Reviews on Mechanisms of In Vitro

It is widely acknowledged that the excessive reactive oxygen species (ROS) or reactive nitrogen species (RNS) induced oxidative stress will cause significant damage to cell structure and biomolecular function, directly or indirectly leading to a number of diseases. The overproduction of ROS/RNS will be balanced by nonenzymatic antioxidants and antioxidant enzymes. Polysaccharide or glycoconjugates derived from natural products are of considerable interest from the viewpoint of potent in vivo and in vitro antioxidant activities recently. Particularly, with regard to the in vitro antioxidant systems, polysaccharides are considered as effective free radical scavenger, reducing agent, and ferrous chelator in most of the reports. However, the underlying mechanisms of these antioxidant actions have not been illustrated systematically and sometimes controversial results appeared among various literatures. To address this issue, we summarized the latest discoveries and advancements in the study of antioxidative polysaccharides and gave a detailed description of the possible mechanisms

Structural characterization of an α-1, 6-linked galactomannan from natural Cordyceps 2 sinensis

An α-1, 6-linked galactomannan was isolated and purified from natural Cordyceps sinensis. The fine structure analysis of this polysaccharide was elucidated based on partial acid hydrolysis, monosaccharide composition, methylation and 1D/2D nuclear magnetic resonance (NMR) spectroscopy. Monosaccharide composition analysis revealed that this polysaccharide was mainly composed of galactose (68.65%), glucose (6.65%) and mannose (24.02%). However, after partial acid hydrolysis the percentages of galactose, glucose and mannose were changed to 3.96%, 13.82% and 82.22%, respectively. The molecular weight of this polysaccharide was 7207. Methylation and NMR analysis revealed that this galactomannan had a highly branched structure, mainly consisted of a mannan skeleton and galactofuranosyl chains. The structure of galactofuranosyl part was formed by alternating (1 → 5)-lined β-Galf and (1 → 6)-liked β-Galf or a single (1 → 6)-liked β-Galf, attaching to the O-2 and O-4 of the mannose chain, and terminated at β-T-Galf. The mannan core was revealed by analyzing the partial acid hydrolysate of the galactomannan and the structure was composed of (1 → 6)-linked α-Manp backbone, with substituted at C-2 by short chains of 2-substituted Manp or Galf branches

Effect of Frying Conditions on Acrylamide and 5-Hydroxymethylfurfural Formation in French Fries

In this study, the relationship between the formation of acrylamide (AA) and that of 5-hydroxymethylfurfural (5-HMF), as well as the correlation with the content of α-dicarbonyl compounds as intermediate products in French fries were studied using Pearson correlation analysis and principal component analysis (PCA), and the correlation between the formation of AA and 5-HMF and the sensory score, color, water content and oil absorption of French fries was also discussed. The results showed that with an increase in frying time or temperature, the contents of AA, 5-HMF and α-dicarbonyl compounds in French fries increased significantly, water content decreased, and oil absorption increased gradually. In addition, lightness (L* value) and yellowness (b* value) tended to decrease, while redness (a* value) tended to increase. There was a significantly positive correlation between AA and 5-HMF contents under the different conditions tested. Moreover, AA and 5-HMF contents showed a significantly positive correlation with the content of α-dicarbonyl compounds and oil absorption, but a significantly negative correlation with water content, L* value and b* value. AA content was positively correlated with a* value. It was found that the results of the PCA model were consistent with the linear curves of the contents of AA, 5-HMF and α-dicarbonyl compounds versus frying temperature and time. Frying for 5 min at 170 ℃ not only ensured the best sensory quality of French fries, but also helped to reduce the formation of hazardous substances

Cordyceps Sinensis: anti-fibrotic and inflammatory effects of a cultured polysaccharide extract

It has been suggested that the traditional Chinese herbal preparation Cordyceps Sinensis (CS) may have a beneficial effect in renal disease. To satisfy increasing demand, CS derivatives have been produced by aseptic mycelia cultivation. We have demonstrated antifibrotic activity of cultured CS previously. The aim of this study was to examine bioactivity of a polysaccharide isolated from cultured CS with a complicated monosaccharide composition, mainly consisting of Gal, Glc and Man. This polysaccharide antagonised the effect of TGF-b1 in stimulating the expression of collagen in the HK2 renal cell line. This was associated with down regulation of the TGF-b receptor Alk5. In addition the polysaccharide antagonised IL-1b stimulated sICAM-1 dependent adherence of monocytes to a monolayer of HK2 cell. This was associated with increased expression of the primary receptor for hyaluronan CD44, and was abrogated by removal of the cell surface hyaluronan pericellular coat. In summary we describe both anti-fibrotic and anti-inflammatory activity in a polysaccharide isolated from cultured CS

