Fetal adrenal development: Comparing effects of combined exposures to PCB 118 and PCB 153 in a sheep model

This study investigated the effects of exposure to the ubiquitous contaminants polychlorinated biphenyls (PCBs) on the fetal adrenal cortex and on plasma cortisol using the domestic sheep (Ovis aries) as a model. Pregnant ewes were intendedly subjected to oral treatment with PCB 153 (98 μg/kg bw/day), PCB 118 (49 μg/kg bw/day) or the vehicle corn oil from mating until euthanasia on gestation day 134 (±0.25 SE). However, because of accidental cross‐contamination occurring twice causing a mixed exposure scenario in all three groups, the focus of this paper is to compare three distinct groups of fetuses with different adipose tissue PCB levels (PCB 153high, PCB 118high and low, combined groups) rather than comparing animals exposed to single PCB congeners to those of a control group. When comparing endocrine and anatomical parameters from fetuses in the PCB 153high (n = 13) or PCB 118high (n = 14) groups with the low, combined group (n = 14), there was a significant decrease in fetal body weight (P < 0.05), plasma cortisol concentration (P < 0.001) and adrenal cortex thickness (P < 0.001). Furthermore, adrenal weight was decreased and plasma ACTH was increased only in the PCB 118high group. Expression of several genes encoding enzymes and receptors related to steroid hormone synthesis was also affected and mostly down‐regulated in fetuses with high PCB tissue levels. In conclusion, we suggest that mono‐and di‐ortho PCBs were able to interfere with growth, adrenal development and cortisol production in the fetal sheep model. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2013.     

Acute alteration of cardiac ECG, action potential, I(Kr) and the human ether-a-go-go-related gene (hERG) K+ channel by PCB 126 and PCB 77

Polychlorinated biphenyls (PCBs) have been known as serious persistent organic pollutants (POPs), causing developmental delays and motor dysfunction. We have investigated the effects of two PCB congeners, 3,3′,4,4′-tetrachlorobiphenyl (PCB 77) and 3,3′,4,4′,5-pentachlorobiphenyl (PCB 126) on ECG, action potential, and the rapidly activating delayed rectifier K⁺ current (I_Kr) of guinea pigs' hearts, and hERG K⁺ current expressed in Xenopus oocytes. PCB 126 shortened the corrected QT interval (QTc) of ECG and decreased the action potential duration at 90% (APD₉₀), and 50% of repolarization (APD₅₀) (P < 0.05) without changing the action potential duration at 20% (APD₂₀). PCB 77 decreased APD₂₀ (P < 0.05) without affecting QTc, APD₉₀, and APD₅₀. The PCB 126 increased the I_Kr in guinea-pig ventricular myocytes held at 36 °C and hERG K⁺ current amplitude at the end of the voltage steps in voltage-dependent mode (P < 0.05); however, PCB 77 did not change the hERG K⁺ current amplitude. The PCB 77 increased the diastolic Ca²⁺ and decreased Ca²⁺ transient amplitude (P < 0.05), however PCB 126 did not change. The results suggest that PCB 126 shortened the QTc and decreased the APD₉₀ possibly by increasing I_Kr, while PCB 77 decreased the APD₂₀ possibly by other modulation related with intracellular Ca²⁺. The present data indicate that the environmental toxicants, PCBs, can acutely affect cardiac electrophysiology including ECG, action potential, intracellular Ca²⁺, and channel activity, resulting in toxic effects on the cardiac function in view of the possible accumulation of the PCBs in human body.     

Development of TEFs for PCB congeners by using an alternative biomarker — Thyroid hormone levels

