Exogenous Nitric Oxide Alleviated the Inhibition of Photosynthesis and Antioxidant Enzyme Activities in Iron-Deficient Chinese Cabbage (Brassica chinensis L.)

The effects of exogenous nitric oxide （NO） on plant growth, chlorophyll contents, photosynthetic and chlorophyll fluorescence parameters as well as lipid peroxidation and activities of antioxidant enzymes were investigated in Chinese cabbage plants exposed to iron （Fe） deficiency. Iron deficiency led to serious chlorosis in Chinese cabbage leaves, and resulted in significant decrease in plant growth, photosynthetic pigments, net photosynthetic rate, Fv/Fm, Ф ps Ⅱ and activities of antioxidant enzymes, and increase in lipid peroxidation. While treatment with SNP, a NO donor, it could revert the iron deficiency symptoms, increased photosynthetic rate as well as activities of antioxidant enzymes, and protected membrane from lipid peroxidation, as a result, the growth inhibition of Chinese cabbage by Fe deficiency was alleviated.

Anti-nitric oxide production, anti-proliferation and antioxidant effects of the aqueous extract from Tithonia diversifolia

Objective: To determine the cytotoxicity, reduction in nitric oxide production and antioxidative activity of the aqueous leaf extract from Tithonia diversifolia(T. diversifolia) in an in vitro model.Methods: Leaves of T. diversifolia were collected from natural habitats and extracted with distilled water using the decoction method. The cytotoxic effect of the extract in terms of cell viability was determined using RAW264.7 cells and human peripheral blood mononuclear cells(PBMCs) via the mitochondrial respiration method using the MTT reagent. The effect of the extract on lipopolysaccharide(LPS)-induced nitric oxide production in RAW264.7 cells was measured using the Griess reagent. The chemical antioxidant was evaluated by ABTS- and DPPH-radical scavenging assays.Results: The half-maximal cytotoxic concentration values were 145.87 mg/m L and73.67 mg/m L for human PBMCs and RAW264.7 cells, respectively. In the presence of phytohemagglutinin-M, the IC_(50) on PBMCs proliferation was 4.42 mg/m L. The noncytotoxic range of the extracts inhibited LPS-induced nitrite production in RAW264.7 cells with an IC_(50) value of 11.63 mg/m L. To determine the anti-oxidative properties, the N-acetyl cysteine equivalent antioxidant capacity of the extract was(32.62 ± 1.87) and(20.99 ± 2.79)mg N-acetyl cysteine/g extract, respectively determined by the ABTS-radical and DPPHradical assay. However, the extract did not confer death protection in a hydrogen peroxideinduced RAW264.7 co-culturing model.Conclusions: Our study demonstrated the immunomodulation caused by the aqueous leaf extract of T. diversifolia, resulting from the inhibition of phytohemagglutinin-Minduced PBMCs proliferation and LPS-induced nitric oxide production in RAW264.7macrophages. Although the anti-oxidative activity was presented in the chemical-based anti-oxidant assay, the extract cannot protect cell death from stress conditions.

Dietary L-citrulline supplementation modulates nitric oxide synthesis and antioxidant status of laying hens during summer season

