Sumei Zhou

Antitumor and immunomodulatory activity of arabinoxylans: a major constituent of wheat bran.

We aimed to investigate the antitumor activity of wheat bran arabinoxylans, including the role of its immunostimulatory effect. In S180 tumor-bearing mice arabinoxylan administration significantly inhibited the growth of mouse transplantable tumors and remarkably promoted thymus and spleen indexes, splenocyte proliferation, natural killer cell and macrophage phagocytosis activity, interleukin 2 production, and delayed-type hypersensitivity reaction. In addition, it increased peripheral leukocyte count, and bone-marrow cellularity in tumor-bearing mice. As the antitumor activity of arabinoxylans may be mediated via the improvement in the immune response, they can be considered an antitumor agent with immunomodulatory activity.

Extraction and radicals scavenging activity of polysaccharides with microwave extraction from mung bean hulls

Extraction variables of microwave extraction mung polysaccharides (MEMPs) from mung bean hulls were optimized by Box-Behnken design. The optimal extraction parameter of MEMP was 700 W, 70 s and 17 mL/g, and highest recovery was 60.03±2.56 mg GE/g DW, which was agreed closely with predicted values. Two purified polysaccharide fractions (MEMP-1 and MEMP-2) were successfully isolated through DEAE cellulose-52 chromatography and Sephadex G-100 size-exclusion chromatography in steps. MEMP-1 was mainly composed of mannose and galactose while that of MEMP-2 was rhamnose and galactose. MEMP and purified fractions both had great radicals scavenging activities of hydroxyl and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals, and MEMP-2 possessed highest antioxidant activity. The results suggested that MEMP-2 could be the suitable natural antioxidants and may be the functional foods for humans.

Oat oil lowers the plasma and liver cholesterol concentrations by promoting the excretion of faecal lipids in hypercholesterolemic rats

The aim of the present study is to investigate the hypocholesterolemic effect of dietary oat oil in rats, fed with a hypercholesterolemic diet. The rats were divided into three groups and fed with the experiment diets for 30days, containing soybean oil, oat oil, or rice bran oil at a dose of 70g/kg. It was found that the oat oil lowered plasma total and LDL-cholesterol, and also reduced liver total, free cholesterol, cholesterol ester, and triglycerides concentrations significantly, as well as rice bran oil. Moreover, the faecal weight, total lipids, and bile acids concentrations, in the oat oil and rice bran oil groups, were significantly increased compared with that in the soybean oil group. We can conclude that dietary oat oil improves hypercholesterolemia in rats fed a hypercholesterolemic diet, by promoting excretions of faecal lipids and bile acids.

Effects of dietary hull-less barley β-glucan on the cholesterol metabolism of hypercholesterolemic hamsters.

The aim of the present study is to investigate the hypocholesterolemic effects of dietary hull-less barley β-glucan (HBG) on cholesterol metabolism in hamsters which were fed a hypercholesterolemic diet. The hamsters were divided into 3 groups and fed experimental diets, containing 5‰ HBG or 5‰ oat β-glucan (OG), for 30days. The HBG, as well as OG, lowered the concentration of plasma LDL-cholesterol significantly. The excretion of total lipids and cholesterol in feces were increased in HBG and OG groups compared with the control group. The activity of 3-hydroxy-3-methyl glutaryl-coenzyme A (HMG-CoA) reductase in liver was reduced significantly in the HBG group compared with the control and OG groups. The activity of cholesterol 7-α hydroxylase (CYP7A1) in the liver, in the HBG and OG groups, was significantly increased compared with the control group. The concentrations of acetate, propionate and total short chain fatty acids (SCFAs) were not significantly different between the HBG and control groups. These results indicate that dietary HBG reduces the concentration of plasma LDL cholesterol by promoting the excretion of fecal lipids, and regulating the activities of HMG-CoA reductase and CYP7A1 in hypercholesterolemic hamsters.

