Evaluation of in vivo antioxidant activities of Ganoderma lucidum polysaccharides in STZ-diabetic rats

Effects of Low-Molecular-Weight Fucoidan and High Stability Fucoxanthin on Glucose Homeostasis, Lipid Metabolism, and Liver Function in a Mouse Model of Type II Diabetes

The combined effects of low-molecular-weight fucoidan (LMF) and fucoxanthin (Fx) in terms of antihyperglycemic, antihyperlipidemic, and hepatoprotective activities were investigated in a mouse model of type II diabetes. The intake of LMF, Fx, and LMF + Fx lowered the blood sugar and fasting blood sugar levels, and increased serum adiponectin levels. The significant decrease in urinary sugar was only observed in LMF + Fx supplementation. LMF and Fx had ameliorating effects on the hepatic tissue of db/db mice by increasing hepatic glycogen and antioxidative enzymes, and LMF was more effective than Fx at improving hepatic glucose metabolism. As for glucose and lipid metabolism in the adipose tissue, the expression of insulin receptor substrate (IRS)-1, glucose transporter (GLUT), peroxisome proliferator-activated receptor gamma (PPARγ), and uncoupling protein (UCP)-1 mRNAs in the adipose tissue of diabetic mice was significantly upregulated by Fx and LMF + Fx, and levels of inflammatory adipocytokines, such as adiponectin, tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6), were significantly modulated only by LMF + Fx supplementation. The efficacy of LMF + Fx supplementation on the decrease in urinary sugar and on glucose and lipid metabolism in the white adipose tissue of db/db mice was better than that of Fx or LMF alone, indicating the occurrence of a synergistic effect of LMF and Fx.

Antioxidant and antigenotoxic potential of Ramaria largentii Marr & D. E. Stuntz, a wild edible mushroom collected from Northeast Romania

Ramaria largentii Marr & D. E. Stuntz (orange coral mushroom) is a wild edible mushroom whose chemical composition and bioactivity have not been investigated. Herein, we present a study on the phenolic constituents, antioxidant and antigenotoxic effects of a hydromethanolic extract of the fruiting bodies. Total phenolic content, estimated by Folin-Ciocalteu assay, was found to be 42.33 ± 0.18 mg GAE/g. Protocatechuic and vanillic acids were detected by HPLC-DAD-ESI-MS. The extract showed good free radical scavenging and reducing capacities (EC₅₀ = 64.3 ± 0.2 and 61.54 ± 0.46 μg/mL, respectively). In normal Vero cells, the extract (100, 200 and 300 μg/mL) showed no genotoxic potential and moreover, almost completely protected DNA against H₂O₂-induced damage (2.09-7.91% tail DNA) (24 and 48 h pre-treatment). Taken together, the results of our study show that Ramaria largentii extract is devoid of genotoxicity and has a remarkable DNA protective activity against H₂O₂-induced damage.

Resveratrol ameliorates oxidative stress and organ dysfunction in Schistosoma mansoni infected mice

Schistosoma mansoni causes a major chronic debilitating disease in more than 230 million people around the world. The pathognomonic granuloma is a major cause of the oxidative stress encountered as a consequence of infection not only in the liver, but also in other important organs as spleen, lung, brain and kidney. Resveratrol administration at a dose of 20 mg/kg once daily for two weeks to mice infected with Schistosoma mansoni resulted in improvement in serum cholesterol and triglyceride levels. Enzymatic antioxidant profile showed significant modulations in Superoxide dismutase, catalase activities and reduced glutathione levels. Specific biomarkers for homeostasis of brain and lung i.e. Tau and RAGE respectively, showed significant improvement after resveratrol administration.

Effect of High Fat Dietary Intake during Maternal Gestation on Offspring Ovarian Health in a Pig Model

