Advances in antitumor polysaccharides from phellinus sensu lato: Production, isolation, structure, antitumor activity, and mechanisms.

Edible and medicinal fungi (mushrooms) are widely applied to functional foods and nutraceutical products because of their proven nutritive and medicinal properties. Phellinus sensu lato is a well-known medicinal mushroom that has long been used in preventing ailments, including gastroenteric dysfunction, diarrhea, hemorrhage, and cancers, in oriental countries, particularly in China, Japan, and Korea. Polysaccharides represent a major class of bioactive molecules in Phellinus s. l., which have notable antitumor, immunomodulatory, and medicinal properties. Polysaccharides that were isolated from fruiting bodies, cultured mycelia, and filtrates of Phellinus s. l. have not only activated different immune responses of the host organism but have also directly suppressed tumor growth and metastasis. Studies suggest that polysaccharides from Phellinus s. l. are promising alternative anticancer agents or synergizers for existing antitumor drugs. This review summarizes the recent development of polysaccharides from Phellinus s. l., including polysaccharide production, extraction and isolation methods, chemical structure, antitumor activities, and mechanisms of action.

The Antioxidant Inhibition of Clove Effective Fraction on Lipid, Protein and Spectra Variation of LDL.

Oxidation of low density lipoprotein (LDL) has been considered as the critical factor which led to atherosclerosis (AS). Lipid and protein in LDL were oxidized to cause change of spectra during oxidation. Clove has been demonstrated to possess the strongest antioxidant capacity among 87 both medical and edible plants proclaimed by China. However, whether LDL oxidation is inhibited by clove? If so, whether it inhibits the oxidation of lipid and protein in LDL, and how does spectral characteristic of LDL change during oxidation when clove was added into LDL. Currently, these questions are still unclear. Therefore, the inhibition efficiency of the effective fraction from clove (EFC) on oxidation of LDL was studied by UV-Visible spectra and fluorescence spectra. The results indicated that EFC might effectively delay propagation of conjugated diene (CD) during LDL oxidation and postpone reaching maximum of its content. Likewise, it might inhibit cholesterol degradation, tryptophan (Trp) fluorescence quenching, lysine (Lys) residues from being modified, and lipofuscins from being generated in peroxidatic reaction among lipid and protein. Besides, EFC also might affect variation of UV-Visible spectra of LDL during oxidation. This study provides reference for future research and development of clove functional food inhibiting AS.

Sulfation and enhanced antioxidant capacity of an exopolysaccharide produced by the medicinal fungus Cordyceps sinensis.

EPS-1 was an exopolysaccharide produced by the medicinal fungus Cordyceps sinensis (Cs-HK1). In the present study, EPS-1 was sulfated with chlorosulfonic acid (CSA)-pyridine (Pyr) at different volume ratios, yielding four sulfated derivatives, SEPS-1A, B, C and D, with different degrees of substitution (DS: 0.25-1.38) and molecular weights (17.1-4.1 kDa). The sulfation of EPS-1 occurred most frequently at the C-6 hydroxyl groups due to their higher reactivity. In aqueous solution, the native EPS-1 formed random coils or aggregated networks, but the sulfated derivatives formed single helices. The antioxidant activities of the sulfated EPS-1 derivatives for scavenging hydroxyl radicals (•OH) and 2,2-azinobis-3-ehtylbenzothiazolin-6-sulfonic acid radicals (ABTS•+) were significantly increased with increasing DS and decreasing molecular weight (MW). Sulfation has thus been shown to be an effective and favorable strategy for improving the physico-chemical properties and bioactivities of fungal polysaccharides.

[Study on Ca2+ transmembrane behaviors of magnetic-treated S. aureus with Fura-2/AM fluorescence probe and LCSM].

The purpose of the present paper is to study Ca2+ transmembrane behaviors of the S. aureus treated with high intensity pulsed magnetic field. For this purpose, the method of Fura-2/AM fluorescence probe was investigated to determine the change in intracellular Ca2+ concentration in S. aureus, fluorescence intensities of S. aureus cells treated by pulsed magnetic field under different pulse number were determined, and the change in intracellular Ca2+ concentration was observed by laser confocal scanning microscope (LCSM). Research results showed that Fura-2/AM can load in S. aureus successfuuly, and can be used to determine the change in intracellular free Ca2+ concentration. After being treated with high intensity pulsed magnetic field, intra cellular free Ca2+ concentration of S. aureus went up significantly, and the regulation of Ca2+ increase was close consistent with the decrease in living bacterium number, and relatedness reached to -0.989 15; the number and fluorescence intensity of intracellular lightspot increased significantly, meaning that large amount of exocellular calcium ions across cell membrane enter into inside of cells. So, it was judged that the change in microbial membrane permeability and increase in intracellular free Ca2+ concentration are important reasones why high intensity pulsed magnetic field has sterilization effect.

