Purple Napiergrass (Pennisetum purpureum Schumach) Hot Water Extracts Ameliorate High-Fat Diet-Induced Obesity and Metabolic Disorders in Mice

Purple Pennisetum (Pennisetum purpureum Schumach), a hybrid between Taihucao No. 2 and the local wild species of purple Pennisetum, has dark red stems and leaves due to its anthocyanin content. This study explores the potential of purple napiergrass extracts (PNE) in alleviating obesity and metabolic disorders induced by a high-fat diet in mice, where 50% of the caloric content is derived from fat. Mice were orally administered low-dose or high-dose PNE alongside a high-fat diet. Experimental findings indicate that PNE attenuated weight gain, reduced liver, and adipose tissue weight, and lowered blood cholesterol, triglyceride, low-density lipoprotein, and blood sugar levels. Stained sections showed that PNE inhibited lipid accumulation and fat hypertrophy in the liver. Immunoblotting analysis suggested that PNE improved the inflammatory response associated with obesity, dyslipidemia, and hyperglycemia induced by a high-fat diet. Furthermore, PNE potentially functions as a PPAR-γ agonist, increasing the adiponectin (ADIPOQ) concentration and suppressing inflammatory factors, while elevating the anti-inflammatory factor interleukin-10 (IL-10) in the liver. PNE-treated mice showed enhanced activation of the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) and AMP-activated protein kinase (AMPK) pathways and increased fatty acid oxidation and liver lipolysis. In conclusion, this study elucidated the mechanisms underlying the anti-inflammatory, PI3K/Akt, and AMPK pathways in a high-fat diet-induced obesity model. These findings highlight the potential of PNE in reducing weight, inhibiting inflammation, and improving blood sugar and lipid levels, showing the potential for addressing obesity-related metabolic disorders in humans.

Effect of hot water extracts of Arthrospira maxima (spirulina) against respiratory syncytial virus

BACKGROUND

Spirulina (Arthrospira maxima) hot water extracts such as calcium spirulan (Ca-SP) have demonstrated antiviral effects against herpes simplex virus (HSV), human immunodeficiency virus-1 (HIV-1), and influenza virus infections. There is no prior evidence suggesting the anti-viral activity of the spirulina hot water extract against respiratory syncytial virus (RSV).

PURPOSE

There are currently no effective antivirals available to treat RSV infection. Therefore, the development of safe and novel anti-RSV drugs is urgent and necessary. The aim of this work was to demonstrate the anti-RSV activity of spirulina hot water extracts and determine the potential mechanism of action.

METHODS

Cytotoxicity and anti-RSV activity of spirulina hot water extracts were measured using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and neutralization assays, respectively. Potential mechanisms and components were assessed using time of addition, attachment, internalization, pull-down assays, and composition analysis.

RESULTS

The polysaccharide-enriched high-molecular weight fraction (>100 kDa, SHD1) had a high total sugar content, with rhamnose accounting for approximately 60 mol% of total monosaccharides. The main glycosyl linkages included 3-, 4-, and 2,3-rhamnopyranosyl linkages. All spirulina hot water extracts showed no toxicity toward human epithelial type 2 (HEp-2) cells but demonstrated anti-RSV activity. The SHD1 had a half maximal effective concentration (EC₅₀) of 0.0915 mg/ml and a selective index (SI) of >261.5 against RSV. SHD1 significantly reduced viral yield in a dose-dependent manner during the RSV attachment stage. SHD1 disrupted RSV internalization and inhibited RSV attachment (G) protein binding to heparan sulfate receptors on the host cell surface, thus preventing RSV attachment and entry.

CONCLUSION

SHD1 serves as an effective candidate for novel drug development against RSV infection.

A multi-targeting strategy to ameliorate high-fat-diet- and fructose-induced (western diet-induced) non-alcoholic fatty liver disease (NAFLD) with supplementation of a mixture of legume ethanol extracts

NAFLD (non-alcoholic fatty liver disease) is a multifactorial liver disease related to multiple causes or unhealthy conditions, including obesity and chronic inflammation. The accumulation of excess triglycerides, called steatosis, is known as a hallmark of an imbalance between the rates of hepatic fatty acid uptake/synthesis and oxidation/export. Furthermore, occurrence of NAFLD may lead to a cocktail of disease consequences caused by the altered metabolism of glucose, lipids, and lipoproteins, for instance, insulin resistance, type II diabetes, nonalcoholic steatohepatitis (NASH), liver fibrosis, and even hepatocarcinogenesis. Due to the complexity of the occurrence of NAFLD, a multi-targeting strategy is highly recommended to effectively address the issue and combat the causal loop. Ethanol extracts of legumes are popular supplements due to their richness and diversity in phytochemicals, especially isoflavones and anthocyanins. Although many of them have been reported to have efficacy in the treatment of different metabolic syndromes and obesity, there have not been many studies on them as a supplemental mixture. In this study, the alleviative effects of selected legume ethanol extracts (CrE) on high-fat-diet- and fructose-induced obesity, liver steatosis, and hyperglycemia are discussed. As revealed by the findings, CrE not only ameliorated obesity in terms of weight gained and enlargement of adipose tissue, but also significantly reduced the incidence of steatosis via phosphorylation of AMPK, resulting in inhibition of the downstream SREBP-1c/FAS pathway and an increase in an indicator of β-oxidation (carnitine palmitoyl transferase 1a, CPT1A). Furthermore, CrE dramatically alleviated inflammatory responses, including both plasma and hepatic TNF-α, IL-6, and MCP-1 levels. CrE also had attenuating effects on hyperglycemia and insulin resistance and significantly reduced the fasting glucose level, fasting insulin level, and plasma leptin, and it exhibited positive effects in the Oral glucose tolerance test (OGTT) and Homeostatic Model Assessment for Insulin Resistance (HOMA-IR). At the molecular level, CrE could activate the PI3K/Akt/Glut2 pathway, which indicated an increase in insulin sensitivity and glucose uptake. Taken together, these results suggest that ethanol extracts of legumes could be potential supplements for metabolic syndromes, and their efficacy and effectiveness might facilitate the multi-targeting strategy required to mitigate NAFLD.

