Protective properties of filamentous blue–green alga Spirulina against the oxidative stress induced by cadmium in freshwater mussel Unio ravoisieri

ABSTRACT

Cadmium (Cd) is a toxic-heavy metal that induces a wide range of behavioural, biochemical and physiological effects in aquatic organisms. Oxidative damage has been proposed as a possible mechanism involved in cadmium toxicity. The current study was carried out to evaluate the antioxidant activity of Spirulina as feed additive (1?mg/L) against the toxicity of cadmium (Cd) 0.5?mg/L in freshwater mussel Unio ravoisieri. At the end of the exposed period of 4 days, digestive gland antioxidant status Superoxide dismutase, Catalase, Glutathione-S-transferase and damage markers such as Malondialdehyde and Protein carbonyl were determined. Associations between biomarkers were assessed by a multivariate analysis technique, principal component analysis (PCA). The results of this study revealed that digestive gland antioxidant status showed a significant decrease when mussels were exposed to Cd. Superoxide dismutase, Catalase and Glutathione-S-transferase activities in the Cd?+?SP group were significantly higher than the Cd group (p P?相似文献   

锚固系统与锚固介质材料中应力波波速的关系

应用低应变反射波法对锚杆锚固系统进行无损检测时,常因锚杆底端反射很微弱而影响锚固系统中应力波波速的准确确定,导致锚固质量无法准确判读,为此,采用低应变反射波法测试了不同围岩和锚固介质中的锚固系统应力波波速,并与采用超声波法测试的由锚固介质材料所制作标准试块中的应力波波速进行对比分析。结果表明,这2种波速与锚固介质材料强度密切相关;锚固系统中的应力波波速介于锚固介质材料与自由锚杆中的应力波波速之间,锚固系统中的应力波波速和锚杆介质材料中的应力波波速随龄期和强度均呈指数关系变化且对称分布。     

Sensorimotor performance deficits induced by chronic chlorpyrifos exposure in Wistar rats: mitigative effect of vitamin C

This study was aimed at evaluating the ameliorative effect of vitamin C on chlorpyrifos-induced sensorimotor changes involving postural reflex, limb placing, and vibrissae touch in Wistar rats. Forty adult Wistar rats of either sex were divided into 4 groups of 10 animals in each group. Group I was administered soya oil (2?mL?kg^?1) while group II was given vitamin C (100?mg?kg^?1); group III was dosed with chlorpyrifos (10.6?mg?kg^?1, i.e. ～1/8th of the LD₅₀); group IV was administered vitamin C (100?mg?kg^?1) and then exposed to chlorpyrifos (10.6?mg?kg^?1), 30?min later. The regimens were administered by gavage once daily for a period of 17 weeks. Neurobehavioral parameters involving postural reflex, limb placing, and vibrissae touch responses measured at various intervals revealed a deficit in postural reflex, limb placing, and vibrissae touch responses in the CPF group, which was mitigated by vitamin C pretreatment. The neuronal and glial cell degeneration, increased brain malonaldehyde concentration, and decrease in superoxide dismutase, catalase, and acetylcholinesterase activities recorded in the group given chlorpyrifos were ameliorated by vitamin C. Therefore, vitamin C was shown to mitigate chlorpyrifos-induced sensorimotor deficits partly due to its antioxidant and acetylcholinesterase restoration properties.     

Effects of chronic bisphenol A exposure on hepatic antioxidant parameters in medaka (Oryzias latipes)

Bisphenol A (BPA), the plastic monomer and plasticizer with well-known endocrine-disrupting chemical properties, is widely present in the aquatic environment, but little is known regarding hepatic toxicity in fish. This study assessed the effects of chronic exposure to BPA on the antioxidant defense system of Japanese medaka liver. Fish were exposed to sub-lethal concentrations of BPA (0.1, 1, 10, 100, or 1000?µg?L^?1) for 60 days. Antioxidant parameters were determined and compared with controls. The results showed that the activities of catalase (CAT), superoxide dismutase, glutathione peroxidase, glutathione S-transferase, and the content of reduced glutathione were all induced at 10?µg?L^?1 BPA after 60 days. Further, hepatic CAT was sensitive to BPA at 1?µg?L^?1 concentration. In conclusion, CAT may serve as a potential early biomarker of BPA exposure in aquatic environment.     

