Combining magnet-assisted soil washing and soil amendment with zero-valent iron to restore safe rice cultivation in real cadmium-contaminated paddy fields.

Local villagers in Mae Sot District, Tak Province, Thailand are at risk of diseases related to cadmium (Cd) due to excessive consumption of rice contaminated with Cd due to zinc mining. This study verifies the hypothesis that to achieve safe rice cultivation, magnet-assisted soil washing followed by soil amendment using zero-valent iron (ZVI) is required not only for rapid remediation of the existing Cd contamination but also for the prevention of Cd recontamination caused by contaminated run-off from an upgradient contaminated paddy. Accordingly, this study conducted a pilot-scale demonstration of the combined technique to restore a real Cd-contaminated paddy (41.02 ± 5.47 mg/kg-1) and compared it with remediation using only soil amendment with ZVI or only magnet-assisted soil washing. The Cd concentration in rice grains from the contaminated rice field without treatment was 0.86 ± 0.01 mg/kg-1, and thus higher than the acceptable level of 0.4 mg/kg-1. Even though the use of magnet-assisted soil washing without amendment initially removed all the bioavailable Cd from the soil, it failed to reduce Cd uptake by the rice plants. This failure was caused by heavy off-season rain, which flooded and re-contaminated the experimental fields with Cd-contaminated run-off from an upgradient contaminated field, leading to a Cd concentration in rice grains of 1.21 ± 0.01 mg/kg-1. Similarly, the use of ZVI as a soil amendment without magnet-assisted soil washing could not ensure safe rice cultivation during the off-season flood, as Cd concentration in the rice grains was still 0.60 mg/kg-1. However, magnet-assisted soil washing followed by soil amendment using ZVI successfully removed Cd from soil and sequestered Cd from Cd-contaminated run-off, resulting in protection against Cd re-contamination in soil and the reduction of Cd content in rice grains to 0.33 mg/kg-1, representing a 60% removal efficacy. Also, this combined technique remained positive for rice growth compared to non-treatment.

Increased expression of apoptotic markers in human full-term placenta after exposure to elevated environmental cadmium levels during pregnancy.

Cadmium (Cd), a toxic heavy metal, produces various forms of environmental contaminations and health problems in human. In this study, we aimed to examine the localization of several apoptotic markers in human placentas from pregnant women who were environmentally exposed to Cd. Twelve pregnant women participated in this analysis and they were divided into 2 groups according to their living areas: high-Cd (H-Cd) and low-Cd (L-Cd) groups. After delivery, the placentas were immediately harvested, and the placental width, length, and weight were measured. The placental Cd concentration was determined by using ICP-MS. The expression of three apoptotic markers, cleaved caspase-3, cleaved lamin A/C, and TUNEL, was examined in immunohistochemistry. In results, the placental Cd concentration in the H-Cd group was higher than that in the L-Cd group. In contrast, a significant decrease in the BW (birth weight):PW (placenta weight) ratio representing the placental nutrient transport function was found in the H-Cd group, and an inverse correlation between placental Cd concentration and BW:PW ratio was demonstrated. Additionally, significant elevations in the expression of cleaved caspase-3, cleaved lamin A/C proteins, and TUNEL were shown in the H-Cd placenta. Moreover, positive correlations were found between the placental Cd concentration and the expression of cleaved caspase-3 and TUNEL. Collectively, our findings suggest that the exposure of pregnant women to environmental Cd might induce Cd to be transferred to the body and then accumulated in the placenta, resulting in disturbance of the placental function and eventual apoptosis.

Increased DMT-1 expression in placentas of women living in high-Cd-contaminated areas of Thailand.

