Journal of Toxicology最新文献

Liver disease is a major health problem and its treatment is costly in most developing countries with attendant adverse effects. This study aimed at determining the acute hepatoprotective efficacy of Duranta erecta hydroethanolic extracts of leaves, ripe and unripe fruits against CCl₄-, and acetaminophen-induced hepatotoxicity in animals. Materials and Methods. CCl₄ (1 mL/kg body weight in olive oil) and acetaminophen (500 mg/kg b.wt) were used to induce hepatotoxicity in the animals. Animals were treated with extracts at 250 mg/kg b.wt and standard drug, silymarin (100 mg/kg), for 7 days. Hepatoprotective efficacy was assessed by assaying serum biochemical markers such as alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), gamma-glutamyl transferase (γGT), bilirubin (Bil), antioxidative biomarkers including reduced glutathione (GSH), glutathione peroxidase (GPx), glutathione transferase (GST), superoxide dismutase (SOD), malondialdehyde (MDA), hydrogen peroxidase (H₂0₂), and nitric oxide (NO), as well as histological observations. Results. Exposure of the animals to CCl₄ and acetaminophen resulted in liver injury as evidenced by elevated ALT, AST, ALP, γGT, Bil, MDA, H₂O₂, and NO levels with resultant derangement in liver microarchitecture. Pretreatment with hydroethanolic extracts, particularly ripe fruits of Duranta erecta, led to a reduction in these indicators and an increase in GSH, GPx, GST, and SOD levels. Biochemical data were supported by improvement in liver structure. Conclusion. The findings suggest that hydroethanolic Duranta erecta ripe fruits extract possesses hepatoprotective and antioxidative activities against CCl₄- and acetaminophen-induced toxicity and could be developed as a potent agent for drug-induced liver diseases.

Insecticide imidacloprid and herbicide glyphosate have a broad spectrum of applicable use in the agricultural sector of Egypt. Their ability to induce in vitro cytotoxic and oxidative stress on normal human cells (prostate epithelial WPM-Y.1 cell line) was evaluated with the methyl tetrazolium test (MTT) and histopathological investigation. Cell viability was evaluated with an MTT test for 24 h. The median inhibition concentration (IC₅₀) values were 0.023 and 0.025 mM for imidacloprid and glyphosate, respectively. Sublethal concentrations: 1/10 and 1/50 of IC₅₀ and IC₅₀ levels significantly induced an increase in the lactate dehydrogenase (LDH) activity and malondialdehyde (MDA) level compared with the untreated cells. Rapid decrease in the glutathione (GSH) content and glutathione-S-transferase (GST) activity was induced. Significant increases were recorded in activities of catalase (CAT), glutathione peroxidase (GPx), and glutathione reductase (GR), respectively, compared with the control group. Transmission electron microscopic (TEM) investigation showed significant defects in the cells following pesticide treatments for 24 h. Therefore, it is concluded that imidacloprid and glyphosate are very toxic in vitro assays and able to induce apoptotic effects as well as oxidative stress. So, these findings provide a scenario of multibiomarkers to achieve the imposed risks of pesticides at low doses.

Combustion-derived nanomaterials are noxious ultrafine (<100 nm) aerosol by-products of human activity. They pose threats to pulmonary health due to their small size, allowing them to penetrate alveoli causing detrimental responses downstream. Information regarding the cellular activity that connects nanocarbon particle exposure to poor pulmonary health remains lacking. We hypothesized that low-dose and long-term administrations of carbonaceous nanoparticles contribute to lung irritation by adversely affecting respiratory cells that function as the first line of defense. Responses to ultrafine black carbon (UBC), a key component of airborne pollutants, by human lung A549, murine lung LA4 epithelial cells, human peripheral-blood monocytes THP1, and murine macrophages RAW264.7 were investigated. The cells were first plated on day zero and were fed fresh UBC suspended in culture media on days one, four, and seven. The exposure regimen included three different concentrations of UBC. On day ten, all cells were harvested, washed, and assayed. The impact on cellular viability revealed that UBC was only moderately cytotoxic, while metabolic activity was significantly diminished in a dose-dependent manner. Additionally, beta-galactosidase proportionally increased with UBC concentration compared to untreated cells, indicating that cellular senescence was promoted across all cell types. The implemented regimen caused minimal toxicity yet demonstrated different cellular modifications across the cell lines of both species, inducing changes to enzyme vitality and cellular fitness. The data suggested that compounding nanosized black carbon exposure could negatively impair overall pulmonary health by distinctively modifying intracellular behavior.

