Characterisation of polysaccharides from green tea of Huangshan Maofeng with antioxidant and hepatoprotective effects

Characterization of Polysaccharides with Antioxidant and Hepatoprotective Activities from the Edible Mushroom Oudemansiella radicata

The preliminary structure, in vitro antioxidant and in vivo hepatoprotective activities of water-soluble polysaccharides (ORWP) and alkali-soluble polysaccharides (ORAP), prepared from the mushroom Oudemansiella radicata, were investigated. Both ORWP and ORAP were heteropolysaccharides with mannose, glucose and galactose being the main monosaccharide components. Regarding the antioxidant activities, ORWP and ORAP showed effective 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, hydrogen peroxide scavenging activity and lipid peroxidation inhibitory effects, as well as moderate reducing power and Fe²⁺ chelating activity. For the hepatoprotective activity, administration of ORWP and ORAP prevented the increase in serum alanine aminotransferase and aspartate aminotransferase activities in a carbon tetrachloride-induced acute liver damage model, suppressed hepatic malondialdehyde formation and stimulated the activities of hepatic superoxide dismutase and glutathione peroxidase. Thus, we speculate that ORWP and ORAP may protect the liver from CCl₄-induced hepatic damage via antioxidant mechanisms.

Targeting of growth factors in the treatment of hepatocellular carcinoma: The potentials of polysaccharides

Hepatocellular carcinoma (HCC) has become a leading cause of cancer-associated mortality worldwide and is thus of great concern. Although various chemotherapeutic drugs are currently used for the treatment of HCC, severe side effects associated with these treatments have prompted interest in novel therapies, including the use of certain biological macromolecules such as polysaccharides. Several studies have shown that polysaccharides have anticancer and antiproliferative effects on HCC. Vascular endothelial growth factor, transforming growth factor β, epidermal growth factor and fibroblast growth factor may be effective targets for polysaccharides and may modulate tumor growth and immunity through increasing the expression levels of cytokines. The present review focuses on the ways in which growth factors contribute to the development of HCC, and on the anti-growth factor activities of natural and synthetic polysaccharides, as well as their effect on proinflammatory cytokines.

Review on cell models to evaluate the potential antioxidant activity of polysaccharides

Owing to various health functions, natural polysaccharides are becoming a kind of popular dietary nutritional supplement.

Composition, antioxidant activities and hepatoprotective effects of the water extract of Ziziphus jujuba cv. Jinsixiaozao

In this study, we aimed to evaluate the composition, antioxidant activities, and hepatoprotective effects of water extracts ofZiziphus jujubacv. Jinsixiaozao.

Tea Polysaccharides and Their Bioactivities

Tea (Camellia sinensis) is a beverage beneficial to health and is also a source for extracting bioactive components such as theanine, tea polyphenols (TPP) and tea polysaccharides (TPS). TPS is a group of heteropolysaccharides bound with proteins. There is evidence showing that TPS not only improves immunity but also has various bioactivities, such as antioxidant, antitumor, antihyperglycemia, and anti-inflammation. However, inconsistent results concerning chemical composition and bioactivity of TPS have been published in recent years. The advances in chemical composition and bioactivities of TPS are reviewed in the present paper. The inconsistent and controversial results regarding composition and bioactivities of TPS are also discussed.

Safety and anti-hyperglycemic efficacy of various tea types in mice

Tea, a beverage consumed worldwide, has proven anti-hyperglycemic effects in animal models. Better efficacies of tea beverages are frequently associated with high-dose levels, whose safety attracts considerable attention. Based on the inherent nature of tea catechin oxidation, fresh tea leaves are manufactured into diverse tea types by modulating the oxidation degree of catechins. The present study aimed to assess various tea types for their safety properties and anti-hyperglycemic effects. Mice were allowed free access to tea infusion (1:30, w/v) for one week, and the rare smoked tea caused salient adverse reactions, including hepatic and gastrointestinal toxicities; meanwhile, the widely-consumed green and black teas, unlike the rare yellow tea, suppressed growth in fast-growing healthy mice. When mice were fed a high-fat diet and allowed free access to tea infusion (1:30, w/v) for 25 days, only yellow tea significantly reduced blood glucose. Therefore, various teas showed different safety profiles as well as anti-hyperglycemic efficacy strengths. To achieve an effective and safe anti-hyperglycemic outcome, yellow tea, which effectively suppressed high-fat diet-induced early elevation of hepatic thioredoxin-interacting protein, is an optimal choice.

