Nitric Oxide Scavenging Ability Research Articles

Antioxidant Activity of Food Protein: Yellow Pea Protein Isolate NUTRALYS® S85F in a cell free Environment

In recent years, the demand for “all natural” products is increasing because of the increasing limitations on the use of synthetic antioxidants and enhanced public awareness of health issues. Many natural food components like oils and oilseeds, proteins and protein hydrolysates, fruits and vegetables, oat and rice bran, spices, herbs and tea have antioxidant properties. Natural antioxidants from these food components provide oxidative stability to the food product. The antioxidant activity of proteins is mainly due to interactions between their ability to inactivate reactive oxygen species, chelate pro-oxidative transition metals, scavenge free radicals, and reduction of hydroperoxides. The objective of this study was to verify the antioxidant potential of Pea Protein Isolate ‘NUTRALYS® S85F' through different in vitro tests: TOTAL ANTIOXIDANT RADICAL SCAVENGING ACTIVITY (ORAC ASSAY); SUPEROXIDE RADICAL SCAVENGING ACTIVITY (NBT ASSAY); LIPID PEROXIDATION INHIBITION ASSAY (MDA KIT); HYDROXYL RADICAL SCAVENGING ACTIVITY (HRS ASSAY); NITRIC OXIDE SCAVENGING ABILITY NUTRALYS® S85F clearly demonstrates intrinsic antioxidant activities as can be observed from its scavenging activity toward the peroxyl radicals (ORAC), scavenger of the superoxide radicals (NBT), hydroxyl radical scavenging (HRS), prevention of lipid oxidation (MDA) and nitric oxide scavenging (NO) capabilities. Based on our results, NUTRALYS® S85F will provide oxidative stability to food products and health benefits to the consumer.

In Vitro Evaluation of The Antioxidant and Anti-Skin Aging Properties of Green Algal Sulfated Polysaccharides

Abstract Skin aging is a natural phenomenon witnessed by humans. However various intrinsic and extrinsic factors lead to early skin aging. There have been a variety of approaches to combat skin aging one approach uses antioxidants that are known to fight oxidative stress as well as combat problems of aging. In this study, the antioxidant and anti-skin aging properties of sulfated polysaccharides (SPs) from fresh water microalgae Chlamydomonas reinhardtii (Cr) are evaluated. Sulfated polysaccharides were isolated by hot water extraction method and purified by anion-exchange chromatography. The biochemical composition of the extract showed carbohydrate content of 785.07 mg/g, 324.26 mg/g of sulphate and 393.32 mg/g of uronic acid. These extracts which are enriched with SPs were further used for checking antioxidant and anti-skin aging properties. Cr-SPs showed Superoxide anion scavenging activity of 38-92% at 0.1-2 mg/mL, 51-89% of nitric oxide scavenging ability at 0.2-2 mg/mL, 10-58% of hydrogen peroxide scavenging ability at 1- 10 mg/mL, and 28-68% of ferric ion reducing potential at 0.5-5 mg/mL respectively. Furthermore, Cr-SPs showed 90% anti-elastase enzyme activity at 1 mg/mL, 83% and 89% anti-collagenase and anti-hyaluronidase activities at 1 mg/mL and 2 mg/mL respectively. These promising antioxidant and anti- skin aging properties of Cr-SPs pave way to explore the potential of Cr-SPs in cosmeceutic and pharmaceutical formulations as anti-skin aging agents in a cost-effective manner.

