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The Physiological Activities of Bark Extract of Albizia julibrissin
Abstract
Three bark extracts of Albizia julibrissin were prepared using water (AW), 70% (v/v) ethanol (AE), and hot water (AHW). Organic solvent fractions were analyzed for total flavonoids and polyphenols, antioxidant activities, and inhibitory activities against xanthine oxidase. Total flavonoid and polyphenol contents of the AHW extract were 8.57 mg/g and 108.67 mg/g, respectively. The SOD-like activities of all extracts, assayed at 1.0 mg/mL, were 10.46-16.73%. The nitrite-scavenging ability of the AHW extract, assayed at pH 1.2, was 60.82%, and the value was /mL. The electron-donating ability of the AHW extract, at 0.3 mg/mL, was 92.30%; the values of the AW and AHW extracts were /mL and /mL, respectively; thus higher than that of ascorbic acid (/mL). Xanthine oxidase inhibition by the AHW extract, at 1.0 mg/mL, was 94.05%. These results indicate that the AHW of A. julibrissin has potential as a natural antioxidant, for addition to foods and nutraceuticals.
In an acute toxicity test for Chrysanthemum indicum Linne, 0.5~10 g/kg of Chrysanthemum indicum Linne extracts were administered. Chrysanthemum indicum Linne did not produce acute toxicity even at high doses of 10 g/kg, making it a highly safe material. In the chronic toxicity test, oral administration of Chrysanthemum indicum Linne up to 2 g/kg was carried out for 13 weeks, showing liver non-toxicity. The gout inhibitory effect of Chrysanthemum indicum Linne extracts was measured by inflammatory cytokine expression and foot thickness after 24 h of monosodium urate crystal (MSU) oral administration when inflammatory cytokine production reached a maximum. The group administered 2~4 g/kg of Chrysanthemum indicum Linne extract showed an inhibitory effect on gout inflammation and edema, whereas the 10 g/kg administered group showed an increase in inflammation. Therefore, the moderate concentration of Chrysanthemum indicum Linne extract for gout inhibitory effect was under 4 g/kg. Chrysanthemum indicum Linne extract showed an anti-inflammatory effect on MSU as a relatively safe material at high capacity. These results indicate that Chrysanthemum indicum Linne extract is thought to be an excellent substance for gout prevention. © 2016, Korean Society of Food Science and Nutrition. All rights reserved.
This study was carried out to analyze the change of major nutrient components of spaghetti squash by boiling. The moisture, crude protein, fat, ash and carbohydrate contents in fresh squash were 94.2%, 0.6%, 0.1%, 0.7% and 4.4% respectively as against 95.1%, 0.5%, 0.1%, 0.5% and 3.8% in boiled squash. The decrease in protein and ash contents of the boiled sample were found to be significant. Major component of the minerals were potassium and the fresh and boiled squash had the contents of 330 mg and 256 mg, respectively. There were no differences of dietary fiber between the fresh and boiled squash. Beta-carotene contents of the fresh and boiled spaghetti squash were and , respectively. The contents of tocopherol were decreased as like 4.3 mg and 2.0 mg. A total of 17 kinds of amino acids were isolated from squash and they were decreased by boiling and the high content of amino acids in order were aspartic acid, glutamic acid, arginine, lysine, and leucine in raw squash. Particularly, total amino acid of fresh squash were 6,739.5 mg per 100 g edible portion and higher than that of boiled squash(4,820.3 mg). Total polyphenolic compound of the fresh squash from was slightly decreased to by boiling.
In our study, as many as 29 edible medicinal herbs were selected for testing their ability in the effective treatment of gout based on oriental medicine theory. We extracted each medicinal herb (135 g) with 4 L of distilled water at for 210 min. Thereafter, we evaluated both the antioxidant and xanthine oxidase inhibition activities of the extracts obtained. Among all the edible medicinal herbs used in our study, only the extract from Scutellaria baicalensis Georgi (Korean name: hwang-geum) showed (1) the maximum total phenolic content (TPC) (2.25 mg gallic acid equivalent/mL), (2) DPPH radical scavenging activity (94.04%), and (3) xanthine oxidase inhibition activity (87.75%). We also observed that TPC was relatively highly correlated with both the DPPH radical scavenging activity (r=0.63) and xanthine oxidase inhibition activity (r=0.77). Our results suggest that S. baicalensis G. may be a potent antioxidant source for the extraction and development of nutraceuticals that may be utilized for effective treatment of gout.
