Degree Of Oxidative Damage Research Articles

Scutellarin Prevents Nonalcoholic Fatty Liver Disease (NAFLD) and Hyperlipidemia via PI3K/AKT-Dependent Activation of Nuclear Factor (Erythroid-Derived 2)-Like 2 (Nrf2) in Rats.

BackgroundNonalcoholic fatty liver disease (NAFLD) is a condition characterized by excessive fat accumulation in the form of triglycerides. The incidence of NAFLD and hyperlipidemia, with their associated risks of end-stage liver and cardiovascular diseases, is increasing rapidly. This study aimed to investigate the effects of scutellarin on the experimental NAFLD in high-fat diet fed and chronic stress rats, and its possible mechanism.Material/MethodsSprague-Dawley rats were fed with high-fat diet and subjected to chronic stress for 12 weeks, and administered orally with scutellarin for 4 weeks (n=8), and then blood and livers were harvested for analyzing. Enzyme activity assay, immunofluorescence, Western blot, and quantitative RT-PCR were performed to analyze the factors of the oxidant/antioxidant system and pathway.ResultsAfter the high-fat diet and chronic stress administration for 12 weeks, serum and liver lipid metabolism of treatment groups with the different doses of SCU effectively improved and the degree of oxidative damage reduced. Using Western blot assay and immunofluorescence (IF) staining assay, Nrf2, HO-1, and PI3K, and AKT proteins significantly increased after SCU treatment for 4 weeks (P<0.01). The hepatic mRNA expression of HO-1, NQO1, and Nrf2 in SCU treatment groups was upregulated significantly through quantitative RT-PCR assay (P<0.05). However, compared to the positive control group, no difference was detected in the SCU (100 or 300 mg/kg) groups (P>0.05). These results indicate that SCU protects against NAFLD in rats via attenuation of oxidative stress.ConclusionsThe antioxidant effects of SCU on NAFLD are possibly dependent on PI3K/AKT activation with subsequent Nrf2 nuclear translocation, which increases expression of HO-1 and NQO1. We therefore suggest that breviscapine may be a potentially useful therapeutic strategy for NAFLD and hyperlipidemia.

Activation of nuclear β-catenin/c-Myc axis promotes oxidative stress injury in streptozotocin-induced diabetic cardiomyopathy

Myocardial oxidative stress injury plays a crucial role in the pathogenesis of diabetic cardiomyopathy (DCM). Wnt/β-catenin signaling has been reported to involve in various heart diseases. However, the underlying mechanism associated with β-catenin in DCM remains elusive. This study intended to explore the effect of β-catenin on oxidative damage of DCM by establishing streptozotocin (STZ)-induced diabetic mouse model and hydrogen peroxide (H2O2)-treated myocardial cell model. Cardiac oxidative stress in DCM was detected by measurements of lipid peroxidation and anti-oxidative enzyme activities as well as DHE staining. Nuclear β-catenin activity and oxidative damage degree were measured by western blotting, qPCR, MTT assay and TUNEL staining. Cardiac function and morphology were evaluated by echocardiography and histopathology. Under diabetic oxidative stress or H2O2 stimulation, nuclear β-catenin accumulation upregulated downstream c-Myc and further facilitated DNA damage and p53-mediated apoptosis as well as cell viability reduction, followed by phenotypic changes of cardiac dysfunction, interstitial fibrosis deposition and myocardial atrophy. Conversely, through directly inhibiting nuclear β-catenin/c-Myc axis, not only did siRNA knockdown of β-catenin or c-Myc attenuate cell injury in H2O2-stimulated cardiomyocytes, but also diabetic cardiac-specific β-catenin-knockout mice displayed the same prevention of heart injury as insulin-treated diabetic mice. The present study demonstrated that activated nuclear β-catenin/c-Myc axis was responsible for oxidative cardiac impairment of DCM. Therefore, repressing functional nuclear β-catenin may provide a hopeful therapeutic strategy for DCM.