Background:L-citrulline(L-Cit),a non-protein amino acid,has been implicated in several physiological functions including anti-inflammatory,anti-oxidative,and hypothermic roles,however,there is a paucity of information with regards to its potential in poultry production.Methods:This study was designed to investigate the effects of dietary L-Cit supplementation on the production performance,nitric oxide production,and antioxidant status of laying hens during summer period.Hy-Line Brown laying hens(n=288,34 weeks old)were allotted to four treatment,6 replicates of 12 chickens each.Dietary treatments of control(basal diets),0.25%,0.50%and 1.00%L-Cit supplementation were fed to chickens for eight(8)weeks.Production performance,free amino acid profiles,nitric oxide production,and antioxidant properties were measured.Blood samples were collected at the 4th and 8th weeks of the experiment.Results:Air temperature monitoring indicated an average daily minimum and maximum temperatures of 25.02°C and 31.01°C respectively.Dietary supplementation with L-Cit did not influence(P>0.05)the production performance,and rectal temperature of laying hens.Egg shape index was increased(P<0.05)with increasing levels of L-Cit.Serum-free content of arginine,citrulline,ornithine,tryptophan,histidine,GABA,and cystathionine were elevated,but taurine declined with L-Cit diets.Plasma nitric oxide(NOx)concentration was highest at 1%L-Cit.Likewise,nitric oxide synthase(NOS)activity for total NOS(tNOS)and inducible NOS(iNOS)were upregulated with increasing L-Cit levels,although,tNOS was not affected at the 4th week.Anti-oxidant enzymes including catalase and superoxide dismutase(SOD)were increased with L-Cit supplementation,however,SOD activity was unchanged at 4th week,while total anti-oxidant capacity increased at the 8th week.L-Cit supplementation attenuated the extent of lipid peroxidation,and also inhibited glutathione peroxidase activity.Conclusion:Dietary L-Cit supplementation modulated systemic arginine metabolism,nitric oxide synthesis,antioxidant defense system,and increased the egg shape index of laying hens during the summer season.1%L-Cit supplementation proved most effective in potentiating these effects and may be adopted for feed formulation strategies.

Antioxidants,inflammation and cardiovascular disease

Multiple factors are involved in the etiology of cardiovascular disease(CVD). Pathological changes occur in a variety of cell types long before symptoms become apparent and diagnosis is made. Dysregulation of physiological functions are associated with the activation of immune cells,leading to local and finally systemic inflammation that is characterized by production of high levels of reactive oxygen species(ROS). Patients suffering from inflammatory diseases often present with diminished levels of antioxidants either due to insufficient dietary intake or,and even more likely,due to increased demand in situations of overwhelming ROS production by activated immune effector cells like macrophages. Antioxidants are suggested to beneficially interfere with diseases-related oxidative stress,however the interplay of endogenous and exogenous antioxidants with the overall redox system is complex. Moreover,molecular mechanisms underlying oxidative stress in CVD are not fully elucidated. Metabolic dybalances are suggested to play a major role in disease onset and progression. Several central signalingpathways involved in the regulation of immunological,metabolic and endothelial function are regulated in a redox-sensitive manner. During cellular immune response,interferon γ-dependent pathways are activated such as tryptophan breakdown by the enzyme indoleamine 2,3-dioxygenase(IDO) in monocyte-derived macrophages,fibroblasts,endothelial and epithelial cells. Neopterin,a marker of oxidative stress and immune activation is produced by GTP-cyclohydrolase Ⅰ in macrophages and dendritic cells. Nitric oxide synthase(NOS) is induced in several cell types to generate nitric oxide(NO). NO,despite its low reactivity,is a potent antioxidant involved in the regulation of the vasomotor tone and of immunomodulatory signaling pathways. NO inhibits the expression and function of IDO. Function of NOS requires the cofactor tetrahydrobiopterin(BH4),which is produced in humans primarily by fibroblasts and endothelial cells. Highly toxic peroxynitrite(ONOO-) is formed solely in the presence of superoxide anion(O2-). Neopterin and kynurenine to tryptophan ratio(Kyn/Trp),as an estimate of IDO enzyme activity,are robust markers of immune activation in vitro and in vivo. Both these diagnostic parameters are able to predict cardiovascular and overall mortality in patients at risk. Likewise,a significant association exists between increase of neopterin concentrations and Kyn/Trp ratio values and the lowering of plasma levels of vitamin-C,-E and-B. Vitamin-B deficiency is usually accompanied by increased plasma homoycsteine. Additional determination of NO metabolites,BH4 and plasma antioxidants in patients with CVD and related clinical settings can be helpful to improve the understanding of redox-regulation in health and disease and might provide a rationale for potential antioxidant therapies in CVD.

