Most frequently encountered freshwater cyanobacterial toxin is Microcystin-LR (MC-LR). Microcystins released from cells into water have been responsible for the death of humans, domestic and wild animals. Removal of microcystin by active carbon has been one of the best methods available so far. This study evaluates three grades of active carbon namely 40, 60 and 80 CTC for their removal efficiency of MC-LR from contaminated water. Kinetics of toxin removal was studied in time course experiments. Protection in mouse model was studied for the samples after the adsorption. Toxin quantitation was done by HPLC method. The MC-LR concentration after 24 hr treatment with 40, 60 and 80 CTC carbons were 4.8, 3.3 and 1.3 microg/ml respectively from an initial concentration of 5.2 microg/ml. Protection in mouse bioassay was seen after 48, 24 and 2 hr of adsorption time respectively for 40, 60 and 80 CTC carbons. 80 CTC carbon was found to be most efficient in removing MC-LR from contaminated water. 相似文献
Eutrophication with a large number of Microcystis aeruginosa commonly occurs worldwide, thereby threatening the aquatic ecosystem and human health. In this study, four kinds of algicides were tested to explore their influence on cell density and chlorophyll-a of M. aeruginosa. Results showed that aluminum silicate agent, which inhibited more than 90% cell growth compared with the control group, demonstrated the strongest inhibition effect immediately on M. aeruginosa growth. Furthermore, the production and release of microcystin (MC)-LR were investigated. Aluminum silicate, CuSO4, and Emma-11 were more effective than pyrogallic acid in disrupting the cells of M. aeruginosa, thereby increasing the extracellular MC-LR concentration. Aluminum silicate caused the highest extracellular MC-LR concentration of more than 45 mg·L–1. Biotoxicity was also detected to evaluate the environmental risks of MC-LR release, which were related to the usages of different algicides. Extracellular MC-LR concentration mostly increased when the biotoxicity of algae solution increased. The experiments were also designed to reveal the effects of physical conditions in riverways, such as natural sunlight, aeration and benthal sludge, on MC-LR degradation. These findings indicated that UV rays in sunlight, which can achieve a MC-LR removal efficiency of more than 15%, played an important role in MC-LR degradation. Among all the physical pathways of MC-LR removal, benthal sludge adsorption presented the optimal efficiency at 20%.
Isatis cappadocica has been reported to be an arsenic (As) hyperaccumulator. Antioxidant enzymes and compounds have been proposed to play an important role in the detoxification and tolerance of As. In the present study, As-induced oxidative stress and antioxidant responses were investigated on I. cappadocica grown hydroponically in response to application of arsenate (0–1200?μmol). As accumulation increased with an increase in arsenate concentration in the medium. Along with a significant increase in arsenate concentration, a build up in hydrogen peroxide, indicators of oxidative stress, was observed. The activity of superoxide dismutase and peroxidase was induced after arsenate treatment, reached a maximal value at 800?μmol arsenate and then declined at the highest arsenate treatment. Glutathione reductase activity and contents of non-enzymatic antioxidants (carotenoids, flavonoids and anthocyanins) increased significantly as arsenate concentration augmented. These results indicated that high efficient antioxidant system may play significant roles in As detoxification and improve I. cappadocica tolerance against As toxicity. 相似文献
The mutualistic benefits and disadvantages of non-clavicipitaceous endophytes for their hosts are not well studied and are postulated as being distinct from free-living or pathogenic counterparts. The defensive metabolites and antioxidants produced by endophytes are postulated to be the benefits offered for the hosts. Therefore, the antimicrobial and free-radical-scavenging activities of a foliar endophyte Chaetomium globosum HYML55 isolated from Hypericum mysorense of Western Ghats, India were studied. RNA secondary structure analysis refuted the unique biotope postulation because strain HYML55 was more similar to a coprophilous strain than to endophytic strains. Ethyl acetate extract of the fungus inhibited bacteria and fungi. The extract also quenched 98.65% 1,1-diphenyl- 2-picrylhydrazyl radicals with total antioxidant capacity of 13.62 mg ascorbic acid equivalent/g. A yellow amorphous antimicrobial compound purified from the extract was identified as chaetoglobosin F, which had a minimum inhibitory concentration of 7.8–15.6 μg/mL, except against Pseudomonas aeruginosa. This is the first report on the antimicrobial activity of chaetoglobosin F and other bioactivities of any endophytes from H. mysorense. The study emphasises the inter-habitat cycling of endophytes and possible benefits of C. globosum for the host. Chaetoglobosin F is an anti-inflammatory and anti-neoplastic compound, and C. globosum HYML55 could be exploited for the industrial production of this compound. 相似文献
