牦牛血抗氧化低聚肽的稳定性及与其他食源性低聚肽抗氧化互作分析

通过菌酶联合法发酵制备牦牛血低聚肽(分子量<1ku),研究其氨基酸组成、热稳定性、酸碱稳定性、金属离子稳定性、冻融稳定性及对食品辅料的稳定性;同时,运用等辐射分析法评价3种食源性低聚肽按不同比例组合后组合肽的抗氧相互作用。结果表明,牦牛血低聚肽具有良好的热稳定性,100℃水浴热处理5h后的·OH清除活性仍有84.32%。牦牛血低聚肽在pH值为6~10,即高pH值下·OH清除活性几乎没有受到影响,而低pH值条件下的·OH清除能力较差。Zn^2+、Cu^2+对牦牛血低聚肽的·OH清除活性影响较大,当二者浓度达到500mg/L时,其·OH清除活性保持率仅为49.35%、46.15%;K^+、Mg^2+对其·OH清除活性影响较小。牦牛血低聚肽对·OH清除活性保持率随冻融次数增多而降低。食品辅料NaCl对其·OH自由基清除活性有增效作用,特别是NaCl添加量为0.5%~1.5%时,而当NaCl添加量为1.5%~2.5%时,增效作用不明显;葡萄糖浓度为8%~10%时,对其·OH清除活性有明显抑制作用;柠檬酸对其·OH清除活性有明显抑制作用,但柠檬酸浓度变化对其·OH清除活性影响不大。牦牛血低聚肽的体外抗氧化活性优于商品化的大豆低聚肽以及鱼胶原低聚肽,将3种食源性低聚肽按比例组合后,在DPPH模型和脂质过氧化抑制能力模型中,大部分组合低聚肽表现出较强的协同作用,组合低聚肽中的牦牛血低聚肽比例超过50%时表现出拮抗作用;在ABTS模型中组合低聚肽中的牦牛血低聚肽比例越高协同作用越低。

Study on Antioxidants and Lipid Peroxidation from Pea Crops of Platean

[ Objective] The aim of this study was to discuss the effect of antioxidants and lipid peroxidation from pea crops of plateau. [ Method] SOD enzyme liquid from pea crops of plateau was extracted by means of protein concentration assay, enzyme activity assay and antioxidant activity determination by DPPH method, peroxide activity inhibition of in vitro tissues from mice by homogenate MDA colorimetry method and lipid peroxidation assay of in vitro tissues. [ Result ] IC50 of the crude enzyme liquid extracted from pea on DPPH was 55.16 mg/L, while the scavenging rate of the crude enzyme liquid was lower than that of ascorbic acid, tea polyphenol and citric acid with the same concentration. The synergistic effect was found in ascorbic acid and crude enzyme liquid, but the synergism of ascorbic acid was better than that of citric acid. IC50 of SOD enzyme liquid extracted from pea on DPPH was 11.1 mg/L, which was better than that of tea polyphenol and closely similar to that of ascorbic acid. SOD enzyme liquid extracted from pea had an inhibitory effect on MDA production from in vitro tissues such as liver, kidney and heart, especially for a significantly inhibitory effect on MDA from liver in vitro. When the concentration was 0.25 mg/ml, the inhibition rate reached 78.3%, and then the inhibition rate increased little with the concentration incresas, while its effect on heart and kidney were inferior. [ Conclusion] SOD crude enzyme liquid and SOD enzyme liquid extracted from pea all have certain DPPH scavenging capacity, while SOD enzyme liquid extracted from pea has an inhibitory effect on lipid peroxidation.