Cadmium (Cd) is a toxic heavy metal and contamination was reported in soil and rice in several areas of Thailand. Humans are normally exposed to environmental Cd, leading to gradual Cd accumulation in their bodies, including the placenta. DMT-1 is a divalent metal transporter which is found in placental tissue and plays a vital role in the transportation of Fe2+ and Cd2+. This study investigated DMT-1 protein and mRNA expressions in full term human placentas comparing those from high-Cd-contaminated areas (high-Cd group) and low-Cd-contaminated areas (low-Cd group), n = 6 per group. The maternal blood Cd (B-Cd) and placental Cd (P-Cd) of the high-Cd group was significantly raised in comparison with those in the low-Cd group. DMT-1 in the fetal portion of the placentas was localized in the apical and basal portions of the cytoplasm of the syncytiotrophoblastic cells, the endothelium of fetal capillaries which is functional structure of the placental barrier, and was also found in the cytoplasm of Hofbauer cells. Moreover, DMT-1 localization in the maternal portion was also detected in most decidual cells. In addition, the DMT-1 protein and mRNA expressions in the high-Cd group were significantly higher than those in the low-Cd group. Therefore, we suggest that pregnant women, who are exposed to environmental Cd, show an increased level of Cd in their maternal blood and this Cd can accumulate in the placenta. Intracellular Cd may induce DMT-1 mRNA transcription which further translates into DMT-1 protein, which can then function as a reciprocal Cd transporter in placental tissue.

Antioxidative and neuroprotective activities of peanut sprout extracts against oxidative stress in SK-N-SH cells

Objective: To evaluate the protective effect of peanut sprout extract (PSE) against paraquat (PQ) induced SK-N-SH cells. Methods: Three groups of cells were used in the experiment, together with a fourth, control group. One group was treated with PQ, the second group was treated with PSE, and the third group was pre-treated with PSE. The control group was untreated. Cell viability and toxicity were detected by MTT assay, cellular reactive oxygen species (ROS) was detected by Muse Cell Analyzer, quantitative RT-PCR was applied to investigate the expression of SIRT1 and a-synuclein genes, and Ab42 was detected by western blot. Results: The 50% effective concentration of PQ was 0.75 mmol/L. PSE had no sig-nificant cytotoxicity at a concentration of 1.5 mg/mL. In the group of cells pre-treated with PSE, cell death was significantly inhibited. In the PQ treated group, PQ was increased in the intracellular ROS in the cells. Intracellular ROS was significantly decreased in the cells treated with PSE and also those pre-treated with PSE. PSE significantly downregulated the expression of SIRT1 and a-syn genes, and it was found that PQ significantly increased b-amyloid 42 levels whereas this action was inhibited by PSE. Conclusions: PSE has neuroprotective activities against oxidative stress in SK-N-SH cells induced by PQ, suggesting that PSE is a highly promising agent in the preven-tion of neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease.

Increasing CACNA1C expression in placenta containing high Cd level: an implication of Cd toxicity.

Cadmium (Cd) has known to produce many adverse effects on organs including placenta. Many essential transporters are involved in Cd transport pathways such as DMT-1, ZIP as well as L-VDCC. Fourteen pregnant women participated and were divided into two groups: high and low Cd-exposed (H-Cd, L-Cd) groups on the basis of their residential areas, Cd concentrations in the blood (B-Cd), urine (U-Cd), and placenta (P-Cd). The results showed that the B-Cd and U-Cd were significantly increased in H-Cd group (p < 0.05). Interestingly, the P-Cd in H-Cd group was elevated (p < 0.05) and positively related to their B-Cd and U-Cd values (p < 0.05). However, the mean cord blood Cd (C-Cd) concentration in H-Cd group was not significantly increased about 2.5-fold when comparing to L-Cd group. To determine the Cd accumulation in placental tissues, metallothionein-1A (MT-1A) and metallothionein-2A (MT-2A) expressions were used as biomarkers. The results revealed that mean MT-1A and MT-2A mRNAs and MT-1/2 proteins were up-regulated in H-Cd group (p < 0.05). In addition, the Ca channel alpha 1C (CACNA1C) mRNA and protein expressions were noticeably elevated in H-Cd group (p < 0.05). From these findings, we suggested that CACNA1C might be implicated in Cd transport in human placenta.