Polychlorinated biphenyls (PCBs) are ubiquitous toxic contaminants. Health risk assessment for this class of chemicals is complex: the current toxic equivalency factor (TEF) method covers dioxin-like (DL-) PCBs, dibenzofurans, and dioxins, but excludes non-DL-PCBs. To address this deficiency, we evaluated published data for several PCB congeners to determine common biomarkers of effect. We found that the most sensitive biomarkers for DL-non-ortho-PCB 77 and PCB 126 are liver enzyme (e.g., ethoxyresorufin-O-deethylase, EROD) induction, circulating thyroxine (T4) decrease, and brain dopamine (DA) elevation. For DL-ortho-PCB 118 and non-DL-ortho-PCB 28 and PCB 153, the most sensitive biomarkers are brain DA decrease and circulating T4 decrease. The only consistent biomarker for both DL- and non-DL-PCBs is circulating T4 decrease. The calculated TEF-_TH, based on the effective dose to decrease T4 by 30% (ED₃₀) with reference to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), is identical to both TEF-_WHO98 and TEF-_WHO05 for TCDD and DL-PCBs (correlation coefficients are r = 1.00, P < 0.001; and r = 0.99, P < 0.001, respectively). We conclude that T4 decrease is a prospective biomarker for generating a new TEF scheme which includes some non-DL-congeners. The new TEF-_TH parallels the TEF-_WHO for DL-PCBs and, most importantly, is useful for non-DL-PCBs in risk assessment to address thyroid endocrine disruption and potentially the neurotoxic effects of PCBs.     

Influence of PCB153 on Oxidative DNA Damage and DNA Repair-Related Gene Expression Induced by PBDE-47 in Human Neuroblastoma Cells In Vitro

We studied the relationship between 2,2,4,4-tetrabromodiphenylether (PBDE-47) and oxidative DNA damage as well as the modeof interaction between PBDE-47 and 2,2,4,4,5,5-hexachlorobiphenyl(PCB153) by incubating SH-SY5Y cells in four doses of PBDE-47(0, 1, 5, 10µM) and/or 5µM PCB153 and 100µMNAC (N-acetylcysteine) for 24 h. Results showed that reactiveoxygen species (ROS) production in the 5µM PBDE-47 + PCB153and 10µM PBDE-47 + PCB153 groups were significantly higherthan that of the control group (p < 0.05). DNA strand breakageand 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels were significantlyincreased in the 10µM PBDE-47, 5µM PBDE-47 + PCB153,and 10µM PBDE-47 + PCB153 groups compared with the control(p < 0.05). Furthermore, ROS formation and DNA strand breakagewere dramatically increased in the 5µM PBDE-47 + PCB153and 10µM PBDE-47 + PCB153 groups compared with the correspondingPBDE-47 only group and the PCB153 group (p< 0.05). The levelof 8-OHdG was significantly increased in the 10µM PBDE-47+ PCB153 group compared with the corresponding PBDE-47 onlygroup and the PCB153 group (p < 0.05). The PBDE-47 groupcoincubated with NAC decreased the ROS level and amelioratedPBDE-47–mediated DNA damage. The mRNA expression levelsof X-ray repair cross-complementing gene 1 (Xrcc1) were significantlydecreased in the 10µM PBDE-47, 5µM PBDE-47 + PCB153,and 10µM PBDE-47 + PCB153 groups, whereas X-ray repaircross-complementing gene 3 (Xrcc3) were significantly increasedin the 10µM PBDE-47 and 10µM PBDE-47 + PCB153 groupscompared with the control (p < 0.05). The PBDE-47 groupscoincubated with NAC, however, considerably increased Xrcc1while decreasing Xrcc3 mRNA expression (p < 0.05). Theseresults indicate that PBDE-47 induced oxidative DNA damage andthat PBDE-47 combined with PCB153 may increase such effectsin SH-SY5Y cells in vitro. Furthermore, our results suggestthat oxidative stress is responsible for DNA damage inducedby PBDE-47.     

Involvement of prostaglandin F2α in the adverse effect of PCB 77 on the force of contractions of bovine myometrium

Polychlorinated biphenyls (PCBs) stimulate in vitro both the force of myometrial contractions and endometrial secretion of PGF2α in cattle. Therefore, the goal of this study was to investigate the participation of PGF2α in the effect of PCBs on uterine contractility. For this aim, the myometrial strips were incubated (48 h) with PCB 77 at the dose of 1, 10 and 100 ng/ml (i.e., 0.0034, 0.034 and 0.34 nmol/ml) separately or jointly with indomethacin (INDO, 10⁻⁴ M), which blocks the PGF2α synthesis. Next, the force of myometrial strips contractions was measured. Further, the influence of PCB 77 (0.1, 1 and 10 ng/ml) on the PGF2α secretion from myometrial cells after 6, 24, and 48 h and PCB 77 (1 and 10 ng/ml) on the mRNA expression of cyclooxygenase 2 (COX-2) and PGF2α synthase (PGFS) in myometrial cells after 6 and 24 h, was investigated. The increase (P < 0.05–0.001) of the contractions force of myometrial strips evoked by each dose of PCB 77, was markedly reduced (P < 0.05–001) by INDO. There was an increase (P < 0.05–0.001) of both PGF2α secretion after all studied periods of cell incubation and mRNA expression for COX-2 and PGFS after 6 h treatment of myometrial cells with PCB 77. It can be concluded that myometrial synthesis of PGF2α and its further secretion is a part of the mechanism by means of which PCB 77 may affect the force of myometrial contractions in cattle.     