Excessive fat intake is a global health concern as women of childbearing age increasingly ingest a high fat diet. We therefore determined the association of a maternal high fat diet in pregnancy with offspring ovarian health during the gestation and postnatal female offspring in pig a model. Thirty-two Yorkshire gilts with similar bodyweights mated at the third estrus were randomly assigned to two nutrition levels of either a control (CON, crude fat: 7.27%) or a high fat diet (HFD, crude fat: 11.78%). Ovary samples were collected during the fetal (Day 55 (g55) and Day 90 of gestation (g90)) and offspring (prepuberty Day 160 (d160) and age at puberty) period to detect ovary development, antioxidant status and apoptosis cells. Maternal HFD did not influence notch signaling gene expression, which regulates primordial follicle formation and transformation, and ovarian histological effect at g55 and g90. However, maternal HFD reduced the numbers of large follicles at d160 and small follicle numbers upon puberty compared to CON in offspring. The results also revealed that the antioxidant index of total antioxidative capability (T-AOC), cytoplasmic copper/zinc superoxide dismutase (CuZn-SOD), glutathione peroxidase (GPx) activities and mRNA expression were higher in the CON than the HFD at g90 and d160, whereas, malondialdehyde (MDA) concentration was decreased in the CON. Maternal HFD increased the inhibitor of the apoptosis-related gene of B-cell lymphoma-2 (bcl2) mRNA expression at g90 and d160, whereas, pro-apoptotic-related gene bcl-2 assaciated X protein (bax) was reduced. These data show that the maternal high fat diet does not delay fetal ovarian development, but it changes ovarian health by the induction of oxidative stress and accelerating cell apoptosis in offspring.

Extracellular polysaccharides from Ascomycota and Basidiomycota: production conditions, biochemical characteristics, and biological properties

Fungal polysaccharides (PSs) are the subject of research in many fields of science and industry. Many properties of PSs have already been confirmed and the list of postulated functions continues to grow. Fungal PSs are classified into different groups according to systematic affinity, structure (linear and branched), sugar composition (homo- and heteropolysaccharides), type of bonds between the monomers (β-(1 → 3), β-(1 → 6), and α-(1 → 3)) and their location in the cell (cell wall PSs, exoPSs, and endoPSs). Exopolysaccharides (EPSs) are most frequently studied fungal PSs but their definition, classification, and origin are still not clear and should be explained. Ascomycota and Basidiomycota fungi producing EPS have different ecological positions (saprotrophic and endophytic, pathogenic or symbiotic-mycorrhizae fungi); therefore, EPSs play different biological functions, for example in the protection against environmental stress factors and in interactions with other organisms. EPSs obtained from Ascomycota and Basidiomycota fungal cultures are known for their antioxidant, immunostimulating, antitumor, and antimicrobial properties. The major objective of the presented review article was to provide a detailed description of the state-of-the-art knowledge of the effectiveness of EPS production by filamentous and yeast Ascomycota and Basidiomycota fungi and techniques of derivation of EPSs, their biochemical characteristics, and biological properties allowing comprehensive analysis as well as indication of similarities and differences between these fungal groups. Understanding the role of EPSs in a variety of processes and their application in food or pharmaceutical industries requires improvement of the techniques of their derivation, purification, and characterization. The detailed analyses of data concerning the derivation and application of Ascomycota and Basidiomycota EPSs can facilitate development and trace the direction of application of these EPSs in different branches of industry, agriculture, and medicine.

Antioxidants of Edible Mushrooms

Oxidative stress caused by an imbalanced metabolism and an excess of reactive oxygen species (ROS) lead to a range of health disorders in humans. Our endogenous antioxidant defense mechanisms and our dietary intake of antioxidants potentially regulate our oxidative homeostasis. Numerous synthetic antioxidants can effectively improve defense mechanisms, but because of their adverse toxic effects under certain conditions, preference is given to natural compounds. Consequently, the requirements for natural, alternative sources of antioxidant foods identified in edible mushrooms, as well as the mechanistic action involved in their antioxidant properties, have increased rapidly. Chemical composition and antioxidant potential of mushrooms have been intensively studied. Edible mushrooms might be used directly in enhancement of antioxidant defenses through dietary supplementation to reduce the level of oxidative stress. Wild or cultivated, they have been related to significant antioxidant properties due to their bioactive compounds, such as polyphenols, polysaccharides, vitamins, carotenoids and minerals. Antioxidant and health benefits, observed in edible mushrooms, seem an additional reason for their traditional use as a popular delicacy food. This review discusses the consumption of edible mushrooms as a powerful instrument in maintaining health, longevity and life quality.