Increasing of syncytial knot and fibrinoid deposit in high-Cd accumulated human placentas / Aumento del nodo sincicial y depósitos de fibrinoide en placenta humanas con alta acumulación de cadmio

A toxic metal, cadmium (Cd), can accumulate in human organs. Placenta is usually used as indicator organ for Cd exposure. Therefore, we aim to investigate the different of placental morphology between the low- and high-Cd accumulated placentas. The samples were collected from 14 pregnant women who resided in low-Cd contaminated (L-Cd group) and high-Cd contaminated (H-Cd group) areas. The concentrations of Cd in blood (B-Cd), urine (U-Cd) and placentas (P-Cd) were measured by ICP-MS and AAS. The morphological appearance of placentas was examined by using routine paraffin section and H & E staining. The results showed that levels of B-Cd, U-Cd and P-Cd were significantly higher in H-Cd group than in L-Cd group (p= 0.001). Moreover, the B-Cd was positively correlated with U-Cd (rs= 0.823, p= 0.000) and P-Cd concentrations (rs= 0.854, p= 0.000). The appearances of syncytial knot (STK) and fibrinoid deposit (Fd) were obviously greater in H-Cd group than in L-Cd group (p= 0.007, p= 0.026). The STK was positively correlated with both Fd (rs= 0.572, p= 0.032) and P-Cd concentration (rs= 0.766, p= 0.001). Although the chorioamnitis and decidual inflammation features were found in both groups but the appearance in H-Cd group seems to be more severe than in L-Cd group. From these results, we suggested that high Cd level in placenta may be involved in morphological changes, especially STK and Fd increasing and probably disturb the connection between maternal and fetal circulation.

Un metal tóxico, el cadmio (Cd), se puede acumular en órganos humanos. La placenta se utiliza, por lo general, como órgano indicador de la exposición a Cd. Nuestro objetivo fue investigar la diferente morfología placentaria entre las placentas con baja y alta acumulación de Cd. Las muestras fueron recolectadas de 14 mujeres embarazadas que residían áreas con alta (grupo H-Cd) y baja contaminación por Cd (grupo L-Cd). Las concentraciones de Cd en la sangre (B- Cd), orina (U-Cd) y placentas (P-Cd) se midieron por ICP-MS y AAS. La apariencia morfológica de las placentas fue examinada usando cortes histológicos teñidos con H-E. Los resultados mostraron que los niveles de B-Cd, U-Cd y P-Cd fueron significativamente mayores en el grupo H-Cd (p= 0,001). Por otra parte, el B-Cd se correlacionó positivamente con las concentraciones de U-Cd (rs= 0,854, p = 0,000 ) y P-Cd (rs= 0,823, p = 0,000). Las apariciones de nodos sinciciales (NS) y depósitos fibrinoides (Fd) fueron mayores en el grupo H-Cd (rs= 0,007, p= 0,026). Los ND se correlacionaron positivamente con los Fd (rs= 0,572, p= 0,032) y la concentración de P-Cd (rs= 0,766, p = 0,001). Aunque características de corioamnitis e inflamación de la decidua se encontraron en ambos grupos, su aparición en el grupo H-Cd pareció ser más grave que en el grupo L-Cd. A partir de estos resultados, sugerimos que el nivel alto de Cd en la placenta puede estar involucrado en los cambios morfológicos, especialmente el aumento de NS y Fd, los que probablemente alteran la relación entre la circulación materna y fetal.

Urinary cadmium concentrations in a population downstream: from a zinc mining area in Mae Sot District, Tak Province, Thailand.

Urinary cadmium (UCd) is a good indicator of long-term exposure to cadmium. UCd concentrations resulting from juvenile cadmium exposure in 3 sub-districts of Tak Province, Thailand, were investigated. The target population was divided by gender and into 2 age subgroups: 9-12 and 13-15 years. A total of 748 urine samples were collected and analyzed by spectrophotometer. All samples had UCd of more than 1.0 µg/g creatinine (Cr). Total UCd means among the 3 sub-districts were 1.31, 1.01, and 0.87 µg/g Cr; the Thai population mean is 0.5 µg/g. The difference among the three sub-districts was statistically significant (p < 0.05). Total means for UCd were 1.13 µg/g Cr for boys, 1.00 for girls, 1.01 µg/g Cr for those 9-12 years old, and 1.18 for those 13-15. UCd concentrations were not significantly different between genders and age groups. Likely dietary sources of cadmium exposure for the subject population were surveyed.