Fermented Soy Paste Alleviates Lipid Accumulation in the Liver by Regulating the AMPK Pathway and Modulating Gut Microbiota in High-Fat-Diet-Fed Rats

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of liver disease due to lipid accumulation in the hepatocyte. Diet, especially a high-fat diet, is one risk factor that leads to NAFLD. Many natural compounds such as isoflavones have antiobesity effects. Therefore, intake of these functional compounds through daily dietary choices is a method of improving health. Miso is a kind of fermented soy paste, which is rich in isoflavones and has a different biological activity. In this study, we investigated the effects of different concentrations of fermented soy paste on NAFLD in high-fat-diet (HFD)-fed Sprague-Dawley (SD) rats. The results showed that 2% fermented soy paste decreased serum triacylglycerol (TG) and alanine aminotransferase (ALT) and reduced lipid accumulation in the liver through induced fatty acid oxidation by activating the adenosine 5'-monophosphate -activated protein kinase (AMPK) pathway and increasing PGC1α and CPT1α protein expression. Furthermore, we found that 2% fermented soy paste increased the abundance of Prevotellaceae NK3B31 and Desulfovibrio. Taken together, fermented soy paste improved HFD-induced lipid accumulation in the liver by activating fatty acid oxidation and modulating gut microbiota.

Chinese olive (Canarium album L.) fruit regulates glucose utilization by activating AMP-activated protein kinase

A growing body of evidence demonstrates obesity-induced insulin resistance is associated with the development of metabolic diseases. This study was designed to investigate ethyl acetate fraction of Chinese olive fruit extract (CO-EtOAc)-mediated attenuation of obesity and hyperglycemia in a mouse model. About 60% HFD-fed mice were treated intragastrically with CO-EtOAc for last 6 weeks, and body weight, blood biochemical parameters as well as hepatic inflammation response were investigated. Our results showed that CO-EtOAc treatment significantly reduced the formation of hepatic lipid droplets, body weight gain, blood glucose, and improved serum biochemical parameters in HFD-induced obese and insulin resistant mice. We further explored the molecular mechanism underlying the blood glucose modulating effect of CO-EtOAc using L6 myotubes model. We conclude that CO-EtOAc effectively increases the glycogen content and glucose uptake by stimulating the membrane translocation of glucose transporter 4. In addition, CO-EtOAc depolarizes the mitochondrial membrane and decreases the mitochondrial oxygen consumption, which may result in AMPK activation and the consequent mitochondrial fission. This study shows that CO-EtOAc prevents the development of obesity in mice fed with HFD and is also capable of stimulating glucose uptake. The possible mechanism might be due to the effects of CO-EtOAc on activation of AMPK and promotion of mitochondrial fission.

A (1→6)-Branched (1→4)-β-d-Glucan from Grifola frondosa Inhibits Lipopolysaccharide-Induced Cytokine Production in RAW264.7 Macrophages by Binding to TLR2 Rather than Dectin-1 or CR3 Receptors

Mushroom polysaccharides including β-glucans possess various health-promoting properties and are known to be the major bioactive constituents of Grifola frondosa (GF), which is a popular edible and medicinal mushroom. Dectin-1, a pattern-recognition receptor, is responsible for recognizing β-glucans. In this study, parental RAW264.7 macrophages and Dectin-1-expressing RAW264.7 macrophages were used to investigate the anti-inflammatory activity and receptor involvement of the water-soluble polysaccharides from GF. Results indicated that the high molecular weight fraction of GF (GF70-F1; 1260 kDa) inhibited TNF-α and IL-6 production as well as NF-κB activation in lipopolysaccharide-induced macrophages. Chemical and enzymatic linkage analyses indicated that GF70-F1 mainly contained the known (1→3),(1→6)-β-d-glucan and a polysaccharide not previously isolated from GF, a nondigestible glucan with a β-(1→4)-linked backbone and β-(1→6)-linked branches. The ability of GF70-F1 to inhibit cytokine production was not affected by the expression level of Dectin-1 in cells, and a similar inhibitory activity was observed after removing the (1→3),(1→6)-β-d-glucan from GF70-F1. Blockade of Toll-like receptor 2 (TLR2) but not Dectin-1 or complement receptor 3 (CR3) attenuated the inhibitory activity of GF70-F1. The nondigestible (1→6)-branched (1→4)-β-d-glucan in GF70-F1 may contribute to the anti-inflammatory activity via interacting with TLR2 rather than Dectin-1 or CR3 receptors.