This study was performed to develop a therapeutic diet against aging and obesity, using Yangha(Zingiber mioga R.). Before development of a therapeutic diet, we performed cell viability assay, analysis of general composition, macrominerals and antioxidantive activities of Yangha. Based on the findings from analyzing the results, mook using Yangha powder(0~20%) was processed, and tested for quality characteristics such as color values, sensory evaluation and mechanical properties. The result of cell viability assay of myoga, using liver cells, revealed that within the concentration range from 500 to 10,000 , cell survivability increased in line with the concentration rate. Therefore, it will not be harmful to consume it as food. Regarding the normal substance of myoga, the water substance of myoga was 94%, which exceeds that of ginger and tumeric with 89% and 83%, respectively. As for crude protein, fat, carbon hydrates and ash, myoga contained less than the other two, which I think is due to the high water substance. Regarding the minerals, potassium had the highest contents among macrominerals of 234.74 mg%. As for the antioxidant test, hydroxy radical scavenging activity and superoxide radical scavenging activity were shown. As for the production of Yangha mook(Yangha powder levels were 0~20%) for quality characteristics, the more of the powder, the less the L, but the greater the a and b values. Also, for the material property, an increased amount of the powder, resulted in chewiness and springiness, but less gumminess in a correlated manner. However, there were no significant differences in the springiness and cohesiveness in relation to the powder. For the sensory test, jelly type ZM5 with 5% powder showed highest overall preference. According to the sensory test, based on the powder substance, the jelly with 5% powder showed the highest overall score, including preference.
The objectives of this study were to form comparisons of total polyphenol compounds, the antioxidant activities and the urushiol contents of lacquer tree(Rhus verniciflua) bark and the sensory properties of chicken soup was made with lacquer tree bark that was cultivated from different cultivation areas; Hamyang, Wonju and China. Total polyphenol contents of Hamyang, Wonju and China were estimated as , and mg/g. The total flavonoids contents of Hamyang, Wonju and China were measured as , and mg/g. The total phenolic compounds and flavonoids concentration, DPPH radical scavenging activity, and ABTS radical scavenging of lacquer tree cultivated in Wonju were higher than the others; Hamyang and China. The urushiol content of lacquer tree bark from Hamyang was ppm and higher than others. Urushiol was not detected in China lacquer tree bark. Sensory evaluation tests for chicken soup containing lacquer tree bark showed that the scores of Wonju lacquer tree bark chicken soup was highest, however there are no differences between Hamyang, Wonju, and China significantly(p
Antioxidant activities of water extracts of 20 medicinal plants (1 mg/mL) on peroxidation of linolic acid were evaluated by thiocyanate method, among which 11 showed strong antioxidant activity (> 70%). Higher hydroxy radical scavenging activity (> 60%) were shown in Corner officinalis, Acanthopanax sessiliflorus, and Epimedium koreanum than the other plants. Epimedium koreanum than the other plants extract showed highest superoxide radical scavenging activity (42%). Total polyphenol contents ranged from . Direct correlation between the antioxidant activity and polyphenol content (r=0.8) was established through simple regression analysis. for selected four plant extracts, showing highest polyphenol contents and antioxidant activities, were significantly higher than positive control. Total antioxidant activity of vitamin c was significantly lower than those of Acanthopanax sessiliflorus, Epimedium koreanum, and Erythrina variegata. Superoxide radical scavenging activity of Acanthopanax sessiliflorus was similar to BHA. Results suggest water extracts of some medicinal plants could be potential candidates for natural antioxidants.
The aerobic oxidation of xanthine by rat liver supernatant was greatly stimulated by the addition of methylene blue or of
NAD+: the latter was reduced during the reaction. Storage of the supernatant at -20° brought about an enhancement of the xanthine
oxidation rate measured without addition of cofactors. A similar "activation" was caused by prior incubation at 37° of the
unfractionated liver homogenate, or of the supernatant separated after sonic disruption of the homogenate. The same effect
was obtained by treatment with solvents, or by prior incubation at 37° of the supernatant in the presence of proteolytic enzymes
or under anaerobic conditions. The presence of xanthine accelerated the effect of proteolytic enzymes and of anaerobiosis.