PCB153-elicited hepatic responses in the immature, ovariectomized C57BL/6 mice: Comparative toxicogenomic effects of dioxin and non-dioxin-like ligands

Polychlorinated biphenyls (PCBs) are ubiquitous contaminants found as complex mixtures of coplanar and non-coplanar congeners. The hepatic temporal and dose-dependent effects of the most abundant non-dioxin-like congener, 2,2′,4,4′,5,5′-hexachlorobiphenyl (PCB153), were examined in immature, ovariectomized C57BL/6 mice, and compared to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), the prototypical aryl hydrocarbon receptor (AhR) ligand. Animals were gavaged once with 300 mg/kg PCB153 or sesame oil vehicle and sacrificed 4, 12, 24, 72 or 168 h post dose. In the dose-response study, mice were gavaged with 1, 3, 10, 30, 100 or 300 mg/kg PCB153 or sesame oil for 24 h. Significant increases in relative liver weights were induced with 300 mg/kg PCB153 between 24 and 168 h, accompanied by slight vacuolization and hepatocellular hypertrophy. The hepatic differential expression of 186 and 177 genes was detected using Agilent 4 × 44 K microarrays in the time course (|fold change| ≥ 1.5, P1(t) ≥ 0.999) and dose-response (|fold change| ≥ 1.5, P1(t) ≥ 0.985) studies, respectively. Comparative analysis with TCDD suggests that the differential gene expression elicited by PCB153 was not mediated by the AhR. Furthermore, constitutive androstane and pregnane X receptor (CAR/PXR) regulated genes including Cyp2b10, Cyp3a11, Ces2, Insig2 and Abcc3 were dose-dependently induced by PCB153. Collectively, these results suggest that the hepatocellular effects elicited by PCB153 are qualitatively and quantitatively different from TCDD and suggestive of CAR/PXR regulation.     

Study on PCB 101, PCB 153, mercury and methyl mercury content in blue crab Portunus Pelagicus from Khuzestan shore (Persian Gulf)

Distribution of polychlorinated biphenyl (PCB 101, PCB 153), Mercury (Hg) and methyl mercury (MMHg) in muscle, gill and hepatopancreas of blue swimming crab Portunus segnis from Persian Gulf were investigated. In addition, the relationships between crab size (carapace width) and PCBs, Hg, MMHg levels in tissues were investigated by linear regression analysis. There were significant differences in crab PCB 101, PCB 153, Hg and MMHg concentrations were detected between different tissues (ANOVA, P<0.05). The pollutants concentrations were highest in hepatopancreas whereas lowest in the muscle of all crab species. The recorded mean concentrations were 0.485 μg g^?1 PCB 101, 1.89 μg g^?1 PCB 0.463, 0.815 μg g^?1 Hg and 0.471 μg g^?1 MMHg. The results showed that significant relationships between PCB and Hg-MMHg levels and crab size were positive. Comparison between male and female indicated that the average PCBs and Hg-MMHg concentrations in tissues of male crab were found to be significantly higher than those found in the female crab.     