The Anti-Obesity Effect of Polysaccharide-Rich Red Algae (Gelidium amansii) Hot-Water Extracts in High-Fat Diet-Induced Obese Hamsters

This study investigated the anti-obesity effect of a polysaccharide-rich red algae Gelidium amansii hot-water extract (GHE) in high-fat (HF) diet-induced obese hamsters. GHE contained 68.54% water-soluble indigestible carbohydrate polymers. Hamsters were fed with a HF diet for 5 weeks to induce obesity, and then randomly divided into: HF group, HF with 3% guar gum diet group, HF with 3% GHE diet group, and HF with orlistat (200 mg/kg diet) group for 9 weeks. The increased weights of body, liver, and adipose in the HF group were significantly reversed by GHE supplementation. Lower plasma leptin, tumor necrosis factor-α, and interleukin-6 levels were observed in the GHE+HF group compared to the HF group. GHE also increased the lipolysis rate and decreased the lipoprotein lipase activity in adipose tissues. GHE induced an increase in the phosphorylation of AMP-activated protein kinase (AMPK) and the protein expressions of peroxisome proliferator-activated receptor alpha (PPARα) and uncoupling protein (UCP)-2 in the livers. The decreased triglyceride and total cholesterol in the plasma and liver were also observed in obese hamsters fed a diet with GHE. These results suggest that GHE exerts a down-regulation effect on hepatic lipid metabolism through AMPK phosphorylation and up-regulation of PPARα and UCP-2 in HF-induced obese hamsters.

Application of thermal stability difference to remove flammutoxin in fungal immunomodulatory protein, FIP-fve, extract from Flammulina velutipes

Fungal immunomodulatory protein (FIP-fve) is a potential functional food ingredient. However, undesirable component flammutoxin (FTX) would occur in the extracted fraction of FIP-fve. In this paper, an application of heating processing instead of the intensive separation process was employed in fractionation of FIP-fve, meanwhile, exclusion of FTX was reached. Contents of FIP-fve and FTX were monitored by HPLC-UV-ESI-MS. Both FIP-fve and FTX had higher thermal stability in a lower concentration solution. Cold water could effectively extract FIP-fve and FTX from fresh mushroom without acetic acid and disulfide-bond breaking agent β-mercaptoethanol commonly used in biochemical studies. Heating cold water extract contained 580 μg/mL FIP-fve and 452 μg/mL FTX at 60 °C for 5 min could effectively exclude FTX and remain 75% of FIP-fve. Adding 0.1 M trehalose or 20% ethanol did not significantly alter the stability of both proteins. The method developed is an applicable procedure for preparing FIP-fve solution free of FTX.

Ultrasonically extracted β-d-glucan from artificially cultivated mushroom, characteristic properties and antioxidant activity

Ganoderma mushroom cultivated recently in Malaysia to produce chemically different nutritional fibers has attracted the attention of the local market. The extraction methods, molecular weight and degree of branching of (1-3; 1-6)-β-d-glucan polysaccharides is of prime importance to determine its antioxidant bioactivity. Therefore three extraction methods i.e. hot water extraction (HWE), soxhlet extraction (SE) and ultrasound assisted extraction (US) were employed to study the total content of (1-3; 1-6)-β-d-glucans, degree of branching, structural characteristics, monosaccharides composition, as well as the total yield of polysaccharides that could be obtained from the artificially cultivated Ganoderma. The physical characteristics by HPAEC-PAD, HPGPC and FTIR, as well as the antioxidant in vitro assays of DPPH scavenging activity and ferric reducing power (FRAP) indicated that (1-3; 1-6)-β-d-glucans of Malaysian mushroom have better antioxidant activity, higher molecular weight and optimal degree of branching when extracted by US in comparison with conventional methods.

Hyperproduction of β-Glucanase Exg1 Promotes the Bioconversion of Mogrosides in Saccharomyces cerevisiae Mutants Defective in Mannoprotein Deposition

Bacteria and fungi can secrete extracellular enzymes to convert macromolecules into smaller units. Hyperproduction of extracellular enzymes is often associated with alterations in cell wall structure in fungi. Recently, we identified that Saccharomyces cerevisiae kre6Δ mutants can efficiently convert mogroside V into mogroside III E, which has antidiabetic properties. However, the underlying efficient bioconversion mechanism is unclear. In the present study, the mogroside (MG) bioconversion properties of several cell wall structure defective mutants were analyzed. We also compared the cell walls of these mutants by transmission electron microscopy, a zymolyase sensitivity test, and a mannoprotein release assay. We found zymolyase-sensitive mutants (including kre1Δ, las21Δ, gas1Δ, and kre6Δ), with defects in mannoprotein deposition, exhibit efficient MG conversion and excessive leakage of Exg1; such defects were not observed in wild-type cells, or mutants with abnormal levels of glucans in the cell wall. Thus, yeast mutants defective in mannoprotein deposition may be employed to convert glycosylated bioactive compounds.