Only the changes caused by anaerobiosis could be reversed by incubating the supernatant in air before the assay.
The reaction rate was apparently unaffected by these treatments if activity of the enzyme was measured in the presence of
methylene blue or of NAD+. The latter, however, was not reduced during the oxidation of xanthine by "activated" supernatants stored at -20° if the
reaction was run in the presence of oxygen. If the reaction was in anaerobiosis, uric acid and a corresponding amount of NADH
were formed by fresh, supernatant, and by supernatants activated at -20° or by prior incubation in anaerobiosis, but not by
supernatant activated by trypsin.
The hypothesis is formulated that most of the xanthine oxidase of rat liver supernatant is a dehydrogenase (Type D), and may
be converted (activated) into an oxidase (Type O).
A free radical is any molecule that has an odd number of electrons. Free radicals, which can occur in both organic (i.e., quinones) and inorganic molecules (i.e., O(2)), are highly reactive and, therefore, transient. Free radicals are generated in vivo as by products of normal metabolism. They are also produced when an organism is exposed to ionizing radiation, to drugs capable of redox cycling, or to xenobiotics that can form free radical metabolites in situ. Cellular targets at risk from free radical damage depend on the nature of the radical and its site of generation. In this review we survey cellular sources of free radicals and the reactions they can undergo and discuss cellular defenses and adaptive mechanisms.
This study was investigated antioxidatve activity for the purpose of developing antioxidant from Moms bombycis Koidzumi. Antioxidant activities of four different organs of Moms bombycis Koidzumi such as fruit, leaf, stem, and root were examined by radical scavenging effect with 1,1-diphenyl-2- picrylhydrazyl (DPPH). 80% methanol extract from the stem showed strongly antioxidative activity and 80% ethanol extracts from the root, stem, and fruit had high antioxidative activity among 24 samples tested. The 80% ethanol extract has strong absorbency at UVA region (350 nm). The ethyl acetate (EtOAc) fraction exhibited antioxidative activity with IC50 of 15.0 μg/ml similar to those of synthetic antioxidant, BHT. The EtOAc fraction has a good absorbency property as synthetic filter. In the absorbance of various extracts, the 80% ethanol and ethyl acetate extracts from the root of Morus bombycis Koidzumi showed higher absorbancy at 285 nm. The ethyl acetate fraction from the root of Morus bombycis Koidzumi contained total phenolic compounds of 654.8 mg/100 g. These results indicate that phenolic compounds are the major was biological components in the root of Morus bombycis Koidzumi extracts. Considering these biological activities, the extracts of Morus bombycis Koidzumi showed a possibility to be used as a new material for natural antioxidants and substitutes for synthetic UV sunscreen agents.
Albizzia julibrissin belonging to the family Leguminosae has been used for the treatment of contusion, sore throat, amnesia, and insomnia in Oriental traditional medicine. The water extract of A. julibrissin induced apoptosis in Jurkat T-acute lymphoblastic leukemia (ALL) cells as measured by cell morphology. The capability of this herb medicine to induce apoptosis was associated with proteolytic cleavage of specific target protein such as beta-catenin protein suggesting the possible involvement of caspases. The purpose of the present study is also to investigate the effect of A. julibrissin on cell cycle progression. Our results showed that G1 checkpoint related gene products (cyclin D1, cyclin dependent kinase 4, retinoblastoma, E2F1) were decreased in their protein levels in a dose-dependent manners after treatment of the extract. These results indicate that the increase of apoptotic cell death by A. julibrissin may be due to the inhibition of cell cycle progression in wild type p53-lacking Jurkat cells.
The degradation of nitrite and the inhibition towards formation of carcinogenic nitrosamines by melanoidins, produced from the glucose-glycine system were investigated at various conditions. The degradation of nitrite was highest at pH 1.2 (29%), when the ratio of melanoidins to nitrite was 1: 3. The inhibition towards formation of nitrosamines by melanoidins had the same tendency as the degradation of nitrite, the inhibition also being highest at pH 1.2 (99%). In addition, melanoidins after nitrite treatment exhibited a little higher mutagenicity and much stronger desmutagenicity than those of the original melanoidins. The change of the structure of melanoidins after treating with nitrite was also investigated by HPLC and CP-MAS NMR.