In Utero Exposure to Environmentally Relevant Concentrations of PCB 153 and PCB 118 Disrupts Fetal Testis Development in Sheep

Polychlorinated biphenyls (PCB) are environmental pollutants linked to adverse health effects including endocrine disruption and disturbance of reproductive development. This study aimed to determine whether exposure of pregnant sheep to three different mixtures of PCB 153 and PCB 118 affected fetal testis development. Ewes were treated by oral gavage from mating until euthanasia (d 134), producing three groups of fetuses with distinct adipose tissue PCB levels: high PCB 153/low PCB 118 (n = 13), high PCB 118/low PCB 153 (n = 14), and low PCB 153/low PCB 118 (n = 14). Fetal testes and blood samples were collected for investigation of testosterone, testis morphology, and testis proteome. The body weight of the offspring was lower in the high PCB compared to the low PCB group, but there were no significant differences in testis weight between groups when corrected for body weight. PCB exposure did not markedly affect circulating testosterone. There were no significant differences between groups in number of seminiferous tubules, Sertoli cell only tubules, and ratio between relative areas of seminiferous tubules and interstitium. Two-dimensional (2D) gel-based proteomics was used to screen for proteomic alterations in the high exposed groups relative to low PCB 153/low PCB 118 group. Twenty-six significantly altered spots were identified by liquid chromatography (LC)–mass spectroscopy (MS)/MS. Changes in protein regulation affected cellular processes as stress response, protein synthesis, and cytoskeleton regulation. The study demonstrates that in utero exposure to different environmental relevant PCB mixtures exerted subtle effects on developing fetal testis proteome but did not significantly disturb testis morphology and testosterone production.     

Non-additive hepatic gene expression elicited by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and 2,2',4,4',5,5'-hexachlorobiphenyl (PCB153) co-treatment in C57BL/6 mice

Interactions between environmental contaminants can lead to non-additive effects that may affect the toxicity and risk assessment of a mixture. Comprehensive time course and dose-response studies with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), non-dioxin-like 2,2′,4,4′,5,5′-hexachlorobiphenyl (PCB153) and their mixture were performed in immature, ovariectomized C57BL/6 mice. Mice were gavaged once with 30 μg/kg TCDD, 300 mg/kg PCB153, a mixture of 30 μg/kg TCDD with 300 mg/kg PCB153 (MIX) or sesame oil vehicle for 4,12, 24,72 or 168 h. In the 24 h dose-response study, animals were gavaged with TCDD (0.3,1, 3, 6, 10, 15, 30, 45 μg/kg), PCB153 (3,10, 30, 60, 100, 150, 300, 450 mg/kg), MIX (0.3 + 3, 1 + 10, 3 + 30, 6 + 60, 10 + 100, 15 + 150, 30 + 300, 45 μg/kg TCDD + 450 mg/kg PCB153, respectively) or vehicle. All three treatments significantly increased relative liver weights (RLW), with MIX eliciting significantly greater increases compared to TCDD and PCB153 alone. Histologically, MIX induced hepatocellular hypertrophy, vacuolization, inflammation, hyperplasia and necrosis, a combination of TCDD and PCB153 responses. Complementary lipid analyses identified significant increases in hepatic triglycerides in MIX and TCDD samples, while PCB153 had no effect on lipids. Hepatic PCB153 levels were also significantly increased with TCDD co-treatment. Microarray analysis identified 167 TCDD, 185 PCB153 and 388 MIX unique differentially expressed genes. Statistical modeling of quantitative real-time PCR analysis of Pla2g12a, Serpinb6a, Nqo1, Srxn1, and Dysf verified non-additive expression following MIX treatment compared to TCDD and PCB153 alone. In summary, TCDD and PCB153 co-treatment elicited specific non-additive gene expression effects that are consistent with RLW increases, histopathology, and hepatic lipid accumulation.     

Various effects of antidepressant drugs on bone microarchitectecture, mechanical properties and bone remodeling