Effective extraction method through alkaline hydrolysis for the detection of starch maleate in foods

A high-performance liquid chromatography (HPLC) method was developed for the determination of maleic acid which was released from starch maleate (SM) through the alkaline hydrolysis reaction. The proper alkaline hydrolysis conditions and LC separation are reported in this study. The starch samples were treated with 50% methanol for 30 minutes, and then hydrolyzed by 0.5N KOH for 2 hours to release maleic acid. A C18 column and gradient mobile phase consisting of 0.1% phosphoric acid and methanol at a flow rate of 1.0 mL/minute were used for separation. The method showed a good linearity in the range of 0.01–1.0 ìg/mL, with a limit of quantification (LOQ) at 10 mg/kg in starch. The recoveries in corn starch, noodle, and fish balls were between 93.9% and 108.4%. The relative standard deviation (RSD) of precision was <4.9% (n = 3). This valid method was rapid, sensitive, precise, and suitable for routine monitoring of the illegal adulteration of SM in foods.

A 3-D elasticity theory based model for acoustic radiation from multilayered anisotropic plates

A theoretical model built upon three-dimensional elasticity theory is developed to investigate the acoustic radiation from multilayered anisotropic plates subjected to a harmonic point force excitation. Fourier transform technique and stationary phase method are combined to predict the far-field radiated sound pressure of one-side water immersed plate. Compared to equivalent single-layer plate models, the present model based on elasticity theory can differentiate radiated sound pressure between dry-side and wet-side excited cases, as well as discrepancies induced by different layer sequences for multilayered anisotropic plates. These results highlight the superiority of the present theoretical model especially for handling multilayered anisotropic structures.

Structurally characterized arabinogalactan from Anoectochilus formosanus as an immuno-modulator against CT26 colon cancer in BALB/c mice

In this study, the innate immuno-modulatory effects and anti-cancer action of arabinogalactan (AG), a derivative of a well-known orchid, Anoectochilus formosanus, were investigated. The innate immuno-modulatory effects of AG were determined in vitro using RAW 264.7 cells for microarray analysis, and in vivo using BALB/c mice administrated with AG at 5 and 15 mg/kg intra-peritoneally for 3 weeks. The anti-cancer activity of AG was evaluated by CT26 colon cancer-bearing BALB/c mice. The microarray analysis was performed to evaluate the innate immunity and demonstrated that AG significantly induced the expression of cytokines, chemokines, and co-stimulatory receptors, such as IL-1α, CXCL2, and CD69. An intraperitoneal injection of AG in mice increased the spleen weight, but not the body weight. The treatment of mitogen, LPS significantly stimulated splenocyte proliferation in AG treated groups. The AG treatment also promoted splenocyte cytotoxicity against YAC-1 cells and increased the percentage of CD3(+)CD8(+) cytotoxic T cells in innate immunity test. Our experiments revealed that AG significantly decreased both tumour size and tumour weight. Besides, AG increased the percentage of DC, CD3(+)CD8(+) T cells, CD49b(+)CD3(-) NK cells among splenocytes, and cytotoxicity activity in tumour-bearing mice. In addition, the immunohistochemistry of the tumour demonstrated that the AG treatments increased the tumour-filtrating NK and cytotoxic T-cell. These results demonstrated that AG, a polysaccharide derived from a plant source, has potent innate immuno-modulatory and anti-cancer activity. AG may therefore be used for cancer immunotherapy.

Concentration variation and molecular characteristics of soluble (1,3;1,6)-β-D-glucans in submerged cultivation products of Ganoderma lucidum mycelium

(1,3)-β-D-Glucans with (1,6)-β-D-glucosyl branches are bioactive polysaccharides in fruiting bodies and mycelia of Ganoderma lucidum, a mushroom used in traditional Chinese medicine. Submerged cultivation of mycelium is one of the more efficient means of generating polysaccharides from this fungus. Twelve mycelium samples examined in this study demonstrated the quantitative and qualitative molecular characteristics of soluble (1,3;1,6)-β-D-glucans. It was observed that the concentration of soluble (1,3;1,6)-β-D-glucan varied substantially from 1.3 to 79.9 mg/dL. (1,3;1,6)-β-D-Glucans also preserved their molecular characteristics with degrees of branching (DB) of 0.21-0.36 and molecular masses of 10(5)-10(6) g/mol for those samples with substantial quantities of β-D-glucan. Using the high aggregating tendency of these molecules, (1,3;1,6)-β-D-glucans were successfully purified via fractional precipitation with 35% (v/v) ethanol. (1,3;1,6)-β-D-Glucan was proposed as a putative bioactive marker for immunomodulation because it was the most abundant polysaccharide in G. lucidum mycelium products to stimulate macrophage RAW 264.7 cells to release TNF-α.

Establishment of reporter platforms capable of detecting NF-κB mediated immuno-modulatory activity

Cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) are transcriptional targets of nuclear factor kappa B (NF-κB) that are involved in inflammatory responses. The aim of this study is to develop a method for efficiently detecting inflammation modulatory activities. Here we established RAW264.7 macrophage cells stably expressing a luciferase reporter gene directed by iNOS or COX-2 promoter. Lipopolysaccharide (LPS) treatment stimulated the luciferase activity which paralleled with increased iNOS and COX-2 mRNA levels determined by RT-q-PCR. The LPS-stimulated luciferase activity was blocked by NF-κB inhibitor CAPE and by nobiletin, an anti-inflammatory natural product from citrus peels. We have applied the platforms to screen various mushroom species; analysis by scatter plot revealed a strong correlation to the results obtained by ELISA-based detection of TNF-α. Together we have established luciferase reporter systems sensitive to NF-κB-dependent iNOS and COX-2 activation, which provides an alternative screening method for identifying food components with immune-modulatory activities.