[Study on the structure of defatted wheat germ protein isolate under ultrasonic treatment].

The structure changes of defatted wheat germ protein Isolate (DWGP) treated by ultrasonic was determined by FTIR and fluorescence spectra, and the effect of its structure changes on the high-efficient enzymatic hydrolysis was studied. Research showed that the efficiency of hydrolysate could be improved by ultrasonic treatment. Compared with control group, inhibitory activity of the hydrolysate was increased by 23.96% after the treatment of 600 W for 10 min. The fluorescence intensity of DWGP after ultrasonic treatment was found discovered to be changed. An appropriate ultrasonic treatment can unfold the protein molecule and make the chromogenic groups uncovered, which contribute to the acquirement of the higher-activity inhibitory peptide. The effects of various ultrasonic power and time on the secondary structure of DWGP were quantitatively determined via analysis of the amide I changes of infrared spectra using curve fitting method. Content of beta-sheet was decreased and beta-turn was increased after ultrasonic treatment, which could be the main factor to make the prepared inhibitory peptides high efficient. The results provide a theoretical basis for the mechanism research of enzymatic hydrolysis of ultrasonic treated protein.

pH-Responsive Smart Wettability Surface with Dual Bactericidal and Releasing Properties.

Biomaterial-associated infections caused by pathogenic bacteria have important implications on human health. This study presents the design and preparation of a smart surface with pH-responsive wettability. The smart surface exhibited synergistic antibacterial function, with high liquid repellency against bacterial adhesion and highly effective bactericidal activity. The wettability of the surface can switch reversibly between superhydrophobicity and hydrophobicity in response to pH; this controls bacterial adhesion and release. Besides, the deposited silver nanoparticles of the surface were also responsible for bacterial inhibition. Benefiting from the excellent liquid repellency, the surface could highly resist bacterial adhesion after immersing in a bacterial suspension for 10 s (85%) and 1 h (71%). Adhered bacteria can be easily eliminated using deposited silver nanoparticles during the subsequent treatment of alkaline bacterial suspension, and the ratio of deactivated bacteria was above 75%. After the pH returned to neutral, the deactivated bacteria can be easily released from the surface. This antibacterial surface showed an improved bacterial removal efficiency of about 99%. The results shed light on future antibacterial applications of the smart surface combining both bactericidal and adhesion-resistant functionalities.

[Study on the effect of ultrasound on the secondary structure of BSA by FTIR].

Structure changes of bovine serum albumin (BSA) under ultrasound treatment were studied using Fourier transform infrared spectroscopy (FTIR) and fluorescence spectroscopy. The largest emission peak of BSA solution's fluorescence spectra shifted in blue orientation, indicating that the environment of the Trp residues in BSA had altered with ultrasound treatment. The fluorescence intensity of the solution has also decreased with ultrasound, which showed fluorescence quenching effect and the conformation changes of the BSA. The relative contents of a-helix, beta-fold, beta-turn and random coil under different ultrasound treatment power and time were quantitatively determined via analysis of the amide I changes of infrared spectra of BSA using curve fitting method, the secondary structure of BSA had variation trend from alpha-helix to beta-sheet, however, the relative contents random coil had not significant change.

Antioxidant and immunity activity of water extract and crude polysaccharide from Ficus carica L. fruit.

The antioxidative activities of water extract (WE) and crude hot-water soluble polysaccharide (PS) from Ficus carica L. fruit were investigated using various assays in vitro, including scavenging abilities on DPPH, superoxide and hydroxyl radicals and reducing power. The immunity activities of PS were evaluated using the carbon clearance test and serum hemolysin analysis in mice. In addition, total phenolics and flavonoids contents were also determined. Both WE and PS have notable scavenging activities on DPPH with the EC(50) values of 0.72 and 0.61 mg/ml, respectively. The PS showed higher scavenging activity than WE on superoxide radical (EC(50), 0.95 mg/ml) and hydroxyl anion radical (scavenging rate 43.4% at concentration of 4 mg/ml). The PS (500 mg/kg) also has a significant increase in the clearance rate of carbon particles and serum hemolysin level of normal mice. The results indicate that both WE and PS might be applicable in healthy medicine and food industry.