STATE OF THE ANTIOXIDANT SYSTEM OF RAPANA VENOSA (VALENCIENNES, 1846) UNDER ACTION OF ANIONIC DETERGENT

The antioxidant system in the ctenidium, hepatopancreas and nephridia of gastropod Rapana venosa under stress caused by an anionic detergent – sodium dodecyl sulfate were studied. The experimental animals were kept for 3, 24 and 72 hours in aquariums with sea water with addition of sodium dodecyl sulfate in concentration of 5 and 20, the maximum permissible concentration (MPC). We determined the total antioxidant activity (TAA) and the content of reduced glutathione (GSH). The degree of oxidative damage to biopolymers was evaluated by the level of malondialdehyde (MDA). It was shown that the MDA content under the action of sodium dodecyl sulfate increased only in ctenidium after 72 hours from the start of the experiment. The index remained unchanged in the hepatopancreas and nephridia. The level of GSH in the shellfish ctenidium increased in presence of sodium dodecyl sulfate in all periods of observation. The hepatopancreas GSH level was not changed, and in nephridia GSH level increased only after three days of observation. TAA decreased in the ctenidium within the first 3 hours of observation, and in hepatopancreas and nephridia only after 72 hours at the maximum concentration of the detergent. In the other terms of the experiment at all concentrations of sodium dodecyl sulfate TAA in the tested bodies remained at the control level. It is concluded that the antioxidant system is resistant to sodium dodecyl sulfate and has a great adaptive capacity.

Alleviation of the effects of saline-alkaline stress on maize seedlings by regulation of active oxygen metabolism by Trichoderma asperellum.

This study investigated the influence of Trichoderma asperellum on active oxygen production in maize seedlings under saline–alkaline stress conditions. Two maize cultivars were tested: ‘Jiangyu 417’ (‘JY417’), which can tolerate saline–alkaline stress; and, ‘Xianyu 335’ (‘XY335’), which is sensitive to saline–alkaline stress. The seedlings were grown on natural saline–alkaline soil (pH 9.30) in plastic pots. To each liter of saline–alkaline soil, 200 mL of T. asperellum spore suspension was applied; three fungal suspensions were used, namely, 1 × 103, 1 × 106, and 1 × 109 spores/L. A control with only the vehicle applied was also established, along with a second control in which untreated meadow soil (pH 8.23) was used. Root and leaf samples were collected when the seedlings had three heart-shaped leaves and the fourth was in the developmental phase. Physical and biochemical parameters related to oxidation resistance were assessed. The results indicated that the ‘JY417’ and ‘XY335’ seedlings showed different degrees of oxidative damage and differences in their antioxidant defense systems under saline–alkaline stress. As the spore density of the fungal suspension increased, the K+ and Ca2+ contents in the seedlings increased, but Na+ content decreased. Moreover, fungal treatment promoted the synthesis or accumulation of osmolytes, which enhanced the water absorbing capacity of the cells, increased antioxidant enzyme activities, enhanced the content of non-enzyme antioxidants, and reduced the accumulation of reactive oxygen species. Fungal treatment alleviated oxidative damage caused by the saline–alkaline stress in roots and leaves of the seedlings. The application of T. asperellum overcame the inhibitory effect of saline–alkaline soil stress on the growth of maize seedlings. In the present experiment, application with 1 × 109 spores/L gave the optimal results.

Fructose-Rich Diet Affects Mitochondrial DNA Damage and Repair in Rats.