Biotransformation of mogrosides from Siraitia grosvenorii Swingle by Saccharomyces cerevisiae

Mogrosides are a group of triterpenoidal saponins from the fruit of Siraitia grosvenorii Swingle; they are intensely sweet and have consequently been used as a substitute for sugar by the food industry. The lack of efficient methods to produce specific mogrosides has hindered investigation of the relationship between their structure and bioactivity, e.g., down-regulation of blood glucose levels, anti-inflammation, and antiviral infection. Here, we attempt to selectively convert the major saponin mogroside V, a mogrol pentaglucoside, into mogroside III E, a triglucoside, via the β-glucosidases of the budding yeast Saccharomyces cerevisiae. We report that the β-glucopyranosyl and β-glucopyranosyl-(1→2)-β-d-glucopyranosyl attached on C-3 and -24 of mogrol, respectively, were resistant to hydrolysis by yeast β-d-glucosidases. We further screened 16 mutants bearing single defective glucanase or glucosidase genes, thereby demonstrating that Exg1 is a major enzyme of the initiation of mogroside V conversion. Deletion of the KRE6 gene unexpectedly facilitated the production of mogroside III E in yeast culture. This paper demonstrates that yeast knockout mutants are a valuable tool for saponin modification and for studying the specificity of glucosidase function.

Cembrane derivatives from the soft corals, Sinularia gaweli and Sinularia flexibilis

A new norcembranoidal diterpene, 1-epi-sinulanorcembranolide A (1), and a new cembranoidal diterpene, flexibilin D (2), were isolated from the soft corals, Sinularia gaweli and Sinularia flexibilis, respectively. The structures of new metabolites 1 and 2 were elucidated by spectroscopic methods, and compound 2 was found to significantly inhibit the accumulation of the pro-inflammatory iNOS and COX-2 proteins of the lipopolysaccharide (LPS)-stimulated RAW264.7 macrophage cells. In addition, S. flexibilis yielded a known cembrane, 5-dehydrosinulariolide (3); the structure, including its absolute stereochemistry, was further confirmed by single-crystal X-ray diffraction analysis.

Effects of mean flow on transmission loss of orthogonally rib-stiffened aeroelastic plates

This paper investigates the sound transmission loss (STL) of aeroelastic plates reinforced by two sets of orthogonal rib-stiffeners in the presence of external mean flow. Built upon the periodicity of the structure, a comprehensive theoretical model is developed by considering the convection effect of mean flow. The rib-stiffeners are modeled by employing the Bernoulli-Euler beam theory and the torsional wave equation. While the solution for the transmission loss of the structure based on plate displacement and acoustic pressures is given in the form of space-harmonic series, the corresponding coefficients are obtained from the solution of a system of linear equations derived from the plate-beam coupling vibration governing equation and Helmholtz equation. The model predictions are validated by comparing with existing theoretical and experimental results in the absence of mean flow. A parametric study is subsequently performed to quantify the effects of mean flow as well as structure geometrical parameters upon the transmission loss. It is demonstrated that the transmission loss of periodically rib-stiffened structure is increased significantly with increasing Mach number of mean flow over a wide frequency range. The STL value for the case of sound wave incident downstream is pronouncedly larger than that associated with sound wave incident upstream.

Characterization and prebiotic activity of aqueous extract and indigestible polysaccharide from Anoectochilus formosanus

Anoectochilus formosanus (Orchidaceae) is a folk medicine in Asia. This study investigated the in vivo and in vitro prebiotic effects of an aqueous extract of A. formosanus (SAEAF) and of an indigestible polysaccharide (AFP) isolated from SAEAF. Chemical analyses showed AFP was mainly composed of arabinogalactan type II (AG-II), with an average molecular weight of 29 kDa. Following 4 weeks of oral administration to rats, SAEAF exhibited prebiotic effects including a decrease in cecum pH and increases of calcium absorption and fecal bifidobacteria. Furthermore, through a bioactivity-guided separation strategy, AFP was proven to be a bifidogenic component in vitro fecal strains fermentation and in vivo administration to mice. In RT-PCR analysis of Bifidobacterium , AFP increased the expression of ABC transporter related to nutrient uptake. Thus, AFP, a polysaccharide from A. formosanus, was demonstrated to be a prebiotic that has a positive health effect on gut microbiota.

Fluid flow induced calcium response in osteoblasts: mathematical modeling

Fluid flow in the bone lacuno-canalicular network can induce dynamic fluctuation of intracellular calcium concentration ([Ca(2+)](i)) in osteoblasts, which plays an important role in bone remodeling. There has been limited progress in the mathematical modeling of this process probably due to its complexity, which is controlled by various factors such as Ca(2+) channels and extracellular messengers. In this study we developed a mathematical model to describe [Ca(2+)](i) response induced by fluid shear stress (SS) by integrating the major factors involved and analyzed the effects of different experimental setups (e.g. [Ca(2+)](i) baseline, pretreatment with ATP). In this model we considered the ATP release process and the activities of multiple ion channels and purinergic receptors. The model was further verified quantitatively by comparing the simulation results with experimental data reported in literature. The results showed that: (i) extracellular ATP concentration has more significant effect on [Ca(2+)](i) baseline (73% increase in [Ca(2+)](i) with extracellular ATP concentration varying between 0 and 10 μM), as compared to that induced by SS (25% variation in [Ca(2+)](i) with SS varying from 0 to 3.5 Pa); (ii) Pretreatment with ATP-medium results in different [Ca(2+)](i) response as compared to the control group (ATP-free medium) under SS; (iii) Relative [Ca(2+)](i) fluctuation over baseline is more reliable to show the [Ca(2+)](i) response process than the absolute [Ca(2+)](i) response peak. The developed model may improve the experimental design and facilitate our understanding of the mechanotransduction process in osteoblasts.

