Changes of lipid peroxidation in carbon disulfide-treated rat nerve tissues and serum

Maternal residential exposure to solvents from industrial sources during pregnancy and childhood cancer risk in California

BACKGROUND

Maternal solvent exposure has been suspected to increase offspring cancer risk. The study aimed to evaluate the associations between maternal residential exposure to solvents from industrial pollution during pregnancy and childhood cancer.

METHODS

The present study included 15,744 cancer cases (aged 0-19 years at diagnosis) identified from California Cancer Registry and 283,141 controls randomly selected from California Birth Registry (20:1 frequency-matched by birth year: 1998-2016). We examined industrial releases of tetrachloroethylene and 1,1,1-trichloroethane within 3 km of the birth address, while we used a 5 km buffer for carbon disulfide. We calculated the total exposure from all linked Toxic Release Inventory sites during each index pregnancy and assigned "ever/never" and "high/low exposed/unexposed" exposure, using median values. We performed quadratic decay models to estimate cancer risks associated with maternal solvent exposure in pregnancy.

RESULTS

1,1,1-Trichloroethane was associated with rhabdomyosarcoma (adjusted Odds Ratio (aOR): 1.96; 95% Confidence Interval (CI): 1.16, 3.32) in the "ever exposed" group. Ever exposure to carbon disulfide was associated with increased risks of medulloblastoma (OR = 1.85, 95% CI 1.01, 3.40) and ependymoma (OR = 1.63, 95% CI 0.97, 2.74).

CONCLUSIONS

Overall, our findings suggested maternal residential exposure to solvents from industrial sources might be associated with elevated childhood cancer risks.

Bioorthogonal Delivery of Carbon Disulfide in Living Cells

Carbon disulfide (CS2) is an environmental contaminant, which is deadly hazardous to the workers under chronic or acute exposure. However, the toxicity mechanisms of CS2 are still unclear due to the scarcity of biocompatible donors, which can release CS2 in cells. Here we developed the first bioorthogonal CS2 delivery system based on the "click-and-release" reactions between mesoionic 1,3-thiazolium-5-thiolates (TATs) and strained cyclooctyne exo-BCN-OH. We successfully realized intracellular CS2 release and investigated the causes of CS2-induced hepatotoxicity, including oxidative stress, proteotoxic stress and copper-dependent cell death. It is found that CS2 can be copper vehicles bypassing copper transporters after reacting with nucleophiles in cytoplasm, and extra copper supplementation will exacerbate the loss of homeostasis of cells and ultimately cell death. These findings inspired us to explore the anticancer activity of CS2 in combination with copper by introducing a copper chelating group in our CS2 delivery system.

Carbon disulfide exposure induced lung function reduction partly through oxidative protein damage: A cross-sectional and longitudinal analysis

Carbon disulfide (CS₂) exposure has been associated with lung function reduction in occupational population. However, evidence on the general population with relatively low CS₂ exposure is lacking and the mechanism involved remains largely unknown. Urinary CS₂ metabolite (2-mercaptothiazolidine-4-carboxylic acid, TTCA) and lung function were determined in the urban adults from the Wuhan-Zhuhai cohort at baseline in 2011-2012 and were repeated every 3 years. Cross-sectional and longitudinal associations between TTCA and lung function were estimated using linear mixed models. Inflammation and oxidative damage biomarkers in blood/urine were measured to evaluate their potential mediating roles involved. Cross-sectionally, participants in the highest quartile of TTCA level showed a 0.64% reduction in FEV₁/FVC and a -308.22 mL/s reduction in PEF, compared to those in the lowest quartile. Longitudinally, participants with consistently high TTCA level had annually -90.27 mL/s decline in PEF, compared to those with consistently low TTCA level. Mediation analysis revealed that plasma protein carbonyl mediated 49.89% and 22.10% of TTCA-associated FEV₁/FVC and PEF reductions, respectively. Conclusively, there was a cross-sectional and longitudinal association between CS₂ exposure and lung function reduction in the general urban adults, and protein carbonylation (oxidative protein damage) partly mediated lung function reduction from CS₂ exposure.

Response of earthworm coelomocytes and catalase to pentanone and hexanone: a revelation of the toxicity of conventional solvents at the cellular and molecular level

Organic solvents like 2-pentanone and 2-hexanone which are widely used in industrial production make up a large proportion of the source of chemical pollution. What is worrisome is that the cellular and molecular toxicity of 2-pentanone and 2-hexanone has not been reported yet. Based on this, earthworms and catalase (CAT) were chosen as target receptors for the toxicity studies. The cytotoxicity of 2-pentanone and 2-hexanone was revealed by measuring the multiple intracellular indicators of oxidative stress. At the molecular level, changes in the structure and function of CAT were characterized in vitro by the spectroscopy and molecular docking. The results show that 2-pentanone and 2-hexanone that induced the accumulation of reactive oxygen species can eventually reduce coelomocytes viability, accompanying by the regular changes of antioxidant activity and lipid peroxidation level. In addition, the exposure of 2-pentanone and 2-hexanone can shrink the backbone structure of CAT, quench the fluorescence, and misfold the secondary structure. The decrease in enzyme activity should be attributed to the structural changes induced by surface binding. This study discussed the toxicological effects and mechanisms of conventional solvents at the cellular and molecular level, which creatively proposed a joint research method.