Effects of Differently Processed Carrots on Ulcerative Colitis in Mice

The incidence of ulcerative colitis (UC) has been increasing in recent years. Due to the limitations of traditional drug therapies for UC, natural foods that can prevent this disease and alleviate its symptoms are becoming a research hot topic, but the effects of processing methods on their activity remain unknown. Therefore, the effects of three different processing methods (pulping, high-temperature cooking, and fermentation) on carotenoid and dietary fiber contents as well as carotenoid bioaccessibility in carrots were explored in this study. C57BL/6J mice were used to create a mouse model of UC induced by dextran sulfate sodium (DSS) and the mice received dietary intervention with freeze dried powder of carrots (5.05%, on a dry mass basis) for 14 days. Body mass change, disease activity index (DAI) and colon parameters (length, pathology, inflammatory factors, oxidative stress level, goblet cell number, tight junction protein expression, and short-chain fatty acid content) were analyzed to evaluate the effects of three differently processed carrots on UC. The results showed compared with pulping, high-temperature cooking and fermentation significantly decreased the soluble, insoluble and total dietary fiber contents of carrots (P < 0.05), increased the bioaccessibility of carotenoids (P < 0.05), while fermentation significantly increased the proportion of soluble dietary fiber in total dietary fiber (P < 0.05). Compared with the model group, all processed carrots could significantly inhibit the change of body mass loss and DAI (P < 0.05), decrease the levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β and IL-6 (P < 0.05), increase the level of IL-10 (P < 0.05), and up-regulate the expression of tight junction proteins (ZO-1, claudin-1, and occludin) (P < 0.05). High-temperature cooked or fermented carrots could significantly alleviate colon shortening (P < 0.05), and relieve the pathological damage of colon tissue (P < 0.05). Meanwhile, fermented carrots could significantly inhibit the production of malondialdehyde (MDA) (P < 0.05), improve the decrease in the number of goblet cells (P < 0.05), increase the level of butyric acid (P < 0.05) and possess the best inhibitory effect on IL-6 production. In summary, differently processed carrots could ameliorate ulcerative colitis to different extends, the most pronounced effect being observed with fermented carrots

Natural foods resources and dietary ingredients for the amelioration of Helicobacter pylori infection

Helicobacter pylori (H. pylori) is a gastric-persistent pathogen that can cause peptic ulcer disease, gastric cancer, and mucosal-associated lymphoid tissue lymphoma. This pathogen is commonly treated with antibiotic-based triple or quadruple therapy. However, antibiotic therapy could result in the bacterial resistance, imbalance of gut microbiota, and damage to the liver and kidneys, etc. Therefore, there is an urgent need for alternative therapeutic strategies. Interestingly, natural food resources, like vegetables, fruits, spices, and edible herbs, have potent inhibitory effects on H. pylori. In this review, we systematically summarized these foods with supporting evidence from both animal and clinical studies. The results have indicated that natural foods may possess temporary inhibition effect on H. pylori rather than durable eradication, and may help to reduce H. pylori colonization, enhance the effect of antibiotics and modulate the host’s immune response

Advanced Glycation End Products and Nitrosamines in Sausages Influenced by Processing Parameters, Food Additives and Fat during Thermal Processing

Advanced glycation end products (AGEs) and nitrosamines (NAs) in sausage are associated with pathogenic and carcinogenic risks. However, the multiple reaction parameters affecting the production of AGEs and NAs during sausage processing remain unclear. This experiment evaluated the effects of processing parameters, food additives and fat ratios on the formation of AGEs and NAs in sausages. The results showed a 2–3-fold increase in Nε-(carboxymethyl)lysine (CML) and Nε-(carboxyethyl)lysine (CEL) when the sausage processing temperature was increased from 90 °C to 130 °C, and N-nitrosodimethylamine (NDEA) increased from 3.68 ng/g to 6.41 ng/g. The addition of salt inhibited the formation of AGEs and NAs, and the inhibitory ability of 2 g/100 g of salt was 63.6% for CML and 36.5% for N-nitrosodimethylamine (NDMA). The addition of 10 mg/kg nitrite to sausages reduced CML formation by 43.9%, however, nitrite had a significant contribution to the formation of NAs. The addition of fat only slightly contributed to the production of CML. In addition, the relationship between α-dicarbonyl compounds and the formation of AGEs was investigated by measuring the changes in α-dicarbonyl compounds in sausages. The results showed two trends of AGEs and α-dicarbonyl compounds: AGEs increased with the increase in α-dicarbonyl compounds and AGE level increased but α-dicarbonyl compound level decreased