Interference prevention in size-exclusion chromatographic analysis of debranched starch glucans by aqueous system

Branch chain-length distribution of amylopectin plays an important role on the characteristics of starch. One of the adapted protocols for determining the chain-length distribution and mass proportion of starch molecules is that starch is debranched with isoamylase and then analyzed by using high-performance size-exclusion chromatography coupled with multiangle laser-light scattering and refractive index detection (HPSEC-MALS-RI). However, ammonium sulfate in commercial isoamylase and acetate in debranching buffer give significant interferences on the chromatograms because of their undesirable ionic interactions with column sorbent materials. This study deals with development for correcting those interferences. A weak anion-exchange resin or selective precipitation with barium acetate was employed to remove sulfate prior to HPSEC determination. The interference of acetate was overcome by means of high ionic strength eluent, 0.3 M sodium nitrate. The specific refractive index increment (dn/dc) of amylodextrin was determined to be 0.147 using the modified conditions and was applied to calculate the molecular weight distribution of debranched starch molecules.

Transmission loss of orthogonally rib-stiffened double-panel structures with cavity absorption

The transmission loss of sound through infinite orthogonally rib-stiffened double-panel structures having cavity-filling fibrous sound absorptive materials is theoretically investigated. The propagation of sound across the fibrous material is characterized using an equivalent fluid model, and the motions of the rib-stiffeners are described by including all possible vibrations, i.e., flexural displacements, bending, and torsional rotations. The effects of fluid-structure coupling are account for by enforcing velocity continuity conditions at fluid-panel interfaces. By taking full advantage of the periodic nature of the double-panel, the space-harmonic approach and virtual work principle are applied to solve the sets of resultant governing equations, which are eventually truncated as a finite system of simultaneous algebraic equations and numerically solved insofar as the solution converges. To validate the proposed model, a comparison between the present model predictions and existing numerical and experimental results for a simplified version of the double-panel structure is carried out, with overall agreement achieved. The model is subsequently employed to explore the influence of the fluid-structure coupling between fluid in the cavity and the two panels on sound transmission across the orthogonally rib-stiffened double-panel structure. Obtained results demonstrate that this fluid-structure coupling affects significantly sound transmission loss (STL) at low frequencies and cannot be ignored when the rib-stiffeners are sparsely distributed. As a highlight of this research, an integrated optimal algorithm toward lightweight, high-stiffness and superior sound insulation capability is proposed, based on which a preliminary optimal design of the double-panel structure is performed.

Analytical modeling of sound transmission across finite aeroelastic panels in convicted fluids

An analytical approach is formulated to account for the effects of mean flow on sound transmission across a simply supported rectangular aeroelastic panel. The application of the convected wave equation and the displacement continuity condition at the fluid-panel interfaces ensures the exact handling of the complex aeroelastic coupling between panel vibration and fluid disturbances. To explore the mean flow effects on sound transmission, three different cases (i.e., mean flow on incident side only, on radiating side only, and on both sides) are separately considered in terms of refraction angular relations and sound transmission loss (STL) plots. Obtained results show that the influence of the incident side mean flow upon sound penetration is significantly different from that of the transmitted side mean flow. The contour plot of refraction angle versus incident angle for the case when the mean flow is on the transmitted side is just a reverse of that when the mean flow is on the incident side. The aerodynamic damping effects on the transmission of sound are well captured by plotting the STL as a function of frequency for varying Mach numbers. However, as the Mach number is increased, the coincidence dip frequency increases when the flow is on the incident side but remains unchanged when in the flow is on the radiating side. In the most general case when the fluids on both sides of the panel are convecting, the refraction angular relations are significantly different from those when the fluid on one side of the panel is moving and that on the other side is at rest.

A multi-scale view of skin thermal pain: from nociception to pain sensation

All biological bodies live in a thermal environment, including the human body, where skin is the interface with a protecting function. When the temperature is out of the normal physiological range, skin fails to protect, and the pain sensation is evoked. Furthermore, in medicine, with advances in laser, microwave and similar technologies, various thermal therapeutic methods have been widely used to cure disease/injury involving skin tissue. However, the corresponding problem of pain relief has limited further application and development of these thermal treatments. Skin thermal pain is induced through both direct (i.e. an increase/decrease in temperature) and indirect (e.g. thermomechanical and thermochemical) ways, and is governed by complicated thermomechanical-chemical-neurophysiological responses. However, a complete understanding of the underlying mechanisms is still far from clear. In this article, starting from an engineering perspective, we aim to recast the biological behaviour of skin in engineering system parlance. Then, by coupling the concepts of engineering with established methods in neuroscience, we attempt to establish multi-scale modelling of skin thermal pain through ion channel to pain sensation. The model takes into account skin morphological plausibility, the thermomechanical response of skin tissue and the biophysical and neurological mechanisms of pain sensation.