Paeonol increases the antioxidant and anti-inflammatory capacity of gibel carp (Carassius auratus gibelio) challenged with Aeromonas hydrophila

Paeonol, a naturally occurring polyphenol isolated from medical plant, has been known to exhibit anti-oxidative and anti-inflammatory effects. In order to evaluate the effect of paeonol on Carassius auratus gibelio infected by pathogenic bacteria Aeromonas hydriphila. 750 fish were randomly divided into 5 groups, which separately treated with 0.85% sterile saline (blank), A. hydriphila (negative control), A. hydriphila with paeonol (4 mg/kg, 64 mg/kg), and A. hydriphila with enrofloxacin (12 mg/kg, positive control). Fish were anaesthetized with MS-222 (100 mg/L), and samples were collected at 6 and 72 h after A. hydriphila challenge. The results showed that compared with the negative group, the survival in paeonol groups marked increased by 14.75% and 18.94%. The plasma immunoglobulin M (IgM) was notably increased, and low density lipoprotein (LDL) was significantly decreased in paeonol groups at 6 h (P < 0.05). The antioxidative enzymes catalase (CAT), total antioxidant capacity (T-AOC) and glutathione peroxidase (GSH-Px) were significantly increased in paeonol groups at 6 h, while malondialdehyde (MDA) and myeloperoxidase (MPO) contents were lower (P < 0.05). The inflammatory related genes MyD88 and TLR-5 were significantly downregulated, and the TLR-3 was significantly increased in paeonol groups at 72 h (P < 0.05). In addition, histopathological analyses showed that the lesion in liver, spleen and caudal kidney were considerably attenuated in paeonol groups. In conclusion, paeonol could increase the survival rate, mitigate oxidative damage, inflammation, tissue lesions, and improve the immunity of gibel carp challenged with A. hydrophila.

How to Differentiate General Toxicity-Related Endocrine Effects from Endocrine Disruption: Systematic Review of Carbon Disulfide Data

This review provides an overview of the assessment of the endocrine disrupting (ED) properties of carbon disulfide (CS₂), following the methodology used at the European level to identify endocrine disruptors. Relevant in vitro, in vivo studies and human data are analyzed. The assessment presented here focuses on one endocrine activity, i.e., thyroid disruption, and two main adverse effects, neurotoxicity and cardiotoxicity. The data available on the different ED or non-ED modes of action (MoA), known to trigger these adverse effects, are described and the strength of evidence of the different MoA is weighted. We conclude that the adverse effects could be due to systemic toxicity rather than endocrine-mediated toxicity. This assessment illustrates the scientific and regulatory challenges in differentiating a specific endocrine disruption from an indirect endocrine effect resulting from a non-ED mediated systemic toxicity. This issue of evaluating the ED properties of highly toxic and reactive substances has been insufficiently developed by European guidance so far and needs to be further addressed. Finally, this example also raises questions about the capacity of the technics available in toxicology to address such a complex issue with certainty.

Immersion immunization of common carp with bacterial ghost-based DNA vaccine inducing prophylactic protective immunity against spring viraemia of carp virus

The interactive applications of immunization route, vaccine type and delivery vectors are emerging as a key area of research within the field of mass immunization in fishery production. In an effort to improve DNA vaccine's immune efficiency in large-scale immunization, a promising bacterial ghost-loaded DNA vaccine was constructed based on Escherichia coli DH5α. In common carp was investigated the immune response to immersion immunization via related indicator analysis, and the challenge test of spring viraemia of carp virus (SVCV) was carried out. The result indicated that BG-loaded DNA vaccine induced higher serum antibody level than naked pEG-G. Simultaneously, the immunophysiological indicators and genes change at the more advanced levels in the BG/pEG-G immune group. At the treatment concentration of 20 mg/L of the BG/pEG-G group, IgM and IgZ expressions in vivo were markedly increased by 21.62 times and 6.91 times, respectively, and the relative percentage survival reached the peak of 59.57%. This study paves the way for future aquatic animal vaccine research, which aimed to develop the highly effective immersion vaccine system by delivery vectors, with the ultimate aim to prevent and restrict SVCV in actual production.

Assessing the effects of Thiram to oxidative stress responses in a freshwater bioindicator cladoceran (Daphnia magna)

Thiram (TMTD) is able to induce antioxidant defense and oxidative stress in different organisms. Moreover, Thiram can act as a prooxidant resulting in the formation of reactive oxygen species (ROS). To our knowledge, this is the first study assessing the oxidative stress induced by Thiram in the cladoceran Daphnia magna. At present, literature focus on the determination of toxicity in vertebrate organisms or cells, however, very few studies were interested to evaluate Thiram's effects in aquatic organisms such as cladoceran. To assess these effects, antioxidant GSH content, CAT and GST enzyme activities, cellular damages and lipid peroxidation indicators (MDA) were evaluated as oxidative stress biomarkers. Our results showed that acute Thiram exposure resulted in significant biochemical responses, demonstrating that Thiram induced oxidative damage. Indeed, following exposure to Thiram, we noticed an intracellular (GSH) depletion, associated with a marked increase of lipid membrane peroxidation as shown by high (MDA) production. Moreover, a dose-dependent induction of antioxidant key enzymes (CAT) and (GST) was found which led to an oxidative stress and finally death of Daphnia magna.