Antibacterial and antioxidant potentials of leave extracts of Helianthus annuus

Helianthus annuus has been widely used for its medicinal and nutritional properties. This study was aimed at assessing the ethyl acetate, n-hexane and methanol extracts of Helianthus annuus for antibacterial and antioxidant potentials. The phytochemical screening, total phenols, DPPH radical scavenging assay and nitric oxide radical scavenging activity were carried out following standard procedures. Preliminary screening of the antibacterial activities of the extracts was carried out on five bacterial species (Bacillus subtilis, E. coli, Pseudomonas aeruginosa, Staphylococcus aureus and Klebsiella pneumoniae), using the agar-diffusion method. Growth rate studies in presence of the extract was investigated on two bacterial species (Bacillus subtilis and E. coli). The methanol extract was observed to inhibit the growth of the five bacterial species while ethyl acetate and N-hexane extracts showed inhibition against Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa. Extended lag periods of 5 - 6 h were observed when the Bacillus subtilis and Escherichia coli were grown in broth medium that contained the respective extracts. In broth medium with mixture of extract and ascorbic acid, there was no observed growth of the Bacillus subtilis and Escherichia coli throughout the 7 h incubation period. The total phenolics content of the extracts revealed concentrations of 6.66 ±0.45, 5.58 ±0.11 and 6.06±0.41 mg TAE.g-1) for the methanol, N-hexane and ethyl acetate extracts respectively. The DPPH radical scavenging assay results displayed gradual increase in percentage inhibition from the lowest to the highest concentration across all the standard groups, a similar trend was observed with the extracts, the ethyl acetate extract showed highest percentage inhibition amongst the other extracts. All the extracts showed high reducing power ability. The nitric oxide scavenging ability of the extracts showed constant increase with increase in concentration. Helianthus annus, it could be a good source of antimicrobial and antioxidant especially in a world where resistance to antibiotic has increasingly become a global concern.

Phytochemical Composition and in vitro Antioxidant Activity of Golden Melon (Cucumis melo L.) Seeds for Functional Food Application

Aim: Golden melon (Cucumis melo) is an annual herbaceous plant belonging to the family of Cucurbitaceae (Cucurbit). This study was carried out to evaluate the phytochemical composition and in vitro antioxidant activity of golden melon seed extract.
 Place and Duration of Study: The study was carried out between a period of July and August 2017 at Baking Milling Division, Federal Institute of Industrial Research Oshodi Nigeria. 
 Methodology: The crude methanolic extracts of the seed were tested for phytochemical and antioxidant activities according to standard analytical procedure. The antioxidant potential of the seed extracts was examined using different assays by determining total phenolic content, total flavonoid content, total antioxidant capacity. The free radical scavenging activities of the extract such as 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, in vitro lipid peroxidation, and nitric oxide (NO) scavenging assay were determined spectrophotometrically.
 Results: The phytochemical screening of the seed extracts revealed the presence of some secondary metabolites such as alkaloids, phenolic, steroids, flavonoids, terpenoids and cardiac glycosides. The total phenolic content of extract was found to be 29.39 mg/100 g while the amount of total flavonoid content was 20.67 mg/100 g. Scavenging ability was observed to increase in proportion to concentration for all the scavenging assays and at the highest concentration of 100 µg/ml. Total antioxidant capacity assay showed 19.44 mg per 100 g. This high scavenging ability in the seed extracts may be attributed to the presence of phenolic and flavonoids compounds in the extract. The DPPH free radical scavenging activity of 100µg/ml Cucumis melo extract was 75.20% ± 0.72 while the reference standard (Ascorbic acid) was 83.24% ±0.31. Lipid peroxidation inhibition ability of 100 µg/ml Cucumis melo extract was 87.18% ± 0.16 while the standard (ascorbic acid) was 94.96% ± 0.16 at the same concentration. Results obtained from this study showed that the nitric oxide scavenging ability of the extract was 80.50%±0.63 while the standard antioxidant was 85.94% ± 0.54.
 Conclusion: In all the assays, Cucumis melo extract showed maximum percentage of antioxidant potentials at 100 µg/ml. Additionally, golden melon seed possess appreciable amount of phenols and high antioxidant properties which could be explored and incorporated in functional food applications particularly in baked products.

Influence of Sourdough Fermentation on Amino Acids Composition, Phenolic Profile, and Antioxidant Properties of Sorghum Biscuits.