The aim of this study was to evaluate the effects of various drugs which present antidepressant properties: selective serotonin-reuptake inhibitors (SSRIs, fluoxetine), serotonin and noradrenaline-reuptake inhibitors (Desipramine) and phosphodiesterase inhibitors (PDE, rolipram and tofisopam) on bone microarchitecture and biomechanical properties.Twelve female mice were studied per group starting at an age of 10 weeks. During 4 weeks, they received subcutaneously either placebo or 20 mg kg^− 1 day^− 1 of desipramine, fluoxetine or 10 mg kg^− 1 day^− 1 of rolipram or tofisopam. Serum Osteocalcin and CTx were evaluated by ELISA. Bone microarchitecture of the distal femur was characterized by X-ray microCT (Skyscan1072). Mechanical properties were assessed by three-point bending test (Instron 4501) and antidepressant efficacy by forced swimming and open field tests.Fluoxetine displayed lower TbTh (− 6.1%, p < 0.01) and tofisopam higher TbTh (+ 5.0%, p < 0.05) versus placebo. Rolipram and tofisopam treatments induced higher BV/TV than placebo (+ 23.8% and + 18.3% respectively). Desipramine group had significantly higher cortical area (+ 4.8%, p < 0.01) and fluoxetine lower cortical area (− 6.1%, p < 0.01) compared to placebo. The stiffness and Young's modulus were lower in the fluoxetine group (77 ± 13 N mm^− 1, 6431 ± 1182 MPa) than in placebo (101 ± 9 N mm^− 1, 8441 ± 1180 MPa). Bone markers indicated a significantly higher bone formation in tofisopam (+ 8.6%) and a lower in fluoxetine (− 56.1%) compared to placebo.These data suggest deleterious effects for SSRIs, both on trabecular and cortical bone and a positive effect of PDE inhibitors on trabecular bone. Furthermore tofisopam anabolic effect in terms of bone markers, suggests a potential therapeutic effect of the PDE inhibitors on bone.     

Evaluation of the direct systemic and cardiopulmonary effects of diesel particles in spontaneously hypertensive rats

Recent data suggest that ultrafine pollutant particles (diameter <0.1 μm) may pass from the lung into the systemic circulation. However, the systemic and cardiorespiratory effects of translocated particles are not well known. In this study, we determined the direct acute (24 h) effect of the systemic administration of 0.01 mg/kg and 0.02 mg/kg diesel exhaust particles (DEP) on systolic blood pressure, heart rate, and both systemic and pulmonary inflammation in spontaneously hypertensive rats (SHR). Compared to the blood pressure in control group, rats exposed to DEP exhibited a dose-dependent increase in systolic blood pressure, at 0.01 mg/kg (P < 0.05) and 0.02 mg/kg (P < 0.01). Likewise, the heart rate was also dose-dependently increased at 0.01 mg/kg (P:NS) and 0.02 mg/kg (P < 0.01) compared to control SHR. DEP exposure (0.02 mg/kg) significantly elevated the number of leukocytes in blood (P < 0.05), interleukin-6 (IL-6, P < 0.005), tumor necrosis factor alpha (P < 0.05) and leukotriene B4 (LTB4, P < 0.005) concentrations in plasma. Moreover, in SHR given 0.02 mg/kg, the number of platelet was significantly reduced (P < 0.05), whereas the tail bleeding time was prolonged (P < 0.05). Pulmonary inflammations were confirmed by the presence of a significant increase in the number of macrophages (0.02 mg/kg) and neutrophils (0.01 and 0.02 mg/kg) and protein contents (0.02 mg/kg) in bronchoalveolar lavage (BAL) compared to saline-treated SHR. Also, IL-6 (0.01 mg/kg; P < 0.05 and 0.02 mg/kg; P < 0.01), LTB4 (0.02 mg/kg; P < 0.05) concentrations in BAL and the superoxide dismutase activity (0.02 mg/kg; P = 0.01) were significantly elevated compared to control group. We conclude that, in SHR, the presence of DEP in the systemic circulation leads not only to cardiac and systemic changes, but also triggers pulmonary inflammatory reaction involving IL-6, LTB4 and oxidative stress.     

Avian liver organochlorine and PCB from South coast of the Caspian Sea,Iran

Liver samples (n = 43) of 9 avian species representing the families Phalacrocoracidae, Podicipedidae, Laridae, and Anatidae, were collected from the Iranian coast of the Caspian Sea. Samples were analyzed for organochlorine pesticides (OCPs), such as dichlorodiphenyltrichloroethane (DDT) and its metabolites, hexachlorobenzene (HCB), hexachlorocyclohexane isomers (HCHs), and seven PCB congeners. p,p′-DDE was predominantly found in all species, at concentrations ranging from the limit of quantification (LOQ) to 340 ng/g ww. Most frequently encountered PCB congeners, in all samples, were 118, 153 and 138; and birds in Phalacrocoracidae had the highest liver PCB (mean 90 ± 32; ranging from <LOQ to 106 ng/g ww) whereas Podicipedidae had the highest OCP (mean 147 ± 49; ranging from <LOQ to 340 ng/g ww) (P < 0.05). Differences in the diet, and migratory routes, were important species-specific factors that affected hepatic concentration of OCP and PCB in the species we studied. Range of OCP and PCB concentrations in the present study was lower than those reported for birds in other regions of the world. Hepatic PCB concentration found in our avian species was below toxic effect levels that have been previously reported in birds. To our knowledge this is the first report of persistent organochlorine pollutants in liver of birds from Iran.     