Associations of urinary carbon disulfide metabolite with oxidative stress, plasma glucose and risk of diabetes among urban adults in China

Carbon disulfide (CS₂) has been reported to induce disorder of glucose metabolism. However, the associations of CS₂ exposure with plasma glucose levels and risk of diabetes have not been explored in general population, and the underlying mechanisms remain unclear. We aim to examine the relationships between CS₂ exposure and fasting plasma glucose (FPG) levels, as well as diabetes, and assess the potential role of oxidative stress among the abovementioned relationships in Chinese general adults. The concentrations of urinary biomarkers of CS₂ exposure (2-thiothiazolidin-4-carboxylic acid, TTCA), and biomarkers for lipid peroxidation (8-isoprostane, 8-iso-PGF_2α) and DNA oxidative damage (8-oxo-7,8-dihydro-20-deoxyguanosine, 8-OHdG) were measured among 3338 urban adults from the Wuhan-Zhuhai cohort. Additionally, FPG levels were tested promptly. Generalized linear models and logistic regression models were used to quantify the associations among urinary TTCA, oxidative damage markers, FPG levels and diabetes risk. Mediation analysis was employed to estimate the role of oxidative damage markers in the association between urinary TTCA and FPG levels. We discovered a significant relationship between urinary TTCA and FPG levels with regression coefficient of 0.080 (95% CI: 0.002,0.157). Besides, the risk of diabetes was positively related to urinary TTCA (OR:1.282, 95% CI: 1.055,1.558), particularly among those who did not exercise regularly. Each 1% increase of urinary TTCA concentration was associated with a 0.096% and 0.037% increase in urinary 8-iso-PGF_2α and 8-OHdG, respectively. Moreover, we found an upward trend of FPG level as urinary 8-iso-PGF_2α gradually increased (P_trend<0.05), and urinary 8-iso-PGF_2α mediated 21.12% of the urinary TTCA-associated FPG increment. Our findings indicated that urinary CS₂ metabolite was associated with increased FPG levels and diabetes risk in general population. Lipid peroxidation partly mediated the association of urinary CS₂ metabolite with FPG levels.

Benzotriazole alleviates copper mediated lysosomal membrane damage and antioxidant defense system responses in earthworms (Eisenia fetida)

Benzotriazole (BTR) is a common corrosion inhibitor used to protect copper (Cu) and Cu alloys. To reveal the combined subacute toxicity of BTR and Cu at environmental levels on terrestrial animals, the activity of antioxidative enzymes and the glutathione levels in earthworms (Eisenia fetida) of the single or co-exposure treatments were determined. The activity of both antioxidant enzymes and non-enzymatic antioxidants was affected by BTR in earthworms. Moreover, the analyses of lysosomal neutral red retention time and total antioxidant capacity indicated a detoxification effect of BTR on Cu-induced impairments of the antioxidant defense capacity in earthworms. The apoptotic rate of coelomocytes in earthworms of the co-exposure treatment was lower than that in earthworms treated with Cu only, indicating that BTR alleviates Cu mediated lysosomal membrane damage and antioxidant defense system responses in earthworms.

Effects of α-ethinyl estradiol (EE2) and diethylhexyl phthalate (DEHP) on growth performance, antioxidant status and immune response of juvenile yellow catfish Pelteobagrus fulvidraco

The four experimental groups were carried out to test the response of yellow catfish to EE2 and DEHP: control group was exposed to DMSO; EE2 group was exposed to 1.0 μg/L EE2; DEHP group was exposed to 1.0 mg/L DEHP; mix group was exposed to 1.0 μg/L EE2 and 1.0 mg/L DEHP. The experiment continued for 56 days. Fish survival rate was not different among experimental groups. Fish in DEHP and mix groups had the highest weight gain, and lowest value appeared in control group. The highest hepatosomatic index was found in DEHP and mix groups. Serum alanine transaminase of fish in control group was lower than other groups, but the alkaline phosphatase value was the highest. Serum total anti-oxidation capacity, superoxide dismutase and catalase activities of fish in control group were higher than other groups, but malondialdehyde content is opposite. Respiratory burst and phagocytic indices of fish in EE2 group were the lowest. After 96 h of ammonia stress, the survival rate of fish in mix group was significantly lower than control group. This study indicates that EE2 and DEHP exposure can lead to gain weight of yellow catfish, which is related to liver damage and fat accumulation; EE2 and DEHP exerts its toxic effects by inducing ROS generation, leading to lipid peroxidation and immunosuppression.

Effects of different selenium sources and levels on antioxidant status in broiler breeders

OBJECTIVE

This study was conducted with the objectives to examine the impacts of inorganic selenium (Se) and different types and levels of organic selenium on the serum and tissues Se status and antioxidant capacity in broiler breeders.

METHODS

Five hundred and forty 48-wk-old Lingnan Yellow broiler breeders were randomly assigned to 6 dietary treatments, provided same basal diet (0.04 mg/kg of Se) with 0.15 mg/kg, or 0.30 mg/kg of Se from sodium selenite (SS) or from selenium-enriched yeast (SY) or from selenomethionine (SM). The broiler breeders were slaughtered after an 8-wk experiment.

RESULTS

The results showed that SM was better than SY and SS, 0.30 mg/kg level was better than 0.15 mg/kg level in Se deposition (p<0.05) in serum, liver, kidney, pancreas and muscle; in antioxidant status, organic selenium had better effects than SS in broiler breeders (p<0.05), but SM and SY had a similar result, and 0.15 mg/kg level was better than 0.30 mg/kg (p<0.05).

CONCLUSION

The results demonstrated the evident advantage of supplementation of broiler breeders with 0.15 mg/kg SM, which improved tissue Se concentrations and antioxidant status, and can be considered as the best selenium source.