Biscuits were produced from sorghum with and without the addition of sourdough. The influence of sourdough fermentation on the amino acids composition, phenolic profile, and antioxidant properties of the biscuits were evaluated. Phenolic compounds of the biscuits were identified and quantified using gas chromatography/mass spectrometer. The total phenol contents (TPC), total flavonoid contents (TFC), ferric reducing antioxidant properties (FRAP), 2,2’-azinobis( 3-ethylbenzothiazoline-6-sulphonic) (ABTS) scavenging ability, 1,1-diphenyl-2-picryl-hydrazy (DPPH) scavenging ability, and nitric oxide (NO) scavenging ability of the biscuits were determined. Addition of sourdough increased the total essential amino acids, total non essential amino acids, hydrophobic, and aromatic amino acids contents of the biscuits. Essential amino acid index, biological value, and predicted protein efficiency were higher in biscuits with sourdough than in biscuits without sourdough. Six phenolic compounds were identified and quantified in the biscuits. Ferulic acid was the most prominent phenolic compound, followed by chlorogenic acid. TPC, TFC, FRAP, ABTS, DPPH, and NO scavenging abilities increased significantly with the addition of sourdough. Sorghum biscuits with sourdough could be useful in dietary interventions to prevent protein-energy malnutrition. Similarly, the presence of bioactive phenolic compounds and their antioxidant efficacy suggest health benefits in the management of oxidative stress and degenerative diseases.

A study of antioxidant potential of Perilladehyde

The use of plants as food, medicine is credited to a biological property of their secondary metabolites. These naturally occurring secondary metabolites are found to have great importance in controlling the formation of free radicles. These antioxidants are capable to catch the free radicles present in the body and maintain its balance. Antioxidant activity and potency of Perillaldehyde using various in vitro biochemical assays were studied. The assay involves various levels of antioxidant action such as free radical scavenging activity through DPPH, reducing power determination, nitric oxide scavenging ability, metal chelation power, scavenging of hydrogen peroxide, membrane stabilizing activity, and lipid peroxidation study.

Antibacterial and Nitric Oxide Production Inhibitory Activities of Prunus sargentii Branches Extract and Its Fractions against Pathogens of Acne

Background: In this study, we investigated the antibacterial and nitric oxide (NO) production inhibitory activities of 75% ethanol extract of Prunus sargentii branches and its fractions against acne pathogens. Methods and Results: The antibacterial activity against acne causing pathogens was determined using the disc diffusion assay. The ethyl acetate fraction showed higher activities against Propionibacterium acnes, Staphylococcus aureus and Staphylococcus epidermidis than those shown by other fractions. In the DPPH radical and NO scavenging assays, the butanol fraction showed strong DPPH radical and NO scavenging abilities. These activities were related to the total polyphenol and flavonoid contents of butanol fraction. On the other hand, the chloroform and ethyl acetate fractions exhibited the highest NO production inhibitory activity in Lipopolysaccharide (LPS)-stimulated Raw 264.7 cells compared to those exhibited by other fractions. Conclusions: The extract and its ethyl acetate fraction from the branches of P. sargentii exhibited antibacterial activity and could be used as functional materials in antimicrobial related fields. Moreover, the chloroform and ethyl acetate fractions are potential antiinflammatory agents and butanol fraction acts as an effective radical scavenger.

Quantum Chemical Studies on Detail Mechanism of Nitrosylation of NAMI-A-HSA Adduct.

Hydrolysis of NAMI-A in NAMI-A-HSA (HSA = human serum albumin) and nitrosylation of hydrolyzed NAMI-A-HSA adduct have been studied in detail using density functional theory method. It has been observed that the chloride exchange reaction with water in the NAMI-A-HSA adduct follows an interchange dissociative mechanism passing through an unstable heptacoordinated activated complex. The computed free energy of activation (ΔG) and rate constant (k) for the hydrolysis process in aqueous medium are observed to be 24.85 kcal mol(-1) and 3.81 × 10(-6) s(-1), respectively. Nitrosylation of hydrolyzed NAMI-A-HSA adduct with nitric oxide is found to be thermodynamically more favorable with the incorporation of solvent effect and provides a detailed understanding related to the antimetastatic activity of the NAMI-A drug. This investigation shows that nitric oxide coordinates linearly to NAMI-A-HSA adduct leading to the reduction of ruthenium(III) to more active ruthenium(II), with the reduction potential of -2.32 V. Negative relative solvation and relative binding free energies suggest that the hydrolysis and nitrosylation reactions are found to be thermodynamically favorable and faster. Our computed results provide a detailed thermodynamics and kinetics which may be highly beneficial for understanding antimetastatic activity as well as the nitric oxide scavenging ability of NAMI-A.