Evidence indicates that many forms of fructose-induced metabolic disturbance are associated with oxidative stress and mitochondrial dysfunction. Mitochondria are prominent targets of oxidative damage; however, it is not clear whether mitochondrial DNA (mtDNA) damage and/or its lack of repair are events involved in metabolic disease resulting from a fructose-rich diet. In the present study, we evaluated the degree of oxidative damage to liver mtDNA and its repair, in addition to the state of oxidative stress and antioxidant defense in the liver of rats fed a high-fructose diet. We used male rats feeding on a high-fructose or control diet for eight weeks. Our results showed an increase in mtDNA damage in the liver of rats fed a high-fructose diet and this damage, as evaluated by the expression of DNA polymerase γ, was not repaired; in addition, the mtDNA copy number was found to be significantly reduced. A reduction in the mtDNA copy number is indicative of impaired mitochondrial biogenesis, as is the finding of a reduction in the expression of genes involved in mitochondrial biogenesis. In conclusion, a fructose-rich diet leads to mitochondrial and mtDNA damage, which consequently may have a role in liver dysfunction and metabolic diseases.

Oral submucous fibrosis: A quantitative assessment of serum malondialdehyde, superoxide dismutase and correlation with clinical staging.

Background:Oral submucous fibrosis (OSMF) is a progressive disorder affecting the oral mucosa. OSMF predominantly seen in South-east Asian countries. There are some biochemicals parameters which are modify in oral submucous fibrosis; this alteration can be used as a tool for diseases progress and avert malignant transformation.Aims and Objectives:The aim of this study is to evaluate the serum malondialdehyde (malondialdehyde [MDA]), and Superoxide dismutase (SOD) in oral sub mucous fibrosis cases and compare clinical stages.Materials and Methods:Thirty cases of clinical and histopathological established oral submucous fibrosis and thirty cases of nonsymptomatic features of oral submucous fibrosis preferred as controls. Venous blood was collected and separation of serum for estimation of MDA and SOD levels was done using an ultraviolet spectrophotometer.Statistical Analysis:Data were analyzed using SPSS software using Student's t-test and Kruskal–Wallis ANOVA test.Results:Serum MDA levels were elevated when clinical staging increases, where as SOD levels were decreased when clinical stage increases when compared with control cases and it showed stastically significant.Conclusion:Estimation of serum MDA and SOD in patients with OSMF, we can assess the degree of oxidative damage of the disease. This can be used as an early diagnostic tool for preventing malignant transformation of oral submucous fibrosis.

Adelmidrol, a palmitoylethanolamide analogue, as a new pharmacological treatment for the management of acute and chronic inflammation

The aim of study was to examine the anti-inflammatory and analgesic effects of adelmidrol, an analogue of palmitoylethanolamide (PEA), in animal models of acute and chronic inflammation [carrageenan-induced paw edema (CAR) and collagen-induced arthritis (CIA)].In order to elucidate whether the action of adelmidrol is related to activation of peroxisome proliferator-activated receptors (PPAR-α or PPAR-γ), we investigated the effects of PPAR-γ antagonist, GW9662 on adelmidrol mechanism. CAR induced paw edema, hyperalgesia and the activation of pro-inflammatory NF-κB pathway were markedly reduced by treatment with adelmidrol. GW9662, (administered prior to adelmidrol treatment), antagonized the effect of adelmidrol abolishing its positive action. On the contrary, the genetic absence of PPAR-α receptor did not modify the beneficial results of adelmidrol treatment in the acute model of inflammation.In addition, for the first time, we demonstrated that adelmidrol was able to ameliorate both the clinical signs and the histopathology of the joint and the hind paw during chronic inflammation. In particular, the degree of oxidative damage and proinflammatory cytokines and chemokines production were significantly reduced in adelmidrol-treated mice. Moreover, in CIA model, the effect of GW9662 pre-treatment on adelmidrol mechanism was also confirmed. Thus, in this study, we report that adelmidrol reduces the development of acute and chronic inflammation and could represent a novel therapeutic approach for inflammation and pain.

Caveolin-1 Expression Ameliorates Nephrotic Damage in a Rabbit Model of Cholesterol-Induced Hypercholesterolemia.