Antioxidant Activity of Polysaccharides in Yam Bulbils and Their Hypoglycemic Effect in Diabetic Mice

The polysaccharides in yam bulbils were extracted, and their antioxidant activity and hypoglycemic effect in diabetic mice were discussed. The results showed that the antioxidant activity of polysaccharides in yam bulbils was signifi- cantly enhanced with the increase of concentration; they showed a strong scaveng- ing ability against DPPH. and .OH, and the scavenging ability was dose dependent to some extent; the scavenging rates reached 91.15% and 89.06% respectively when the dose reached 4.0 mg/ml; the polysaccharides in yam bulbils significantly educed the blood glucose in model rice, and the hypoglycemic effect of large-dose polysaccharides was more obvious. The polysaccharides in yam bulbils has good antioxidant activity and hypoglycemic effect, which provides a new source for devel- opment of safe and natural food antioxidants and blood sugar-lowering agents.

Protective Effects of Tea Polyphenol on Cerebral Ischemia-Reperfusion Injury in Rats and Its Scavenging Oxy-radical and Anticerebral Lipid Peroxidation Effects

AIM To study the protective effects of tea polyphenol (TP) on cerebral ischemia reperfusion injury in rats and its scavenging oxygen free radical(OFR) activities and antilipid peroxidation in vitro . METHODS Cerebral ischemia reperfusion injury was produced by bilateral ligation of the common carotid arteries with vagus nerves and reperfusion for 45 min. The mitochondrial lipid peroxidation of rat brain induced by oxygen free radical was measured by thiobarbituric acid spectrophotometry. Superoxide anion (O 2) from xanthine xanthine oxidase system and hydroxyl radical (·OH) from Fe 2+ -H 2O 2 system were determined with spectrophotometry. RESULTS During Cerebral ischemia reperfusion,TP improved the activities of superoxide dismutase ( P 【0 05), GSH peroxidase( P 【0 01) and catalase( P 【0 01), while decreasing the maiondialdchyde content in the brain( P 【0 05) and brain water content ( P 【0 01). Tea polyphenol possessed significantly scavenging effects on ·OH produced by Fenton reaction and O 2 produced by xanthine xanthine oxidase system (the IC 50 were 2 2 mmol·L -1 and 1 9 mmol·L -1 respectively). Tea polyphenol could significant inhibit the lipid peroxidation of cerbral mitochondrial membrane induced by ·OH in a concentration dependent manner. CONCLUSION The results indicate that tea polyphenol could protect the injury on cerebral ischemia reperfusion in rats for OFR, these effects may be related to its scavenging effects on oxygen free radicals and antilipid peroxidant.

Comparisons between Phenolic Compounds and Antioxidation of Momordica charantia L. in Different Varieties

[Objective] The aim was to compare contents of free and bound polyphenol and antioxidation of balsam pear in different varieties. [Method] Fourteen varieties of balsam pear were chosen to analyze total contents of free or bound phenol and components of free phenol. FRAP （Freeic reducing/antioxidant power）, DPPH （1,1diphenyl-2-picrylhydrazy）, and ABTS ＋· （2, 2’-azinobis-3-ethylbenzothiazoline-6-sulphonic acid diammonium salt） were used to measure antioxidation and analyze relationship between polyphenol content and antioxidation. [Result] Among the fourteen varieties of balsam pear, free, bound and total phenols were 157.58 -382.92, 6.46 -54 and 175.27 -413.79 mg GAE/100 g DW; coefficients of variance were 23.50% , 61.04% and 21.58%, respectively; free phenol accounted for 91.34% of total phenol and bound phenol accounted for 8.66% ; contents of total flavone for the fourteen varieties were from 8.97 to 18.22 mg CE/100 g DW and the coefficient was at 22.80%; vanillic aldehyde acid, epicatechin and rutin differed in contents among different varieties, which changed in 1.83-9.29, 35.17-114.52 and 0.91-4.53 mg/100 g DW and the coefficients were 43.85%, 26.97% and 33.09%; FRAP antioxidation was at 272.16 -713.32 mg TE/100 g DW and coefficient at 27.67% ; IC 50 of DPPH and ABTS ＋· clearance were 11.43-34.14 and 21.57-119.71 mg GAE/100 g DW and coefficients were at 35.10% and 63.75% , accordingly; content of total phenol was of extremely positive correlation with FRAP （P0.01） and of extremely negative correlation with IC 50 of DPPH and ABTS ＋ · clearance （P0.01）. [Conclusion] Contents of phenolic compounds and antioxidation are of significant genotype differences; and phenolic substance and antioxidation are mainly in free form and phenolic substance is the major basis for antioxidation.