유산균 발효에 의한 밤송이추출물의 항산화 효과

The aim of this study was to show the antioxidant properties of chestnut (Castanea crenata) bur extracts fermented by Lactobacillus casei. The chestnut has been used as a cosmetic material in Korea for many years. This study showed that reactive oxygen species (ROS) were inhibited by the fermentation materials of chestnut bur extracts. The antioxidant activities were analyzed and expressed as EDA, ABTS, reducing power, SOD-like activity, hydrogen peroxide scavenging activity, superoxide anion radical scavenging activity, and nitric oxide scavenging ability. The antioxidant activities of fermentation materials from L. casei of chestnut bur extracts were higher than those of butylated hydroxyanisole (BHA), epigallocatechin gallate (EGCG), and ascorbic acid (AA). Therefore, we expect that fermentation materials from L. casei of chestnut bur extracts are valuable resources as natural antioxidants and functional cosmetics ingredients.

Protective effects of resveratrol oligomers from Vitis amurensis against sodium nitroprusside-induced neurotoxicity in human neuroblastoma SH-SY5Y cells.

Nitric oxide (NO) induces apoptosis in neuronal cells, and has been implicating in a variety of neuronal pathological process. Thus, there is much interest in identifying natural substances which have protective effects against damage induced by nitrosative stress. The roots of Vitis amurensis have been used as traditional medicine and contain structurally diverse resveratrol oligomers with various biological activities. However, there have been few studies on the protective effect of resveratrol oligomers against neurotoxic reactive nitrogen species. In this study, we evaluated the protective effects of two resveratrol oligomers from V. amurensis, vitisin A and heyneanol A, against NO-induced toxicity. Additionally, their antioxidant activities were determined by measuring NO and hydroxyl radical scavenging ability. Both vitisin A and heyneanol A reduced cell death and DNA fragmentation induced by sodium nitroprusside in SH-SY5Y cells. The present study indicates that radical scavenging activities of vitisin A and heyneanol A contribute to protecting neuronal cells against nitrosative stress.

Fibrinogen effects on erythrocyte nitric oxide mobilization in presence of acetylcholine

AimsThe objectives of this study were to evaluate the effects of high fibrinogen concentration on erythrocyte deformability on mobilization of nitric oxide (NO) and of its metabolites in the presence of acetylcholine (ACh) in healthy human blood samples. Main methodsLevels of NO were evaluated by amperometric method. Nitrite, nitrate and S-nitrosoglutathione (GSNO) were measured using the spectrophotometric Griess reaction. Erythrocyte deformability was determined using the Rheodyn SSD laser diffractometer. Key findingsIn the presence of high concentrations of fibrinogen and ACh (10μM) in the blood samples from healthy humans the erythrocyte nitrites, nitrates and GSNO concentrations increased without significant changes in NO efflux. Mobilization of NO in erythrocytes' presence was enhanced in the presence of ACh and high fibrinogen levels. SignificanceThese results suggest that during inflammation when both ACh and high levels of fibrinogen are present, NO delivery by erythrocytes might be compromised by their NO scavenging ability that acts as a compensatory mechanism against the overproduced NO by endothelial inducible nitric oxide synthase.

산벚나무 부위별 추출물의 생리활성 비교

In this study, we investigated the antibacterial activity, antioxidative activity and whitening effect of 75% ethanol extracts from different parts of Prunus sargentii. The total phenolic compound content of the branch extract was 277.92 ㎎/g as the highest level. In the measurement of DPPH radical scavenging ability, SC50 values of the cork layer and branch extract were 26.79㎍/㎖ and 30.13㎍/㎖. In nitric oxide (NO) scavenging ability, SC50 values of the branch and leaf extract were 49.19㎍/㎖ and 55.55㎍/㎖. All extracts exhibited higher NO scavenging ability than ascorbic acid used as positive control. On the other hand, in antibacterial activity against Staphylococcus epidermidis and Staphylococcus aureus by disc diffusion assay, the pure bark extract showed the highest activity. Moreover, tyrosinase inhibitory activity of cork layer, pure bark and branch extracts showed higher activity than arbutin used as positive control. In the cytotoxicity measurement by MTT assay, leaf extract was exhibited Raw 264.7 cell viabilities of 44.68~61.83% as cytotoxic result in tested concentration. In conclusion, the branch extract of Prunus sargentii will be a functional materials without damage compared to other parts such as pure bark or cork layer in the plant.