Preconditioning L6 Muscle Cells with Naringin Ameliorates Oxidative Stress and Increases Glucose Uptake

Enhanced oxidative stress contributes to pathological changes in diabetes and its complications. Thus, strategies to reduce oxidative stress may alleviate these pathogenic processes. Herein, we have investigated Naringin mediated regulation of glutathione (GSH) & intracellular free radical levels and modulation of glucose uptake under oxidative stress in L6 cell lines. The results from the study demonstrated a marked decrease in glutathione with a subsequent increase in free radical levels, which was reversed by the pretreatment of Naringin. We also observed that the increased malondialdehyde level, the marker of lipid peroxidation on induction of oxidative stress was retrieved on Naringin pretreatment. Addition of Naringin (100 μM) showed approximately 40% reduction in protein glycation in vitro. Furthermore, we observed a twofold increase in uptake of fluorescent labeled glucose namely 2-(N-(7-Nitrobenz-2-oxa-1,3-diazol-4-yl)Amino)-2-Deoxyglucose (2 - NBDG) on Naringin treatment in differentiated L6 myoblast. The increased uptake of 2-NBDG by L6 myotubes may be attributed due to the enhanced translocation of GLUT4. Our results demonstrate that Naringin activate GSH synthesis through a novel antioxidant defense mechanism against excessive Reactive Oxygen Species (ROS) production, contributing to the prevention of oxidative damage in addition to its effect on glycemic control.

Chemical features of Ganoderma polysaccharides with antioxidant, antitumor and antimicrobial activities

Ganoderma genus comprises one of the most commonly studied species worldwide, Ganoderma lucidum. However, other Ganoderma species have been also reported as important sources of bioactive compounds. Polysaccharides are important contributors to the medicinal properties reported for Ganoderma species, as demonstrated by the numerous publications, including reviews, on this matter. Yet, what are the chemical features of Ganoderma polysaccharides that have bioactivity? In the present manuscript, the chemical features of Ganoderma polysaccharides with reported antioxidant, antitumor and antimicrobial activities (the most studied worldwide) are analyzed in detail. The composition of sugars (homo- versus hetero-glucans and other polysaccharides), type of glycosidic linkages, branching patterns, and linkage to proteins are discussed. Methods for extraction, isolation and identification are evaluated and, finally, the bioactivity of polysaccharidic extracts and purified compounds are discussed. The integration of data allows deduction of structure-activity relationships and gives clues to the chemical aspects involved in Ganoderma bioactivity.

Protective effect of polysaccharides from Opuntia dillenii Haw. fruits on streptozotocin-induced diabetic rats

In this study, a novel water-soluble polysaccharide fraction with molecular weight of 6479.1kDa was isolated from the fruits of Opuntia dillenii Haw., which consisted of rhamnose, xylose, mannose and glucose in the molar ratio of 14.99:1.14:1.00:6.47. The protective effect of O. dillenii Haw. fruits polysaccharide (ODFP) against oxidative damage in streptozotocin (STZ)-induced diabetic rats was investigated. The results showed that oral administration of ODFP significantly decreased food intake, water intake, urine production, organ weights and blood glucose level, and increased body weight in STZ-induced diabetic rats. ODFP also significantly increased the activities of SOD, GPx and CAT, and decreased malondialdehyde level in serum, liver, kidney, and pancreas in STZ-induced diabetic rats. Moreover, histopathological examination showed that ODFP could markedly improve the structure integrity of pancreatic islet tissue in STZ-induced diabetic rats. These results suggest that ODFP have hypoglycemic and antioxidant properties and can protect rats from STZ-induced oxidative damage.

Effect of postnatal nutrition restriction on the oxidative status of neonates with intrauterine growth restriction in a pig model

OBJECTIVE

In offspring with intrauterine growth restriction (IUGR), where oxidative stress may play an important role in inducing metabolic syndrome, nutrition restriction has been shown to improve oxidative status. In this study, we aimed to investigate the effect of postnatal nutrition restriction on the oxidative status of IUGR neonates.

METHODS

A total of twelve pairs of piglets, of normal birth-weight (NBW) and with IUGR (7 days old), respectively, were randomly allocated to have adequate nutritional intake (ANI) and restricted nutritional intake (RNI) for a period of 21 days, respectively. This design produced 4 experimental groups: NBW-ANI, IUGR-ANI, NBW-RNI and IUGR-RNI (n = 6 per group). Serum, ileum and liver samples were analyzed for antioxidant parameters and the mRNA expression of genes with regard to oxidative status. The data were subjected to general linear model analysis and Duncan's test with a 5% significance level.