This study was carried out to investigate the antioxidative and antitumor activities of Saussurea lappa for the purpose of developing a functional food. The methanol extract of Saussurea lappa was fractionated with five solvents (hexane, chloroform, EtOAc, BuOH, water) and examined for antioxidative activities and xanthine oxidase inhibitory activity in addition to growth inhibitory activity of human cancer cell (HT-29, SNU-1, HeLa). Total phenol compound contents were higher in EtOAC fraction than other fractions. Also, electron donating ability was over 90% at 500?g/ml (93.1 %) and 1000?g/ml (94.3%). The hexane fraction revealed stronger nitrite scavenging ability than the positive control (ascorbic acid) and its abilities were 22.4% and 42.8% at 500?g/ml and 1000?g/ml, respectively. Xanthine oxidase inhibitory activity had similar tendency to electron donating ability. The EtOAc fraction showed high inhibition to xanthien oxidase activities at 500?g/ml(81.9%) and 1000?g/ml(90.4%). In the antitumor activity test, the hexane fraction exhibited potent growth inhibition activity against HT-29, SNU-1 and HeLa cells. Therefore, we believe that Saussurea lappa can be developed into a functional food with antioxidant activity. Additional studies are required for the hexane and chloroform fractions of Saussurea lappa to develop them into therapeutic supplements for stomach cancer, colon cancer, and cervical cancer.
Antioxidative activities of ethanol extracts of seed, branch, leaves, and aerial part of Crotalaria sessiflora L. were compared using in vitro experimental model. Solid contents of each extracts were 12.68, 16.28, 13.04, and 18.59 g/ 100 mL, and phenolic acid contents were in branch, aerial part, seed, and leaves, respectively. Extracts prepared from leaves showed highest electron-donating ability toward DPPH. SOD-liked activities were 78.95, 70.85, 74.65, and 87.49% in aerial part, branch, seed, an leaves respectively. Extracts prepared from leaves showed 59.39% inhibitory effect on peroxidation of egg yolk lecithin.
A heat-stable antioxidant component was observed to co-purify with the superoxide dismutase (SOD) activity from dried peas. The heat-stable component co-purified by size (gel filtration on Sephadex G-75) and by charge (flat-bed isoelectric focusing (IEF) and Rotofor IEF) coincidently with the SOD activity. Throughout the purification procedure the SOD fractions all exhibited heat-stable antioxidant activity. The autoxidation of linoleic acid in the presence of the pea SOD fraction was delayed for more than four weeks. Purified pea SOD may provide a novel protein-bound, thermostable natural oxidant.
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For this study, extracts of Vitex rotundifolia stems were prepared using reflux water extraction (WE), reflux ethanol extraction (EE) and hot water extract under high pressure (HWE). The extracts were investigated for the total content of phenolic compounds, antioxidant activities, and inhibitory potencies for xanthine oxidase and tyrosinase. The EE extraction method yielded the highest content of polyphenol compounds (176.34 mg/g). The electron donating abilities (EDA) were 93.4696.92%, when extracts were assayed at 1.0 mg/mL. The superoxide dismutase (SOD)-like activity was the highest in the WE extract (47.32% at 1.0 mg/mL). The nitrite scavenging abilities (pH 1.2) were 84.6188.36% and the inhibition of xanthine oxidase were over 90% at 0.5 mg/mL. Tyrosinase inhibition of HWE and WE were 57.84% and 53.47% respectively. It implies that V. rotundifolia stems have potent physiological activities and their activities were differently exhibited depending on solvent fractions.
Heat-stable antioxidant activity co-purified with the pea Superoxide dismutase (SOD) activity is believed to be due to bound phenolic compounds. Digestion with trypsin showed that the native SOD protein structure was not required for the expression of the thermostable antioxidant activity. Part of the bound phenolic compounds can be removed from the SOD protein by alkaline hydrolysis. The dissociated phenolic fraction was able to inhibit the autoxidation of linoleic acid by more than one week. Incubation of the phenolic fraction with bovine SOD (BSOD) and serum albumin (BSA) resulted in the transfer of thermostable antioxidant activity to the SOD protein but not to serum albumin.The results indicate that pea SOD can act as a carrier for certain pea phenolic compounds and thus facilitate a protein-bound thermostable antioxidant.