Bioaccumulation and Toxicity of Neodymium in the Planarian Dugesia japonica

In this study, the bioaccumulation and toxicity of neodymium （Nd） in pla-narian Dugesia japonica were investigated. The results showed that with the in-creasing dietary Nd supplementation, the concentration of Nd in the planarian showed a significant linear increase and the balance of mineral elements was bro-ken with the decrease of Ca, Fe and Mo, and the increase of K and Mg. The content of soluble proteins and the activities of superoxide dismutase （SOD） and catalase （CAT） decreased with the increase of Nd concentration, while the content of H2O2 rose gradual y. The mortality was directly proportional to the Nd concentra-tion. The results indicated that planarian is a very sensitive aquatic animal to Nd contamination and can be an indicator organism for Nd pol ution.

Ascorbic Acid Promotes Arsenic-induced Cytotoxicity in Human Hepatocarcinoma Cells and Their Underlying Mechanisms

Objective: To study synergistic effect with Ascorbic acid(AA) on arsenic trioxide inducing human Hepatocarcinoma cell apoptosis, and provide theoretical basis for promoting human Hepatocarcinoma cell apoptosis induced by arsenic trioxide(AT). Methods: Human Hepatocarcinoma cell line BEL-7402 being cultured in vitro, the effect of AT and (or) AA on its growth inhibition and its two intracellular signal molecules was evaluated separately using MTT and Western blot. Results: AT at a few μmol/L concentration could suppress abnormal proliferation of human hepatocarcinoma cells, and initiate their apoptosis by activation of caspase-3, and activate extracellular-signal regulated kinases (ERKs), which were dependent on the dosage of AT conspicuously. The effect of AA on BEL-7402 was not significant; However, AA could effectively enhance AT-induced hepatocarcinoma cell apoptosis and lesion severity through activation of caspase-3 but not ERKs. Conclusion: Caspase-3 and ERKs proteins could involve in arsenic-induced hepatocarcinoma cell apoptosis and differentiation respectively as intracellular signaling molecules; The effect between AT and AA on hepatocarcinoma is synergistic, which further inhibits cell growth and induces apoptosis in human hepatocarcinoma cells through activation of caspase-3 but not ERKs.

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.

ANTI-HYPOXIA AND ANTI-OXIDATION EFFECTS OF AMINOPHYLLINE ON HUMAN WITH ACUTE HIGH-ALTITUDE EXPOSURE

Objective To investigate the anti-hypoxia and anti-oxidation effects of aminophylline on human with acute high- altitude exposure. Mothoda Totally 100 young male army members newly recruited from Sichuan province （400 meters above sea level） were enrolled. They were randomly divided into two groups： 50 in aminophylline group （A group） and 50 in control group （ C group）. A group and C group orally took aminophylline and placebo respectively for 10 days, 7 days before entering Lhasa （3 658 meters above sea level） by air and 3 days after it. Several parameters were measured at three time points： before drug taken, 7 days after drug taken, and 3 days after ascending high altitude. These parameters included serum levels of nitric oxide （NO）, superoxide dismutase （SOD）, catalase （CAT）, hydrogen dioxide （H2O2）, lactic acid （LA）, as well as arterial oxygen saturation （SO2）, arterial oxygen partial pressure （PaO2）, and arterial carbon dioxide partial pressure （PaCO2）. Statistical analysis was conducted to compare the difference between two groups with Stata 7.0 software system. Results There were no statistical differences between groups in hypoxia and oxidation indicators before and after drug taken in plain area. Three days after ascending high altitude, the serum levels of SOD, CAT, H202, LA, PaCO2 increased in both groups, yet to a much larger degree in C group than A group （P 〈0. 01 ） ; and NO, SO2 , PaO2 decreased more markedly in C group （ P 〈 0. 05 for NO, P 〈 0. 0001 for SO2 and PaO2 ）. Conclusion Aminophylline has significant anti-hypoxia and anti-oxidation effects at high altitude.

