大枣多糖体外对小鼠腹腔巨噬细胞功能的影响

目的：探讨大枣多糖（ＪＤＰＮ）体外对小鼠腹腔巨噬细胞细胞毒活性和分泌ＴＮＦα、ＩＬ１、ＮＯ等功能的影响。方法：ＭＴＴ法测细胞增殖活性；胸腺细胞增殖法测ＩＬ１；Ｌ９２９细胞株细胞毒法测ＴＮＦα；Ｇｒｅｅｓ试剂测ＮＯ。结果：ＪＤＰＮ能显著增强巨噬细胞（ＭΦ）对Ｌ９２９细胞株的细胞毒活性和ＴＮＦα、ＩＬ１、ＮＯ的分泌功能。ＪＤＰＮ最佳诱导浓度对促进ＭΦ分泌ＩＬ１为５０μｇ／ｍｌ，促ＴＮＦα分泌为１００μｇ／ｍｌ。ＪＤＰＮ不能协同ＬＰＳ促进ＩＬ１和ＴＮＦα的分泌。１００μｇ／ｍｌＪＤＰＮ诱导ＭΦ分泌ＮＯ能力最强。结论：大枣多糖体外可增强小鼠腹腔巨噬细胞的细胞毒作用，诱导ＴＮＦα、ＩＬ１、ＮＯ的产生。

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.

Tannins from Canarium album with potent antioxidant activity

The contents of total phenolics and extractable condensed tannins in the leaves, twigs and stem bark of Canarium album were determined. The structural heterogeneity of condensed tannins from stem bark was characterized by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry （MALDI-TOF MS） and nuclear magnetic resonance （NMR） analyses The results show the predominance of signals representative of procyanidins and prodelphinidins. In addition, epicatechin and epigallocatechin polymers with galloylated procyanidin or prodelphinidin were also observed. The tannins were screened for their potential antioxidant activities using l,l-diphenyl-2-picrylhydrazyl （DPPH） and ferric reducing/antioxidant power （FRAP） model systems. Tannins extracted from leaves, twigs and stem bark all showed a very good DPPH radical scavenging activity and ferric reducing power.

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.

Antioxidative Activity of Polysaccharide Fractions Isolated from Tricholoma Matsutake Sing. with Ultrafiltration

Polysaccharides of Tricholoma matsutake Sing. were extracted with boilingwater, followed by precipitating with ethanol. Two membranes of different molecular weight cut-off, namely, 30 kD and 10 kD were chosen with ultrafiltration. The antioxidant activity of the purification polysaccharides was evaluated by various antioxidant assay, including DPPH （l,l-diphenyl-2-picrylhydrazyl） radical scavenging, superoxide anion radical scavenging and hydrogen peroxide scavenging. The scavenging effect on hydroxyl radical and DPPH radical, which may be comparable to Vitamin C, while the scavenging effect on superoxide anion radicals was not obvious.

Antioxidation and ATPase activity in the gill of mud crab Scylla serrata under cold stress

Mud crab （Scylla serrata） is an important commercial crustacean in China. An experiment was designed to study the effect of cold stress on S. serrata. After a one-week adaptation at 28℃, the temperature is suddenly reduced to 4℃. The crabs were sampled every 2 h for 10 h and dissected immediately to measure the enzyme activity. The crabs at room temperature （28℃） were used as the control group. The activity of superoxide dismutase （SOD）, catalase （CAT） and gkttathione peroxidase （GPX）, the content of malondialdehyde （MDA） and the activity of 4 ATPases （Na^＋, K^＋-ATPase, Mg^2＋-ATPase; Ca^2＋-ATPase; Ca^2＋, Mg^2＋-ATPase） were measured biochemically. In contrast to the control group, the SOD activity increased significantly from 2 to 6 h after the cold stress, and then decreased. The CAT and GPX activities increased in 2 h, and then decreased gradually. The content of MDA increased gradually in 4 h. The activity of Na^＋, K^＋-ATPase decreased in 2 h, increased up to the top value at Hour 6, then decreased again. The activities of Mg^2＋-ATPase, Ca^2＋-ATPase and Ca^2＋, Mg^2＋-ATPase increased significantly in 6 h, insignificantly in any other hours. Under cold stress, the activity of antioxidative enzymes in S, serrata was reduced at first then stabilized, ROS-scavenging weakened, and MDA accumulated gradually in the gill after 6 h. The activity of the 4 ATPases in the crab decreased after 6 h, suggesting that the ability to regulate ion concentration has been paralyzed. Therefore, the maximum period to sustain healthy meat in the crab under cold stress is 6 hours.