Can Phlorotannins Purified Extracts Constitute a Novel Pharmacological Alternative for Microbial Infections with Associated Inflammatory Conditions?

Bacterial and fungal infections and the emerging multidrug resistance are driving interest in fighting these microorganisms with natural products, which have generally been considered complementary to pharmacological therapies. Phlorotannins are polyphenols restricted to brown seaweeds, recognized for their biological capacity. This study represents the first research on the antibacterial, antifungal, anti-inflammatory and antioxidant activity of phlorotannins purified extracts, which were obtained from ten dominant brown seaweeds of the occidental Portuguese coast.Phlorotannins content was determined by the specific dimethoxybenzaldehyde (DMBA) method and a yield between 75 and 969 mg/Kg phloroglucinol units (dry matter) was obtained. Fucus spiralis ranked first, followed by three Cystoseira species. The anti-inflammatory potential of the purified extracts was assessed via inhibitory effect on nitric oxide (NO) production by lipopolysaccharide-stimulated RAW 264.7 macrophage cells, Cystoseira tamariscifolia being the one showing promising activity for the treatment of inflammation. NO scavenging ability was also addressed in cell free systems, F. spiralis being the species with highest capacity. The antimicrobial potential of the extracts was checked against five Gram-positive and four Gram-negative bacteria and three fungi strains, that commonly colonize skin and mucosa and are responsible for food contamination. The different extracts were more effective against Gram-positive bacteria, Staphylococcus epidermidis being the most susceptible species. Concerning antifungal activity, Trichophyton rubrum was the most sensitive species.Although the molecular mechanisms underlying these properties remain poorly understood, the results obtained turn phlorotannins purified extracts a novel and potent pharmacological alternative for the treatment of a wide range of microbial infections, which usually also present an inflammatory component. In addition to the biological properties demonstrated herein, phlorotannins extracts may also be preferred, in order to avoid side effects and allergic reactions commonly associated with synthetic drugs.

Antioxidant activity of acetone and ethanolic leaves extracts of Hippobromus pauciflorus (L.f.) Radlk.

This study focused on determining the antioxidant activities and phenolic contents of 70% acetone and ethanolic leave extracts of Hippobromus pauciflorus (L.f.) Radlk. The measured antioxidant properties included free radical scavenging activities against 1, 1-diphenyl-2-picrylhydrazyl (DPPH), 2,2-azinobis-3ethylbenzothizoline 6-sulfonic acid (ABTS), ferric reducing power activities, hydrogen peroxide, nitric oxide scavenging properties and lipid peroxidation. The results show that the two extracts had good antioxidant potential. 70% acetone extract had higher ABTS, reducing power ability, hydrogen peroxide, nitric oxide and lipid peroxidation scavenging ability, but lower DPPH activities when compared with the ethanolic extract. The antioxidant capacity of the two extracts as determined by ABTS, DPPH, reducing power, hydrogen peroxide and nitric oxide scavenging ability were lower when compared with tannic acid and BHT standard. Phytochemical analyses revealed that the level of total flavonoid, flavonol, proanthocyanidin and tannins were relatively similar. On the other hand, 70% acetone extract had higher level of total phenolics than ethanol extract. The present results indicate that the extracts of H. pauciflorus possesses antioxidant properties and could serve as free radical inhibitors or scavengers, acting possibly as primary antioxidants and could be used in the treatment and management of free radical-mediated diseases.