The Response of Duckweed (Lemna minor L.) Roots to Cd and Its Chemical Forms

The response of duckweed (Lemna minor L.) roots to Cd and its chemical forms was investigated. The relative root growth rate and concentrations of Cd and its different chemical forms in the root, that is, ethanol-extractable (FE-Cd), HCl-extractable (FHCl-Cd), and residual fractions (Fr-Cd), were quantified. Weibull model was used to unravel the regression between the relative root elongation (RRL) with chemical forms of Cd. Parameters assessed catalase (CAT), peroxidases (POD), and superoxide dismutase (SOD), as well as malondialdehyde (MDA) and total antioxidant capacity (A-TOC). Our results show that both the relative root growth rate and relative frond number were affected by Cd concentrations. The chemical forms of Cd were influenced by Cd content in the medium. Relative root elongation (RRL) showed a significant correlation with chemical forms of Cd. Additionally, POD and SOD increased at lower Cd concentrations followed by a decrease at higher Cd concentrations (at more than 5 μM Cd). Moreover, MDA and A-TOC increased and CAT decreased with increasing Cd exposure. Furthermore, CAT showed a significant correlation with FHCl-Cd. Taken together, it can be concluded that the chemical forms of Cd are statistically significant predictors of Cd toxicity to duckweed and to the other similar aquatic plants.

Display of GCRV vp7 protein on the surface of Escherichia coli and its immunoprotective effects in grass carp (Ctenopharyngodon idella)

Infection with Grass carp reovirus (GCRV) is becoming unprecedentedly widespread in grass carp (Ctenopharyngodon idella) aquaculture industry, yet the management of GCRV infection still remains a challenge. Therefore, it is of importance to develop effective means against GCRV. As a delivery system of viral antigens, surface displaying of heterologous proteins on bacteria using anchoring motifs has successfully been implemented in human and veterinary vaccines research. In this study, a novel vaccine (BL21/InpN/vp7) was developed based on surface displaying a major capsid protein (vp7) of GCRV using the anchoring motif of N-terminal unique domain of ice-nucleation protein (InpN) on Escherichia coli BL21 (DE3) vaccine. Then the grass carp were immunized by surface displaying BL21/InpN/vp7 vaccine against GCRV using both intraperitoneal injection and bath immunization and their immune responses were tested. The results revealed that some non-specific immune parameters (acid phosphatase (ACP), alkaline phosphatase (AKP) and total antioxidant capacity (T-AOC)) were strongly increased in grass carp post injection inoculation (vp7 dose ranged from 10 to 20 μg). The specific antibody levels against GCRV and the transcriptional of immune-related genes (TNF-α, IL-1β, MHCI and IgM) were also significantly enhanced in grass carp by injection inoculation (vp7 dose ranged from 5 to 20 μg). On the other hand, only the highest dose of bath vaccination significantly induced the production of specific antibody and up-regulated transcriptions of several immune-related genes (IgM and MHCI) in grass carp. The lower cumulative mortality of grass carp in vaccinated groups after GCRV challenge clearly demonstrated that surface displayed vp7 vaccine could protect fish against GCRV infection. The relative percentage survival (RPS) value in injection vaccinated group (88.89%) was much higher compared to bath group (18.89%), which was in consistent with the production of specific serum antibodies, non-specific immune response and immune related genes expression. To sum up, our results indicated the surface display of heterologous antigenic proteins on E. coli BL21 (DE3) using the anchoring motif of ice-nucleation protein may provide a promising approach to the vaccine development of aquatic animals and suggested its potential to be used as vaccine to fight against GCRV infection.

H2S and polysulfide metabolism: Conventional and unconventional pathways

It is now well established that hydrogen sulfide (H₂S) is an effector of a wide variety of physiological processes. It is also clear that many of the effects of H₂S are mediated through reactions with cysteine sulfur on regulatory proteins and most of these are not mediated directly by H₂S but require prior oxidation of H₂S and the formation of per- and polysulfides (H₂S_n, n = 2-8). Attendant with understanding the regulatory functions of H₂S and H₂S_n is an appreciation of the mechanisms that control, i.e., both increase and decrease, their production and catabolism. Although a number of standard "conventional" pathways have been described and well characterized, novel "unconventional" pathways are continuously being identified. This review summarizes our current knowledge of both the conventional and unconventional.

Melatonin Treatment Reduces Oxidative Damage and Normalizes Plasma Pro-Inflammatory Cytokines in Patients Suffering from Charcot-Marie-Tooth Neuropathy: A Pilot Study in Three Children

Charcot-Marie-Tooth neuropathy (CMT) is a motor and sensory neuropathy comprising a heterogeneous group of inherited diseases. The CMT1A phenotype is predominant in the 70% of CMT patients, with nerve conduction velocity reduction and hypertrophic demyelination. These patients have elevated oxidative stress and chronic inflammation. Currently, there is no effective cure for CMT; herein, we investigated whether melatonin treatment may reduce the inflammatory and oxidative damage in CMT1A patients. Three patients, aged 8–10 years, were treated with melatonin (60 mg at 21:00 h plus 10 mg at 09:00 h), and plasma levels of lipid peroxidation (LPO), nitrites (NOx), IL-1β, IL-2, IL-6, TNF-α, INF-γ, oxidized to reduced glutathione (GSSG/GSH) ratio, and the activities of superoxide dismutase (SOD), glutathione-S transferase (GST), glutathione peroxidase (GPx), and reductase (GRd), were determined in erythrocytes at 3 and 6 months of treatment. Healthy age- and sex-matched subjects were used as controls. The results showed increased activities of SOD, GST, GPx, and GRd in CMT1A patients, which were reduced at 3 and 6 months of treatment. The GSSG/GSH ratio significantly increased in the patients, returning to control values after melatonin treatment. The inflammatory process was confirmed by the elevation of all proinflammatory cytokines measured, which were also normalized by melatonin. LPO and NOx, which also were elevated in the patients, were normalized by melatonin. The results document beneficial effects of the use of melatonin in CMT1A patients to reduce the hyperoxidative and inflammatory condition, which may correlate with a reduction of the degenerative process.