Effects of dietary wheat bran arabinoxylans on cholesterol metabolism of hypercholesterolemic hamsters

The aim of the present study is to investigate the effects of dietary wheat bran arabinoxylans (AXs) on cholesterol metabolism in hypercholesterolemic hamsters. The hamsters were divided into 3 groups and fed the experimental diets containing AXs or oat β-glucan at a dose of 5 g/kg for 30 days. As the results, the AXs lowered plasma total cholesterol and LDL-cholesterol concentrations, and increased excretions of total lipids, cholesterol and bile acids, as well as oat β-glucan. The AXs reduced the activity of 3-hydroxy-3-methyl glutaryl-coenzyme A (HMG-CoA) reductase, and increased the activity of cholesterol 7-α hydroxylase (CYP7A1) in liver. Moreover, the AXs increased propionate and the total short-chain fatty acids (SCFAs) concentrations. These results indicated that dietary AXs reduced the plasma total cholesterol and LDL-cholesterol concentrations by promoting the excretion of fecal lipids, regulating the activities of HMG-CoA reductase and CYP7A1, and increasing colonic SCFAs in hamsters.

Molecular weight degradation and rheological properties of schizophyllan under ultrasonic treatment

Molecular weight degradation effects of schizophyllan (SPG) under ultrasonic treatments were investigated in this study. The degradation product was treated by alcohol fractional precipitation technology, and the molecular weight and rheological properties of ultrasonic-treated SPG (USPG) fractions were evaluated. Average molecular weight of SPG decreased significantly after ultrasonic treatments, and degradation product had more narrow distribution of molecular weight. The molecular weight degradation kinetics of SPG is adequately described by a second-order reaction. USPG fractions with different molecular weight were obtained by fractional precipitation for final alcohol concentration fractions 0-40%, 40-60% and 60-80%, respectively. USPG fractions had near-Newtonian flow behaviors, and USPG₈₀% exhibited viscous responses over the entire accessible frequency range. Therefore, ultrasonic treatment is a viable modification technology for SPG and other polymer materials with high molecular weight.

Effects of Cultivar on Phenolic Content and Antioxidant Activity of Naked Oat in China

To evaluate the effects of naked oat cultivars on their phenolic contents and antioxidant activities, the oat seeds from 21 different cultivars in China were collected, and their major nutritional components, compositions of polyphenols, and antioxidant activities were measured. As the results, oat cultivars affected its phenolic composition and antioxidant activity significantly. Vanillin, chlorogenic acid, ferulic acid, avenanthramide C (Bc), avenanthramide A (Bp), and avenanthramide B (Bf) in oat polyphenols extracts were detected in all cultivars of oat, while caffeic acid, p-coumaric acid and rutin were partly detected. All oat cultivars showed significant free radical scavenging activity, although their activities were lower than that of vitamin C (VC). Different oat varieties showed different antioxidant activities, among which Yanke 1 had the best ability to scavenge ·OH ((58.78±1.99) μg mL−1), Baiyan 10 showed the strongest DPPH· ((22.00±0.43) μg mL−1) and ABTS·+ ((6.92±0.44) μg mL−1) scavenging activity, and Dingyou 1 showed good scavenging ability of DPPH· ((22.71±0.42) μg mL−1) and ·OH ((81.50±1.73) μg mL−1). In addition, the correlation coefficients of contents between the major nutritional components in different cultivars of oat and phenolic compounds indicated that determination of main nutrients could be used as an easy technique to evaluate approximately the contents and compositions of oat polyphenols, which simplifies the selection of good oat cultivar.