Benzo(a)pyrene (B(a)P) is a commonly used indicator for polycyclic aromatic hydrocarbons (PAHs) contamination. The use of certain phytochemicals and some polyphenolic compounds proved to be effective in blocking PAH-induced effects. The aim of the present study was to examine the possible inhibitory effects of ellagic acid (EA), present in berries and nuts, against B(a)P-mediated toxicity using in vitro and in vivo test systems. In vitro method included the Ames test, using Salmonella typhimurium tester strain TA100. In vivo experiments were based on mouse bone marrow micronucleus (MN) assay and immunoblotting. EA produced a decrease in the number of revertant colonies against B(a)P in the Ames assay. Further, there was a reduction in the mean number of micronucleated polychromatic erythrocytes in the presence of EA in the co-treatment protocol of the MN test. Western blotting results showed downregulation of CYP450 isoform CYP1A1 which prevented bioactivation of B(a)P. Thus, the present study demonstrates antimutagenic role played by EA against the mutagenic activity of B(a)P in both in vitro and in vivo systems. 相似文献
AbstractAcrylamide is a highly soluble and widely produced industrial chemical that has been shown to pose numerous health hazards. This study aimed to assess the effects of acrylamide on the cytotoxicity and oxidative damage in embryonic fibroblast cells (BALB/c 3T3) and to measure protective roles of the natural antioxidants vitamin C and curcumin. Embryonic fibroblast cells were exposed to acrylamide at concentrations of 1, 10, 100, and 1000?μmol/L and vitamin C (50?μmol/L) or curcumin (2.5?μmol/L) for 24?h. Cell viability, cytotoxicity, the activities of antioxidant enzymes superoxide dismutase, glutathione-S-transferase, glutathione peroxidase and catalase, and the markers of oxidative lipid peroxidation, hydroxyl radical, hydrogen peroxide and glutathione were measured. Co-treatment of the acrylamide-exposed fibroblast cells with vitamin C or curcumin attenuated the cytotoxicity and formation of reactive oxygen species and decreased the antioxidant enzyme activity. Thus, it was concluded that vitamin C and curcumin may play a protective role against acrylamide toxicity; the treatment with 50?μmol/L vitamin C was found to be more effective than the treatment with 2.5?μmol/L curcumin. 相似文献
Role of mitochondrial dysfunction and oxidative stress has been well documented in various cognitive-related disorders such as Alzheimer's disease (AD). Evidence indicates that Aß formation impairs mitochondrial function and that mitochondrial dysfunction is an early event in the pathogenesis of AD. The present study was, therefore, designed to investigate the direct toxicity of Aß peptide on isolated mitochondria obtained from rat brain. Various mitochondrial toxicity/integrity parameters such as succinate dehydrogenase activity, reactive oxygen species (ROS) formation, mitochondrial membrane potential collapse (MMP), mitochondrial swelling, and cytochrome c release were measured following the addition of Aß peptide on isolated mitochondria and then, mitoprotective effect of aqueous extracts of Mangifera indica and Juglans regia against mitochondrial toxicity endpoints parameters induced by Aß peptide were assessed. Our results showed that exposure to Aß peptide (30 nM) in isolated brain mitochondria induced mitochondrial ROS formation, MMP collapse, mitochondrial swelling, and cytochrome c release which is the starting point of apoptosis signaling. All these mitochondrial toxic endpoints induced by Aß peptide inhibited by aqueous extracts of Mangifera indica (100–400 µg/ml) and Juglans regia (200–400 µg/ml). To our knowledge, this is one of the first apparent studies to claim directly targeting of brain mitochondria and induction of apoptosis by Aß peptide as a new hypothesis for etiology of AD and other related neurodegenerative diseases as well as mitopreventive role of common antioxidant nutritional products including walnut and mango. 相似文献