Nitric oxide mediated Staphylococcus aureus pathogenesis and protective role of nanoconjugated vancomycin

Objective:To investigate the relation between fruit seeds,plants residuals and appendicitis. Methods:Among cases that underwent appendectomy,the appendicitis cases having fruit seeds and undigested plant residuals in their etiology were examined retrospectively.Also, histopathological features,age,sex,and parameters of morbidity and mortality were used. Results:Fruit seed was found in one case(0.05%) with presence of pus in appendix lumen, undigested plant residuals in 7 cases(0.35%).It was determined that there were appendix inflammation in 2 of the plant residuals cases,while there were obstruction and lymphoid hyperplasia in the appendix lumen of 5 cases.No mortality was observed.Conclusions:The ratio of acute appendicitis caused by plants is minimal among all appendectomised patients, but avoidence of eating undigested fruit seeds and chewing plants well may help to prevent appendicitis.

Cross-talk between calcium-calmodulin and nitric oxide in abscisic acid signaling in leaves of maize plants

Using pharmacological and biochemical approaches, the signaling pathways between hydrogen peroxide （H2O2）, calcium （Ca^2＋）-calmodulin （CAM）, and nitric oxide （NO） in abscisic acid （ABA）-induced antioxidant defense were investigated in leaves of maize （Zea mays L.） plants. Treatments with ABA, H2O2, and CaCl2 induced increases in the generation of NO in maize mesophyll cells and the activity of nitric oxide synthase （NOS） in the cytosolic and microsomal fractions of maize leaves. However, such increases were blocked by the pretreatments with Ca^2＋ inhibitors and CaM antagonists. Meanwhile, pretreatments with two NOS inhibitors also suppressed the Ca^2＋-induced increase in the production of NO. On the other hand, treatments with ABA and the NO donor sodium nitroprusside （SNP） also led to increases in the concentration of cytosolic Ca^2＋ in protoplasts of mesophyll cells and in the expression of calmodulin 1 （CaM1） gene and the contents of CaM in leaves of maize plants, and the increases induced by ABA were reduced by the pretreatments with a NO scavenger and a NOS inhibitor. Moreover, SNP-induced increases in the expression of the antioxidant genes superoxide dismutase 4 （SOD4）, cytosolic ascorbate peroxidase （cAPX）, and glutathione reductase 1 （GR1） and the activities of the chloroplastic and cytosolic antioxidant enzymes were arrested by the pretreatments with Ca^2＋ inhibitors and CaM antagonists. Our results suggest that Ca^2＋-CaM functions both upstream and downstream of NO production, which is mainly from NOS, in ABA- and H2O2-induced antioxidant defense in leaves of maize plants.

Screening of Antioxidant Potential of Selected Barks of Indian Medicinal Plants by Multiple in vitro Assays

Objective To evaluate the antioxidant potential in herbal extract barks of five therapeutically important medicinal plants native to India, i.e. Crataeva nurvala Buch.-Ham., Buchanania lanzan Spreng., Aegle marmelos Corr., Dalbergia sissoo Roxb. ex DC., and Cedrela toona Roxb. Methods Standardized aqueous alcoholic extracts from the selected barks having different target radicals, such as superoxide radical, nitric oxide, ABTS radical, and peroxidative decomposition of phospholipids, were prepared and screened by multiple in vitro assays. These extracts were also tested for total phenolic and tannin content and correlated with antioxidant capacity. Results Total phenolic and tannin contents were found to be the highest in C. nurvala （195 GAE mg/g and 218.3 mg/g CE）. SOD mimetic activity was found to be the highest in Crataeva nurvula, although all barks showed activity more than IO3 units/mg extract. Lipid peroxidation inhibitory potential was found to be the highest in Crataeva nurvala （83.4% inhibition of MDA formation/10 μg extract）, and also showed a comparatively high NO quenching capacity （45.5% per 10 μg extract）. The highest NO quenching potential was found in Aegle marmelos （47.3% per 10 μg extract）. Cedrela toona showed the lowest LPO inhibitory potential and NO quenching capacity （50.5% and 30.5%, respectively）. Buchanania lanzan, a medicinal plant extensively used for inflammatory disorders and Dalbergia sissoo also showed 72.5% and 69.1% LPO inhibitory potential/10 μg extract. Trolox equivalent antioxidant capacity ranged from 0.24 to 0.39 mmol/L TEAC/mg extract, indicating that all the barks tested had ABTS^＋ radical quenching capacity. Conclusion Bark of Crataeva nurvula has the highest antioxidant capacity and a positive correlation between antioxidant activity and their plendic content was found.