Recent advances in tea polysaccharides: Extraction, purification, physicochemical characterization and bioactivities

Tea has a long history of medicinal and dietary use. Tea polysaccharide (TPS) is regarded as one of the main bioactive constituents of tea and is beneficial for health. Over the last decades, considerable efforts have been devoted to the studies on TPS: extraction, structural feature and bioactivity of TPS. However, it has been received much less attention compared with tea polyphenols. In order to provide new insight for further development of TPS in functional foods, in present review we summarize the recent literature, update the information and put forward future perspectives on TPS covering its extraction, purification, quantitative determination techniques as well as physicochemical characterization and bioactivities.

Purification, characterization and hepatoprotective activities of mycelia zinc polysaccharides by Pleurotus djamor

This study was designed to investigate the physicochemical properties (molecular weights, bond types and monosaccharide compositions), antioxidant activities, and hepatoprotective effects on carbon tetrachloride (CCl4)-induced acute liver damage of mycelia zinc polysaccharides (MZPSs) and its major fractions (MZPS-1, -2 and -3) separated from Pleurotus djamor. In vitro assays, the MZPS-3 demonstrated relatively strong antioxidant activities in dose-dependent manners. For in vivo hepatoprotective activities, administration of MZPS-3 at 800 mg/kg significantly decreased the levels of AST, ALT, MDA and LPO, remarkably increased the levels of TC, TG and ALB, and prominently restored the activities of SOD, GSH-Px, CAT and T-AOC in serum/liver homogenate against CCl4-induced injures. Findings presented in this study clearly demonstrated that MZPSs, especially MZPS-3, might be suitable for functional foods and natural drugs in preventing the CCl4-induced acute liver damage.

Dissipation Pattern, Processing Factors, and Safety Evaluation for Dimethoate and Its Metabolite (Omethoate) in Tea (Camellia Sinensis)

Residue levels of dimethoate and its oxon metabolite (omethoate) during tea planting, manufacturing, and brewing were investigated using a modified QuEChERS sample preparation and gas chromatography. Dissipation of dimethoate and its metabolite in tea plantation followed the first-order kinetic with a half-life of 1.08-1.27 d. Tea manufacturing has positive effects on dimethoate dissipation. Processing factors of dimethoate are in the range of 2.11-2.41 and 1.41-1.70 during green tea and black tea manufacturing, respectively. Omethoate underwent generation as well as dissipation during tea manufacturing. Sum of dimethoate and omethoate led to a large portion of 80.5-84.9% transferring into tea infusion. Results of safety evaluation indicated that omethoate could bring higher human health risk than dimethoate due to its higher hazard quotient by drinking tea. These results would provide information for the establishment of maximum residue limit and instruction for the application of dimethoate formulation on tea crop.

Myricetin derived from Hovenia dulcis Thunb. ameliorates vascular endothelial dysfunction and liver injury in high choline-fed mice

The present study was conducted to explore the protective effects of myricetin (MYR) purified from Hovenia dulcis Thunb. against vascular endothelial dysfunction and liver injury in mice fed with 3% dietary choline water.

