Barbara Frydrych

Hepatotoxicity of tetrabromobisphenol-A: effects of repeated dosage in rats.

Tetrabromobisphenol-A (TBBP-A) is used as a reactive flame retardant and as an intermediate in the production of other flame-retardants. In our study, TBBP-A was administered intragastrically, daily for 7 or 7-28 days at three dose levels. Significant changes of biochemical indicators were noted with regard to glutathione (GSH), malondialdehyde (MDA) and 5-aminolevulinate dehydratase (ALA-D). The level of GSH was lowered by the two higher doses (female rats only) and MDA was elevated by the highest dose (male rats only). The ALA-D activity reacted in opposite directions for both sexes. Other indicators did not yield any conclusive results. The 28-day study was performed on female rats. For GSH and MDA the medium dose resulted in a systematic increase. Insignificant changes in ALA-D activity in the liver were observed throughout the experiment. The activity of 5-aminolevulinate synthase had a decreasing tendency at 250 mg/kg of TBBP-A during the whole time of observation. Other general indices such as the activity of gamma-glutamyltransferase, concentration of microsomal proteins and the level of cytochrome P-450 did not show any significant changes. The most pronounced changes were noted with regard to indicators of porphyrogenic action. The results suggest that TBBP-A is capable of disturbing the heme metabolism in rats.

The effect of short-term intoxication of rats with pentabromodiphenyl ether (in mixture mimic commercial products)

Until quite recently, pentabromodiphenyl ether (PentaBDE) was most commonly used as a flame retardant. Due to the considerably long atmospheric half-life of PentaBDE and its contribution to environmental pollution, it is categorized as a persistent organic pollutant (POP). As the data on the toxicity of PentaBDE is rather scarce, its potential acute toxicity was the subject of this study. PentaBDE was administered intragastrically to female rats, in a single dose (25, 200 or 2000 mg/kg b.w.). PentaBDE administered to rats disturbed redox homeostasis, which was manifested by lower total antioxidant status (TAS) in serum and by higher liver glutathione reduced (GSH) concentration. The toxic effect of PentaBDE intensified lipid peroxidation. On histopathological examination, administration of the highest PentaBDE dose (2000 mg/kg b.w.) was seen to induce symptoms of fatty liver. PentaBDE caused an increase in relative liver mass, cytochromes P-450 (after two highest doses), a dose-dependent increase in the activity of CYP lA (12—26 fold) and CYP 2B (5—6 fold) as well as the levels of CYP lAl (16—50 fold) and CYP 4A (2—3 fold) in liver.

Octabromodiphenyl ether — porphyrogenicity after repeated administration to rats

ObjectivesOctabromodiphenyl ether (OctaBDE) is a flame retardant which has been withdrawn from common use due to its negative effect on the environment. The literature data regarding its toxicity addresses its effect on liver function, the endocrine and reproductive systems, as well as its developmental toxicology aspects. The aim of this study was to investigate the effect of repeated administration of OctaBDE on heme biosynthesis in rats.Materials and MethodsThe study was performed on female Wistar rats. OctaBDE was administered intragastrically at four different doses (2, 8, 40 or 200 mg/kg/day) for 7, 14, 21 or 28 days. The following measures of heme synthesis disturbance were used: urinary excretion of porphyrins, liver concentration of porphyrins, the activity of delta-aminolevulinate synthase (ALA-S) and delta-aminolevulinate dehydratase (ALA-D) in the liver.ResultsAfter 28 days of exposure, lower ALA-S and ALA-D activity was observed in the liver. Additionally, increased concentrations of high carboxylated porphyrins (octa- and heptacarboxyporphyrins) were found in the liver: from 2- to 10-fold after the 2 mg/kg/day doses and from 4- to 14-fold after the 8-200 mg/kg/day doses. The porphyrogenic effect of OctaBDE was also evidenced by augmented, dose-dependent and exposure time-dependent, concentrations of total porphyrins in urine (2–7.5-fold increase) and their urinary excretion (2-9-fold increase). Tetracarboxyporphyrins predominated in the urine; their concentrations increased 2.5–10 fold. Conclusions: The study revealed that repeated exposure to OctaBDE affects heme biosynthesis and the levels of porphyrins. The lowest effective level which induced changes in porphyrin concentration was 2 mg/kg/day.

Comparison of chemical composition of selected essential oils used in respiratory diseases

BACKGROUND Essential oils are fragrances extracted from plants. They have a smooth consistency and pleasant smell. Essential oils have been applied in aromatherapy, cosmetics, food and pharmaceutical products. The aim of the study was to analyze the composition of selected essential oils used in respiratory diseases. MATERIAL AND METHODS The qualitative analysis was performed by gas chromatography with mass spectrometry. For the study 6 essential oils available in Polish shops and used in various respiratory diseases were chosen. The results were compared with the information provided by the manufacturer and the literature. RESULTS The method used in the presented work allowed to qualitatively identify the main components in studied essential oils. In the analyzed samples generally occurred: α- i β-pinene, limonene, terpinen-4-ol and caryophyllene. In addition to limonene, the presence of linalool, eugonol and geraniol, potentially allergenic substances, were also detected. CONCLUSIONS The qualitative composition of the studied essential oils comply with the existing literature data. Their main ingredients show antimicrobial and antiviral activities, therefore they are used to eradicate the symptoms of infection. However, the attention should be paid to the composition of the products because they often comprise potential allergens. Information on the presence of such a substance in the preparation should be clearly marked by the manufacturer on the packaging. Fragrances are also found in a number of household products that increase their concentration in the air of living premises, thereby increasing the risk of side effects especially in people with allergies or sensitive. Med Pr 2018;69(2):167-178.

Selected oxidative stress parameters after single and repeated administration of octabromodiphenyl ether to rats.

ObjectivesOctabromodiphenyl ether (OctaBDE) was used as a flame retardant applied mostly in the manufacture of plastics utilized in the electrical and electronic industries. Owing to its long half-life and being regarded as an environmental pollutant, OctaBDE, like other polybrominated diphenyl ethers, has been classified as a persistent organic pollutant (POP). This study was carried out to assess the effects of oxidative stress (redox homeostasis) induced in rats by OctaBDE.Material and MethodsFemale Wistar rats exposed intragastrically to OctaBDE at single (25, 200 or 2000 mg/kg b.w.), or repeated (0.4, 2, 8, 40 or 200 mg/kg/day) doses during 7–28 days were used in the experiment. Selected oxidative stress parameters were determined in the liver and blood serum.ResultsAdministration (single or repeated) of OctaBDE to rats resulted in the impaired redox homeostasis, as evidenced by the increased levels of reduced (GSH) and oxidized (GSSG) glutathione in the liver, the reduced total antioxidant status (TAS) in serum and the increased concentration of malondialdehyde (MDA) in the liver. After multiple doses of OctaBDE, elevated activity of glutathione transferase (GST) in the liver was also noted.ConclusionsAfter repeated administration of OctaBDE at the lowest dose (0.4 mg/kg/day), changes were observed in the parameters (MDA, TAS, GSSG) indicative of oxidative stress.