Caveolin-1 (CAV-1) participates in regulating vesicular transport, signal transduction, tumor progression, and cholesterol homeostasis. In the present study, we tested the hypothesis that CAV-1 improves dyslipidemia, inhibits cyclophilin A (CypA)- mediated ROS production, prevents mitochondrial compensatory action and attenuates oxidative stress responses in cholesterol-induced hypercholesterolemia. To determine the role of CAV-1 in mediating oxidative and antioxidative as well as cholesterol homeostasis, hypercholesterolemic rabbits were intravenously administered antenapedia-CAV-1 (AP-CAV-1) peptide for 2 wk. AP-CAV-1 enhanced CAV-1 expression by ˃15%, inhibited CypA expression by ˃50% (P < 0.05) and significantly improved dyslipidemia, thus reducing neutral lipid peroxidation. Moreover, CAV-1 attenuated hypercholesterolemia-induced changes in mitochondrial morphology and biogenesis and preserved mitochondrial respiratory function. In addition, CAV-1 protected against hypercholesterol-induced oxidative stress responses by reducing the degree of oxidative damage and enhancing the expression of antioxidant enzymes. CAV-1 treatment significantly suppressed apoptotic cell death, as evidenced by the reduction in the number of terminal deoxynucleotidyl transferase dUTP nick end-labeling-positive cells. We concluded that CAV-1 plays a critical role in inhibiting CypA-mediated ROS production, improving dyslipidemia, maintaining mitochondrial function, and suppressing oxidative stress responses that are vital for cell survival in hypercholesterol-affected renal organs.

Study on DNA damage induced by the reactive oxygen species generated in situ based on the multi-walled carbon nanotubes and hemoglobin

In order to explore the DNA damage mechanism induced by endogenous factors and the activities of the antioxidants, an electrochemical biosensor was fabricated based on multi-walled carbon nanotubes (MWCNTs) and hemoglobin (Hb). When the glassy carbon electrode (GCE) modified with chitosan (CS), double stranded DNA (ds-DNA), MWCNTs and Hb was subjected to a negative potential of −1.4V in PBS of pH5.8, the dissolved oxygen was reduced to hydrogen peroxide (H2O2) on the surface of the MWCNTs. Then the H2O2 reacted with Hb and formed a Compound I (Hb–C–HOOH) and H2O. The Compound I, a highly oxidizing specie, can be used as reactive oxygen species (ROS) and to damage DNA in situ in the membrane. The ascorbic acid (AA) can protect the DNA from damage by scavenging the H2O2 to inhibit the formation of the Compound I. The ds-DNA oxidative damage degree and the protective effect of AA from DNA damage were monitored by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and ultraviolet–visible spectroscopy (UV–vis). The consistent conclusions were obtained by electrochemical methods and UV–vis. The studies may be helpful for understanding the DNA damage mechanism, the protection of AA from DNA damage in vivo, and the toxicity of nanomaterials in organism.

Ultrastructural Study Reveals That Mouse Hippocampal Neurons Are More Protected Than The Cerebrocortical Neurons From Age Related Cytological Alterations

Neurons are post mitotic cells. They are more vulnerable to oxidative damage because of high content of unsaturated fatty acids and high oxygen consumption per unit weight. As the age of an organism progresses, the oxidative damage to molecules also increases which leads to increase in oxidatively modified molecules in the cell. Damage to membrane lipids causes alterations in the membrane functions. In the present study we have assessed the oxidative damage to membrane lipids in the form of nM of malondialdehyde (MDA) in cerebral cortex and hippocampus of 12, 18 and 24 month old male albino mice. We found that the degree of oxidative damage was higher in cerebral cortex than the hippocampus. This indicates that hippocampus is more resistant to oxidative damage than cerebral cortex. We have also studied the ultrastructure of cerebrocortical and hippocampal neurons. We found that the RER, Golgi apparatus and mitochondria were well organized in hippocampal neurons, whereas in cerebrocortical neurons, these cell organelles exhibited degenerative changes at 24 months of age. Nucleus of cerebrocortical neurons exhibited predominantly heterochromatinised form, whereas in hippocampal neurons it was in Euchromatin form.