RESULTS

Irrespective of nutritional intake, the IUGR pigs had markedly lower activity of glutathione peroxidase (GPX), gene expressions of liver mitochondrial manganese superoxide dismutase (Mn-SOD) and ileum cytoplasmic copper/zinc (CuZn)-SOD and, accordingly, there was a markedly higher malondialdehyde concentration in the liver of these pigs compared to in the NBW pigs. Irrespective of body weight, pigs receiving ANI treatment had significantly lower activities of antioxidant enzymes in the serum (total antioxidative capability, CuZn-SOD and GPX) and liver (total SOD and glutathione reductase) and decreased gene expression of liver CuZn-SOD and Mn-SOD compared to the pigs receiving RNI. In addition, the IUGR pigs had a markedly lower concentration of liver reduced glutathione (GSH), ratio of GSH to oxidized glutathione, gene expression of ileum CuZn-SOD and extracellular SOD than the NBW pigs when receiving ANI, but not all of these differences were observed in those receiving RNI.

CONCLUSION

IUGR neonates may have poor antioxidant defense systems, and postnatal nutrition restriction has the potential to prevent oxidative stress.

Correlation between the production of exopolysaccharides and oxalic acid secretion by Ganoderma applanatum and Tyromyces palustris

The secretion of exopolysaccharides and oxalic acid in cultures of a white rot Ganoderma applanatum strain and a brown rot Tyromyces palustris strain were tested in terms of culture time, pH range, and temperature. The high yield of exopolysaccharides (EPS) required a moderate temperature of 28 °C for G. applanatum and 20 °C for T. palustris. G. applanatum and T. palustris accumulated more EPS when the concentration of the carbon source (maltose for G. applanatum and fructose for T. palustris) was 30 g/L. The results indicate that the production of oxalic acid by G. applanatum is correlated with the initial pH value of the culture medium and the concentration of oxalic acid increased to 1.66 ± 0.2 mM at the initial pH of 6.5 during the fungal growth. During the growth of T. palustris, the reduction of the initial pH value of the growing medium lowered the oxalic acid concentration from 7.7 ± 0.6 mM at pH 6.0 to 1.99 ± 0.2 mM at pH 3.5. T. palustris accumulated considerably more oxalic acid than G. applanatum and its presence did not affect significantly the production of exopolysaccharides. We also observed that the maximum amounts of exopolysaccharides secreted during cultivation of G. applanatum and T. palustris were 45.8 ± 1.2 and 19.1 ± 1.2 g/L, respectively.

Castanea sativa by-products: a review on added value and sustainable application

Castanea sativa Mill. is a species of the family Fagaceae abundant in south Europe and Asia. The fruits (chestnut) are an added value resource in producing countries. Chestnut economic value is increasing not only for nutritional qualities but also for the beneficial health effects related with its consumption. During chestnut processing, a large amount of waste material is generated namely inner shell, outer shell and leaves. Studies on chestnut by-products revealed a good profile of bioactive compounds with antioxidant, anticarcinogenic and cardioprotective properties. These agro-industrial wastes, after valorisation, can be used by other industries, such as pharmaceutical, food or cosmetics, generating more profits, reducing pollution costs and improving social, economic and environmental sustainability. The purpose of this review is to provide knowledge about the type of chestnut by-products produced, the studies concerning its chemical composition and biological activity, and also to discuss other possible applications of these materials.

Exopolysaccharide from Ganoderma applanatum as a promising bioactive compound with cytostatic and antibacterial properties

A new exopolysaccharide preparation isolated from stationary cultures of the white rot fungus Ganoderma applanatum (GpEPS) was tested in terms of its bioactive properties including its cytotoxic and immunostimulatory effect. The results indicate that the tested GpEPS (at concentrations above 22.85 µg/mL and 228.5 µg/mL) may exhibit selective activity against tumor cells (cell lines SiHa) and stimulate production of TNF-α THP-1-derived macrophages at the level of 752.17 pg/mL. The GpEPS showed antibacterial properties against Staphyloccoccus aureus and a toxic effect against Vibrio fischeri cells (82.8% cell damage). High cholesterol-binding capacity and triglycerides-binding capacity (57.9% and 41.6% after 24 h of incubation with the tested substances, resp.) were also detected for the investigated samples of GpEPS.