Antioxidant Activity and Anti-Hyperglycemic Effect of Lagenaria Siceraria Fruit Extract

Lagenaria siceraria （Molina） Standl., known as bottle gourd is widely available throughout Vietnam as an edible vegetable. Bottle gourd is a commonly fruit but there are little reports about its biological activities. The aim of the present study was to evaluate antioxidant activity and anti-hyperglycemic potential of ethanolic extract of bottle gourd. The ethanolic extract was tested for its antioxidant activity on chelating power, the ferric reducing/antioxidant power assay （FRAP） and the 1, 1-diphenyl-2-picryl-hydrazyl （DPPH） free radical scavenging assay. The results showed that chelating activity was 80.02%, FRAP value was 92.84 μmol Fe^2＋/g and active radical scavenging which showed an IC50 was 49.50 μg/ml. The five different doses of ethanolic extract were treated by oral tolerance to mice body before oral glucose tolerance and blood glucose level was measured using glucose oxidase method. The result indicated that inhibition percentage of ethanolic extract of bottle gourd at the dose of 400 mg/kg in glucose-induced hyperglycemic mice was effectively similar to standard drug glibenclamide. The results obtained indicate that ethanolic extract from bottle gourd is the potential antioxidant and anti-hyperglycemic agent.

Effects of Thallium Stress on Photosynthesis, Chlorophyll Fluorescence Parameters and Antioxidant Enzymes Activities of Coix Lacryma-jobi

Levels of T1 （Thallium） in soil from 0 （control） to 50 μg/L through 0.2, 0.5, 1 and 2.5μg/L were directly and positively correlated to levels of T1 in plant tissue, the accumulation being maximum in roots, intermediate in leaves and minimum in stems. Thallium, especially at higher concentrations, adversely affected photosynthesis （as judged based on chlorophyll fluorescence parameters）, suggesting inhibition of photo-activation of PSII （Photosystems II）, and also decreased the rate of photosynthesis, the rate of transpiration and stomatal conductivity drastically. Exposure to TI also increased the activity of CAT （Catalase） （except at 1 μg/L） and POD （Peroxidase） （except at 0.2 μg/L）, suggesting that the antioxidant systems in Coix lacryma-jobi were the main contributors of CAT and SOD （Superoxide Dismutase） and that the tolerance of C. lacryma-jobi to T1 is mainly due to this induced antioxidant machinery.

In vivo antioxidant activity and its protective effects of green tea extract on acute myocardial infarction

The antioxidant activity and its protective effects of Green Tea Extract （GTE） from a Chinese green tea, Hangzhou Longjing, on acute myocardial inthrction （AMI） were investigated in rats. Blood, liver and heart were collected to perform DNA damage test, hepatic antioxidant test, gene expression as well as capillary distribution study. A well-known angiotensin II type I receptor antagonist, Losartan was used as control. It was fbund there were significant reductions in certain DNA damage products＇ levels in GTE and Losartan treated groups compared to saline-treated group. In addition, significant increases in antioxidant enzyme activities and antioxidant gene expressions were observed in GTE and Losartan treated groups. Molphological study also demonstrated the cardioprotective effects of GTE on AMI. In conclusion, GTE has potent and similar cardioprotective effect as Losartan that mav due to its ability to scavenge free radicals.

Characterization of pumpkin polysaccharides and protective effects on streptozotocin-damaged islet cells

The polysaccharides from pumpkin fruit （PP） were obtained and purified by hot-water extraction, anion-exchange chromatography, and gel column chromatography. The physicochemical properties of PP were determined by gel filtration chromatography, gas chromatography, fourier transform infrared （FTIR） spectroscopy, and nuclear magnetic resonance （NMR） spectroscopy. Results indicated that the molecular weight of PP was about 23 kDa and PP was composed of D-Arabinose, D-Marmose, D-Glucose, and D-Galactose with a molar ratio of 1 ： 7.79 ： 70.32 ： 7.05. FTIR and NMR spectra indicated that PP was the polysaccharide containing pyranose ring. Additionally, PP protected islets cells from streptozotocin （STZ） injury in vitro via increasing the levels of super-oxide dismutase （SOD） and malondialdehyde （MDA） and reducing the production of NO. The experiment of reverse transcriptase-polymerase chain reaction further proved that PP inhibited apoptosis via modulating the expression of Bax/Bcl-2 in STZ-damaged islet cells. In conclusion, PP could be explored as a novel agent for the treatment of diabetes mellitus.