Variations of Antioxidant Properties and NO Scavenging Abilities during Fermentation of Tea

Tea is known as one of the most popular beverages in the world, which is believed to be beneficial for health. The main components in tea will change a lot depending on the different processes of fermentation, and thus the effects of different teas on human health may differ. The aim of this study is to explore the varied abilities of reactive oxygen species (ROS) and nitric oxide (NO) scavenging during the fermentation of tea. In this study, we conducted the in vitro experiments which involved some reaction systems indicating the abilities of scavenging ROS and NO. We also investigated the effects of tea and their components (catechins, theabrownins, caffeine) on the intracellular levels of ROS and NO, using Raw 264.7 cells as the model. We found that regardless of whether it was out of cell system or in Raw 264.7 cells, the abilities of scavenging ROS would decrease during the fermentation of tea. Further, the post-fermented pu-erh tea showed the best effect on inhibiting the lipopolysaccharide (LPS)-induced production of NO. These findings indicated that the fermentation process caused a change of the components which might be due to the changes of their antioxidant properties and NO scavenging abilities.

Nitric oxide scavenging by food: implications for in vivo effects of diet

Recent advice to the general public is to increase intake of fresh fruit and vegetables, a message based on the assumed benefits of the antioxidant content of plant substances. Although there have been numerous studies on the reactive oxide species scavenging of fresh food products, few studies have focused on whether or not compounds in the diet can modulate the levels of nitric oxide (NO). Nitric oxide is a key signalling molecule that controls vasodilation and blood pressure, along with a range of other physiological events. Here, it is shown that commonly used food substances, such as cabbage, broccoli, kidney bean and oranges, all have the capacity to scavenge NO from solution, and therefore can potentially alter the level of NO in humans, with ramifications for the physiological systems that NO regulates. Using spinach, at least one element of the NO scavenging ability was shown to be heat-unstable, although heat-treating of other leaf materials had little effect, showing that NO scavenging will still occur after cooking. It is proposed that the NO scavenging of dietary components needs to be investigated more thoroughly before the full effects of increasing antioxidants through increased intake of fresh fruit and vegetables can truly be understood.

Nitric oxide scavenging ability of ethyl acetate fraction of methanolic leaf extracts of Chromolaena odorata (Linn.)

The nitric oxide (NO.) scavenging activities of Chromolaena odorata (Linn) King and Robinson, was investigated and compared with standard Plant Phenolic antioxidant Quercetin. Disodium pentacyanonitrosyl ferrate (2- ) dihydrate (sodium nitroprusside) was used as a nitric oxide donor. On disintegration at a physiological pH (7.2), 5 mmol/l of sodium nitroprusside generated a time dependent nitric oxide concentration which was scavenged in vitro by the extract. Inhibition of nitrite formation by Ethyl Acetate Fraction of Methanolic Extract of C. odorata (EAFCO), showed a dose-dependent response. Ability of EAFCO to scavenge nitric oxide radicals in vitro was compared to a standard Plant phenolic compound (Quercetin). Quercetin and EAFCO had IC50 = 50 and 380 µg/ml respectively and an IC100 of 2000 and 2800 µg/ml respectively. The overall result showed that the plant C. odorata is a good nitric oxide radical scavenger. The preliminary phytochemical analysis of chromolaena odorata extracts revealed the presence of alkaloids, glycosides, flavonoids, saponins and tannins. Quantitative determination of total phenolic content shows that the EAFCO contains an appreciable amount of phenolic compounds and may be responsible for the observed potential. Key words: Chromolaena odorata, nitric oxide scavenger, ethyl acetate fraction.

Radiomodulatory and Free-Radical Scavenging Activity of the Fractionated Aquo-Alcoholic Extract of the Adaptogenic Nutraceutical (Rhodiola imbricata)—A Comparative In Vitro Assessment with Ascorbate