The structures of Julibrosides I, II, and III, isolated from dried stembark of Albizzia julibrissin Durazz (Albizziae Cortex), were characterized as complex triterpenoidal glycosides linked to the monoterpene glycoside dimer, mainly by means of an NMR spectroscopic method. These compounds have a common structure comprising from acacic acid, the (6S)-2-trans-6-hydroxy-2,6-dimethyl-2,7-octadienoyl-6-O-quinovopyranos ide dimer, and α-L-arabinofuranosyl-(1 → 4)-[β-D-glucopyranosyl-(1 → 3)]-α-L-rhamnopyranosyl-(1 → 2)-β-D-glucopyranoside. The diversity of the oligosaccharides attached to the C-3 hydroxyl group of acacic acid, an oleanane-type triterpene, makes a distinction between Julibrosides I, II, and III.
METHODS for measuring antioxidants and appraising antioxidant activity appear to be of two general types. If the chemical nature of the antioxidant is known, one may strive for a test specific for the compound or group of interest; for example, the nitroprusside test for sulphydryl groups. Alternatively one may observe the inhibition of some natural oxidative process such as the β-oxidation of fats, as a function of the added antioxidant.
The autoxidation of pyrogallol was investigated in the presence of EDTA in the pH range 7.9–10.6.
The rate of autoxidation increases with increasing pH. At pH 7.9 the reaction is inhibited to 99% by superoxide dismutase, indicating an almost total dependence on the participation of the superoxide anion radical, O2·−, in the reaction. Up to pH 9.1 the reaction is still inhibited to over 90% by superoxide dismutase, but at higher alkalinity, O2·− -independent mechanisms rapidly become dominant.
Catalase has no effect on the autoxidation but decreases the oxygen consumption by half, showing that H2O2 is the stable product of oxygen and that H2O2 is not involved in the autoxidation mechanism.
A simple and rapid method for the assay of superoxide dismutase is described, based on the ability of the enzyme to inhibit the autoxidation of pyrogallol.
A plausible explanation is given for the non-competitive part of the inhibition of catechol O-methyltransferase brought about by pyrogallol.
From the stembark ofAlbizzia julibrissin. 3′, 4′, 7-trihydroxyflavone and α-spinasteryl-d-glucoside were isolated.
Propolis is extensively used in Argentine folk medicine. Alcoholic extracts of propolis from different regions of Argentina were prepared. The extracts were analysed for the determination of total flavonoid content (from 13.3 to 42.6 mg/g of propolis) by using the aluminum nitrate method, UV spectrophotometry and thin layer chromatography. All of them contained high total flavonoid content. It was also observed that all samples of ethanolic extracts of propolis showed free radical-scavenging activity in terms of scavenging of the radical DPPH but the highest activities were found for samples from Tucumán and Santiago del Estero. In all cases with 20 μg/ml of soluble principles, the percentage of DPPH degradation was different (Banda Oeste: 67.5%; Verónica: 45%; Forres: 35%; Saenz Peña: 20% and Juan José Castelli: 55%). These results may justify their use as a source of natural antioxidants.
The importance of superoxide dismutase (SOD) in providing a defence against the superoxide radical in living systems has been increasingly established during the last twenty years. More recently, the occurrence and role of SOD in post-harvest and post-mortem foods and its significance as a natural antioxidant have been studied. This review highlights the importance of superoxide dismutase in foods. Current knowledge in aspects such as assay methods and the potential role of superoxide dismutase in the preservation of quality of harvested fruits and vegetables is reviewed.
The occurrence of superoxide dismutase activity (SOD) in extracts of cabbage (Brassica oleracea var. capitata) was detected by use of the nitroblue tetrazolium assay method for the measurement of superoxide anion (O−2). The SOD activity found in aqueous extracts of cabbage was destroyed at temperatures greater than 45°C, whereas, for commercial preparations of bovine SOD, temperatures in excess of 65°C were required for deactivation of the enzyme. Heat inactivation energies have been calculated. Tests for sensitivity to cyanide have indicated that a substantial proportion of the cabbage SOD activity is due to the CuZn type of enzyme. As shown by isoelectric focusing, three SOD isoenzymes were present in the aqueous extracts of cabbage.