ANTIOXIDANT SYSTEM OF RAPANA VENOSA (VALENCIENNES, 1846) REPRESENTATIVES, THE INHABITANTS OF DIFFERENT WATER AREAS OF THE ODESSA BAY ( THE BLACK SEA)

Have been studied the antioxidant system in males and females of the introduced species of the Black Sea gastropod Rapana venosa, dwelling in two different water areas of the Odesa bay. One of the zone distinguishes from another more expressed periodic storm sewer variation in water quality (salinity, degree, chemical pollutants, etc.) due to the presence in its area. Another have characterized by a lack of nearby industrial facilities and municipal and has more stable environmental situation. In esophageal (leybleynov) rapan gland there were determined activity of superoxide dismutase (SOD), catalase, glutathione peroxidase (GP), glutathione reductase (GR) and the content of reduced glutathione (GSH). The degree of oxidative damage of biopolymers evaluated by the level of malondialdehyde (MDA). We haven’t found any gender differences in investigated rapanas in content of MDA – the integral index of lipid peroxidation (LPO), the content of GSH and the activity of antioxidant enzymes, except catalase and SOD. MDA content and SOD activity in the esophageal gland of rapan collected in the reservoir as higher, and the content of GSH and the activity of GP – lower than rapan living in more cleaning area. It is concluded that high adaptive capacity of R. venosa and the importance of studying the role of genetic and environmental factors in the differential display of some rapan adaptation reactions in different areas of the Black Sea.

Oxidative stress during cystic ovarian disease in water buffalo

Follicular fluid and serum concentrations of antioxidants such as catalase, ascorbic acid (AA) and total antioxidant capacity (TAC) along with reactive oxygen species (ROS) and degree of oxidative damage to follicular cells, using protein carbonyl (PC) as marker of oxidative stress, were investigated during cystic ovarian disease in buffalo. Follicular fluid was aspirated from cystic follicles (&gt;20 mm) and also from large size (10-17 mm) of cycling buffaloes. Estradiol and progesterone were estimated to determine functional status (E: P ratio) of the follicles. Cystic follicles had greater concentrations of ROS and PC and lesser concentrations of catalase, ascorbic acid and TAC than normal follicles. An interesting finding was a simultaneous decrease of TAC and increase of ROS in serum of cystic buffaloes. Results indicated a pronounced follicular fluid oxidant-antioxidant imbalance and oxidative damage to follicular proteins during cystogenesis. In conclusion, this study provided evidence about role of oxidative stress in pathogenesis of cystic ovarian disease.

Resveratrol Attenuates Oxidative Stress and Extends Life Span in the Annual Fish Nothobranchius guentheri

Resveratrol is a natural polyphenol derived mainly from the skin of grapes and from red wine. Resveratrol prolongs life span in several invertebrates, but this function is not found in mice. Our recently published paper demonstrated that resveratrol prolonged longevity of the annual fish Nothobranchius guentheri, a promising vertebrate model for anti-aging research. However, the anti-aging process by resveratrol remains largely unexplored, and little is known about its effects on oxidative stress. In this study, by long-term supplementation of resveratrol from sexual maturity onward in the annual fish, we detected survivorship and oxidative stress at three different developmental stages in vivo. A total of 112 fish were fed with resveratrol in the concentration of 200 μg/gram food and 111 fish without resveratrol from 16 weeks of age until to the end of their lives. The mean and maximum life spans of the fish treated with resveratrol were extended by 17.34% and 17.66%, respectively, compared to the fish in control group. The markers of oxidative stress, such as the levels of reactive oxygen species (ROS), the activities of anti-oxidant enzymes, and the degree of oxidative damage, were detected at 6, 9, and 12 months, respectively. The results showed that levels of ROS and oxidative damage increased and activities of anti-oxidant enzymes appeared to decrease with age. Resveratrol treatment significantly attenuated the increase of ROS and oxidative damage and up-regulated the decrease of anti-oxidant enzyme activities induced by aging. Our results demonstrated that resveratrol decreased oxidative stress and extended life span in this short-lived fish.