Protective immunity of grass carp induced by DNA vaccine encoding capsid protein gene (vp7) of grass carp reovirus using bacterial ghost as delivery vehicles

Grass carp reovirus (GCRV) is one of the most pathogenic aquareovirus and can cause lethal hemorrhagic disease in grass carp (Ctenopharyngodon idella). However, management of GCRV infection remains a challenge. Therefore, it is necessary to find effective means for the control of its infection. The uses of bacterial ghost (BG, non-living bacteria) as carriers for DNA delivery have received considerable attentions in veterinary and human vaccines studies. Nevertheless, there is still no report about intramuscular administration of bacterial ghost-based DNA vaccines in fish. In the current study, a novel vaccine based on Escherichia coli DH5α bacterial ghost (DH5α-BG), delivering a major capsid protein gene (vp7) of grass carp reovirus encoded DNA vaccine was developed to enhance the efficacy of a vp7 DNA vaccine against GCRV in grass carp. The grass carp was injected intramuscularly by different treatments -i) naked pcDNA-vp7 (containing plasmid 1, 2.5 and 5 μg, respectively), ii) DH5α-BG/pcDNA-vp7 (containing plasmid 1, 2.5 and 5 μg, respectively) and iii) naked pcDNA, DH5α-BG or phosphate buffered saline. The immune responses and disease resistance of grass carp were assessed in different groups, and results indicated that the antibody levels, serum total antioxidant capacity (T-AOC), superoxide dismutase (SOD) activity, acid phosphatase (ACP) activity and alkaline phosphatase (AKP) activity and immune-related genes were significantly enhanced in fish immunized with DH5α-BG/pcDNA-vp7 vaccine (DNA dose ranged from 2.5 to 5 μg). In addition, the relative percentage survival were significantly enhanced in fish immunized with DH5α-BG/pcDNA-vp7 vaccine and the relative percentage survival reached to 90% in DH5α-BG/pcDNA-vp7 group than that of naked pcDNA-vp7 (42.22%) at the highest DNA dose (5 μg) after 14 days of post infection. Moreover, the level of pcDNA-vp7 plasmid was higher in DH5α-BG/pcDNA-vp7 groups than naked pcDNA-vp7 groups in muscle and kidneys tissues after 21 days. Overall, those results suggested that DH5α bacterial ghost based DNA vaccine might be used as a promising vaccine for aquatic animals to fight against GCRV infection.

Rhein exhibits antioxidative effects similar to Rhubarb in a rat model of traumatic brain injury

Background

The brain is secondarily harmed by pathological, physiological, and biological reactions that are caused by traumatic brain injury (TBI). Rhein, a significant composition of Rhubarb, is a well-known traditional Chinese treatment method and has a strong oxidation-resisting characteristic, but Rhein’s mechanism remains unclear.

Methods

This study aimed to identify Rhein in the brain tissues of TBI model of rats, and confirm whether Rhein induced an antioxidative effect similar to its parent medicine, Rhubarb. First, the ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was applied to identify Rhein in the brain tissue of the controlled cortical impact (CCI) rats after intra-gastric administration of Rhubarb. Further, for the purpose of calculating the oxidant stress of the CCI rats, the malondialdehyde (MDA), catalase (CAT), superoxide dismutase (SOD), and glutathione disulfide (GSSG), as well as the proportion of glutathione (GSH)/GSSG were measured in the brain tissues.

Results

The results showed that Rhein was absorbed in the brain tissues of CCI rats. Rhubarb and rhein elevated the SOD, CAT activities, GSH level, and GSH/GSSG ratio, and diminished the MDA and GSSG levels.

Conclusion

The data demonstrated that Rhubarb and Rhein had the potential to be used as a neuroprotective drug for TBI, and that Rhein induced an antioxidative effect similar to its parent medicine, Rhubarb.

Oxidative Stress Mediated Hippocampal Neuron Apoptosis Participated in Carbon Disulfide-Induced Rats Cognitive Dysfunction

Occupational exposure to carbon disulfide (CS₂) exhibits central nervous systems toxicity. But the mechanism is unclear. The present study was designed to investigate the relationship between the CNS damage and cognitive dysfunction caused by CS₂, and eventually reveal the possible oxidative-related mechanism of hippocampus pathological changes in CS₂ exposed rats. Male Wistar rats were administrated with CS₂ at dosage of 200, 400 and 600 mg/kg for consecutive 20 days, respectively. Cognitive performances were evaluated by Morris water maze tests. Thionin and immunohistochemical analysis were used to investigate the hippocampal neuron damage, and the expression of apoptosis related proteins (cleaved-caspase 3, Bax and Bcl-2) were detected to explore the possible mechanisms of neuronal loss. Oxidative stress parameters were checked by commercial assay kits. Rats exposed to CS₂ displayed cognitive dysfunction manifested as decreased spatial learning ability and memory lesion. Pathological changes and significant neuron loss were observed in hippocampus, especially in CA1 and CA3 sub-regions. Mitochondria-dependent apoptosis pathway was implicated in the CS₂-induced neuronal loss which was demonstrated by the up-regulation of cleaved-caspase 3 and Bax accompanied with down-regulation of Bcl-2. Furthermore, extensive oxidative stress induced by CS₂ was also revealed by the measurement of ROS, RNS, MDA, GSH&GSSG and antioxidant enzymes (CAT, T-SOD, and GSH-Px). Our study suggested that oxidative stress mediated hippocampal neuron apoptosis might play an important role in CS₂ induced CNS damage and cognitive dysfunction.