Strain rate sensitivity of skin tissue under thermomechanical loading

There have been limited studies addressing the thermally dependent mechanical properties of skin tissue, although this can contribute to a variety of medical applications. To address this, an experimental study on the tensile behaviour of pig skin tissue under different thermal loading conditions and different mechanical stretching rates was performed. The results indicate that there is a significant variation among skin tensile behaviours under different temperatures and loading rates, which is correlated with dermal collagen denaturation. The Ogden model was used to summarize the effect of the strain rate and the temperature upon the measured constitutive response through two parameters (alpha and mu). These results can be used in future models to improve clinical thermal treatments for skin tissue.

Analytical and experimental investigation on transmission loss of clamped double panels: implication of boundary effects

The air-borne sound insulation performance of a rectangular double-panel partition clamp mounted on an infinite acoustic rigid baffle is investigated both analytically and experimentally and compared with that of a simply supported one. With the clamped (or simply supported) boundary accounted for by using the method of modal function, a double series solution for the sound transmission loss (STL) of the structure is obtained by employing the weighted residual (Galerkin) method. Experimental measurements with Al double-panel partitions having air cavity are subsequently carried out to validate the theoretical model for both types of the boundary condition, and good overall agreement is achieved. A consistency check of the two different models (based separately on clamped modal function and simply supported modal function) is performed by extending the panel dimensions to infinite where no boundaries exist. The significant discrepancies between the two different boundary conditions are demonstrated in terms of the STL versus frequency plots as well as the panel deflection mode shapes.

Vibroacoustic behavior of clamp mounted double-panel partition with enclosure air cavity

A theoretical study on the vibroacoustic performance of a rectangular double-panel partition clamp mounted in an infinite acoustic rigid baffle is presented. With the clamped boundary condition taken into account by the method of modal function, a double Fourier series solution to the dynamic response of the structure is obtained by employing the weighted residual method (i.e., the Galerkin method). The double series solution can be considered as the exact solution of the problem, as the structural and acoustic-structural coupling effects are fully accounted for and the solution converges numerically. The accuracy of the theoretical predictions is checked against existing experimental data, with good agreement achieved. The influence of several key parameters on the sound isolation capability of the double-panel configuration is then systematically studied, including panel dimensions, thickness of air cavity, elevation angle, and azimuth angle of incidence sound. The present method is suitable for double-panel systems of finite or infinite extent and is applicable for both low- and high-frequency ranges. With these merits, the proposed method compares favorably with a number of other approaches, e.g., finite element method, boundary element method, and statistical energy analysis method.

Inhibitory mechanisms of Agaricus blazei Murill on the growth of prostate cancer in vitro and in vivo

Agaricus blazei Murill (A. blazei) has been conventionally used as a health food for the prevention of cancer. However, little is known about the direct effects and action mechanisms of A. blazei on human prostate cancer. In the present study, the effects of A. blazei on the growth of human prostate cancer were examined in vitro and in vivo. A. blazei, especially the broth fraction, inhibited cell proliferation in both androgen-dependent and androgen-independent prostate cancer cell lines. The broth of A. blazei induced lactate dehydrogenase leakage in three cancer cell lines, whereas the activities of caspase 3 and the DNA fragmentation were enhanced the most in androgen-independent PC3 cells. The protein expressions of apoptosis-related molecules were elevated by the broth of A. blazei in PC3 cells. Oral supplementation with the broth of A. blazei (with the higher ratio of beta-glucan) significantly suppressed tumor growth without inducing adverse effects in severe combined immunodeficient mice with PC3 tumor xenograft. Tumor xenografts from A. blazei-fed mice showed decreased proliferating cell nuclear antigen-positive cells and reduced tumor microvessel density. Based on these results, we found that the broth of A. blazei may directly inhibit the growth of prostate cancer cell via an apoptotic pathway and suppress prostate tumor growth via antiproliferative and antiangiogenic mechanisms. We therefore suggest that A. blazei might have potential therapeutic use in the prevention and treatment of human prostate cancer.

Characteristics of taro (Colocasia esculenta) starches planted in different seasons and their relations to the molecular structure of starch

Physico-chemical properties and molecular structure of starches from three cultivars (Dog hoof, Mein, and KS01) of taro tubers planted in summer, winter, and spring were investigated. The effects of the planting season on the physico-chemical properties and the molecular structure of starch were determined, and the relations between the physico-chemical properties and the molecular structure of starch are discussed. Results indicate that taro starches from tubers planted in summer had the largest granule size, a low uniformity of gelatinization, and a high tendency to swell and collapse when heated in water. Taro starch planted in summer also showed an elasticity during gelatinization that was higher than that of starches planted in the other seasons. In addition to the planting season and the variety, rheological and pasting properties of taro starches studied are influenced not only by the amylose content but also by the chain-length distribution of amylopectin, whereas swelling power and solubility only depend on the amylose content of starch. Taro starch with relatively high amylose content, high short-to-long-chain ratio, and long average chain length of long-chain fraction of amylopectin displayed high elasticity and strong gel during heating.