Objective: Immense interest has been generated in recent years for the development of drugs of herbal origin for the mitigation of deleterious effects of environmental pollutants like ionizing radiation, mainly to protect against radiation leakages resulting from mishaps in nuclear reactors, deliberate use of dirty bombs, etc. Method: The radio modifying effects of a fractionated extract of the high-altitude Himalayan plant species Rhodiola imbricata, along with its electron-donation potential, super-oxide ion scavenging (IC50 ≤ 0.025 mg/ml), nitric oxide (NO) scavenging potential (IC50 = 0.5 mg/ml), and antihemolytic activity were evaluated in the present study. Reducing power, superoxide ion (O2•−), and nitric oxide scavenging ability of the fractionated extract increased in a dose-dependent manner. Rhodiola imbricata also exhibited antihemolytic potential preventing radiation-induced membrane degeneration of human erythrocytes. Conclusion: Thus, it can be stated that Rhodiola imbricata provides protection against gamma radiation via multifarious mechanisms that act in a synergistic manner. Rhodiola imbricata is widely used as a nutraceutical supplement in the trans-Himalayan region nations, and the current study shows that Rhodiola has immense potential for alleviation of biological damage in a radiation environment.

Second-generation recombinant hemoglobin molecules do not stimulate sphincter of Oddi, gallbladder or duodenal motility in the Australian brush-tailed possum.

Several studies have investigated the effects of hemoglobin-based oxygen carriers on gastrointestinal motility. Diaspirin cross-linked hemoglobin reduces sphincter of Oddi trans-sphincteric flow and increases duodenal motility in the Australian brush-tailed possum, effects attributed to nitric oxide (NO) scavenging. Recently, second-generation recombinant hemoglobin molecules with reduced NO scavenging ability have been developed. To determine the effects of two second-generation recombinant hemoglobin solutions and the prototype recombinant hemoglobin with high NO binding, on duodenal and biliary motility in the Australian brush-tailed possum. Blood pressure; duodenal, sphincter of Oddi and gallbladder motility; and trans-sphincteric flow were recorded. The effects of recombinant hemoglobin or human serum albumin (control) solutions on these parameters were investigated. Each solution was infused intravenously at 1 mL/kg/min to deliver 250 mg/kg or 500 mg/kg. Duodenal contraction frequency was stimulated by the high dose of prototype recombinant hemoglobin, but not by a comparable dose of second-generation recombinant hemoglobin. The induced duodenal activity occurred in the later phase of the experimental period. In contrast, biliary motility and trans-sphincteric flow were not altered by any hemoglobin solution. The high dose of all the hemoglobin solutions elevated blood pressure, whereas the low dose solutions did not alter any parameter measured. At the doses studied, the second-generation recombinant hemoglobin with reduced NO binding capacity did not significantly alter duodenal and biliary motility, supporting the need for further studies to evaluate their potential usefulness as blood substitutes.

Inhibition of reactive nitrogen species effects in vitro and in vivo by isoflavones and soy-based food extracts.

Recent studies have shown that soy isoflavone inhibits inducible nitric oxide (NO) synthase activities and is reported to have peroxynitrite scavenging ability. Consequently, we investigated whether isoflavones (daidzein and genistein) and extracts from soy-based products (miso, soymilk, tofu, soy sprout, black soybean, soybean, and yuba) would inhibit the reactive nitrogen species (RNS) effect in vitro and in vivo. In the in vitro experiments [including the protection of cellular DNA from peroxynitrite or sodium nitroprusside damage, an inhibitory effect on nitric oxide production from lipopolysaccharide (LPS)-induced RAW 264.7 cells, and nitric oxide scavenging ability], extracts from soy-based foods showed a potent antioxidant activity and an inhibiting effect on RNS activity. These effects were correlated with total isoflavone content. In the in vivo experiments, rats were given isoflavones (4.0 mg/kg bw) or soy-based product extracts (1.0 g/kg bw) orally for 1 week and were injected with vehicle H(2)O (1 mL/kg bw) or LPS (10 mg/kg bw) on the day 7. Twelve hours after treatment, the rats were killed, and blood serum was collected for analysis. The intraperitoneal administration of LPS resulted in an increase in serum nitrite, nitrate, and nitrotyrosine concentrations. These are stable metabolite end products of nitric oxide, to 4-, 16-, and 5-fold levels, (4, 10 microM and 58 +/- 14 pmol/mL), of the placebo control, respectively. Results showed that oral administration of isoflavones and extracts from soy-based products significantly decreased serum nitrite, nitrate, and nitrotyrosine levels in LPS-induced rats. This study demonstrates that soy isoflavone supplementation may inhibit RNS-induced oxidation both in vitro and in vivo.