Potential toxic effect of trifloxystrobin on cellular microstructure, mRNA expression and antioxidant enzymes in Chlorella vulgaris

This study investigated the effects of trifloxystrobin that one strobilurin used widely in the world as an effective fungicidal agent to control Asian soybean rust on aquatic unicellular algae Chlorella vulgaris. We determined the potential toxic effect of trifloxystrobin on C. vulgaris, and found median inhibition concentration (IC(50)) value 255.58 (95% confidence interval, 207.81-330.29)μgL(-1). In addition, the algal cells were obviously depressed or shrunk at different concentrations by electron microscopy. In the study, a real-time polymerase chain reaction (PCR) assay showed changes in transcript abundances of three photosynthetic genes, psaB, psbC, and rbcL, and one energy gene, ATPs. The results showed that trifloxystrobin reduced the transcript abundances of the three genes and enhanced expression of ATPs after 48 and 96 h. The lowest abundances of psaB, psbC and rbcL transcripts in response to trifloxystrobin exposure were 58%, 79% and 60% of those of the control, respectively. For the potential toxic influences, trifloxystrobin could decrease the soluble protein and total antioxidant contents (T-AOC), and increase superoxide dismutase (SOD) and peroxidase (POD) activity with a gradual concentration-response relationship. Overall, the present study demonstrated that trifloxystrobin could affect the activities of antioxidant enzymes, disrupts photosynthesis in C. vulgaris, and damage cellular structure.

The neuroprotective effect of treatment with curcumin in acute spinal cord injury: laboratory investigation

The purpose of this study was investigating the effects of curcumin on the histological changes and functional recovery following spinal cord injury (SCI) in a rat model. Following either sham operation or SCI, 36 male Sprague–Dawley rats were distributed into three groups: sham group, curcumin-treated group, and vehicle-injected group. Locomotor function was assessed according to the Basso, Beattie, and Bresnahan (BBB) scale in rats who had received daily intraperitoneal injections of 200 mg/kg curcumin or an equivalent volume of vehicle for 7 days following SCI. The injured spinal cord was then examined histologically, including quantification of cavitation. BBB scores were significantly higher in rats receiving curcumin than receiving vehicle (P < 0.05). The cavity volume was significantly reduced in the curcumin group as compared to the control group (P = 0.039). Superoxide dismutase (SOD) activity was significantly elevated in the curcumin group as compared to the vehicle group but was not significantly different from the sham group (P < 0.05, P > 0.05, respectively) at one and two weeks after SCI. Malondialdehyde (MDA) levels were significantly elevated in the vehicle group as compared to the sham group (P < 0.05 at 1 and 2 weeks). MDA activity was significantly reduced in the curcumin group at 2 weeks after SCI when compared to the vehicle group (P = 0.004). The numbers of macrophage were significantly decreased in the curcumin group (P = 0.001). This study demonstrated that curcumin enhances early functional recovery after SCI by diminishing cavitation volume, anti-inflammatory reactions, and antioxidant activity.

Algicidal activity of Salvia miltiorrhiza Bung on Microcystis aeruginosa--towards identification of algicidal substance and determination of inhibition mechanism

The present study was to isolate and identify a potent algicidal compound from extract of Salvia miltiorrhiza and study the potential inhibition mechanism on Microcystis aeruginosa. Column chromatography and bioassay-guided fractionation methods were carried out to yield neo-przewaquinone A, which was identified by spectral analysis. The EC50 of neo-przewaquinone A on M. aeruginosa were 4.68 mg L(-1). In addition, neo-przewaquinone A showed relatively higher security on Chlorella pyrenoidosa and Scenedesmus obliquus, with the EC50 values of 14.78 and 10.37 mg L(-1), respectively. For the potential inhibition mechanisms, neo-przewaquinone A caused M. aeruginosa cells morphologic damage or lysis, increased malondialdehyde content and decreased the soluble protein content, total antioxidant and superoxide dismutase activity, and significantly inhibited three photosynthesis-related genes (psaB, psbD, and rbcL). The results demonstrated the algicidal effect of neo-przewaquinone A on M. aeruginosa and provided the possible inhibition mechanisms.

Nitric oxide mediated effects on reproductive toxicity caused by carbon disulfide in male rats

This study investigated nitric oxide (NO) mediation of carbon disulfide (CS(2)) toxicity that compromised male rat spermatogenesis and endocrine function. Rats were exposed to multiple levels of CS(2) concentration (0, 50, 250, 1250 mg/m(3)). A 1250 mg/m(3) CS(2)+sodium nitroprusside (SNP) group and a 1250 mg/m(3) CS(2)+NG-monomethyl-L-arginine (L-NMMA) group were established to explore the role of NO in mediating CS(2) toxicity. NO concentrations, NO synthase (NOS) activity, and sex hormone levels were measured, and sperm characteristics were observed and analyzed. Our data show that CS(2) exposure decreased: NOS activity; tissue NO concentrations; serum levels of gonadotropin-releasing hormones, luteinizing hormones, and testosterone; and sperm count and activity. In contrast, increased serum follicle-stimulating hormone concentrations and teratospermia were observed with CS(2) exposure. SNP reduced some of the toxic effects of CS(2), while L-NMMA treatment showed no effect. The results suggests that NO mediates compromised reproductive system function caused by CS(2) exposure.

