Protective effects of silymarin on testis histopathology,oxidative stress indicators,antioxidant defence enzymes and serum testosterone in cadmium‐treated mice

Cadmium is known as an oxidative stress‐inducing factor. Silymarin extracted from Silybum marianum is regarded as a potent antioxidant. The present study investigated the preventing effects of silymarin on cadmium chloride‐induced toxicity in terms of testis histopathology and serum testosterone level as well as oxidative stress indicators in mice. In addition, the activities of antioxidant defence enzymes was evaluated. Adult male mice were divided into four groups (n = 6 in each group): (a) control; (b) cadmium chloride; (c) silymarin + cadmium chloride and (d) Silymarin. In this study, cadmium chloride significantly decreased the diameter and wall thickness of the seminiferous tubule, diameter of the spermatogonia nucleus and serum testosterone levels compared to the control group. Furthermore, in mice treated with this pollutant, a significant increase in malondialdehyde was observed while ferric reducing antioxidant power level, and the activity of catalase, superoxide dismutase and glutathione peroxidase were significantly reduced in the testis. In the silymarin + cadmium chloride group, silymarin could significantly reverse the toxic effects of cadmium chloride. The findings of this study showed that silymarin, as a potent antioxidant, can compensate the adverse effects of cadmium chloride on testis histopathology, testosterone level, oxidative stress indicators and antioxidant defence enzymes in mice.     

Assessment of heavy metals by ICP-OES and their impact on insulin stimulating hormone and carbohydrate metabolizing enzymes

Arsenic (As) and cadmium (Cd) have recently emerged as major health concerns owing to their strong association with diabetes mellitus (DM). We aimed to investigate the heavy metals exposure towards incidence of DM at various enzymatic and hormonal levels. Additionally, association of As and Cd with Zinc (Zn, essential metal) was also evaluated. Spot urine samples were collected to assess As, Cd and Zn through ICP-OES. Serum was analyzed by assay method for fasting blood glucose, liver and renal function biomarkers. ELISA was performed to investigate the impact of heavy metals on HbA1c, α-amylase, DPP-IV, IGF-1, leptin, GSH, MDA, SOD, HDL, FFA, TG and interleukin (IL)-6. Association of heavy metals with DM was measured by odds ratio (OR) and level of significance was assessed by Chi-squared test. Unpaired student's t-test was used to compare DM-associated risk factors in heavy metals-exposed and unexposed participants. As and Cd were detectable in 75.4% and 83% participants with mean concentration of 75.5 ppb and 54.5 ppb, respectively. For As exposure, OR in the third quartile was maximum ie 1.34 (95% CI, 0.80 to 2.23), however the result was not statistically significant (P > .05). For Cd exposure, OR in the fourth quartile was considerably high, 1.62 (95% CI, 1.00 to 2.61), with a significant probability value (P < .05). Urinary Cd was negatively associated with Zn. As and Cd exposure increases the incidence of DM in the general population. Impaired hormonal and enzymatic levels in diabetic and non-diabetic exposed participants reflect the multiple organ damage by heavy metal exposure.     

Glutathione S-transferase in the midgut tissue of gypsy moth (Lymantria dispar) caterpillars exposed to dietary cadmium

Activity of glutathione S-transferase (GST) in midgut of gypsy moth caterpillars exposed to 10 and 30 μg Cd/g dry food was examined. Based on the enzyme reaction through conjugation with glutathione, overall activity remained unaltered after acute and chronic treatment. No-observed-effect-concentration (10 μg Cd/g dry food) significantly increased activity only after 3-day recovery following cadmium administration. Almost all comparisons of the indices of phenotypic plasticity revealed statistically significant differences. Despite the facts that GST has important role in xenobiotic biotransformation, our results indicate that this enzyme in insect midgut does not represent the key factor in cadmium detoxification.     