Antidiabetic effects of Trigonella foenum-graecum seed powder in a rat model

Free radical production and oxidative stress are known to increase in liver during diabetes and may contribute to oxidative damage. In this study, the effect of oral feeding of Trigonella foenum-graecum seed powder (TSP) has been studied on blood glucose, membrane-linked ATPases, antioxidant enzymes, lipid peroxidation, lipofuscin content and membrane fluidity in livers of a diabetic rat. Diabetes was induced by administration of alloxan monohydrate. Hyperglycemia during diabetes has been shown to entail free radical generation, with a concomitant increase in lipid peroxidation and lipofuscin content, inhibition of membrane-linked ATPases, increased antioxidant enzyme activities and decreased membrane fluidity. TSP treatment reverses the changes to near normal levels thereby ameliorating the management of diabetic complications.     

Therapeutic effect of melatonin against aluminum-induced neurotoxicity in cerebellum of albino mice

The therapeutic effect of melatonin (MEL) against aluminum (Al)-induced neurotoxicity was investigated in mouse cerebellum. Two groups of male albino mice were intraperitoneally injected with Al acetate or MEL alone, at doses of 3.5 or 7?mg?kg^?1?day^?1, respectively, for 6 weeks. During this period, another group of animals received a combination of both Al and MEL (3.5?+?7?mg?kg^?1?day^?1). At the end of the treatment cerebellum was removed and processed to examine the oxidative stress markers: superoxide dismutase (SOD), catalase (CAT), and thiobarbituric acid-reactive substances (TBA-RS). Oxidative stress increased significantly with administration of Al which was estimated by increased TBA-RS and reduction in the activities of SOD and CAT. However, these alterations were significantly reversed significantly following MEL treatment which was observed in co-administered group. Protective effects of MEL were also observed at electron microscopic level. Ultrastructural studies revealed an increase in vacuolization, chromatin condensation within the nucleus, degenerated purkinje cell, degenerated axon and degenerated granule cells in the cerebellum of Al-treated mice group whereas concurrent administration of MEL with Al reduced these changes. The results of the present investigation emphasize the potential use of MEL as a supplement in therapy of free radical based neurological disorders in which oxidative stress is involved.     

The effects of evening primrose oil on arsenic-induced oxidative stress in rats

Forty-eight male Wistar albino rats were allocated to the four groups such that each comprised 12 animals. The first group was maintained as the control. In group 2, evening primrose oil was administered at a dose of 0.1 mL rat^?1 day^?1 (～500 mg kg^?1 bw) into the stomach via gavage, whilst in group 3 sodium arsenide was administered at a concentration of 100 mg L^?1 in ad-libitum drinking water for 30 days. The fourth group was given 0.1 mL rat^?1 day^?1 evening primrose oil into the stomach via gavage plus 100 mg L^?1 of sodium arsenide in ad-libitum drinking water for 30 days. At the end of the 30th day, tissue (liver, lung, kidney, brain, heart, spleen, and testis) and blood samples were collected from each group. Malondialdehyde (MDA) and nitric oxide (NO) levels and superoxide dismutase, catalase and glutathione peroxidase activities were measured in the samples. Exposure to arsenic in rats causes oxidative stress by increasing lipid peroxidation (increase of MDA and NO levels) and altering the activity of antioxidant enzymes. Evening primrose oil did not have any adverse effects. Furthermore, it was ascertained that the administration of arsenic with evening primrose oil reduced the severity of oxidative stress.     

