, depressed apoptosis, and also reduced the tubular degeneration. In addition, nesfatin-1 in torsion/detorsion group elevated expressions of transforming growth factor (TGF)-beta and reduced expressions of protein kinase B (AKT) and cAMP response element binding protein (CREB) in the testis tissue. The present findings show that nesfatin-1, by regulating AKT and CREB signaling pathways and pro-inflammatory/anti-inflammatory cytokine balance, preserves the spermatogenic cells and ameliorates torsion-detorsion-induced tubular degeneration.

Oxidative stress burden inhibits spermatogenesis in adult male rats: testosterone protective effect

In this study, we aimed to investigate the protective effects of androgens, using letrozole (LET; an aromatase inhibitor), grape seed extract (GSE; a naturally occurring aromatase inhibitor and antioxidant), and testosterone propionate (Tp), against methotrexate (MTX)-induced testicular toxicity in adult male rats. MTX has been shown to induce oxidative stress and exhibit antiproliferative effects in the testes. Adult male rats received oral saline gavage (control group with no treatment), the potential protective agents (LET, GSE, or Tp) alone, MTX alone, or a combination of one of the potential protective agents and MTX. The testicular levels of oxidative stress markers and cytokines (tumor necrosis factor-α and interleukin-1β) were measured. Spermatogenesis and sperm viability were microscopically evaluated. Administration of LET and GSE 7 days before MTX improved spermatogenesis and sperm viability, as well as reduced the levels of oxidative stress markers and cellular cytokines. Exogenous testosterone exhibited anti-inflammatory and antioxidant activities, similar to GSE and LET. We also showed that enhancing the endogenous androgenic activity by LET and GSE protected spermatogenesis against MTX-induced testicular toxicity via reduction of inflammation and oxidative stress in the testes. Our data suggest that testosterone protected spermatogenesis owing to its antioxidant and anti-inflammatory properties.

The effects of di-2-ethylhexyl phthalate on testicular ultrastructure and hormone-regulated gene expression in male rats

The objective of this study is to determine testicular pathological damage and explore its molecular mechanisms after di-2-ethylhexyl phthalate (DEHP) treatment. A total of 40 healthy 5-week-old male Sprague-Dawley rats were randomly divided into four groups, which received intragastric administration of 0 mg kg^-1, 100 mg kg^-1, 500 mg kg^-1 and 1500 mg kg^-1 DEHP for six continuous weeks. After DEHP treatment, the testes wet weight and testes coefficient were calculated, the histopathological changes of the testes were examined by HE staining and the testicular ultrastructure was examined by transmission electron microscopy. The gene expression levels were analyzed by quantitative RT-PCR and the protein expression levels were analyzed by western blotting. Both 500 mg kg^-1 and 1500 mg kg^-1 DEPH treatments decreased the wet weight of the testes and testes coefficient, due to vacuoles in Sertoli cells, broken mitochondrial ridges, and degranulation. Quantitative RT-PCR showed that the relative gene expression levels of steroidogenic acute regulatory protein (StAR) and 3β-hydroxysteroid dehydrogenase (3β-HSD) increased in the 100 mg kg^-1, 500 mg kg^-1, and 1500 mg kg^-1 DEHP groups, respectively. Additionally, 17β-hydroxysteroid dehydrogenase (17β-HSD) expression levels were increased in the 1500 mg kg^-1 DEHP treatment group. Gonadotropin-releasing hormone (GnRH) expression levels were decreased with 500 mg kg^-1 and 1500 mg kg^-1 DEHP treatments. DEHP induced serious pathological damage and ultrastructure changes in rat testes, caused endocrine disorders, interfered with the synthesis of male hormones, and ultimately led to male reproductive system dysfunction.

Toxicity effects of di-(2-ethylhexyl) phthalate to Eisenia fetida at enzyme, cellular and genetic levels

Di-(2-ethylhexyl) phthalate (DEHP) is a dominant phthalic acid ester (PAE) that has aroused public concern due to its resistance to degradation and its toxicity as an endocrine-disrupting compound. Effects of different concentrations of DEHP on Eisenia fetida in spiked natural soil have been studied in the body of the earthworm by means of soil cultivation tests 7, 14, 21 and 28 days after exposure. The results indicated that, in general, superoxide dismutase (SOD) activity, malondialdehyde (MDA) content, metallothionein (MT) content, the expression of heat shock protein 70 (HSP 70) and all the tested geno-toxicity parameters are promoted as time elapses and with increasing concentration of DEHP. However, peroxidase (POD) activity, neutral red retention time (NRRT) and mitochondrial membrane potential difference values were found to decrease even at a low concentration of DEHP of 1 mg kg^-1 soil (p<0.05). Clear toxic effects of DEHP on E. fetida have been generally recognized by means of the disturbance of antioxidant enzyme activity/content and critical proteins, cell membrane and organelle disorder and DNA damage estimated by length of tail, tail DNA ratio, and tail moment parameters. A concentration of DEHP of 3 mg kg^-1 may be recommended as a precaution against the potential risk of PAEs in soils and for indicating suitable threshold values for other soil animals and soil micro-organisms.