Micromolar concentrations of vanillin were found to enhance the formation of nitrosomorpholine from nitrogen dioxide (NO2) and morpholine in neutral aqueous solution. This effect is attributed to the presence of the hydroxyl group in the vanillin molecule since phenol, guaiacol, and resorcinol also enhanced N-nitrosation over the same concentration range. In contrast, hydroquinone and catechol were potent inhibitors of N-nitrosation by NO2, presumably because these compounds are more easily oxidized by NO2 to the corresponding quinones and therefore do not form N-nitrosating intermediates. All phenols with the exception of p-nitrophenol, which did not affect either N-nitrosation or nitrite formation, were quite efficient at removing bubbled NO2 from air and converting it to nitrite, approaching yields of 100% with millimolar phenol concentrations. This effect was pH dependent for vanillin, increasing significantly above pH 6. N-Nitromorpholine formation was strongly inhibited by all the phenolic compounds tested. It appears that the mechanism by which phenols enhance N-nitrosation by NO2 is different from that proposed for phenolic catalysis of N-nitrosation by nitrite in acidic media and may involve the formation of an intermediate alkyl nitrite.
The content of the potentially anticarcinogenic flavonoids quercetin, kaempferol, myricetin, apigenin, and luteolin of 28 vegetables and 9 fruits was determined by RP-HPLC with UV detection. Fresh foods were purchased in a supermarket, agrocery, and a street market and combined to composites. Processed foods were purchased additionally. Sampling was carried out in spring, summer, winter, and spring of the following year. Quercetin levels in the edible parts of most vegetables were generally below 10 mg/kg except for onions (284-486 mg/kg), kale (110 mg/kg), broccoli (30 mg/kg), French beans (32-45 mg/kg), and slicing beans (28-30 mg/kg). Kaempferol could only be detected in kale (211 mg/kg), endive (15-91 mg/kg), leek (11-56 mg/kg), and turnip tops (31-64 mg/kg). In most fruits the quercetin content averaged 15 mg/kg, except for different apple varieties in which 21-72 mg/kg was found. The content of myricetin, luteolin, and apigenin was below the limit of detection (
Butylated hydroxyanisole and butylated hydroxytoluene are used extensively as food antioxidants. It is estimated that man
consumes ca. 0.1 mg/kg body wt daily of these antioxidants. At levels 500 times this level (50 mg/kg/day), both butylated
hydroxyanisole and butylated hydroxytoluene appear to be free of any obviously injurious effects. However, at larger doses
(500 mg/kg/day), both butylated hydroxyanisole and butylated hydroxytoluene result in certain pathological, enzyme, and lipid
alterations in both rodents and monkeys, and butylated hydroxytoluene, in some cases, has been reported to have certain teratogenic
and carcinogenic effects upon rodents. These alterations appear to differ markedly between rodents and monkeys, apparently
as a result of differences which exist in the metabolism and excretion of butylated hydroxyanisole and butylated hydroxytoluene
by these two species. However, in both animal species, the alterations appear to be physiological responses which are reversible
upon removal of butylated hydroxyanisole and butylated hydroxytoluene from the diet. Long term chronic ingestion of butylated
hydroxyanisole and butylated hydroxytoluene may be beneficial in sparing vitamin E and in modifying the acute toxicity of
a number of mutagenic and carcinogenic chemicals.
The detergent-induced amplification of lucigenin-dependent chemiluminescence of O2-, generated by xanthine oxidase or microsomal NADPH oxidase was studied. An assay system is described which is at least 10 times more sensitive than normal lucigenin-dependent chemiluminescence due to the amplification by high concentrations of octylphenylpolyethylene glycol (Triton X-100). Compared to the superoxide dismutase-sensitive reduction of acetylated cytochrome c, a 3750-fold lower amount of microsomal protein was necessary to produce an O2- signal 10-fold above the background. In contrast to cytochrome c reduction, detergent-amplified chemiluminescence of lucigenin was completely inhibited by superoxide dismutase and therefore more selective for O2-. The membrane-bound and Triton X-100-solubilized NADPH oxidase from microsomes of macrophages was activated by ethylene glycol bis(beta-aminoethyl ether)-N,N'-tetraacetic acid and inhibited by Ca2+ and sodium dodecyl sulfate. The membrane-bound enzyme showed a Km value of 1.35 microM, which decreased to 0.95 microM after the addition of 12% (g/g) Triton X-100. The Km and Vmax values of soluble xanthine oxidase were not influenced by Triton X-100, indicating that the enzyme activities were not impaired by the high concentrations of detergent.