Supplementation of xanthophylls increased antioxidant capacity and decreased lipid peroxidation in hens and chicks

The present study investigated the effects of xanthophyll supplementation on production performance, antioxidant capacity (measured by glutathione peroxidase, superoxide dismutase (SOD), catalase, total antioxidant capacity (T-AOC), and reduced glutathione:oxidised glutathione ratio (GSH:GSSG)) and lipid peroxidation (measured by malondialdehyde (MDA)) in breeding hens and chicks. In Expt 1, 432 hens were fed diets supplemented with 0 (control group), 20 or 40 mg xanthophyll/kg diet. Blood samples were taken at 7, 14, 21, 28 and 35 d of the trial. Liver and jejunal mucosa were sampled at 35 d. Both xanthophyll groups improved serum SOD at 21 and 28 d, serum T-AOC at 21 d and liver T-AOC, and serum GSH:GSSG at 21, 28 and 35 d and liver GSH:GSSG. Xanthophylls also decreased serum MDA at 21 d in hens. Expt 2 was a 2 × 2 factorial design. Male chicks hatched from 0 or 40 mg in ovo xanthophyll/kg diet of hens were fed a diet containing either 0 or 40 mg xanthophyll/kg diet. Liver samples were collected at 0, 7, 14 and 21 d after hatching. Blood samples were also collected at 21 d. In ovo-deposited xanthophylls increased antioxidant capacity and decreased MDA in the liver mainly within 1 week after hatching. Maternal effects gradually vanished during 1–2 weeks after hatching. Dietary xanthophylls increased antioxidant capacity and decreased MDA in the liver and serum mainly from 2 weeks onwards. Data suggested that xanthophyll supplementation enhanced antioxidant capacity and reduced lipid peroxidation in different tissues of hens and chicks.

Short Communication: Effects of duodenal infusion of increasing amounts of α-linolenic acid on composition and susceptibility to peroxidation of blood lipids in lactating dairy cows

Sun, P., Wang, J.-Q., Liu, Q.-S., Khas-Erdene and Yang, G. 2012. Short Communication: Effects of duodenal infusion of increasing amounts of α-linolenic acid on composition and susceptibility to peroxidation of blood lipids in lactating dairy cows. Can. J. Anim. Sci. 92: 219–223. Duodenal infusion of increasing amounts of α-linolenic acid (LNA) in dairy cows linearly decreased the percentages of 18:0, 18:2n-6 and saturated fatty acids (P<0.01), linearly and quadratically reduced 23:0 and 18:1 cis-9 (P<0.01), but linearly increased the content of 18:3 n-3 and PUFA (P<0.01) in blood plasma. As amount infused increased, concentrations of high-density lipoprotein cholesterol and total cholesterol increased quadratically and peaked at 139.9 mg dL−1 and 182.0 mg dL−1, respectively (P<0.01). No differences were observed in the activity of blood serum total superoxide dismutase and total antioxidant capacity, but the thiobarbituric acid reactive substances tended (P=0.07) to increase linearly. Duodenally infused increasing amounts of LNA altered the composition of fatty acids and distribution of lipids in blood, but did not affect the oxidative stability of the blood in dairy cows.

Association between the rs1050450 glutathione peroxidase-1 (C > T) gene variant and peripheral neuropathy in two independent samples of subjects with diabetes mellitus

Glutathione peroxidase-1 (GPx-1) is an endogenous anti-oxidant enzyme. The T allele of the GPx-1 rs1050450 (C > T) gene variant is associated with reduced enzyme activity. Our aim was to examine the association between this gene variant and peripheral neuropathy in two cross-sectional samples of subjects with diabetes: (i) 773 Caucasian subjects were genotyped from the UCL Diabetes and Cardiovascular disease Study (UDACS) and (ii) 382 Caucasian subjects from the Ealing Diabetes Study (EDS). Peripheral neuropathy status (and oxidised-LDL [Ox-LDL:LDL] and plasma Total Ant-ioxidant Status [TAOS] in UDACS), were analysed in relation to genotype. We observed that: (i) In UDACS, the odds ratio (OR) for peripheral neuropathy in the T allele carriers compared to the CC genotype was 1.61 [1.10-2.28], p = 0.01. This remained significant after adjustment for other risk factors. Ox-LDL:LDL ratio was significantly elevated in T allele carriers (CC vs. CT/TT: 16.3 ± 2.4 v 18.0 ± 2.9 U/mmol LDL, p = 0.02). (ii) In EDS, the OR for peripheral neuropathy in the T allele carriers compared to the CC genotype was 1.95 [1.11-3.42], p = 0.02. This remained significant after adjustment for other risk factors. In conclusion, we observed a significant association between the T allele and peripheral neuropathy and LDL oxidation. This is the first paper to examine the rs1050450 variant in two samples of Caucasian subjects with diabetes. Prospective analysis of the gene variant is required in diabetic and healthy cohorts with measured plasma markers of oxidative stress to investigate the described association further.