[This corrects the article DOI: 10.1155/2019/1987935.].

The applications of nanostructures have been limited by their different toxicities. So, the investigation of these toxicities is necessary before nanostructure application. This study aimed to evaluate the effect of aluminum oxide (Al₂O₃) nanoparticles on bone density in Wistar rat. Al₂O₃ nanoparticle was prepared by the sol-gel method. Characterization was done by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Sixty-four male adult Wistar rats were divided into eight groups including six groups intravenously treated with Al₂O₃ nanoparticle at concentrations of 25, 50, 100, 250, 500, and 1000 µg/ml: one group received food and water as the control group, and one group received food and water as well as intravenously distilled water as an injection control group. After 41 days, bone density was analyzed by dual-energy X-ray absorptiometry (DEXA). According to X-ray diffraction, the average particle size for Al₂O₃ nanoparticles was 20.85 nm. The data of densitometry showed that the bone density of right and left foot was reduced in concentrations of 250, 500, and 1000 µg/ml that were statistically significant in comparison with the control group. The reduction of bone density was increased with the enhancement of nanostructures concentration. The effect of Al₂O₃ nanoparticles on bone density was similar in the left and right legs. Histopatholological assessment also showed that Al₂O₃ nanoparticles (250, 500, and 1000 µg/ml) lead to significant reduction of trabeculae. Empty lacunae are observed in these three groups. Considering that high concentrations of Al₂O₃ nanoparticles had toxicity on bone tissue, it must be used by more caution, especially its use as a coating in different devices such as implants, surgical instruments, and bone prostheses.

The modeling of adaptation potential decrease in rats due to modification of the diet's vitamin-mineral composition allows to increase animals' sensitivity to toxic load in reprotoxicological experiments. The threshold values of vitamins B1, B2, B3, and B6 and mineral substances Fe³⁺ and Mg²⁺ in the diet, which lead to a considerable reduction of laboratory animals' adaptation potential, have been determined as 19% (from the basic level in the diet) for males and 18% for females. The efficiency of this model has been confirmed in a reprotoxicological experiment with glyphosate as a toxic factor: the action of the toxic factor against the background of reduced availability of B vitamins and salts Fe³⁺ and Mg²⁺ led to significant changes in such indicators of reproductive function as mating efficiency, postimplantation loss, and the total number of alive pups, while the toxic effect of glyphosate was not so pronounced against the normal level of essential substances. The obtained results prove that this adaptation potential reduction model can be recommended for the research of the low-toxicity objects reproductive toxicity in rats and for the safety assessment of novel food, in particular.

Tamarix articulata (TA) is a wild halophytic plant growing in extremely harsh environmental conditions in the deserts of Saudi Arabia. Evaluating the protective effect of the methanolic extract of different parts (fresh and dry leaves, stem, and root) of TA was determined by MTT assay using Hs27 skin fibroblasts as the cellular model. The study was designed and conducted in two sets. The first set assesses the toxicity profile of TA extracts in both concentration- and time-dependent ways on Hs27 cells. Our MTT results showed that methanolic extracts from all four parts of TA at varying doses (27.5, 55, 110, and 220 μg/mL) display negligible toxicity when exposed for 4 h. However, exposure of Hs27 cells to varying doses of all four TA extracts for 24 and 48 h promotes significant 23%, 24%, 26%, and 25% (p < 0.05) and 35%, 36%, 39%, and 41% (p < 0.05) cell toxicity at 220 μg/mL of all four TA extracts compared to untreated control cells. To evaluate the protection offered by TA extracts against H₂O₂, we perform a second set of experiments to preincubate Hs27 cells with the TA extracts in both dose- and time-dependent way. This is followed by 300 μM hydrogen peroxide- (H₂O₂-) mediated oxidative insult for 1 h. Using MTT assay, we found that methanolic extracts of TA at different time points (4, 24, and 48 h) and higher doses (220 μg/mL) provide significant protection in cell viability when challenged with H₂O₂-induced oxidative stress in Hs27 cells. The protective effect was more pronounced at 48 h and 220 μg/mL and the amounts were 39%, 41%, 41%, and 44% for stem, root, fresh leaf, and dry leaf TA extracts (p < 0.05), respectively, compared to untreated cells (2-4%). Collectively, the current study demonstrates that methanolic extracts of TA contain potential bioactive compounds and offer significant protection against H₂O₂-mediated oxidative stress in Hs27 skin fibroblasts.