Rheological properties and antitumor activity of schizophyllan produced with solid-state fermentation

Schizophyllan (SPG) was produced by the fungus Schizophyllum commune under solid-state fermentation conditions in this study. SPG was physically characterized and its rheological properties and antitumor effects on S180 tumors in vivo were evaluated. SPG is a neutral polysaccharide with three main fractions, and the major fraction comprises 55.5%, with an average molecular weight 4.65 × 10(7) Da. Steady shear rheological measurements showed the typical pseudoplastic flow behavior of SPG at the experimental concentrations. The power law model was used to fit the shear curves of SPG and both its viscosity and consistency indices changed regularly as the concentration increased. SPG solution showed different viscoelastic behaviors at different concentrations: typical viscoelastic behavior was observed at lower concentrations, whereas solid-like behavior was observed at higher concentrations. Experimental doses of SPG exerted extreme antitumor effects in vivo, and the maximum inhibition rate was almost 70%.

Effect of steam explosion-assisted extraction on phenolic acid profiles and antioxidant properties of wheat bran.

BACKGROUNDnThe majority of phenolic acids in wheat bran are bound to the cell walls. Hence, a high proportion of phenolic acids cannot be extracted with conventional extraction methods. This study aimed to investigate the efficiency of steam explosion pre-treatment in increasing the extractability of phenolic compounds from wheat bran.nnnRESULTSnBound phenolic acids (BPA) can be released by steam explosion-assisted extraction. Within the experimental range, soluble free phenolic acids (FPA) and soluble conjugated phenolic acids (CPA) increased gradually with residence time and temperature. After steam explosion at 215u2009°C for 120u2009s, the total FPA and CPA reached 6671.8 and 2578.6u2009µg GAE g(-1) bran, respectively, which was about 39-fold and seven-fold higher than that of the untreated sample. Ferulic acid, the major individual phenolic acids in bran, increased from 55.7 to 586.3u2009µgu2009g(-1) for FPA, and from 44.9 to 1108.4u2009µgu2009g(-1) for CPA. The antioxidant properties of FPA and CPA extracts were significantly improved after treated. Correlation analysis indicated that the antioxidant capacity was in close relationship with phenolic content in FPA and CPA.nnnCONCLUSIONnSteam explosion pre-treatment could be effectively used to release of BPA and enhance the antioxidant capacity of wheat bran.

The cholesterol-lowering effects of oat varieties based on their difference in the composition of proteins and lipids

BackgroundThe aim of present study is to investigate the hypocholesterolemic effects of the oat components other than the β-glucan in rats fed with a hypercholesterolemic diet.MethodsFour-week-old male Wister rats were divided into 6 groups of 7 rats each with similar mean body weights and serum cholesterol concentrations. Rats were fed with the experimental diets containing 10% oats flour for 30xa0days. Food intake was recorded and monitored everyday to ensure the similar contents of protein, starch, lipid and cellulose in all groups. The lipids levels in serum, liver, and faeces were determined.ResultsThe plasma total cholesterol concentrations in different oat groups were significantly reduced compared with the control group, and the effects were different among oat groups. The decrease extent of plasma total cholesterol and low-density lipoprotein-cholesterol concentrations increased with the increase of the proteins and lipids contents. Moreover, liver total cholesterol and cholesterol ester contents were markedly decreased. The fecal bile acids concentrations in the oat groups were significantly increased. Oat proteins had lower Lysine/Arginin (0.59u2009~u20090.66) and Methionin/Glycine (0.27u2009~u20090.35) ratio than casein (Lysine/Arginin, 2.33; Methionin/Glycine, 1.51). Oat lipids contained higher contents of total Vitamin E and plant sterols than that in soybean oil.ConclusionThese results indicated that dietary oat improved hypercholesterolemia by increasing the excretions of fecal bile acids, and this improvement was not only related to β-glucan, but also attributed to the lipids and proteins. Oat proteins decreased serum total cholesterol and low-density lipoprotein-cholesterol contents due to their low Lysine/Arginin and Methionin/Glycine ratio. The co-existence of oleic acid, linoleic, vitamin E, or plant sterols accounted for the hypocholesterolemic properties of oat lipids.