Hepatoprotective effects of antioxidants in chronic hepatitis C

We have read with interest the paper published in issue 2, volume 16 of World Journal of Gastroenterology 2010 by Nakamura et al, demonstrating that the antioxidant resveratrol (RVT) enhances hepatitis C virus (HCV) replication, consequently, they conclude that RVT is not a suitable antioxidant therapy for HCV chronic infection. The data raise some concern regarding the use of complementary and alternative medicine since the most frequent supplements taken by these patients are antioxidants or agents that may be beneficial for different chronic liver diseases. A recent study by Vidali et al on oxidative stress and steatosis in the progression of chronic hepatitis C concludes that oxidative stress and insulin resistance contribute to steatosis, thus accelerating the progression of fibrosis. We are particularly interested in investigating how the oxidative and nitrosative stress mechanisms are involved in the pathogenesis of different chronic liver diseases.

Nitric Oxide Alleviates Oxidative Stress Caused by Lanthanum in Rice Leaves

The effect of NO on lanthanum-induced antioxidant activities in rice was evaluated. The results showed that the uptake and translocation of La from root to shoot were obviously inhibited by 10μmol·L^-1 sodium nitropmsside （SNP）, a donor of NO, in the seedlings grown in Mura B nutrient solution with 100μmol·L^-1 La. Although the content of ascorbate acid （AsA） were scarcely affected by La or NO in our experiment, La decreased significantly the activity of SOD and content of GSH, while promoted H202 content in leaves. Furthermore, NO blocked these La effects. Taken together, the results suggested that NO relieved La toxicity in rice. A possible role for NO effects on antioxidant activity was discussed.

phytochemical analysis and in vitro antioxidant acitivity of hydroalcoholic seed extract of Nymphaea nouchali Burm.f.

Objective:To evaluate the phytochemical constituents and the antioxidant activity of hydroalcoholic extract of Nymphaea nouchali seed locally prescribed as a diet for diabetes mellitus.Methods:The antioxidant and free radical scavenging activity of hydroalcoholic extract of the plant was assessed against 1,1 diphenyl-2-picryl hydrazyl(DPPH),nitric oxide and lipid peroxidation using standard protocols.Total phenolics,flavonoids and tannins were also determined.Results:Phytochemical analysis revealed the presence of phenols,flavones,tannins,protein,reducing sugars,glycosides,saponins,alkaloids and steroids.The activities of plant extract against DPPH,nitric oxide and lipid peroxidation was concentration dependent with IG_(50)value of42.82,23.58 and 54.65μg/mL respectively.The total antioxidant capacity was high with 577.73 mg vitamin E/g of the extract and showed a moderately high vitamin C content of 197.22 mg/g.The total tannin content of hydroalcoholic seed extract was high(195.84 GE/g),followed by phenolics(179.56 GE/g)and flavonoids(23.55 QE/g).Conclusion:Our findings provide evidence that the crude extract of Nymphaea nouchali is a potential source of natural antioxidants and this justifies its use in folkloric medicine.