Ameliorative effects of SLC22A2 gene polymorphism 808 G/T and cimetidine on cisplatin-induced nephrotoxicity in Chinese cancer patients

To investigate the roles of SLC22A2 gene polymorphism 808 G/T and cimetidine on cisplatin-induced nephrotoxicity, a total of 123 Chinese cancer patients treated with cisplatin alone (n = 55) or in combination with cimetidine (n = 68) were genotyped. The changes of serum creatinine (SCr), blood urea nitrogen (BUN) and cystatin C levels were used as biomarkers for the evaluation of cisplatin-induced nephrotoxicity. The changes of BUN and SCr levels showed no significant difference between groups divided by genotypes and treatments (P > 0.05). However, patients with mutant genotype (GT/TT) or with cimetidine treatment had smaller increase of the cystatin C levels compared to those with wild genotype (GG) or without cimetidine treatment (P < 0.05). In the non-cimetidine-treated group, the changes of cystatin C level in patients with mutant genotype (GT/TT) was significantly smaller than those with wild genotype (GG) (P = 0.043). In the wild type group, the cystatin C level change of patients without cimetidine treatment was significantly larger than those with cimetidine treatment (P = 0.007). These results suggested that SLC22A2 gene polymorphism 808 G/T and cimetidine could attenuate cisplatin nephrotoxicity in Chinese cancer patients. But the renoprotection mechanism of cimetidine might be damaged by the mutation.     

Anti-glycative and anti-inflammatory effects of protocatechuic acid in brain of mice treated by d-galactose

Protocatechuic acid (PCA) at 0.5%, 1% or 2% was supplied to d-galactose (DG) treated mice for 8 week. PCA intake at 2% increased its deposit in brain. DG treatment increased brain level of reactive oxygen species, protein carbonyl, carboxymethyllysine, pentosidine, sorbitol, fructose and methylglyoxal (P < 0.05). PCA intake, at 1% and 2%, lowered brain level of these parameters (P < 0.05). DG treatments enhanced activity and protein expression of aldose reductase (AR) and sorbitol dehydrogenase, as well as declined glyoxalase I (GLI) activity and protein expression (P < 0.05). PCA intake at 1% and 2% reduced activity and protein expression of AR (P < 0.05), and at 2% restored GLI activity and expression (P < 0.05). DG injection also elevated cyclooxygenase (COX)-2 activity and expression, and increased the release of interleukin (IL)-1beta, IL-6, tumor necrosis factor-alpha and prostaglandin E₂ in brain (P < 0.05). PCA intake decreased these cytokines (P < 0.05), and at 1% and 2% suppressed COX-2 activity and expression (P < 0.05). PCA intake at 1% and 2% also lowered DG-induced elevation in activity, mRNA expression and protein production of nuclear factor kappa B p65 (P < 0.05). These findings suggest that the supplement of protocatechuic acid might be helpful for the prevention or alleviation of aging.     

Fucoidan, a sulfated polysaccharide from brown algae, against myocardial ischemia-reperfusion injury in rats via regulating the inflammation response