Effects of adlay seed oil on blood lipids and antioxidant capacity in hyperlipidemic rats

BACKGROUND

Adlay (Coix lacryma-jobi L. subsp. ma-yuen (Romanet) T. Koyama (family Poaceae)) seed has been used as a dietary supplement for its therapeutic effects for thousands of years. This study was designed to investigate the effects of adlay seed oil, obtained by supercritical CO₂ extraction, on blood lipids and antioxidant capacity in hyperlipidemic rats.

RESULTS

Adlay seed oil could reduce the abdominal fat tissue and low-density lipoprotein concentration, and increase the total antioxidant capacity in hyperlipidemic rats. Adlay seed oil also significantly decreased the malondialdehyde content in serum, and increased serum total superoxide dismutase activity in hyperlipidemic rats. Therefore, the antioxidant mechanism might be related to the scavenging effects of adlay seed oil on reactive oxidative species, especially on the superoxide anion free radical.

CONCLUSION

The results showed that adlay seed oil had blood lipid-reducing and antioxidant effects, and could be used as a supplement in healthcare food and drugs for the prevention of chronic diseases (especially artherosclerosis and coronary artery disease).

Subcellular Cd distribution and its correlation with antioxidant enzymatic activities in wheat (Triticum aestivum) roots

The subcellular partitioning of Cd in wheat root was obtained by differential centrifugation of root homogenates to quantify the amounts of Cd associated with five operationally defined subcellular fractions, namely Cd-rich granule (MRG), cellular debris, organelles, heat-denatured protein (HDP), and heat-stable protein (HSP). Their correlations were investigated with the changes in antioxidant enzymatic activities under Cd stress (0.01-9.68 μM) for 72 h. The results showed that the relative Cd distribution in detoxified fractions (MRG+HSP) was decreased with increasing [Cd], but in metal-sensitive fractions (HDP+organelles) was increased. Consequently, the content of superoxide dismutase (SOD) and catalase (CAT) was decreased. Additionally, an increase of the total antioxidant capacity (A-TOC) and a slight decrease of malondialdehyde (MDA) were also observed. Interestingly, the relative root elongation (RRL) and CAT were significantly correlated with the Cd-sensitive fractions. These results suggest that the Cd toxicity to wheat roots strongly depends on the subcellular Cd distribution.

Influence of linolenic acid content on the oxidation of milk fat

Increasing the content of alpha-linolenic acid in milk fat might be desirable to meet consumer concerns about dietary healthfulness. However, the rich content of polyunsaturated fatty acids (PUFAs) will influence the oxidative stability of milk fat. This experiment was carried out to determine the effects of infusion with different amounts of high-linolenic perilla fatty acid (HLPFA) emulsion into the duodenum of dairy cows on milk fatty acid profile and the susceptibility of milk fat to oxidation. In a crossover design, 4 multiparous Holstein cows were infused duodenally with increasing amounts (0, 40, 80, 120, or 160 g/day) of free fatty acids from HLPFA emulsion or with carrier alone. Continuous infusions (20 to 22 h/day) were for 7 days at each amount. Infusions were homogenates of HLPFA with 15 g/day of xanthan gum, 5 g/day sodium alginate, and 25 g/day Tween 80; controls received carrier only. The concentration of n-3 PUFAs, especially alpha-linolenic acid, in milk fat increased linearly as HLPFA infusion increased, but the saturated fatty acids decreased linearly. The milk production and the activity of superoxide dismutase, glutathione peroxidase, and catalase in milk tended to decrease quadratically. The milk fat percentage, however, tended to increase. The concentration of malondialdehyde increased quadratically in milk fat. Results suggest that infusion with HLPFA emulsion at varying amounts enhanced the content of n-3 PUFAs in milk fat over the length of experiment but decreased the oxidative stability of milk fat.

Protective effects of pre-germinated brown rice diet on low levels of Pb-induced learning and memory deficits in developing rat

Lead (Pb) is a known neurotoxicant in humans and experimental animals. Numerous studies have provided evidence that humans, especially young children, and animals chronically intoxicated with low levels of Pb show learning and memory impairments. Unfortunately, Pb-poisoning cases continue to occur in many countries. Because the current treatment options are very limited, there is a need for alternative methods to attenuate Pb toxicity. In this study, the weaning (postnatal day 21, PND21) rats were randomly divided into five groups: the control group (AIN-93G diet, de-ionized water), the lead acetate (PbAC) group (AIN-93G diet, 2g/L PbAC in de-ionized water), the lead acetate+WR group (white rice diet, 2g/L PbAC in de-ionized water; PbAC+WR), the lead acetate+BR group (brown rice diet, 2g/L PbAC in de-ionized water; PbAC+BR) and the lead acetate+PR group (pre-germinated brown rice diet, 2g/L PbAC in de-ionized water; PbAC+PR). The animals received the different diets until PND60, and then the experiments were terminated. The protective effects of pre-germinated brown rice (PR) on Pb-induced learning and memory impairment in weaning rats were assessed by the Morris water maze and one-trial-learning passive avoidance test. The anti-oxidative effects of feeding a PR diet to Pb-exposed rats were evaluated. The levels of reactive oxygen species (ROS) were determined by flow cytometry. The levels of 8-hydroxy-2-deoxyguanosine (8-OHdG), gamma-aminobutyric acid (GABA) and glutamate were determined by HPLC. Our data showed that feeding a PR diet decreased the accumulation of lead and decreased Pb-induced learning and memory deficits in developing rats. The mechanisms might be related to the anti-oxidative effects and large amount of GABA in PR. Our study provides a regimen to reduce Pb-induced toxicity, especially future learning and memory deficits in the developing brain.