Antihypertensive and antioxidant activity of Cassytha filiformis L.:A correlative study

Objective: To study the blood pressure lowering effect of Cassytha filiformis extract in animal models of hypertension and its correlation with the antioxidant activity.Methods: Male Sprague–Dawley rats were divided into two groups: endocrine hypertension(HTN group) that received a combination of prednisone and salt for two weeks and oxidative stress-associated hypertension(HTN-OS group) that received additional induction of L-Nitro Arginine Methyl Esther(L-NAME) for two days. Each group was subdivided into 4 and treated intravenously with the extract 5; 10; and 20 mg/kg, and vehicle control. The systolic blood pressure(SBP), diastolic blood pressure(DBP), and mean arterial pressure(MAP) were recorded. The blood was taken before and at the end of recording for the measurement of serum concentration of nitric oxide(NO). The changes of blood pressure were analyzed by two-way ANOVA while its correlation with NO concentration was analyzed by Pearson's Correlation.Results: The study showed a significant antihypertensive effect of the extract as compared with control group(P < 0.05) in both hypertensive models. Extract in the dose of 5 mg/kg showed the best blood pressure lowering effect. However, the correlation analysis did not show an association between NO increase and blood pressure lowering effect(P > 0.05).Conclusions: The study concludes that C. filiformis extract in the dose of 5 mg/kg exhibits the best blood pressure lowering effect in both animal models. Antihypertensive activity of the extract is not correlated with its antioxidant effect.

Oxidative stress in portal hypertension-induced rats with particular emphasis on nitric oxide and trace metals

AIM: To investigate the oxidative-stress-related changes in rats with portal hypertension with particular emphasis on nitric oxide (NO) and trace metals. METHODS: Cirrhosis was induced by partial portal vein ligation (PVL) in Wistar rats. The lipid peroxidation marker (malondialdehyde, MDA), antioxidant defense enzymes including superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), and agents known to have antioxidant features including nitric oxide (NO), zinc (Zn), copper (Cu) were determined both in serum and in liver tissue at 4 wk after surgery in PVL and sham-operated rats. Portal pressure of all experimental animals was measured. MDA was detected by thiobarbituric acid reactivity assay.SOD activity was determined by inhibition of nitroblue tetrazolium reduction with xanthine/xanthine oxidase used asa superoxide generator. CAT activity was determined by the breakdown of hydrogen peroxide. GSH concentrations were measured by using metaphosphoric acid for protein precipitation and 5'-5'-dithio-bis-2-nitrobenzoic acid for color development. NO was detected by the Griess method after reduction of nitrate to nitrite with nitrate reductase, and the concentrations of Zn and Cu were measured by a Shimadzu 680 AA atomic absorption spectrometer. Histopathological confirmation was done under light microscope. Statistical analyses were done by Student's t-test, and significance of the difference was tested by the unpaired Mann-Whitney test. P＜0.05 was considered statistically significant.RESULTS: Histopathological studies confirmed PVL induced cirrhotic changes. There was a statistically significant difference in portal pressure between PVL and control groups (P＜0.001). The results showed significant increases in the levels of MDA and NO in both tissue and serum (P＜0.05 and P＜0.001, respectively in tissue; P＜0.001 for each in serum), and Zn only in tissue (P＜0.001)in rats with PVL compared with sham-operated rats. Besides, PVL rats exhibited reduced plasma and tissue GSH, CAT, SOD (P＜0.001 for each). Serum and tissue Cu concentration did not change.CONCLUSION: Our findings suggest that PVL in rats induces important biochemical and molecular changes related to oxidative stress in the liver.