Maternal cadmium,placental PCDHAC1, and fetal development

Cadmium (Cd) is a ubiquitous environmental contaminant implicated as a developmental toxicant, yet the underlying mechanisms that confer this toxicity are unknown. Mother-infant pairs from a Rhode Island birth cohort were investigated for the potential effects of maternal Cd exposure on fetal growth, and the possible role of the PCDHAC1 gene on this association. Mothers with higher toenail Cd concentrations were at increased odds of giving birth to an infant that was small for gestational age or with a decreased head circumference. These associations were strongest amongst those with low levels of DNA methylation in the promoter region of placental PCDHAC1. Further, we found placental PCDHAC1 expression to be inversely associated with maternal Cd, and PCDHAC1 expression positively associated with fetal growth. Our findings suggest that maternal Cd affects fetal growth even at very low concentrations, and some of these effects may be due to the differential expression of PCDHAC1.     

Onion and garlic extracts as potential antidotes for cadmium‐induced biochemical alterations in prostate glands of rats

Cadmium (Cd) has been implicated in increased prostate gland malignancy risk in both wildlife and humans. This study examines the chemoprotective roles of onion and garlic extracts on Cd‐induced biochemical alterations in the prostate glands of rats. Adult male Wistar rats were randomly divided into nine groups: control group received double distilled water; Cd group received Cd alone (1.5 mg/100 g bwt per day); extract‐treated groups were pre‐treated with varied doses of onion and/or garlic extract (0.5 ml and 1.0 ml/100 g bwt per day) for 1 week and then co‐treated with Cd (1.5 mg/100 g bwt per day) for additional 3 weeks. Oxidant/antioxidant status and acid phosphatase (ACP_total and ACP_prostatic) activity were examined in prostate glands. Cd intoxication caused a marked (P < 0.001) increase in lipid peroxidation (LPO) and glutathione S‐transferase (GST) levels, whereas glutathione (GSH), superoxide dismutase and catalase levels were markedly (P < 0.001) decreased. We also observed significant (P < 0.001) decrease in ACP_total and ACP_prostatic activities in prostate glands and a concomitant significant (P < 0.001) increase in the plasma. However, treatment of Cd‐intoxicated rats with onion and/or garlic extract significantly minimised these alterations. The onion extract offered a dose‐dependent protection. Our findings suggest a chemoprotective capability for onion and garlic extracts against Cd‐induced biochemical alteration in the prostate glands.     

Adsorption of organic compounds and hydrophilicity of bismuth,cadmium and antimony electrodes

The adsorption behavior of various organic compounds at bismuth, antimony, cadmium, mercury and other “mercury-like” metals has been discussed. The systematic trends of the influence of the chemical nature of electrode metal and adsorbate to the molecular interaction parameter, a; limiting Gibbs adsorption, Γ_{A, max}; and Gibbs energy of adsorption, ΔG_A⁰, have been analyzed. The ingredients of the total Gibbs energy of organic compounds adsorption have been found. A new more general method for obtaining the metal-water; interaction Gibbs energy has been worked out and used. It was found that the dependence of Gibbs energy of metal-water interaction on the chemical nature of metal and aliphatic organic compound studied is weak. Only in the case of chemically very different metals, for example for Sb and Zn, the difference of Gibbs energy of metal-water interaction values is somewhat higher than the exactness of the determination of the experimental values of Gibbs energy of organic compound adsorption.     

Environmental exposure of the general population to cadmium as a risk factor of the damage to the nervous system: A critical review of current data