Improved production, purification and bioactivity of a polysaccharide from submerged cultured Ganoderma lucidum

Polysaccharides from Ganoderma lucidum showed multiple biological activities, such as immuno-modulating, antitumor, antioxidant, and hepatoprotective activity, etc. Adlay oil was added into the media to enhance polysaccharide production by submerged culture of G. lucidum in this work. The results revealed the optimal concentration of adlay oil was 1.5 % for polysaccharide production of G. lucidum. Analysis of the polysaccharide components confirmed that no novel components were biosynthesized by the addition of adlay oil. The main fraction of extracellular polysaccharide, GLEP-2, was isolated from the submerged culture broth of G. lucidum by ethanol precipitation, filtration, DEAE cellulose-52 and Sepharose CL-6B chromatography. GLEP-2, which was composed of glucose, galactose, mannose, arabinose, and rhamnose in a ratio of 332:55:32:13:3 respectively, had an average molecular weight of ~2.08 × 10(4) Da. The bioactivity tests demonstrated that GLEP-2 enhanced the T lymphocyte proliferation significantly at a concentration of 200 μg/mL and B lymphocyte proliferation at lower concentrations of 50 μg/mL. The results suggest polysaccharides from the submerged culture of G. lucidum are potential candidates for further development and possible commercial applications, especially in the pharmaceutical and functional foods industries.

L-glutamine supplementation prevents the development of experimental diabetic cardiomyopathy in streptozotocin-nicotinamide induced diabetic rats

The objective of the present investigation was to evaluate the effect of L-glutamine on cardiac myopathy in streptozotocin-nicotinamide induced diabetic rats. Diabetes was induced in overnight fasted Sprague Dawely rats by using intraperitonial injection of streptozotocin (55 mg/kg). Nicotinamide (100 mg/kg, i.p.) was administered 20 min before administration of streptozotocin. Experimental rats were divided into Group I: non-diabetic control (distilled water; 10 ml/kg, p.o.), II: diabetic control (distilled water, 10 ml/kg, p.o.), III: L-glutamine (500 mg/kg, p.o.) and IV: L-glutamine (1000 mg/kg, p.o.). All groups were diabetic except group I. The plasma glucose level, body weight, electrocardiographic abnormalities, hemodynamic changes and left ventricular contractile function, biological markers of cardiotoxicity, antioxidant markers were determined after 4 months after STZ with nicotinamide injection. Histopathological changes of heart tissue were carried out by using H and E stain. L-glutamine treatment improved the electrocardiographic, hemodynamic changes; LV contractile function; biological markers; oxidative stress parameters and histological changes in STZ induced diabetic rats. Results from the present investigation demonstrated that L-glutamine has seemed a cardioprotective activity.

Beneficial Antioxidative and Antiperoxidative Effect of Cinnamaldehyde Protect Streptozotocin-Induced Pancreatic β-Cells Damage in Wistar Rats

The present study was aimed to evaluate the antioxidant defense system of cinnamaldehyde in normal, diabetic rats and its possible protection of pancreatic β-cells against its gradual loss under diabetic conditions. In vitro free radical scavenging effect of cinnamaldehyde was determined using DPPH (1,1-diphenyl-2-dipicrylhydrazyl), superoxide radical, and nitric oxide radical. Streptozotocin (STZ) diabetic rats were orally administered with cinnamaldehyde at concentrations of 5, 10 and 20 mg/kg body weight for 45 days. At the end of the experiment, the levels of plasma lipid peroxides and antioxidants such as vitamin C, vitamin E, ceruloplasmin, catalase, superoxide dismutase, reduced glutathione and glutathione peroxidase were determined. A significant increase in the levels of plasma glucose, vitamin E, ceruloplasmin, and lipid peroxides and significant decrease in the levels of plasma insulin and reduced glutathione were observed in the diabetic rats. Also the activities of pancreatic antioxidant enzymes were altered in the STZ-induced diabetic rats. The altered enzyme activities were reverted to near-normal levels after treatment with cinnamaldehyde and glibenclamide. Histopathological studies also revealed a protective effect of cinnamaldehyde on pancreatic β-cells. Cinnamaldehyde enhances the antioxidant defense against reactive oxygen species produced under hyperglycemic conditions and thus protects pancreatic β-cells against their loss and exhibits antidiabetic properties.