Dynamic Analysis of Nitric Oxide and Total Oxidant Capacity in Cow Uterine Secretion with Subclinical Endometritis

Subclinical endometritis is a physiological inflammation that serves to clear persistent contaminants from the uterus. To investigate the alteration of antioxidant, such as vitamin E（VE） and vitamin C（VC）, total oxidant capacity（TOC） and nitric oxide（NO） in cows with normal and subclinical endometritis（SCE）, we examined the concentrations of NO, VC and VE, TOC and polymorphonuclear neutrophils（PMN） percentage in uterine secretion. The cows were divided into two groups, normal（n=20） and subclinical endometritis（SCE, n=60）, based on endometrial cytology（presence of PMN≥5%）. Uterine secretion and blood were collected as described previously. Griess reaction was used to determine the concentration of NO. The concentrations of TOC, VC and VE were detected by a commercially available assay kit. The results showed that the concentrations of NO, TOC and PMN percentage were significantly higher（P〈0.01, P〈0.05, and P〈0.01, respectively） in uterine secretion with SCE compared to those from normal; however, the levels of VC and VE were significantly lesser（P〈0.01）. In conclusion, the concentrations of NO, TOC, VC, VE and PMN percentage differed between normal and SCE cows. Meanwhile, the relationship between the concentration of NO and PMN percentage from uterine secretion in cows with subclinical endometritis were positively correlated. Consequently, these alterations in NO, TOC, VC, VE levels and PMN percentage contributed to as a diagnostic index of the uterine inflammation, with the aim to increase the reproduction of the cows and the decrease economic losses.

Nitric Oxide: Probably the <i>in Vivo</i>Mediator of the Bisulfite’s Effects

The use of bisulfite in food and beverage preservation, as well as in commercial goods and pharmaceuticals as antimicrobial agents is well known, but not very much is reported on its action in vivo. It has been stressed that its action is connected to the presence of NO, and the only reported/ hypothesized evidence concerns the possible interaction with GSNO (S-nitrosoglutathione), an NO releaser. In this light, we investigated the interaction between GSNO and the bisulfite in an aqueous medium at pH = 6.4;actually, a positive effect of the sulfite was evidenced. i.e., the S-nitrosoglutathione becomes a more efficient NO-releaser. But, the nitrite is the real pool of NO in vivo, therefore we investigate its interaction with the bisulfite in an aqueous acidic solution at pH = 6.4;this time, a definitely efficient and abundant NO release, 3.61 times higher compared to the GSNO, has been evidenced. Therefore, these results allow hypothesizing a fundamental role of NO in the bisulfite’s action in vivo, or most probably the bisulfite acts simply as cofactor of NO-releasers.

Nitric Oxide: The Key Molecule for Polyphenols Antimicrobial Action

The role of hydroxycinnamic acids as antioxidants, in vivo, has been widely discussed, but, recently, a great debate has focused on their antimicrobial action. In general, for the hydroxycinnamic acids’ action, the presence of NO, which is known to be an antimicrobial agent, seems compulsory;its production goes through the intermediacy of the nitrosonium ion, and a very low pH, for instance, as in the stomach, is requested. However, the action of the hydroxycinnamic acids seems to take place even in different biological compartments, i.e., characterized by different pHs and conditions, and then, for NO production, an alternative mechanism could be involved. In this light, evidence for the NO formation, via an E.T. mechanism, even in mildly acidic conditions (pH = 6.4), was obtained by reacting an aqueous buffer solution of acidic nitrite (HNO2) with the hydroxycinnamic acids ferulic, caffeic, p-coumaric and sinapic. Experiments conducted by EPR spectroscopy, let to detect the NO formation, and the efficiency of the process depending on the available amount of free polyphenol, and the intrinsic nature of the hydroxycinnamic acids. Thus, the production of NO through a non-enzymatic mechanism, in light acidic conditions, would account for the antimicrobial action of hydroxycinnamic acids, even in unconventional biological compartments, and for NO as the key-molecule.