Biological activities of a neutral water-soluble agar polysaccharide prepared by agarase degradation

Depolymerization of agar was performed using agarase, which was extracted from the cell-free medium of a culture of marine bacterial Alterornonas sp. nov. SY 37-12. After ethanol fractionation and lyophilization, the water-soluble agar polysaccharide （WSAP3） was collected. The anti-tumor activity of the product was determined by using Sarcoma 180 tumor in mouse. The tumor inhibition rate of WSAP3 the product was determined by using Sarcoma 180 tumor in mouse. The tumor inhibition rate of WSAP3 reached 48.7% at a dose of 64mg kg^-1 after 15 days treatment. WSAP3 enhanced the aetivities of superoxide dismutase and catalase, which suggests that WSAP3 was effective in promoting the antioxidation ability and eliminating danger from free radicals. The result of flow cytometry showed that the WSAP3 had no activities of cell cycle inhibition or apoptosis-inducing activities. The anti-oxidation of WSAP3 was further confirmed by test in vitro, which might play an important role in anti-tumor activity. The immunological regulation of WSAP3, especially its effect on the phagocytosis ratio and phagocytosis index of rophage was also assayed in test in vivo.

Amelioration of experimental colitis by Astragalus membranaceus through anti-oxidation and inhibition of adhesion molecule synthesis

AIM: To investigate the protective effects of Astragalus membranaceus(Am) against hapten-induced colitis in male Sprague-Dawley rats as well as its underlying mechanism.METHODS: Experimental colitis was induced in rats by enema administration of 2,4-dinitrobenzene sulfonic acid (DNBS). Rats were either pretreated with Am extract (2 or 4 g/kg, p.o. once daily) starting from 10 d before DNBS enema, or received Am post-treatment (2 or 4 g/kg, p.o.twice daily) on the three consecutive days following DNBS administration. Colonic lesion area and histological damage were determined, while the activities of myeloperoxidase (MPO) and xanthine oxidase, as well as reduced glutathione (GSH) content were measured in the excised colonic tissues. Besides, protein expression of inducible nitrite oxide synthase (iNOS), intercellular adhesion molecule-1 (ICAM-1) and P-selectin was also detected by Western blot analysis.RESULTS: Our findings had shown that both macroscopic lesion area and histological colonic damage induced by DNBS were significantly reduced by both Am pre- and post-treatments. These were accompanied by attenuation of the elevated colonic MPO activity and downregulation of the iNOS, P-selectin, and ICAM-1 protein expression.Besides, deprivation of colonic GSH level under colitis condition was also preserved.CONCLUSION: These results demonstrate that Am possesses both preventive and therapeutic potential in experimental colitis. The anti-inflammatory actions involve anti-oxidation along with inhibition of adhesion molecule synthesis in the colonic tissues.

Oxidative stress and damage induced by abnormal free radical reactions and IgA nephropathy