The quality of the antioxidant defence system in term and preterm twin neonates

Objective: Multiple pregnancy is associated with an enhanced metabolism and demand for O2, which may lead to the overproduction of reactive oxygen species and the development of oxidative stress. The degree of oxidative damage depends on the level of the antioxidant protection system of the foetus. The objective of the study was to identify the relationship between the state of the maturity and the antioxidant status of twin neonates. Investigations of the umbilical cord blood were carried out to detect differences in the antioxidant defence system between mature and premature twin neonates.Methods: The activities of the superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) enzymes, the levels of reduced glutathione (GSH), protein carbonyls and oxidized lipids and the total antioxidant capacity of the plasma were determined.Results: The level of lipid peroxidation was significantly higher in the premature neonates. An increase in the total antioxidant capacity was accompanied by a decrease in the damaged protein concentration. Significantly elevated activities of GPx alone were observed in the premature twins, though the GSH content too tended to be increased. The activity of SOD was decreased in the premature neonates.Discussion: The antioxidant status of twin neonates are mainly influenced by maturity. We suggest that the level of lipid peroxidation might be of clinical value as a marker of pre- and perinatal distress in twins.

Effect of leptin on the oxidative damage in human retinal pigment epithelial cells

Objective To investigate the effects of leptin on the oxidative damage in human retinal pigment epithelial (RPE) cells.Methods Human RPE cells (ARPE-19) were cultured in vitro,and randomly divided into control group and insulin resistance group.RPE cells were treated with 0,10,100 ng/mL leptin for 24,48,72 hours respectively.Then the levels of reactive oxygen species (ROS) expression in RPE cells were detected by 2',7'-dichlorofluorescin-diacetate (DCFH-DA),and the levels of 8-hydroxy-2′-deoxyguanosine (8-OHdG) expression in RPE cells were observed by immunocytochemistry (ICC),and the levels of human 8-oxoguanine DNA glycosylase 1 (hOGG1) expression in lysate were measured by Western blot.Results After 24,48,72 hours,the level of ROS (Control group:F=37.136,37.178,49.634; P＜0.05.Insulin resistance group:F=9.822,28.881,71.150;P＜0.05),8-OHdG (Control group:F =88.643,390.920,1039.276; P ＜ 0.05.Insulin resistance group:F =273.311,299.155,82.237;P＜0.05) and hOGGl (Control group:F=470.062,1073.113,295.456;P＜0.05.Insulin resistance group:F =240.032,592.389,527.760 ; P＜0.05) expression increased significantly with the increase of leptin concentration in control group and insulin resistance group.Under the same leptin concentration,the level of 8-OHdG has a trend that it was higher in the insulin resistance group than the control group.After 24 hours,the difference of hOGGl expression between control group and insulin resistance group was not significant (F=23.392,P＞0.05).After 72 hours,the level of hOGGl expression was significantly higher in the insulin resistance group than the control group (F=129.394,P＜0.05).The level of hOGGl expression was significantly higher at 48 hours than that at 24 hours and 72 hours (P＜ 0.05).Conclusion Leptin could induce the oxidative damage of RPE cells in normal and insulin resistance status.With the increase of leptin concentration and time extended,the degree of oxidative damage and its repair were both increased.The degree of oxidative repair increased with the increase of leptin concentration,but decreased with time extended. Key words: Retinal pigment epithelium/injuries; Leptin/poisoning; Reactive oxygen species/poisoning

Evaluation of follicular oxidant-antioxidant balance and oxidative damage during reproductive acyclicity in water buffalo (Bubalus bubalis