Antioxidant and Anti-Inflammatory Effects of Peanut Skin Extracts

Peanut skins are regarded as a low economic value by-product of the peanut industry;however, they contain high levels of bioactive compounds including catechins and procyanidins, which are known for their health-promoting properties. The in vitro antioxidant activity of peanut skin extracts (PSE) has been reported but the associated anti-inflammatory properties have not been widely examined. This study investigated the anti-inflammatory effects of PSE on the pro-inflammatory enzyme, Cyclooxygenase-2 (COX-2) protein expression, on its downstream product, prostaglandin E2 (PGE2), and on nitrous oxide (NO) levels. Defatted peanut skins were extracted using two aqueous solvent mixtures (50% acetone and 90% ethanol), in order to compare the effects of the two solvent systems on antioxidant and anti-inflammatory properties. PSE antioxidant activity was determined by the hydrophilic oxygen radical absorbance capacity (H-ORAC) assay, while total phenolics were determined by the Folin-Ciocalteu assay and flavan-3-ols and procyanidins were quantified by HPLC. Acetone extracted PSE (A-PSE) exhibited numerically, but not statistically higher H-ORAC and total phenolic values than the ethanol extracted PSE (E-PSE) (1836 μmol Trolox/100 g and 67.9 mg GAE/g, and 1830 μmol Trolox/100 g and 51.8 GAE/g respectively). A-PSE also had higher levels of flavan-3-ols and procyanidins than E-PSE. RAW 264.7 cells were pretreated with 1.0%, 2.5% and 5.0% (v/v) of A-PSE or E-PSE and induced with the inflammatory marker, lipopolysaccharide (LPS) for 12 hours. COX-2 protein expression, measured by Western blotting was significantly (p 2 and NO levels measured by ELISA, were significantly (p < 0.05) decreased with increasing added levels of A-PSE and E-PSE suggesting that A-PSE and E-PSE not also possess similar antioxidant properties, but also exhibit similar anti-inflammatory effects.

Short-term antioxidant diet prevents hyperfiltration in young male rat kidney subjected to ischemia/reperfusion injury

Objectives: The process of transplantation is associated with exposure to both long and short cold and warm ischemic times that result in ischemia/reperfusion injury. Oxidative stress contributes to tissue fibrosis, renal dysfunction, and/or rejection. Treatments that scavenge oxygen free radicals and have antioxidant properties can ameliorate the damaging results in renal grafts following ischemia/reperfusion injury. The present study tests the hypothesis that an antioxidant-fortified diet given to rats before and after renal ischemia/reperfusion injury will reduce the kidney damage that results and improve renal function. Endothelial and inducible nitric oxide synthases may change with tissue injury, including ischemia/ reperfusion. Materials and Methods: Male Wistar rats were subjected to ischemia/reperfusion injury at 7 or 19 weeks of age with or without dietary antioxidant supplementation. One week later, glomerular filtration rate, mean arterial pressure and urinary nitric oxide were measured, and renal endothelial and inducible nitric oxide synthases examined. Results: The glomerular filtration rate was elevated more than two-fold above the normal range? at 8 weeks in animals on the regular diet exposed to ischemia/reperfu- sion, while in the 8 week antioxidant-fortified diet group the glomerular filtration rate was normal. Also, in 8 week rats, levels of endothelial nitric oxide synthase protein in cortex were higher on the regular than on the antioxidant-fortified diet. Conclusion: Early after ischemia/reperfusion injury renal endothelial nitric oxide synthase levels rise, possibly contributing to vascular dilation and hyperperfusion, and an antioxidant-fortified diet can ameliorate these changes in the younger age group.