Effect of Zinc Oxide nanoparticles on cellular oxidative stress and antioxidant defense mechanisms in mouse liver

Zinc oxide nanoparticles (ZnO₂), a common ingredient of cosmetics has a huge variety of applications. Previous studies reported oxidative stress mediated toxicity of ZnO₂ nanoparticles on various mammalian cell lines. Although zinc (Zn) is an essential mineral at higher concentrations this metal is toxic. The present study focused on size determination by monitoring changes in activities of antioxidant defense mechanism in response to oxidative stress induced by ZnO₂ nanoparticles using mouse liver tissue homogenates. The study also investigated effects of oxidative stress induced DNA damage by determining formation of 8-OHdG in mouse liver homogenate. A cytotoxicity assay was also carried out in L929 cells to determine cell viability. The results of the study indicated that 50μg/ml of ZnO₂ nanoparticles induced 50% cell death. Alterations in antioxidant parameters and 8-OHdG were also noted. Data showed that there was a concentration-dependent fall in cell viability, decrease antioxidant enzyme levels and increase formation of DNA adduct (8-OHdG) when mouse liver tissue homogenate were exposed to ZnO₂ nanoparticles.     

Protective effect of Tamarindus indica fruit pulp extract on collagen content and oxidative stress induced by sodium fluoride in the liver and kidney of rats

Fluorosis is a serious public health problem in many parts of the world. The generation of reactive oxygen species and lipid peroxidation has been considered to play an important role in the pathogenesis of chronic fluoride toxicity. The present study was undertaken to evaluate the protective effect of Tamarindus indica fruit pulp extract on the collagen content and oxidative stress in liver and kidney of fluoride-exposed rats. The first group served as control. The second group received 200 mg L^?1 of sodium fluoride through drinking water. The third and fourth groups received T. indica fruit pulp extract (200 mg kg^?1 body weight) alone and along with fluorinated drinking water respectively, daily by gavage for a period of 90 days. At the end of the experiment, blood samples were collected from all groups, and liver and kidney samples were taken concurrently. Levels of malondialdehyde and glutathione and the activities of superoxide dismutase and catalase were evaluated in the liver and kidney of experimental rats. Furthermore, level of hydroxyproline and histological examination of liver and kidney along with serum biochemical parameters were evaluated. In conclusion, fluoride was determined to cause adverse effects in rats, and the supplementation of tamarind to these animals alleviated the adverse effects of fluoride.     

Comparison of cellular and molecular cytotoxic mechanisms of Cochlodinium polykrikoides in isolated trout and rat hepatocytes

Harmful algal blooms produced by the marine ichthyotoxic dinoflagellate Cochlodinium polykrikoides are responsible for mass mortalities of wild and farmed fish globally. This study compared the cytotoxic mechanisms of C. polykrikoides total extract on both trout and rat liver hepatocytes. Trout hepatocytes were more sensitive than rat hepatocytes against C. polykrikoides extract. The effective concentration 50 after 3 hour incubation (EC50_3hr) concentrations found for C. polykrikoides extract in trout and rat hepatocytes (i.e., 50% membrane lysis in 3 hr) were Eq. 1 cell/ml and Eq. 240 cell/ml, respectively. C. polykrikoides extract exposure in both isolated trout and rat hepatocytes resulted in membrane lysis, reactive oxygen species formation, glutathione depletion, collapse of mitochondrial membrane potential, ATP depletion, increase in adenosine diphosphate (ADP)/adenosine triphosphate (ATP) ratio, cytochrome c release into the hepatocyte cytosol, and activation of caspases cascade. Trout hepatocyte toxicity was also associated with lysosomal membrane injury. Mitochondrial permeability transition in both trout and rat hepatocytes produced cytochrome c release from the mitochondrial intramembrane space into the cytosol. Thus, the cytochrome c release triggered activation of caspase-3 and apoptosis. Finally, data demonstrated that C. polykrikoides extract may induce more apoptotic phenotype in rat than trout hepatocytes, which in the latter favored predominantly necrotic mode of cell death.