The aim of the study was to determine the effects of fucoidan on rat myocardial ischemia-reperfusion (I/R) model and elucidate the potential mechanisms. Myocardial I/R injury was induced by the occlusion of left anterior descending coronary artery for 30 min followed by reperfusion for 2 h. After 2 h reperfusion, hemodynamics parameters were detected. Blood samples were collected to determine serum levels of tumor necrosis factor-α (TNF-α) and interleukin 6, 10 (IL-6, 10). Hearts were harvested to assess histopathological changes, infarct size (IS), and the content of myeloperoxidase (MPO). The expression of high-mobility group box 1 (HMGB1), phosphor-IκB-α and phosphor-nuclear factor kappa B (NF-κB) were assayed by western blot. Compared with control group, treatment with fucoidan improved left ventricular systolic pressure (LVSP), left ventricular end-diastolic pressure (LVEDP) and the contractility index (P < 0.05, P < 0.01). Fucoidan reduced the myocardial IS, the levels of TNF-α and IL-6, and the activity of MPO (P < 0.05, P < 0.01). Fucoidan down-regulated the expression of HMGB1, phosphor-IκB-α and NF-κB, but increased the content of IL-10 when compared with control (P < 0.05, P < 0.01). Besides, the infiltration of polymorph nuclear leukocytes (PMNs) and histopathological damages in myocardium were decreased in fucoidan treated groups (PMNs, P < 0.05, P < 0.01). These findings revealed that the administration of fucoidan could regulate the inflammation response via HMGB1 and NF-κB inactivation in I/R-induced myocardial damage.     

Alleviative effects of s-allyl cysteine and s-ethyl cysteine on MCD diet-induced hepatotoxicity in mice

Alleviative effects of s-allyl cysteine (SAC) and s-ethyl cysteine (SEC) upon methionine and choline deficient (MCD) diet-induced hepatotoxicity in mice were examined. SAC or SEC at 1 g/L was added into drinking water for 7 weeks with MCD diet. MCD feeding significantly increased hepatic triglyceride and cholesterol levels, and elevated the activity of glucose-6-phosphate dehydrogenase (G6PDH), malic enzyme, fatty acid synthase (FAS) and 3-hydroxy-3-methylglutaryl coenzyme A reductase (P < 0.05). However, the intake of SAC or SEC significantly decreased hepatic triglyceride accumulation, and reduced G6PDH and FAS activities (P < 0.05). MCD feeding significantly lowered serum and hepatic glutathione (GSH) levels, increased malondialdehyde (MDA) and oxidized glutathione (GSSG) formation, and suppressed the activity and mRNA expression of glutathione peroxidase (GPX), superoxide dismutase (SOD) and catalase (P < 0.05). The intake of SAC or SEC significantly increased serum and hepatic GSH levels, decreased MDA and GSSG formation, restored the activity and mRNA expression of GPX, SOD and catalase (P < 0.05). MCD feeding significantly enhanced the mRNA expression of interleukin (IL)-1beta, IL-6, tumor necrosis factor (TNF)-alpha, transforming growth factor (TGF)-beta1, matrix metalloproteinases-9 (MMP-9) and collagen-alpha1 (P < 0.05). The intake of SAC and SEC significantly blunted the mRNA expression of IL-1beta, IL-6, TNF-alpha, TGF-beta1 and collagen-alpha1 (P < 0.05). SEC was greater than SAC in suppressing IL-6 and TNF-alpha expression (P < 0.05), but SAC was greater than SEC in suppressing collagen-alpha1 and TGF-beta1 expression (P < 0.05). These data suggest that SAC and SEC are potent agents against MCD-induced hepatotoxicity.     

Effect of environmental pollutants on oxytocin synthesis and secretion from corpus luteum and on contractions of uterus from pregnant cows

Chloro-organic compounds are persistent environmental pollutants and affect many reproductive processes. Oxytocin (OT) synthesized in luteal cells is a local regulator of ovarian activity and uterine contractions. Therefore the effect of xenobiotics on the OT prohormone synthesis, secretion of OT and progesterone (P4) from luteal cells and on myometrial contractions during early pregnancy in cows was investigated.Luteal cells and myometrial strips from a cow at early pregnancy were treated with polychlorinated biphenyl 77 (PCB 77), dichlorodiphenyltrichloroethane (DDT), dichlorodiphenyldichloroethylene (DDE) and hexachlorocyclohexane (HCH) (1 or 10 ng/ml). The mRNA expression of neurophysin-I/oxytocin (NP-I/OT) and peptidyl-glycine-α-amidating mono-oxygenase (PGA) and concentration of OT and P4 were determined by RT-PCR and EIA, respectively. Moreover, the effect of xenobiotics given with P4 (12 ng/ml) on the basal and OT (10⁻⁷ M) stimulated contractions of myometrial strips was studied.Xenobiotics increased (P < 0.05) OT secretion but DDE only stimulated P4 secretion. The ratio of P4 to OT in culture medium was decreased by all xenobiotics during 9-12 weeks of pregnancy. All xenobiotics, except HCH, increased (P < 0.05) mRNA expression of NP-I/OT during all stages of pregnancy and all treatments decreased (P < 0.05) expression of mRNA for PGA during 9-12 weeks of pregnancy. Myometrial strips were relaxed (P < 0.01) after pre-incubation with P4, while each of the xenobiotics jointly with P4 increased (P < 0.01) myometrial contractions.In conclusion, the xenobiotics used increased both expression of mRNA for genes involved in OT synthesis and secretion of OT from luteal cells. This decreases the ratio of P4 to OT and presumably, in this manner, the chloro-organic compounds can influence uterine contractions and enhance risk of abortions in pregnant females.     