Microwave assisted extraction-solid phase extraction for high-efficient and rapid analysis of monosaccharides in plants

Monosaccharides are the fundamental composition units of saccharides which are a common source of energy for metabolism. An effective and simple method consisting of microwave assisted extraction (MAE), solid phase extraction (SPE) and high performance liquid chromatography-refractive index detector (HPLC-RID) was developed for rapid detection of monosaccharides in plants. The MAE was applied to break down the structure of the plant cells and release the monosaccharides, while the SPE procedure was adopted to purify the extract before analysis. Finally, the HPLC-RID was employed to separate and analyze the monosaccharides with amino column. As a result, the extraction time was reduced to 17 min, which was nearly 85 times faster than soxhlet extraction. The recoveries of arabinose, xylose, fructose and glucose were 85.01%, 87.79%, 103.17%, and 101.24%, with excellent relative standard deviations (RSDs) of 1.94%, 1.13%, 0.60% and 1.67%, respectively. The proposed method was demonstrated to be efficient and time-saving, and had been applied to analyze monosaccharides in tobacco and tea successfully.

Antioxidant and hepatoprotective effect of (-)-epigallocatechin 3-O-(3-O-methyl) gallate (EGCG3″Me) from Chinese oolong tea

(-)-Epigallocatechin 3-O-(3-O-methyl) gallate (EGCG3″Me) has exhibited various biological activities in oolong tea. However, little information about its hepatoprotective activity is available. The objectives of the present study, therefore, were to determine the hepatoprotective activity of EGCG3″Me. First, high-purity EGCG3″Me was prepared from Chinese oolong tea by column chromatography. In antioxidant assay in vitro, EGCG3″Me exhibited potential antioxidant activity. For hepatoprotective activity in vitro, it was observed that EGCG3″Me effectively alleviated the changes induced by alcohol in a concentration-dependent manner. For hepatoprotective activity in vivo, the administration of EGCG3″Me at a dose of 100 mg/kg BW per day significantly decreased the serum levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) from 64.6 ± 3.17 and 97.6 ± 3.78 to 39.6 ± 2.72 and 59.6 ± 3.02 U/L, decreased the liver level of malondialdehyde (MDA) from 1.14 ± 0.08 to 0.77 ± 0.03 nmol/mg protein, and remarkably restored the liver activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) from 247 ± 20.1 U/mg and 6.12 ± 0.17 nmol/mg protein to 261 ± 9.98 U/mg and 8.10 ± 0.03 nmol/mg protein, respectively, in alcohol-induced liver injury mice. This suggested that the protective effect of EGCG3″Me against alcohol-induced liver injury is possibly via its antioxidant activity to protect biological systems against oxidative stress.

Characterization of polysaccharides with antioxidant and hepatoprotective activities from the wild edible mushroom Russula vinosa Lindblad

The aim of the present study was to investigate the antioxidant and hepatoprotective effects of water-soluble polysaccharides (RVLWP) and alkali-soluble polysaccharides (RVLAP) from Russula vinosa on carbon tetrachloride (CCl4)-induced acute liver damage in mice. For the in vitro antioxidant activities, RVLWP and RVLAP exhibited potent 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity (IC50 = 1.55 ± 0.04 and 3.37 ± 0.21 mg/mL, respectively), hydrogen peroxide scavenging activity (IC50 = 6.07 ± 0.24 and 9.23 ± 0.54 mg/mL, respectively), lipid peroxidation inhibitory effect (IC50 = 0.52 ± 0.095 and 0.86 ± 0.043 mg/mL, respectively), and moderate reducing power and Fe(2+) chelating activity (IC50 = 1.86 ± 0.0036 and 0.22 ± 0.0057 mg/mL, respectively). Ascorbic acid was employed as the standard antioxidant in the present study. For the in vivo hepatoprotective activity, administration of RVLWP and RVLAP (200 mg/kg) significantly prevented the elevation in serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities in acute liver damage induced by CCl4 and suppressed hepatic malondialdehyde (MDA) formation. Mice treated with RVLWP and RVLAP demonstrated a better profile of antioxidants with augmented activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in the liver. The results suggest that RVLWP and RVLAP protect the liver from CCl4-induced hepatic damage via antioxidant mechanisms.