A novel proteoglycan from Ganoderma lucidum fruiting bodies protects kidney function and ameliorates diabetic nephropathy via its antioxidant activity in C57BL/6 db/db mice

Diabetic nephropathy (DN) is the major cause of morbidity among diabetic patients. Thus, antidiabetic drugs with protection potential in the kidneys would have a higher therapeutic value. The effects of a novel proteoglycan, named FYGL, isolated from G. lucidum fruiting bodies, on the kidney function were investigated systematically in present work. FYGL (250 mg/kg) not only dosedependently reduced the blood glucose concentration (23.5%, p<0.05), kidney/body weight ratio (23.6%, p<0.01), serum creatinine (33.1%, p<0.01), urea nitrogen (24.1%, p<0.01),urea acid contents (35.9%, p<0.01) and albuminuria (30.7%, p<0.01)of DN mice compared to the untreated DN mice but also increased the renal superoxide dismutase (75.3%, p<0.01), glutathione peroxidase (35.0%, p<0.01) and catalase activities (58.5%, p<0.01) compared to the untreated DN mice. The decreasing of renal malondialdehyde content (34.3%, p<0.01) and 8-hydroxy-2'-deoxyguanosine expression (2.5-fold, p<0.01) were also observed in FYGL-treated DN mice compared to the untreated DN mice, along with an amelioration of renal morphologic abnormalities. We conclude that FYGL confers protection against the renal functional and morphologic injuries by increasing activities of antioxidants and inhibiting accumulation of oxidation, suggesting a potential nutritional supplement for the prevention and therapy of DN.

Antioxidant, anti-adipocyte differentiation, antitumor activity and anthelmintic activities against Anisakis simplex and Hymenolepis nana of yakuchinone A from Alpinia oxyphylla

Background

Alpinia oxyphylla is a common remedy in traditional Chinese medicine. Yakuchinone A is a major constituent of A. oxyphylla and exhibits anti-inflammatory, antitumor, antibacterial, and gastric protective activities.

Methods

Antioxidant and antitumor characteristics of yakuchinone A in skin cancer cells as well as novel mechanisms for the inhibition of adipocyte differentiation, cestocidal activities against Hymenolepis nana adults, and nematocidal activities against Anisakis simplex larvae are investigated.

Results

Yakuchinone A presents the ability of the removal of DPPH·and ABTS⁺ free radicals and inhibition of lipid peroxidation. Yakuchinone A suppresses intracellular lipid accumulation during adipocyte differentiation in 3 T3-L1 cells and the expressions of leptin and peroxisome proliferator-activated receptor γ (PPARγ). Yakuchinone A induces apoptosis and inhibits cell proliferation in skin cancer cells. The inhibition of cell growth by yakuchinone A is more significant for non-melanoma skin cancer (NMSC) cells than for melanoma (A375 and B16) and noncancerous (HaCaT and BNLCL2) cells. Treatment BCC cells with yakuchinone A shows down-regulation of Bcl-2, up-regulation of Bax, and an increase in cleavage poly (ADP-ribose) polymerase (PARP). This suggests that yakuchinone A induces BCC cells apoptosis through the Bcl-2-mediated signaling pathway. The anthelmintic activities of yakuchinone A for A. simplex are better than for H. nana.

Conclusions

In this work, yakuchinone A exhibits antioxidative properties, anti-adipocyte differentiation, antitumor activity, and anthelmintic activities against A. simplex and H. nana.

Glucan-rich polysaccharides from Pleurotus sajor-caju (Fr.) Singer prevents glucose intolerance, insulin resistance and inflammation in C57BL/6J mice fed a high-fat diet

Background

Pleurotus sajor-caju (P. sajor-caju) has been extremely useful in the prevention of diabetes mellitus due to its low fat and high soluble fiber content for thousands of years. Insulin resistance is a key component in the development of diabetes mellitus which is caused by inflammation. In this study, we aimed to investigate the in vivo efficacy of glucan-rich polysaccharide of P. sajor-caju (GE) against diabetes mellitus and inflammation in C57BL/6J mice fed a high-fat diet.

Methods

Diabetes was induced in C57BL/6J mice by feeding a high-fat diet. The mice were randomly assigned to 7 groups (n=6 per group). The control groups in this study were ND (for normal diet) and HFD (for high-fat diet). The treated groups were ND240 (for normal diet) (240 mg/kg b.w) and HFD60, HFD120 and HFD240 (for high-fat), where the mice were administrated with three dosages of GE (60, 120, 240 mg GE/kg b.w respectively). Metformin (2 mg/kg b.w) served as positive control. The glucose tolerance test, glucose and insulin levels were measured at the end of 16 weeks. Expressions of genes for inflammatory markers, GLUT-4 and adiponectin in the adipose tissue of the mice were assessed. One-way ANOVA and Duncan’s multiple range tests (DMRT) were used to determine the significant differences between groups.