Antimony (Sb) accumulates in the liver which is one of the target organs for metal-mediated toxicity. Although toxicity of Sb was previously investigated, the precise mechanism of Sb-induced hepatotoxicity remains to be determined. The aim of this study was to examine the role of oxidative stress, and mitochondria in the induction of cell death by Sb. Our results showed that liver cell lysis induced by Sb is mediated by reactive oxygen species (ROS) formation, lipid peroxidation and decline of mitochondrial membrane potential (MMP). Antimony-induced ROS formation, lipid peroxidation and reduction of MMP were significantly diminished by antioxidants and ROS scavengers such as dimethyl sulfoxide and mannitol; mitochondrial permeability transition (MPT) pore sealing agents such as carnitine and trifluoperazine; and adenosine triphosphate (ATP) generator, L-glutamine. Antimony-induced ROS formation, lipid peroxidation and fall in MMP were potentiated by glutathione (GSH) depletion via n-bromoheptane. MPT pore sealing agents and ATP generator inhibited hepatotoxicity, indicating Sb-activated cell death via mitochondrial pathway. Pretreatment of hepatocytes with antioxidants and ROS scavengers also blocked cell death induced by Sb, whereas GSH depletion enhances Sb-induced cell death, suggesting that oxidative stress may be directly involved in the reduction of MMP. These findings contribute to a better understanding of the mechanisms that mediate Sb-induced cell death in isolated rat hepatocytes. 相似文献
Given the wide industrial use of chromium (Cr) and its environmental contamination, chromium represents a risk to humans exposed to the metal. Considering that Cr(VI) is a potent oxidizing agent that increases intracellular oxidation and DNA damage, it would be worth considering the pretreatment of cells with antioxidants as a means of preventing Cr(VI)-induced toxicity. The objective of this study was to pretreat yeast cells with the water-soluble vitamin E analogue Trolox in an effort to increase cell tolerance against reactive chromium and reactive oxygen species formed during Cr(VI) reduction. Results revealed a decrease in Cr(VI)-induced cytotoxicity and mitotic gene conversions in Trolox-pretreated cells. The protective effect of Trolox in Cr(VI) induced genotoxicity was confirmed also with the prokaryotic Salmonella typhimurium SOS/umu test. Pretreatment of cells with Trolox (1) increased total Cr bioaccumulation, (2) decreased Cr(VI)-induced intracellular oxidation, (3) decreased Cr(V) persistence and (4) increased OH? formation in yeast extracts. These findings might be useful in directing future investigations concerning the use of Trolox as a human antioxidant supplement, and in clinical applications related to Cr-induced genotoxicity in occupational and environmental situations where chromium is a problem. 相似文献
AbstractThe effect of microcystin-LR (MC-LR) at 50–1000?nmol/L on blood vessel development of zebrafish embryos has been explored. Upon exposure 72-h-post-fertilization (hpf), the hatching rate was significantly reduced and malformation and fatality rates were increased in a dose-dependent manner. MC-LR induced cell cycle arrest in the G0/G1-phase and damaged DNA structure in a dose-dependent manner. In human umbilical vein endothelial cells (HUVECs), MC-LR led to decreased activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) and increased lipid peroxidation. These findings indicated that MC-LR could cause oxidative DNA damage, which mediated cell cycle arrest and inhibited cell proliferation afterwards, and retarded the blood vessel development. 相似文献
A promising bacterial strain for biodegrading microcystin-LR (MC-LR) as the sole carbon and nitrogen source was successfully isolated from Lake Dianchi, China. The strain was identified as Sphingopyxis sp. USTB-05, which was the first isolated MCs-biodegrading Sphingopyxis sp. in China. The average biodegradation rate of MC-LR by Sphingopyxis sp. USTB-05 was 28.8 mg??L?1 per day, which was apparently higher than those of other bacteria reported so far. The optimal temperature and pH for both strain USTB-05 growth and MC-LR biodegradation were 30??C and 7.0, respectively. The release of MC-LR from the cyanobacterial cells collected from Lake Guishui and the biodegradation of MC-LR by both strain and cell-free extract (CE) were investigated. The results indicated that MC-LR with the initial concentration of 4.0 mg??L?1 in water was biodegraded by Sphingopyxis sp. USTB-05 within 4 d, while MC-LR with the initial concentration of 28.8 mg??L?1 could be completely removed in 3 h by CE of Sphingopyxis sp. USTB-05 containing 350 mg??L?1 protein. During enzymatic biodegradation of MC-LR, two intermediate metabolites and a dead-end product were observed on an HPLC chromatogram. Moreover, the similar scanning profiles of MC-LR and its metabolic products indicate that the Adda side-chain of MC-LR was kept intact in all products. 相似文献