Skin biothermomechanics for medical treatments

Electromagnetic heating, such as microwave, radiofrequency, and laser etc., is widely used in medical treatments. Recent advances in these technologies resulted in remarkable developments of thermal treatments for a multitude of diseases and injuries involving skin tissue. The comprehension of heat transfer and related thermomechanics in skin tissue during these treatments is thus of great importance, and can contribute to the further developments of these medical applications. Biothermomechanics of skin is highly interdisciplinary, involving bioheat transfer, burn damage, biomechanics, and physiology. The aim of this study is to develop a computational approach to examine the heat transfer process, heat-induced mechanical response, as well as the associated pain level, so that the differences among the clinically applied heating modalities can be quantified. In this paper, numerical simulation with the finite difference method (FDM) was used to analyze the temperature, burn damage, and thermal stress distributions in the skin tissue subjected to various thermal treatments. The results showed that the thermomechanical behavior of skin tissue is very complex: blood perfusion has little effect on thermal damage, but a large influence on skin temperature distribution, which, in turn, influences significantly the resulting thermal stress field; for laser heating, the peak temperature is higher for lasers with shorter wavelengths, but the peak is closer to the skin surface; the thermal stress due to laser and microwave heating is mainly limited to the top epidermis layer due to the exponential decrease of heat generation along skin depth; the thin (and commonly overlooked) stratum corneum layer dominates the thermomechanical response of skin tissue.

Quantitative determination of salidroside in rat plasma by on-line solid-phase extraction integrated with high-performance liquid chromatography/electrospray ionization tandem mass spectrometry

A method for the quantification of salidroside, a major biologically active compound in Rhodiola, in rat plasma by on-line SPE LC/MS/MS in negative electrospray mode was developed and validated. A column-switching instrument and two HPLC pumping systems were employed, and salicin was used as the internal standard. A Waters Oasis HLB extraction column and an Agilent TC-C(18) analytical column in a column-switching set-up with gradient elution were utilized. The MS/MS ion transitions monitored were m/z 299.0/119.0 and 285.1/122.9 for salidroside and salicin, respectively. The standard curves were linear within a range of 50-5000 ng/mL using weighted linear regression analysis (1/x). The intra- and inter-day coefficients of variance ranged from 1% to 9%. The recovery was above 90%. The freeze/thaw and long-term stability were validated. This method was subsequently applied to a pharmacokinetic study of salidroside in rats.

Isolation and identification of steroidal saponins in Taiwanese yam cultivar (Dioscorea pseudojaponica Yamamoto)

A new furostanol pentaoligoside and spirostanol tetraoligoside were isolated for the first time from yam tubers (Dioscorea pseudojaponica Yamamoto) from Taiwan, together with four known yam saponins, methyl protodioscin, methyl protogracillin, dioscin, and gracillin. Their structures were characterized as 26-O-beta-D-glucopyranosyl-22alpha-methoxyl-(25R)-furost-5-en-3beta,26-diol, 3-O-alpha-L-rhamnopyranosyl-(1-->2)-O-([alpha-L-rhamnopyranosyl-(1-->4)]-O-[alpha-L-rhamnopyranosyl-(1-->4)])-beta-D-glucopyranoside, and (25R)-spirost-5-en-3beta-ol 3-O-alpha-L-rhamnopyranosyl-(1-->2)-O-([alpha-L-rhamnopyranosyl-(1-->4)]-O-[alpha-L-rhamnopyranosyl-(1-->4)])-beta-D-glucopyranoside. The structural identification was performed using LC-MS and 1H and 13C NMR. The methanol extract of yam tubers was fractionated by XAD-2 column chromatography using a methanol/water gradient elution system to yield furostanol and spirostanol glycoside fractions. Preparative high-performance liquid chromatography, employing a C18 column and a mobile phase of methanol/water (69:31, v/v), was used to separate each furostanol glycoside, whereas a mobile phase of methanol/water (79:21, v/v) was used to resolve the individual spirostanol glycosides. The conversions from steroid saponins to diosgenin after acid hydrolysis were around 68 and 90% for furostanol and spirostanol glycosides, respectively.

Sound absorption of cellular metals with semiopen cells

A combined experimental and theoretical study is presented for the feasibility of using aluminum foams with semiopen cells for sound-absorption applications. The foams are processed via negative-pressure infiltration, using a preform consisting of water-soluble spherical particles. An analytical model is developed to quantify the dependence of pore connectivity on processing parameters, including infiltration pressure, particle size, wetting angle, and surface tension of molten alloy. Normal sound-absorption coefficient and static flow resistance are measured for samples having different porosity, pore size, and pore opening. A theory is developed for idealized semiopen metallic foams, with a regular hexagonal hollow prism having one circular aperture on each of its eight surfaces as the unit cell. The theory is built upon the acoustic impedance of the circular apertures (orifices) and cylindrical cavities due to viscous effects, and the principle of electroacoustic analogy. The predicted sound-absorption coefficients are compared with those measured. To help select processing parameters for producing semiopen metallic foams with desirable sound-absorbing properties, emphasis is placed on revealing the correlation between sound absorption and morphological parameters such as pore size, pore opening, and porosity.

Tyrosine kinase expression profile in bladder cancer

The expression pattern of tyrosine kinase in bladder cancer cells was evaluated by PCR amplification with degenerate primers derived from conserved catalytic domain in tyrosine kinase. The results indicated that TRK-E and Arg kinases were more abundantly expressed than several other kinases in bladder cancer. In addition, we identified a novel clone whose sequence could not be matched in GeneBank. This clone may represent a serine/threonine kinase based on sequence similarity.