Effect of acute alcoholism on hepatic enzymes and oxidation/antioxidation in rats

BACKGROUND: Around the world more and more people suffer from acute alcoholism. The purpose of this study was to determine hepatic enzymes and oxidation/antioxidation in rats with acute alcoholism. METHODS: Rats were randomly divided into three groups; control, low-dose alcohol, and high-dose alcohol. Each al- cohol group ( n = 12) was intravenously infused with etha- nol at a dose of 0.3 or 0.7 g/kg body weight respectively. The control group (n =11) was intravenously infused with normal saline at a dose of 0.5 g/kg body weight. Blood was collected for detection of hepatic enzymes and index of oxidation/antioxidation. RESULTS: The ratio of AST to ALT was 2.44±0.46, 2.57± 0.60 and 3.03 ±0.46 in the three groups, and the difference was significant between the control and high-dose alcohol groups (P^0.05). No significant changes were observed in the levels of serum alanine aminotransferase (ALT), aspar- tate aminotransferase (AST), total protein (Tp), albumin (Alb), alkaline phosphatase (ALP), cholinesterase (ChE), total bilirubin (TB), C-reactive protein (CRP) and amy- lase. The levels of serum nitric oxide (NO) in the 3 groups were 39.2 ±73.25 mol/L, 42.30 ±4.60 mol/L and 47.86± 4.66 mol/L, and significant difference was seen between the control group and the high-dose alcohol group (P < 0.01). No significant difference was found in the levels of serum superoxide dismutase (SOD), glutathione (GSH), malondiethylaldehyde (MDA), and CRP in the 3 groups. CONCLUSION: The ratio of AST to ALT appears to be a useful index for acute alcohol intoxication. NO is involved in the mechanism of acute alcohol intoxication.

Effects of nitric oxide treatment on flavour compounds and antioxidant enzyme activities of button mushroom (Agaricus bisporus) during storage

Button mushroom(Agaricus bisporus)is sold well for its unique flavour and nutritional benefits.However,the mushroom flavour deteriorates quickly during storage because of its delicate structure and high moisture.In this study,the effects of nitric oxide(NO)application on flavour compounds and antioxidant enzyme activities of stored button mushrooms were investigated.The button mushrooms were immersed in the NO donor sodium nitroprusside(15μmol/L)for 3 min and then stored under the condition of 4℃,90%relative humidity for 12 days.Results showed that the treated mushrooms have reduced weight loss rate,uniform white colour,and higher firmness during storage.Compared to the control,the ketones,alcohols,esters,and aldehydes in the NO-treated button mushroom increased sharply at 3 days of storage and then showed a continuing decline trend,except ester compounds which reached the peak value at 6 days of storage.In addition,NO treatment increased the total phenolics and catalase activity and inhibited the polyphenol oxidase activity in the stored button mushroom.These results indicated that NO treatment is an alternative storage technology to enhance antioxidant capacity and maintain flavour and consumer acceptance of stored button mushroom.

Nitric oxide induced by polyamines involves antioxidant systems against chilling stress in tomato (Lycopersicon esculentum Mill.) seedling

Polyamines（PAs） and nitric oxide（NO） are vital signals in modulating plant response to abiotic stress. However, to our knowledge, studies on the relationship between NO and PAs in response to cold stress in tomato are limited. Accordingly, in this study, we investigated the effects of putrescine（Put） and spermidine（Spd） on NO generation and the function of Spd-induced NO in the tolerance of tomato seedling under chilling stress. Spd increased NO release via the nitric oxide synthase（NOS）-like and nitrate reductase（NR） enzymatic pathways in the seedlings, whereas Put had no such effect. Moreover, H2O2 might act as an upstream signal to stimulate NO production. Both exogenous NO donor（sodium nitroprusside（SNP）） and Spd enhanced chilling tolerance in tomato, thereby protecting the photosynthetic system from damage. Compared to chilling treatment alone, Spd enhanced the gene expressions of superoxide dismutase（SOD）, peroxidase（POD）, catalase（CAT）, and ascorbate peroxidase（APX）, and their enzyme activities in tomato leaves. However, a scavenger or inhibitor of NO abolished Spd-induced chilling tolerance and blocked the increased expression and activity due to Spd of these antioxidant enzymes in tomato leaves under chilling stress. The results showed that NO induced by Spd plays a crucial role in tomato＇s response to chilling stress.