Two starfishes, togemomijigai Astropecten polyacanthus and momijigai A. scoparius were collected from the Seto Inland Sea in October 1983 through November 1984, and assayed for toxicity by the standard method for tetrodotoxin (TTX). Most of the 54 A. polyacanthus specimens assayed were toxic, with the highest toxicity score being 520 mouse units (MU) g-1. All seven A. scoparius were toxic, with the highest score being 46 MU g-1. The toxin from A. polyacanthus was purified by a method which consisted mainly of activated charcoal treatment, and chromatography on CM-Sephadex C-25 and Bio-Rex 70 columns. The purified starfish toxin showed a specific toxicity of 4 700 MU mg-1, a value which was almost comparable to that of authentic TTX. From the thin-layer chromatographic and electrophoretic behavior, along with 1H-NMR spectrum, A. polyacanthus toxin was identified as TTX. 相似文献
作为一种新兴的纳米材料,羟基多壁碳纳米管(OH-MWCNTs)可能与其他污染物在水环境中共存,并进一步影响它们的毒性、输移和归趋。因此,评价碳纳米管存在下砷的毒性变化需要得到更多的关注。该试验探索了在不同pH值条件下,OH-MWCNTs诱导砷(As(III)和As(V))对水生生物大型蚤的毒性变化的潜在机制。发现了H2AsO3-和H2AsO4-是对大型蚤毒性最大的As(III)和As(V)。比较As(III)和As(V)的结果,发现pH值是影响砷毒性最重要的因素。此外,OH-MWCNTs影响砷对大型蚤毒性的结果表明,OH-MWCNTs的存在可以提高砷的毒性。通过吸附实验进一步研究了砷与OH-MWCNTs的相互作用。OH-MWCNTs 对As(V)吸附容量高于As(III)。总而言之, OH-MWCNTs对某些形态砷的吸附是解释砷毒性增强的可靠证据。
精选自Xinghao Wang, Ruijuan Qu, Ahmed A. Allam, Jamaan Ajarem, Zhongbo Wei, Zuoyao Wang. Impact of carbon nanotubes on the toxicity of inorganic arsenic [As(III) and As(V)] to Daphnia magna: the role of the certain arsenic species. Environmental Toxicology and Chemistry: Volume 35, Issue 7, pages 1852–1859, July 2016.
DOI: 10.1002/etc.3340
详情请见http://onlinelibrary.wiley.com/doi/10.1002/etc.3340/full 相似文献
This investigation was undertaken to evaluate the chemopreventive effect of hydroalcoholic extract of Indigofera aspalathoides (HAIA) against 20-methylcholanthrene (20-MC)-induced carcinogenesis in mice. Tumor was induced by single subcutaneous administration of 20-MC (200 µg per mouse) in Swiss albino mice. After 24 h of 20-MC administration, HAIA was administered at the doses of 250 and 500 mg kg?1 body weight orally for 90 consecutive days. Mice of all groups were observed for 15 weeks to record tumor incidence (fibrosarcoma) and survival time. After 15 weeks the mice were sacrificed for the estimation of hematological profiles like hemoglobin (Hb), white blood cell (WBC), red blood cell (RBC), and liver biochemical parameters, namely lipid peroxidation, reduced glutathione (GSH), glutathione-S-transferase (GST), superoxide dismutase (SOD), and catalase (CAT). HAIA treatment markedly reduced tumor incidence and prolonged the life span of sarcoma-bearing mice as compared to 20-MC control mice. Hematological profiles were significantly (p < 0.001) restored to normal levels in HAIA-treated mice as compared to 20-MC control mice. HAIA treatment significantly (p < 0.001) modulated the aforesaid liver biochemical parameters as compared to 20-MC control. The results concluded that I. aspalathoides demonstrated a remarkable chemopreventive effect in chemical-induced carcinogenesis in mouse. The potential chemopreventive action may be due to its antioxidant and detoxifying properties. 相似文献
During mate choice, individuals are predicted to assess traits that honestly signal the quality of potential partners. Locomotor
capacity may be such a trait, potentially signalling condition and ability to resist oxidative damage. In this study, we experimentally
manipulated nutritional status: Male wild-type budgerigars, imported from Australia, were provided with either an enhanced
(EQ) or reduced quality (RQ) diet varying in vitamin (particularly retinol and α-tocopherol) and mineral levels. Then, we
assessed whether this influenced locomotor capacity, i.e. escape flight performance, and sexual attractiveness in male budgerigars
Melopsittacus undulatus. Males in the EQ group showed significantly greater total antioxidant capacity and higher blood plasma concentrations of the
dietary antioxidants retinol and α-tocopherol, but not carotenoids, than the RQ group. Over 8 weeks of flight training, males
on the EQ diet showed significantly greater improvement on the most strenuous flight test than RQ males. In mate choice trials,
females preferred EQ over RQ males. EQ males that were relatively fast in escape flight trials were more strongly preferred
in the mate preference arena than their RQ competitors. Interestingly, males with high plasma carotenoid levels flew slower
and were less attractive than males with low carotenoid levels. This might indicate that carotenoids are not effective antioxidants
in birds. Overall, our results show that dietary-derived antioxidants can influence sexual attractiveness and other fitness-related
traits through multiple pathways. Locomotor capacity appears to be an honest signal of male condition in birds. 相似文献