Results

GE treated groups improved the glucose tolerance, attenuated hyperglycemia and hyperinsulinemia in the mice by up-regulating the adiponectin and GLUT-4 gene expressions. The mice in GE treated groups did not develop insulin resistance. GE also down-regulated the expression of inflammatory markers (IL-6, TNF-α, SAA2, CRP and MCP-1) via attenuation of nuclear transcription factors (NF-κB).

Conclusion

Glucan-rich polysaccharide of P. sajor-caju can serve as a potential agent for prevention of glucose intolerance, insulin resistance and inflammation.

Isolation, structure characterization, and immunomodulating activity of a hyperbranched polysaccharide from the fruiting bodies of Ganoderma sinense

A polysaccharide (GSP-6B) with a molecular mass of 1.86 × 10⁶ Da was isolated from the fruiting bodies of Ganoderma sinense . Chemical composition analysis, methylation analysis, infrared spectroscopy, and nuclear magnetic resonance spectroscopy were conducted to elucidate its structure. GSP-6B contains a backbone of (1→6)-linked-β-D-glucopyranosyl residues, bearing branches at the O-3 position of every two sugar residues along the backbone. The side chains contain (1→4)-linked-β-D-glucopyranosyl residues, (1→3)-linked-β-D-glucopyranosyl residues, and nonreducing end β-D-glucopyranosyl residues. An in vitro immunomodulating activity assay revealed that GSP-6B could significantly induce the release of IL-1β and TNF-α in human peripheral blood mononuclear cell (PBMC) and showed no toxicity to either PBMC or a human macrophage cell line THP-1. GSP-6B could also activate dendritic cells (DC) by stimulating the secretion of IL-12 and IL-10 from DC.

Anti-diabetic activities of Acanthopanax senticosus polysaccharide (ASP) in combination with metformin

Combination therapy had become very popular currently for the diabetes mellitus and its complications, because of long term unreasonable drug use and adverse reaction to human body. In this study, a polysaccharide (ASP) from the roots of Acanthopanax senticosus was evaluated as an adjuvant with metformin for antidiabetic therapy in alloxan-induced diabetic rats. The result identified ASP plus metformin had a more beneficial promotion for relieving the symptoms of diabetes and reversing liver and kidney damage to normal level than only metfomin administration to diabetic rats. The blood glucose, blood lipid (TC and TG), thiobarbituric acid reactive substances (TBARS), AST, ALT, ALP, total bilirubin, creatinine and urea levels in diabetic rats were decreased by combination of ASP and metformin. Furthermore, the body weight, liver glycogen formation, antioxidant substance (GSH) and antioxidant enzyme (SOD and GPX) levels increased evidently in diabetic mice treated with both ASP and metformin. In particular, sometimes ASP plus metformin could significantly reverse the pathophysiologic parameters of diabetic rats to normal level than only metformin administration. Therefore ASP could be developed to a new adjuvant combined with metformin for diabetes mellitus therapy in the future.

The protective effect of a mix of Lactarius deterrimus and Castanea sativa extracts on streptozotocin-induced oxidative stress and pancreatic β-cell death

Pancreatic β-cell death or dysfunction mediated by oxidative stress underlies the development and progression of diabetes mellitus. In the present study, we tested extracts from the edible mushroom Lactarius deterrimus and the chestnut Castanea sativa, as well as their mixture (MIX Ld/Cs), for potential beneficial effects on streptozotocin (STZ)-induced pancreatic β-cell death. Analysis of chelating effects, reducing power and radical-scavenging assays revealed strong antioxidant effects of the C. sativa extract and MIX Ld/Cs, while the L. deterrimus extract displayed a weak to moderate effect. The antioxidative effect of the chestnut extract corresponds with the high content of phenolics and flavonoids identified by HPLC analysis. In contrast, the mushroom extract contains relatively small amounts of phenols and flavonoids. However, both extracts, and especially their combination MIX Ld/Cs, increased cell viability after the STZ treatment as a result of a significant reduction of DNA damage and improved redox status. The chestnut extract and MIX Ld/Cs significantly lowered the STZ-induced increases in superoxide dismutase and catalase activities, while the mushroom extract had no impact on the activities of these antioxidant enzymes. However, the L. deterrimus extract exhibited good NO-scavenging activity. Different mechanisms that underlie antioxidant effects of the mushroom and chestnut extracts were discussed. When combined as in the MIX Ld/Cs, the extracts exhibited diverse but synergistic actions that ultimately exerted beneficial and protective effects against STZ-induced pancreatic β-cell death.