Abstract Objective To investigate changes in follicular fluid concentrations of reactive oxygen species (ROS) and total antioxidant capacity (TAC) and degree of oxidative damage to follicular cells, using protein carbonyl (PC) as marker of oxidative stress, were investigated during reproductive acyclicity in buffalo. Methods Follicular fluid was aspirated from follicles grouped into three classes depending upon their diameter [small (5.0–7.0 mm), medium (7.1–10.0 mm), and large (>10.0 mm)]. Progesterone and estradiol were estimated to determine functional status (P:E ratio) of the follicles. Results Acyclic buffaloes had greater concentrations of ROS ( P P =0.0412) and lower concentrations of TAC ( P =0.0280) than cyclic buffaloes. An interesting novel finding was the complete absence of low P:E functionally active follicles in acyclic buffaloes. Results indicated a pronounced follicular fluid oxidant-antioxidant imbalance and oxidative damage to follicular cells during acyclicity in buffalo. Conclusion In conclusion, this study provided evidence about role of oxidative stress in pathogenesis of reproductive acyclicity.

Toxic Effects of Lead Exposure in Rats: Involvement of Oxidative Stress, Genotoxic Effect, and the Beneficial Role of N-Acetylcysteine Supplemented with Selenium

This study was carried out to investigate the in vivo protective role of N-acetylcysteine (NAC) per se, along with selenium (Se), against lead-induced hepatic, nephritic-oxidative, and neuronal-oxidative damage in rats. Lead acetate at a dose of 50 mg/kg body weight administered intraperitoneally for 3 days was preferred as the source of lead. Various oxidative stress markers such as reduced glutathione content, lipid peroxidation, superoxide dismutase, and catalase were measured to determine the degree of oxidative damage and healing due to NAC (50 mg/kg body weight administered orally) and Se (0.5 mg/kg body weight administered orally) and were studied along with the activities of enzymes such as transaminases (aspartate aminotransferase/alanine aminotransferase), δ-aminolevulinic acid dehydratase, δ-aminolevulinic acid synthase, and acetyl cholinesterase activity. The genotoxic effect of lead also was studied in terms of DNA damage using comet assay. The effect of lead was studied in blood biochemical variables such as cholesterol, triglycerides, urea, uric acid, and creatinine. Our data suggest that supplementation of Se with NAC can improve the lead-induced biochemical oxidative stress in blood and tissue, the burden of lead on the body, and molecular alterations by recoupment in mean DNA damage.

Oxidative damage and brain concentrations of free amino acid in chicks exposed to high ambient temperature

High ambient temperatures (HT) reduce food intake and body weight in young chickens, and HT can cause increased expression of hypothalamic neuropeptides. The mechanisms by which HT act, and the effects of HT on cellular homeostasis in the brain, are however not well understood. In the current study lipid peroxidation and amino acid metabolism were measured in the brains of 14 d old chicks exposed to HT (35°C for 24- or 48-h) or to control thermoneutral temperature (CT; 30°C). Malondialdehyde (MDA) was measured in the brain to determine the degree of oxidative damage. HT increased body temperature and reduced food intake and body weight gain. HT also increased diencephalic oxidative damage after 48h, and altered some free amino acid concentrations in the diencephalon. Diencephalic MDA concentrations were increased by HT and time, with the effect of HT more prominent with increasing time. HT altered cystathionine, serine, tyrosine and isoleucine concentrations. Cystathionine was lower in HT birds compared with CT birds at 24h, whilst serine, tyrosine and isoleucine were higher at 48h in HT birds. An increase in oxidative damage and alterations in amino acid concentrations in the diencephalon may contribute to the physiological, behavioral and thermoregulatory responses of heat-exposed chicks.