Objective: To estimate the oxidative stress and oxidative damage induced by abnormal free radical reactions in IgA nephropathy (IgAN) patients' bodies. Methods: Seventy-two IgA N patients (IgANP) and 72 healthy adult volunteers (HAV) were enrolled in a random control study design, in which the levels of nitric oxide (NO) in plasma, lipoperoxide (LPO) in plasma and in erythrocytes, and vitamin C (VC), vitamin E (VE) and β-carotene (β-CAR) in plasma as well as the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX) in erythrocytes were determined with spectrophotometric mothods. Results: Compared with the HAV group, the averages of NO in plasma, and LPO in plasma and in erythrocytes in the IgANP group were significantly increased (P＜0.0001), while those ofVC, VE and β-CAR in plasma as well as those of SOD, CAT and GPX in erythrocytes in the IgANP group were significantly decreased (P＜0.0001). Linear correlation analysis showed that with the increase of the values of NO, and LPO in plasma and in erythrocytes, and with the decrease of those ofVC, VE, β-CAR,SOD, CAT and GPX in the IgAN patients, the degree of histological damage of tubulointerstitial regions was increased gradually (P＜0.0001); and that with the prolongation of the duration of disease the values of NO, and LPO in plasma and erythrocytes were increased gradually, while those of VC, VE, β-CAR, SOD, CAT and GPX were decreased gradually (P＜0.005). The discriminatory correct rates of the above biochemical parameters reflecting oxidative damage of the IgAN patients were 73.8%-92.5%, and the correct rates for the HAV were 70.0%-91.3% when independent discriminant analysis was used; and the correct rate for the IgAN patients was increased to 98.8%, the correct rate for the HAV was increased to 100% when stepwise discriminant analysis was used. The above biochemical parameters' reliability coefficient (alpha) were used to estimate the oxidative damage of the IgAN patients as 0.8145, the standardized item alpha=0.9730, F=53273.5681, P＜0.0001. Conclusions: A series of free radical chain reactions caused serious pathological aggravation in the IgANP' bodies, thus resulting in oxidative damage in their bodies. In treating IgANP, therefore, it is necessary that suitable dose antioxidants should be supplemented to them so as to alleviate the oxidative damage in their bodies.

Estradiol-17β protects against hypoxia-induced hepatocyte injury through ER-mediated upregulation of Bcl-2 as well as ER-independent antioxidant effects

Although many previous studies have suggested that estrogen functions as a cytoprotective agent under oxidative stress conditions, the underlying mechanism by which this effect is exerted remains to be elucidated. This study assessed the effects of estradiol-17β （E2） （10^-8s M） on hypoxia-induced cell injury and its related signaling in primary cultured chicken hepatocytes. Hypoxic conditions were found to augment the level of DNA damage and to reduce cell viability and the level of [^3H]-thymidine incorporation, and these phenomena were prevented through treatment with E2. Hypoxia also increased caspase-3 expression, but showed no evidence of an influence on the expression of Bcl-2. However, E2 induced an increase in the level of Bcl-2 expression under hypoxic conditions and reduced the level of caspase-3 expression. The effects of E2 on Bcl-2 and caspase expression were blocked by ICI 182780 （E2 receptor （ER） antagonist, 10＂7 M）. In addition, hypoxia resulted in an increase in the intracellular reactive oxygen species （ROS） generated. These effects were blocked by E2, but not by E2-BSA and ICI 182780. Hypoxia also activated p38 mitogen-activated protein kinase （MAPK）, c-JUN N-terminal kinase/stress-activated protein kinase （JNK/SAPK） and nuclear factor-kB （NF-kB）. These effects were blocked by E2, but not by ICI 182780. The inhibition of p38 MAPK and JNK/SAPK blocked NF-kB activation. In conclusion, E2 was found to protect against hypoxia-induced cell injury in chicken hepatocytes through ER-mediated upregulation of Bcl-2 expression and through reducing the activity of ROS-dependent p38 MAPK, JNK/ SAPK and NF-kB.

Synthesis of Environmentally Friendly Multifunctional Metal (Calcium,Magnesium) Oleate Detergent with Antioxidation Property

This article covers a method for synthesizing environmentally friendly multifunctional metal (calcium,magnesium) oleate detergents with antioxidation property.These multifunctional metal (calcium,magnesium) oleate detergents with antioxidation property were synthesized using oil-soluble liquid antioxidants (PPIBP,PPIBTSTBP,and PPIBPDA) as reactive functional materials.These oil-soluble liquid antioxidants have the potential to be used as functional materials for application in synthesizing other kinds of substrate detergents.