Therapeutic Effects of Allium sativum and Allium cepa in Schistosoma mansoni experimental infection

The effects of both garlic (Allium sativum) and onion (Allium cepa) on some biochemical parameters in Schistosoma mansoni infected mice individually and mixed either with or without the currently used drug, praziquantel (PZQ) were investigated. These involved some immunological parameters, namely IgM, IgG, interleukins 2 and 6 (IL-2 and 6) and tumor necrosis factor (TNF-α), some antioxidant enzymes [catalase, superoxide dismutase (SOD) and glutathione peroxidase (GPX)]. In addition, parasitological and histopathological investigations were performed. No changes were observed in the normal control mice treated with dry extract of onion or garlic, individually or mixed, with or without PZQ, compared to the normal healthy control group. Infection with S. mansoni showed an increase in IgG, IgM, IL-2, IL-6, TNF-α and catalase enzyme, accompanied with a decrease in GPX and SOD antioxidant enzyme activities. Remarkable amelioration was noticed in the levels of all the measured parameters in S. mansoni infected mice after administration of the studied extracts. Moreover a significant reduction in worm burden, hepatic and intestinal eggs and oogram count was noticed which was reflected in normalization of liver architecture.

Inhibitory effects of dioscorea polysaccharide on TNF-α-induced insulin resistance in mouse FL83B cells

Dioscorea is a traditional medicinal food in Asia. This study investigated the anti-insulin resistance of dioscorea polysaccharide (DPS) in inflammatory factor (tumor necrosis factor-α; TNF-α) induced mouse normal liver FL83B cells. Insulin resistance was induced by treating cells with TNF-α (20 ng/mL) for 5 h; subsequently, the medium was replaced with insulin and DPS for 60 min of incubation (model 1; alleviating group). In addition, cells were cotreated with TNF-α and DPS for 5 h in model 2 (preventing group). DPS effectively increased glucose uptake and glucose transporter 2 (GLUT2) expression of insulin-resistant cells. Furthermore, DPS stimulated insulin receptor substrate (IRS) tyrosyl phosphorylation and increased p-Akt level to alleviate insulin resistance in models 1 and 2. Finally, the possible mechanism of DPS promoting insulin sensitivity in TNF-α-induced FL83B cells was investigated in this study. DPS may attenuate c-Jun N-terminal kinases (JNK) and insulin resistance caused by TNF-α induction; therefore, DPS also elevated the levels of p-IRS(Tyr) and p-Akt(Ser) to improve insulin sensitivity in the TNF-α-induced FL83B cells.

Effects of cultural medium and conditions on the proliferation and hypoglycemic activity of Saccharomyces pastorianus no. 54

A yeast strain of Saccharomyces pastorianus no. 54 with hypoglycemic activity was isolated from soils of a winery. The aims of this study were first to investigate the effects of the cultivation conditions on proliferation and hypoglycemic activity of this yeast using the assay model of the differentiated 3T3-L1 adipocytes, and then, to confirm in vivo the hypoglycemic activity of cultured yeast by oral administration in streptozotocin (STZ)-induced diabetic mice. Among 7 diluted fruit juice samples the diluted strawberry juice (1.74 g/L reducing sugar content) was chosen as the basal medium. After investigation of the effects of addition of various substances, including 1% of 5 different sugars and glycerol, 0.1% of 6 nitrogen-containing substances, and 1 ppm of 7 growth factors, the diluted strawberry juice added with 1% glucose, 0.1% yeast extract and 1 ppm aspartic acid was optimized at 20 °C with initial pH value of 6.0 for cultivating S. pastorianus no. 54 in flask. The scale-up system of a 5-L fermentor was further established by using the same medium with initial pH 6.0 and being incubated at 20 °C with an aeration rate of 1.2 vvm for 96 h. The hypoglycemic activity of yeast cells cultivated in fermentor was 3.11 times of that in flask. Oral administration of the cultured yeast at a dosage of 130 mg/kg body weight/day for 6 days could significantly reduce the plasma glucose content in STZ-induced diabetic mice and keep their body weights in the normal range.