Suprazero cooling rate, rather than freezing rate, determines post thaw quality of rhesus macaque sperm

Sperm become most sensitive to cold shock when cooled from 37 °C to 5 °C at rates that are too fast or too slow; cold shock increases the susceptibility to oxidative damage owing to its influence on reactive oxygen species (ROS) production, which are significant stress factors generated during cooling and low temperature storage. In addition, ROS may be a main cause of decreased motility and fertility upon warming. They have been shown to change cellular function through the disruption of the sperm plasma membrane and through damage to proteins and DNA. The objective of this study was to determine which cryopreservation rates result in the lowest degree of oxidative damage and greatest sperm quality. In the rhesus model, it has not been determined whether suprazero cooling or subzero freezing rates causes a significant amount of ROS damage to sperm. Semen samples were collected from male rhesus macaques, washed, and resuspended in TEST-yolk cryopreservation buffer to 100 × 106 sperm/mL. Sperm were frozen in 0.5-mL straws at four different combinations of suprazero and subzero rates. Three different suprazero rates were used between 22 °C and 0 °C: 0.5 °C/min (slow), 45 °C/min (medium), and 93 °C/min (fast). These suprazero rates were used in combination with two different subzero rates for temperatures 0 °C to −110 °C: 42 °C/min (medium) and 87 °C/min (fast). The different freezing groups were as follows: slow-med (SM), slow-fast (SF), med-med (MM), and fast-fast (FF). Flow cytometry was used to detect lipid peroxidation (LPO), a result of ROS generation. Motility was evaluated using a computer assisted sperm motion analyzer. The MM and FF treated sperm had less viable (P < 0.0001) and motile sperm (P < 0.001) than the SM, SF, or fresh sperm. Sperm exposed to MM and FF treatments demonstrated significantly higher oxidative damage than SM, SF, or fresh sperm (P < 0.05). The SM- and SF-treated sperm showed decreased motility, membrane integrity, and LPO compared with fresh semen (P < 0.001). Slow cooling from room temperature promotes higher membrane integrity and motility post thaw, compared with medium or fast cooling rates. Cells exposed to similar cooling rates with differing freezing rates were not different in motility and membrane integrity, whereas comparison of cells exposed to differing cooling rates with similar freezing rates indicated significant differences in motility, membrane integrity, and LPO. These data suggest that sperm quality seems to be more sensitive to the cooling, rather than freezing rate and highlight the role of the suprazero cooling rate in post thaw sperm quality.

The effect of betulinic acid on TNBS-induced experimental colitis

ABSTRACT: In this study we have investigated the possible protective effect of betulinic acid (BA) on colonic inflammation in rats. Colitis was induced in Sprague-Dawley rats of both sexes by intracolonic administration of 1 ml trinitrobenzene sulphonic acid (TNBS). Colitisinduced rats received orogastrically either betulinic acid (50 mg/kg/day) or vehicle (0.05% DMSO) for 3 days. At the 72nd hour of colitis induction, the rats were decapitated and trunk blood was collected for the measurement of TNF-, IL-1, lactate dehydrogenase (LDH) levels and total antioxidant capacity (AOC). The distal 8 cm of colon were scored macroscopically, and the degree of oxidant damage was evaluated by malondialdehyde (MDA) and glutathione (GSH) levels, myeloperoxidase activity (MPO), collagen content and by histological analysis. Generation of oxidants was evaluated by tissue luminol and lucigenin chemiluminescences (CL). Colitis caused significant increases in the colonic CL values, macroscopic damage scores, MDA, MPO and collagen levels, along with a significant decrease in tissue GSH level. Similarly, serum TNF-, IL-1, as well as LDH were elevated and AOC was reduced in the vehicle-treated colitis group as compared to control group. On the other hand, betulinic acid treatment reversed all these biochemical indices, as well as histopathological alterations induced by TNBS, suggesting that betulinic acid protects the colonic tissue via its radical scavenging and antioxidant activities. KEY WORDS: betulinic acid; colitis; oxidative damage; inflammation; trinitrobenzene sulphonic acid