Nowadays, more and more attention has been focused on the risk of the neurotoxic action of cadmium (Cd) under environmental exposure. Due to the growing incidence of nervous system diseases, including neurodegenerative changes, and suggested involvement of Cd in their aetiopathogenesis, this review aimed to discuss critically this element neurotoxicity. Attempts have been made to recognize at which concentrations in the blood and urine Cd may increase the risk of damage to the nervous system and compare it to the risk of injury of other organs and systems. The performed overview of the available literature shows that Cd may have an unfavourable impact on the human's nervous system at the concentration >0.8 μg Cd/L in the urine and >0.6 μg Cd/L in the blood. Because such concentrations are currently noted in the general population of industrialized countries, it can be concluded that environmental exposure to this xenobiotic may create a risk of damage to the nervous system and be involved in the aetiopathogenesis of neurodegenerative diseases, such as Alzheimer's disease and Parkinson's disease, as well as worsening cognitive and behavioural functions. The potential mechanism of Cd neurotoxicity consists in inducing oxidative stress, disrupting the activity of enzymes essential to the proper functioning of the nervous system and destroying the homoeostasis of bioelements in the brain. Thus, further studies are necessary to recognize accurately both the risk of nervous system damage in the general population due to environmental exposure to Cd and the mechanism of this action.     

Impact of silymarin on cadmium-induced apoptosis in human spermatozoa

Oxidative stress-induced apoptosis in spermatozoa may lead to male infertility. Environmental pollutants and heavy metals such as cadmium cause harmful effects on the reproductive system and sperm parameters through the induction of oxidative stress. Silymarin, as a potent antioxidant, is able to inhibit oxidative stress. This study was performed to investigate the protective effects of silymarin on cadmium-induced toxicity in human spermatozoa. Sperm samples were divided into the following five groups: (a) spermatozoa at 0 min, (b) spermatozoa in the control group, (c) spermatozoa treated with cadmium chloride (20 μM), (d) spermatozoa treated with silymarin (2 μM)+ cadmium chloride (20 μM) and (e) spermatozoa treated with silymarin (2 μM). Sperm parameters related to apoptosis, such as DNA fragmentation, nucleus diameter, mitochondrial membrane potential (MMP) and expression of caspase-3, were evaluated in all groups. After 180 min, spermatozoa treated with cadmium chloride showed a significant decrease in nucleus diameter and MMP but a significant increase in DNA fragmentation; however, caspase-3 expression remained unchanged. At this time point, silymarin in the silymarin + cadmium chloride group could significantly reverse the adverse effects of cadmium chloride on these parameters.Silymarn could partly compensate for the caspase-independent apoptosis in the spermatozoa. Therefore, oxidative stress could be a consequence for cadmium toxicity.     

黄芪多糖减轻慢性镉暴露诱导的大鼠肝脏损伤

目的研究黄芪多糖对慢性镉暴露诱导大鼠肝脏损伤的影响。方法将大鼠随机均分为对照组、模型组和黄芪多糖干预组(用腹腔注射氯化镉复制大鼠肝脏损伤模型),5周后处死大鼠取出肝脏。称重法计算大鼠肝指数;比色分析法检测大鼠血清和肝脏谷丙转氨酶(ALT)活性、谷草转氨酶(AST)活性、乳酸脱氢酶(LDH)活性;用电感耦合等离子质谱仪检测肝脏镉(Cd)含量;酶联免疫吸附试验(ELISA)测定大鼠肝脏白细胞介素-2(IL-2)和转化生长因子β1(TGF-β1)的含量;免疫组化法观察大鼠肝脏Bcl-2和Bax的蛋白表达。结果与对照组比较,模型组大鼠肝指数、ALT活性、AST活性、LDH活性、Cd含量、TGF-β1含量和Bax蛋白表达均升高(P<0.05或P<0.01);但模型组大鼠IL-2含量和Bcl-2蛋白表达下降(P<0.01)。与模型组比较,黄芪多糖能显著降低模型组大鼠肝指数、ALT活性、AST活性、LDH活性、Cd含量、TGF-β1含量和Bax蛋白表达(P<0.05或P<0.01);但黄芪多糖能显著提高模型组大鼠IL-2含量和Bcl-2蛋白表达(P<0.01)。结论黄芪多糖可能是通过调控Bcl-2/Bax蛋白表达来减轻镉致大鼠肝细胞氧化应激损伤。