A relationship between ascorbic acid intake and N-nitrosoproline (NPRO) excretion in humans on a controlled diet was established. Seven healthy males were placed on a low nitrate, low ascorbic acid diet for 12 consecutive days. On days 3-12, a 5.24 mmol oral dose of sodium nitrate was administered in mid-afternoon, at least 2 h after the subject's last meal. On days 4-12, a 4.35 mmol oral dose of L-proline was administered 30 min after the nitrate dose. Ascorbic acid was given in amounts which increased daily from day 5 to day 10 (0.01-5.68 mmol; 1.76-1000 mg) with the proline. Total 24 h urines were assayed for nitrate, NPRO and total ascorbic acid. Nitrate balance was monitored using [15N]nitrate. Average endogenous nitrate synthesis was 1.28 +/- 0.43 mmol/day/person. NPRO excretion was reduced by 6 nmol/day when 0.05 mmol of ascorbic acid was administered. However, as much as 5.68 mmol ascorbic acid did not return NPRO excretion to levels observed before the nitrate and proline were administered. More than 10 times the ascorbic acid required to completely inhibit NPRO formation in vitro did not return NPRO excretion to baseline levels. These data indicate that endogenous nitrosation may be more facile than predicted by the in vitro chemistry.
Nitrite was consistently found in human saliva at levels of usually 6 to 10 ppm. The nitrite level did not seem to be strongly influenced by the composition of a meal, and in some individuals a narrow range of nitrite concentration was maintained for a long time. In agreement with earlier work, parotid ductal saliva was found to be free of nitrite, and a major route of nitrite formation was via microbial reduction of nitrate naturally present in saliva. Exploration of various parameters related to the reduction of nitrate to nitrite did not demonstrate a clear correlation between measurements on individuals and their level of salivary nitrite. The microorganisms responsible for nitrite formation were identified and quantified, and the relationships between nitrate consumption and nitrite formation explored. These complex relationships suggested that the free nitrite in saliva represents the 'spillover' of that formed in microbial cells.
The flowers of Albizzia julibrissin are used as a sedative in oriental traditional medicine. The phytochemical study of this plant allowed the isolation of two flavonol glycosides, quercitrin (1) and isoquercitrin (2). The sedative activity of these compounds was evaluated, and both compounds 1 and 2 increased pentobarbital-induced sleeping time in dose-dependent manner in mice. These results support the use of the flowers of this plant as a sedative agent.
During intercellular induction of apoptosis, transformed fibroblasts are specifically eliminated by their nontransformed neighbours. This potential control step of oncogenesis is based on a sophisticated system of interdependencies and interactions of reactive oxygen and nitrogen species. Activated nontransformed effector cells release a novel peroxidase and nitric oxide. Superoxide anions generated extracellularly by transformed cells participate in intercellular signalling and also determine transformed cells as selective targets for intercellular induction of apoptosis. The interaction of these molecules results in two major signalling pathways, which are based on HOCl/hydroxyl radicals and on NO/peroxynitrite. In addition, involvement of nitrylchloride seems to be conceivable in an alternative pathway. Hydrogenperoxide plays a central and ambivalent role by fostering the HOCl/hydroxyl radical pathway and by inhibiting the NO/peroxynitrite pathway. The interaction of ROS and RNS during intercellular induction of apoptosis seems to represent a general signalling concept utilized by several natural antitumor systems.
A new sapogenin named Julibrogenin A was isolated from the stem bark of Albizzia julibrissin Durazz (Albizziae Cortex). Based on chemical and spectral studies, their structure has been identified as 21-O-(2-hydroxymethyl-6-methyl-6-methoxyl-2,7-octadienoyl)-acacic acid. In addition, machaerinic acid lactone, machaerinic acid methylester, acacigenin B and julibrotriterpenoidal lactone A were also isolated from this plant and characterised.
Free radical scavengers from the leaves of Albizzia julibrissin
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Cytotoxicity of the components of Albizzia julibrissin
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Development of functional tea product using Cirsium japonicum
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Polyphenol contents and physiological activity of the Lespedeza bicolor extracts
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Chemical components in stalks and leaves of Sasa borealis Makino and antioxidative and antimicrobial activities of extracts
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Screening of antioxidative activity of hot water extracts from medicinal plants
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Korean resources plants Part II
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Effect of the water extract of Albizzia julibrissin on apoptotic cell death in the human leukemic Jurket T cell line
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- Bh Jeon