Elimination of PCB Congeners via Milk in Rabbits Administered Fenclor 64

Abstract: A single dose of 100 mg per kg body weight of a commercial mixture of polychlorinated biphenyls (PCB), Fenclor 64 was given intraperitoneally to pregnant rabbits. The distribution in dams and foetuses and excretion in milk was investigated for six of the congeners by quantifying them in fat from maternal adipose tissue, from whole foetuses and newborn bodies and from newborn gastric contents. The cytochrome-P-450 induction after Fenclor 64 in foetuses and suckling off-spring was followed by measuring the following hepatic mixed function oxidase (MFO) activities: p-nitroanisole-demethylase, ethoxyresorufin-deethylase, ethoxycoumarin-deethylase and NADPH cytochrome-C reductase. At the 28th day of pregnancy PCB fat concentrations in foetuses were similar to those in mothers (126.4 ± 7.1 and 152.6 ± 28.1 μg/g of fat, respectively). By the 5th day of life fat concentrations in the youngs were double those of foetuses (216.81 ± 8.12 μg/g) and remained high until weaning (142.2 ± 15.5 μg/g at the 20th day). PCB concentrations in mothers'fat decreased during lactation (104.1 μg/g at the 20th day) but at the end of the experiment they were still high (95.5 μg/g). The cytochrome-P-450 concentration and MFO activities in young rabbits'livers from treated dams were significantly higher than controls from the 5th (P<0.01) to the 10th (P<0.01) day of life, with the exception of NADPH-cyt-C-reductase (P<0.05). By the 20th day the differences between control and treated animals were smaller but significant (P<0.05), except for ethoxycoumarin deethylase; by the 40th day all the MFOs and the cytochrome-P-450 concentration reached the values of control animals.     

Long-term oral Asperosaponin VI attenuates cardiac dysfunction,myocardial fibrosis in a rat model of chronic myocardial infarction

The aim of the study was to determine the effects of Asperosaponin VI (ASA VI), a triterpene saponin isolated from Dipsacus asper Wall, on chronic myocardial infarction (MI) and possible mechanisms in rats. MI was induced by permanent ligation of the left coronary artery. Twenty-four hours after MI, the rats were administered the extract by gavage (once a day). Six weeks after MI/sham surgery, cardiac dysfunction, infarct size (IS), cardiac fibrosis, hydroxyproline concentration, the oxidative stress parameter and inflammation mediators were examined. The results indicated that ASA VI improved left ventricular systolic pressure (LVSP), left ventricular end-diastolic pressure (LVEDP), ±dP/dt, heart weight/body weight, right ventricular weight/body weight and lung weight/body weight (P < 0.01, P < 0.05). These were accompanied by the attenuation of cardiac fibrosis, IS and hydroxyproline concentration (P < 0.01, P < 0.05). ASA VI could decrease the levels of tumor necrosis factor-α (TNF-α) and interleukin 6 (IL-6), but increase IL-10 content (P < 0.01, P < 0.05). Furthermore, it also could raise the activities of catalase, superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), but reduce malonyldialdehyde (MDA) level (P < 0.01, P < 0.05). The results indicated that ASA VI improved cardiac function and myocardial fibrosis from myocardial ischemia injury, and this cardioprotection might be attributed to reduce oxidative stress and regulate inflammation mediators.