Histomorphological and cytochemical changes induced in the liver of goldfish Carassius carassius var. auratus by short-term exposure to lead

Modulation of lead biohazards using a combination of epicatechin and lycopene in rats

The toxicity of many heavy metals is due to their ability to cause oxidative damage to tissues. Lead is one of the most important metals that pollute the natural environment due to man’s impact The aim of this study is to investigate the potential protective effect of epicatechin alone or combined with lycopene against toxicity of lead in male rats. Five groups of rats were involved in this study; the first was control while the other four injected with lead acetate (100 mg/kg BW) subcutaneous for 2 weeks. On the other hand, the third, fourth and fifth groups were injected with epicatechin, lycopene or epicatechin + lycopene, respectively. Results obtained showed that, the combined treatment (epicatechin + lycopene) exert its effects (100%) against toxic effects against lead by lowering the liver enzymes alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP) and gamma glutamyle transferase (GGT) activities and decrease lipid peroixdation (MDA) and enhances the superoxide dismutase (SOD) activity. The high-density lipoprotein cholesterol (HDL-c) level was significantly decreased and low-density lipoprotein cholesterol (LDL-c) level was statistically significantly increased in lead-injected rats as compared with control group. The combined treatment with epicatechin and lycopene justify these levels to nearly normal values. The erythrocyte level of total glutathione was decreased in lead-injected rats as compared with control group ( p < 0.001). The combined effect is significantly higher than individual treatment lycopene alone or epicatechin. A negative correlation was found between the blood lead and SOD (r = −0.6) and glutathione (r = −0.81) while a positive correlation with MDA level (r = 0.7).

Potential use of glycogen level as biomarker of chemical stress in Biomphalaria glabrata

Biomphalaria glabrata, a freshwater gastropod mollusc, was tested as biondicator organism to assess cadmium, lead and arsenic exposure using acute laboratory bioassays. Modifications of glycogen levels were measured in different anatomical regions of B. glabrata in order to test the usefulness of this parameter as a general biomarker of chemical stress. The snails were exposed 96 h to different concentrations of the following contaminants: 0.1 and 0.05 mg Cd/L; 0.5, 0.1 and 0.05 mg Pb/L; 0.5, 0.1 and 0.05 mg As/L. Significant decreases in the polysaccharide content were observed in gonadal region for all treated animals. Arsenic and lead at 0.1 and 0.5 mg/L level of exposure were also able to decrease the levels of glycogen in the pulmonary and digestive gland region. Glycogen content in the cephalopedal region of treated animals presented a significant decrease (p<0.05) when compared with control organisms only for arsenic at the highest level of exposure. To establish possible correlations between glycogen and contaminants accumulated by snails, analyses of the elements bioaccumulated in the different anatomical regions of B. glabrata were also performed. Cadmium and lead followed a similar pattern of bioaccumulation with highest values in the digestive gland region. Arsenic bioaccumulation, however, was highest in the gonadal region.

Melatonin protects against lead-induced hepatic and renal toxicity in male rats

The present study was designed to investigate the potential protective effect of melatonin against the hepatic and renal toxicity of lead in male rats. Three groups of animals were used in this study (control, lead acetate-treated (100 mg/kg), and lead acetate plus melatonin (10 mg/kg) for 30 days. Levels of lipid peroxidation (LPO) products, superoxide dismutase (SOD) activity, total glutathione (GSH), histopathological changes in the liver and kidneys were investigated. In addition, nuclear area (NA), nuclear volume (NV) and the ratio of nuclear volume/cellular volume (N/C) were measured in the liver. The results revealed increased LPO and decreased SOD, GSH, NA, NV and N/C in the studied organs of lead-treated rats. Histopathological observations showed severe damage in the liver and kidneys. Melatonin co-treatment to the lead-administered rats attenuated the increase of LPO and restored the activity of SOD and levels of GSH as well as the mean values of NA, NV and N/C. Also, the morphological damage in the liver and kidneys was reduced and the tissues appeared like those of controls. The present study suggests that melatonin may be useful in combating free radical-induced damage due to lead toxicity.

Histopathological changes in the liver, kidneys, and testes of bank voles environmentally exposed to heavy metal emissions from the steelworks and zinc smelter in Poland

Bank voles were trapped in the neighborhood of the Sendzimir steelworks in Krakow and the ZGH Boleslaw zinc smelter in Bukowno. The Borecka forest in the north of Poland served as a control area. Lead, cadmium, zinc, and iron concentrations were analyzed in the liver, kidneys, testes, and femur bones of the bank voles. Typically, high levels of lead and cadmium were found in the bones and kidneys, respectively. In the femurs of the rodents from Bukowno, 109.26 microg g(-1) dry weight of lead was detected. The kidneys of these animals had accumulated 32.98 microg g(-1) cadmium. Concentrations of zinc and iron in the tissues were at physiological levels. No damage was found in the tissues of the bank voles from the Borecka forest or in the testes of animals from other areas. Histopathological changes in the kidneys of the rodents from Krakow as well as changes to the liver and kidneys of the animals from Bukowno were demonstrated.

Damage to the liver, kidney, and testis with reference to burden of heavy metals in yellow-necked mice from areas around steelworks and zinc smelters in Poland

The influence of the steelworks in Warsaw and Krakow as well as the zinc smelters in Bukowno and Miasteczko Slaskie on lead, cadmium, zinc and iron concentrations and the structure of selected tissues of yellow-necked mice were analysed. The Borecka Forest was chosen as a control area. The highest concentrations of lead, 172.36 g/g dry weight, and cadmium, 23.58 g/g, were detected in the femurs and kidneys, respectively, of rodents caught in Bukowno. Zinc and iron concentrations ranged over physiological values. No histopathological changes were observed in analysed tissues of all rodents in the control area. Damage occurred in the liver and kidneys of animals from all other sites and in the testes of rodents from Bukowno. Decreased glycogen content, interstitial fibrosis, and increased number of pyknotic nuclei as well as necrosis were seen in hepatocytes. In the kidneys hyperplasia of the tubules, atrophy of glomeruli, interstitial fibrosis and necrosis were observed. Degenerate cells were present in the lumen of seminiferous tubules of animals from the Bukowno area. Even relatively low concentrations of lead and cadmium, like those found in the liver and kidneys of rodents from the neighbourhood of the steelworks, caused histopathological changes.

Histochemical demonstration of changes in the activity of hepatic phosphatases induced by experimental lead poisoning in male white rats (Rattus norvegicus)

Seven hepatic phosphatases were histochemically investigated in male white rats (Rattus norvegicus) pretreated with chronic subtoxic doses of lead acetate. Lead has increased the activities of alkaline-, acid-, neutral-, adenosine mono- and glucose-6-phosphatase, but has markedly decreased the activity of membrane-bound Na+-K+, ATPase while the activity of mitochondrial Mg2+-ATPase was not altered. It has also produced heterogenous alterations in the distribution patterns, sites of the enzymatic activities and in the intensity of phosphatase activities among the same type of cells in the terminal afferent and efferent venules of the hepatic lobules. The obtained histochemical findings indicate that the alterations in the activities of hepatic phosphatases could be an adaptation to the metabolic, structural and functional changes in the organelles of hepatic cells due to lead intoxication.