Cosmetologists may be potentially exposed to high levels of formaldehyde as a result of their exposure to formaldehyde released from the various cosmetic products used in the beauty salons. In order to assess the exposure of cosmetologists to formaldehyde, the indoor air in sixty beauty salons across the ten submetros in Kumasi were sampled to determine the formaldehyde levels and the associated noncarcinogenic human health risks. Sampling was done using System Service Innovation Incorporation air sampler model 1000i, and the MBTH spectrophotometric method was used for analysis. The mean levels of formaldehyde concentrations ranged from 88.67 to 170.67 µg/m³. Out of the sixty salons sampled, 36 salons had formaldehyde levels above the WHO permissible limit of 100 µg/m³ for an eight-hour working period and also exceeded the 55 and 9 µg/m³ for chronic and acute reference exposure limit, respectively, set by the Office of Environmental Health Hazard Assessment. The results of this study revealed that the number of customers that visit the salon in a week, number of salon services offered, and age of salon had a positive significant correlation with the level of formaldehyde determined in each salon. The health risk study also revealed that about 50% of the salons had hazard quotient (HQ) above the safety limit (HQ = 1) and may, therefore, pose health risks to cosmetologists in these salons. Results from the analysis of the questionnaire revealed that hairdressers in salons that provide the entire range of salon services captured in the study are at higher risk to the effects of formaldehyde.

Despite plants being a rich source of useful chemical compounds with different pharmacological properties, some of these compounds may be toxic to humans. Parinari curatellifolia, among its other important pharmacological activities, has been shown to have significant antiproliferative activity on cancer cell lines. Toxicity studies are required to determine the safety profile of P. curatellifolia in the consideration of its potential pharmaceutical benefits as a source of lead compounds in cancer therapy. The effects of P. curatellifolia on both the integrity of the erythrocyte membrane and on normal cells were determined. The dried leaf powder of P. curatellifolia was used in serial exhaustive extraction procedures using hexane, dichloromethane, ethyl acetate, acetone, ethanol, methanol, and water as solvents in addition to extraction using DCM: methanol in equal ratio. Alkaloids, flavonoids, and saponins were isolated from the ethanol extract. The leaf extracts were tested for haemolytic activity on sheep erythrocytes at concentrations of 0.625 to 5 mg/ml. The extracts were also tested for toxicity activity on normal mammalian cells such as the BALB/c mice peritoneal cells using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) at the concentrations of 6.3 to 50 μg/ml. In the haemolysis assays, none of the plant extracts had a significant haemolytic activity with the saponin-enriched extract having the maximum haemolytic activity of 12.2% for a concentration of 5 mg/ml. In the MTT cell viability assay, none of the 11 plant extracts had significant cytotoxicity. The water extract, however, had significant (p < 0.01) proliferative activity towards the murine immune cells at all concentrations. P. curatellifolia leaf extracts were, therefore, not toxic to both erythrocytes and immune cells, and the water extract may have immunostimulatory effects. It is concluded that P. curatellifolia leaf extracts are not toxic in vitro and, therefore, our results support the use of the plant for ethnomedicinal use.