Immunomodulatory effects of EGCG fraction of green tea extract in innate and adaptive immunity via T regulatory cells in murine model

Green tea is a widely consumed beverage known for its beneficial anti-inflammatory, anti-oxidative, anti-mutagenic, anti-carcinogenic, and cardioprotective properties. Here, we administered epigallocatechin gallate fraction of green tea extract (EGTE) to mice for 6 weeks and examined the effects on the innate and adaptive immune responses by measuring phagocytic and natural killer (NK) cell activity, as well as antigen-specific proliferation, cytolysis, cytokine secretion, and antibody production. Our data show that EGTE administration increased NK cell cytolysis and peritoneal cell phagocytosis, as well as splenocyte proliferation and secretion of IL-2 and IFN-γ. Of note, EGTE treatment decreased the production antigen-specific IgE via increased the proportion of CD4+ CD25+ regulatory T lymphocytes in the spleen, suggesting that EGTE may play a role in regulating the allergic response.

Purification, characterization and antioxidant activities of polysaccharides from thinned-young apple

Purification, characterization and antioxidant activities of polysaccharides from thinned-young apple (TYA) were investigated in the study. A water-soluble polysaccharide (TYAP) was obtained with hot water extraction, which was further purified by chromatography of Cellulose DEAE-52 and Sephadex G-150 to get three purified fractions of TYAP-1, TYAP-2 and TYAP-3. HPLC analysis showed that the three fractions were mainly composed of galactose and arabinose with the average molecular weights of 115 kDa, 479 kDa and 403 kDa, respectively and the monosaccharide compositions of TYAP-2 and TYAP-3 were more complicated than that of TYAP-1. Moreover, TYAP fractions of three had no absorptions at 260 nm and 280 nm in the UV spectrum, indicating the absence of protein and nucleic acid. Their structure properties were further confirmed by FT-IR. In vitro antioxidant activities of three fractions were characterized by DPPH(•), HO(•), O2(•-) and ferric-reducing antioxidant power systems. The results indicated that TYAP-1, TYAP-2 and TYAP-3 possessed significant antioxidant effects in a concentration-dependant manner in the tested concentration range of 0.25-5.0mg/mL. Among the fractions tested, TYAP-3 showed significantly higher antioxidant activity than that of TYAP-1 and TYAP-2. All of these findings provide a scientific basis for the further use of polysaccharides from thinned-young apple.

Antioxidant and hepatoprotective activity of Veronica ciliata Fisch. extracts against carbon tetrachloride-induced liver injury in mice

Veronica ciliata Fisch. has been traditionally used in Traditional Chinese Medicine prescriptions due to its curative effects for hepatitis, cholecystitis, rheumatism, and urticaria. The present study was focused on investigating the role of ethyl acetate and aqueous extracts of Veronica ciliata Fisch. Furthermore, in vitro antioxidant activity (scavenging of DPPH, ABTS, superoxide, and nitrite radicals; reducing power; β-carotene bleaching) and the hepatoprotective effect of the ethyl acetate extract by means of CCl₄-induced oxidative stress in mice were investigated. The ethyl acetate extract of Veronica ciliata Fisch. displayed more noteworthy in vitro antioxidant activities than the aqueous extract. Moreover, it significantly prevented the increase in serum T-AOC, ALT, AST and ALP level in acute liver damage induced by CCl₄, decreased the extent of MDA formation in liver and elevated the activities of SOD and GSH in liver. This activity was found to be comparable to that of bifendate. Histopathological observation of the liver was also performed to further support the evidence from the biochemical analysis. The results indicated that strong antioxidant activities and a significant protective effect against acute hepatotoxicity induced by CCl₄ of Veronica ciliata Fisch. were concentrated in the ethyl acetate extract. The results suggested that this activity may be due to free radical-scavenging and antioxidant properties.