The Antioxidant Effects of Complexes of Tilapia Fish Skin Collagen and Different Marine Oligosaccharides

An excess of reactive oxygen species（ROS）leads to a variety of chronic health problems.As potent antioxidants,marine bioactive extracts containing oligosaccharides and peptides have been extensively studied.Recently,there is a growing interest in protein-polysaccharide complexes because of their potential uses in pharmaceutical and food industries.However,only few studies are available on the antioxidant activities of such complexes,in terms of their ROS scavenging capability.In this study,we combined and superoxide radicals,and to evaluate the influences on the activities of superoxide dismutase（SOD）,glutathione peroxidase（GSH-Px）and the level of malondialdehyde（MDA）in UV-induced photoaging models.The results indicated that the antioxidant activities of all the complexes were stronger than those of their individual components.Among the 11 complexes tested,two complexes,namely MA1000＋CP and κ-ca3000＋CP,turned out to be highly effective antioxidants.Although the detailed mechanisms of this improved scavenging ability are not fully understood,this work provides insights into the design of highly efficient peptide-oligosaccharide complexes for potential applications in pharmaceutical,cosmetics and food industries.

Study on the Antioxidation of the Compound Beverage of Winter Jujube and Peanut Meal

[ Objective] The aim was to study the antioxidative index of the compound beverage of winter jujube and peanut meal, discuss the im-pact of the storage conditions on its antioxidative activity and provide theoretical basis for the utilization of winter jujube and peanut meal resources. [Method] A kind of compound beverage was prepared with winter jujube and peanut meal, and its antioxidative activity was detected and its best storage conditions were determined. [ Result] The capacity of the compound beverage stored for 20 d to scavenge · OH, DPPH · and nitroso was the highest at freeze conditions, then followed by the refrigeration conditions, room temperature storage and sunlight. The total reducing capacity of the products was the highest under freezing conditions while the lowest under sunlight when some active components were destroyed. [ Conclusion] It is the best to store the compound beverage of winter jujube and peanut meal at freeze conditions and better at the refrigeration conditions. The storage of compound beverage should avoid direct sunlight. Key words Winter jujube; Peanut meal; Compound beverage; Antioxidation; China

Lipid peroxidation and antioxidant status in colorectal cancer

AIM: Reactive oxygen species (ROS) can induce carcinogenesis via DNA injury. Both enzymatic and non-enzymatic parameters participate in cell protection against harmful influence of oxidative stress. The aim of the present study was to assess the levels of final lipid peroxidation products like malondialdehyde (MDA) and 4-hydroxy-2-nonenal (4-HNE) in primary colorectal cancer. Moreover, we analysed the activity of main antioxidative enzymes, superoxide dismutase (Cu, Zn-SOD), catalase (CAT), glutathione peroxidase (GSH-Px) and glutathione reductase (GSSRG-R) and the level of non-enzymatic antioxidants (glutathione, vitamins C and E). METHODS: Investigations were conducted in 81 primary colorectal cancers. As a control, the same amount of sample was collected from macroscopically unchanged colon regions of the most distant location to the cancer. Homogenisation of specimens provided 10% homogenates for our evaluations. Activity of antioxidant enzymes and level of glutathione were determined by spectrophotometry. HPLC revealed levels of vitamins C and E and served as a method to detect terminal products of lipid peroxidation in colorectal cancer. RESULTS: Our studies demonstrated a statistically significant increase in the level of lipid peroxidation products (MDA-Adc. muc.-2.65±0.48 nmol/g, Adc.G3-2.15±0.44 nmol/g, clinical IV stage 4.04±0.47 nmol/g, P<0.001 and 4-HNE-Adc.muc. -0.44±0.07 nmol/g, Adc.G3-0.44±0.10 nmol/g, clinical IV stage 0.52±0.11 nmol/g, P<0.001) as well as increase of Cu,Zn-SOD (Adc.muc.-363±72 U/g, Adc.G3-318?8 U/g, clinical IV stage 421±58 U/g, P<0.001), GSH-Px (Adc.muc. -2143±623 U/g, Adc.G3-2005±591 U/g, clinical IV stage 2467±368 U/g, P<0.001) and GSSG-R (Adc.muc.-880±194 U/g, Adc.G3-795±228 U/g, dinical IV stage 951±243 U/g, P<0.001) in primary tumour comparison with normal colon (MDA-1.39±0.15 nmol/g, HNE-0.29±0.03 nmol/g, Cu, Zn-SOD-117±25 U/g, GSH-Px-1723±189 U/g, GSSG-R-625±112 U/g) especially in mucinous and G3-grade adenocarcinomas as well as clinical IV stage of colorectal cancer. We also observed a decrease of CAT activity (Adc.muc. -40±14 U/g, clinical IV stage 33±18 U/g vs 84±17 U/g, P<0.001) as well as a decreased level of reduced glutathione (clinical IV stage 150±48 nmol/g vs 167±15 nmol/g, P<0.05) and vitamins C and E (vit. C-clinical IV stage 325±92 nmol/g vs 513?4 nmol/g, P<0.001; vit. E-clinical IV stage 13.3±10.3 nmol/g vs 37.5±5.2 nmol/g). CONCLUSION: Colorectal carcinogenesis is associated with serious oxidative stress and confirms that gradual advancement of oxidative-antioxidative disorders is followed by progression of colorectal cancer.

Physiological characteristics and commercial application of edible mushroom dietary fiber

Edible mushrooms are considered as healthy food because they are low in calories and fat but rich in proteins minerals and dietary fiber(DF). Edible mushrooms are recognized as new potential resource of DF since the components of edible mushroom dietary fiber(EMDF) have shown special physiological and pharmacological effects on human and animals. In this article,the soluble and insoluble fractions of DF in different edible mushroom species have been evaluated. Biological effects of EMDF are related to promoting desired responses,for example,reducing blood cholesterol,protecting cells from free radicals attack by antioxidative effects,attenuating levels and fluctuations of blood glucose and selectively supporting the growth of beneficial gut bacteria. The EMDF plays an important role in reducing risk of cardiovascular diseases,diabetes mellitus and intestinal diseases. The non-starch polysaccharides(NSP),a kind of EMDF,is the best known and most potent mushroom-derived substances with antitumor and immunomodulatory properties. EMDF has also been reported to take part in the control of body weight,lipid homeostasis and insulin sensitivity due to its effect on specific chemical structures and physical properties. Many pharmaceutical substances with potent and unique health- enhancing properties were isolated recently from edible mushrooms and distributed worldwide. Mushroom-based dietary supplements(DSs) with potential therapeutic effects are produced from the mycelia or the fruiting bodies of mushrooms,and are consumed in the forms of capsules,tablets,or extracts. The EMDF, based on its special physiological functions on human health,shows a wide range of potential application prospects.

Synthesis of two new thiazolidines and their hepatoprotective effects

Two new 2-substituted thiazolidine-4（R）-carboxylic acids （TCAs）, 2-glusosaminal-TCA （GIcNH2Cys） and 2-N-acetyl-glueosanlinal-TCA （GlcNAeCys）, were synthesized. Their protective effects against liver toxicity induced by acetaminophen （APAP） were investigated in a mice model. The resuits demonstrate that administration of TCAs （ i. p. , 800 mg/kg） 30 min after APAP challenge efficiently decrease ALF, AST, and LDH levels in liver. GlcNAcCys shows the best proteetive eftects, decreasing ALT, AST and LDH levels to 63%, 18.4% and 37% of the APAP group respectively. Comparison with the control showed that APAP greatly decreases total sulfhydlyl （T-SH） levels （43%）, non-protein hound sulfhydryl （NP-SH） levels （50%） and total antioxidative capabilities （57%） in the liver 24 hr after challenge. TCAs treatments 30min after APAP challenge significantly elevate sulfhydryl levels and total antioxidative capabilities. APAP administration also markedly （P 〈 0.05） increases liver lipid peroxidation to 1.65 and 1.17 times that of the control 4 hr and 24 hr after APAP administration respectively. TCAs treatments can inhibit lipid peroxidation as measured by decreased malondialdehyde （MDA） contents in liver. The histopathological results also further confirm the hepatoprotective effects of TCAs. In conclusion, our data show that TCAs, GleNAcCys particularly, have hepatoprotective anti antioxidant etfects.