[Separation and regeneration of protoplast from Phellinus igniarius].

OBJECTIVE: To study the conditions on separation and regeneration of protoplast from Phellinus igniarius. METHOD: The effects of enzymolysis conditions of P. igniarius mycelia on yield of protoplast and culturing conditons on regeneration ratio of protoplast were investigated. RESULT: When the 8 days-old mycelia was hydrolysed by 1.5% of lywallzyme adding to driselase of 0. 5% and at 30 degrees C for 3 h and enzymolysis was stablized by sucrose as a stablisher of osmotic pressure, higher yield of P. igniarius protoplast was obtained. If 10 days-old mycelia was used as raw material of enzymolysis and manntol was selected as stablisher of osmotic pressure of enzymolysis, higher regeneration ratio of P. igniarius protoplast also would be obtained in following regeneration step at same time keeping higher yield. For the regeneration processing, it was beneficial for the regeneration of P. igniarius protoplast that PDA plusing mulberry ramulus was used as the culture medium of regeneration and manntol was selected as the osmotic pressure establisher of regeneration culture medium. CONCLUSION: The method and conditions to keep both higher yield and regeneration ratio of P. igniarius protoplast were obtained.

Stability and activity of immobilized trypsin on carboxymethyl chitosan-functionalized magnetic nanoparticles cross-linked with carbodiimide and glutaraldehyde.

Enzyme cross-linkers, such as 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and glutaraldehyde (GA), have been used to improve the stability of immobilized enzymes. We have developed a relatively stable and high-activity immobilized trypsin through EDC and GA cross-linking. Carboxymethyl chitosan (CM-CTS)-functionalized magnetic nanoparticles (Fe3O4@CM-CTS) were prepared, and characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis, X-ray diffraction, and transmission electron microscopy. The CM-CTS loading of Fe3O4 @CM-CTS was 8.701%, and the CM-CTS coating did not cause any significant changes in the crystal structure of Fe3O4. The Fe3O4@CM-CTS nanoparticles exhibited superparamagnetic properties. Trypsin was successfully immobilized on Fe3O4@CM-CTS via EDC and GA cross-linking (Fe3O4@CM-CTS-EDC-TRY and Fe3O4@CM-CTS-GA-TRY, respectively). Trypsin immobilization was verified by FTIR and enzyme assays. Changes in the secondary structures of the immobilized trypsin were present in both Fe3O4@CM-CTS-EDC-TRY and Fe3O4@CM-CTS-GA-TRY. However, kinetic studies demonstrated that the immobilized trypsin retained efficient biocatalytic activity. Fe3O4@CM-CTS-EDC-TRY and Fe3O4@CM-CTS-GA-TRY both showed maximum catalytic activity at pH 8.4 and 45°C, and retained 71% and 88.5%, respectively, of their initial activities after 6 usage cycles, and 80% and 88% of their initial activities after being stored for 14 d at 4°C. The Fe3O4@CM-CTS-GA-TRY showed higher activity and conformational stability than Fe3O4@CM-CTS-EDC-TRY, which indicates that GA is effective for the immobilization of trypsin on Fe3O4@CM-CTS.

Effects of Laser Shock Processing on Morphologies and Mechanical Properties of ANSI 304 Stainless Steel Weldments Subjected to Cavitation Erosion.

Effects of laser shock processing (LSP) on the cavitation erosion resistance of laser weldments were investigated by optical microscope (OM), scanning electron microscope (SEM) observations, roughness tester, micro hardness tester, and X-ray diffraction (XRD) technology. The morphological microstructures were characterized. Cumulative mass loss, incubation period, erosion rate, and damaged surface areas were monitored during cavitation erosion. Surface roughness, micro-hardness, and residual stress were measured in different zones. Results showed that LSP could improve the damage of morphological microstructures and mechanical properties after cavitation erosion. The compressive residual stresses were generated during the process of LSP, which was an effective guarantee for the improvement of the above mentioned properties.

Ultrasonic effects on the degradation kinetics, preliminary characterization and antioxidant activities of polysaccharides from Phellinus linteus mycelia.

In this study, a high-molecular-weight polysaccharide PL-N isolated from the alkaline extract of Phellinus linteus mycelia was degraded by ultrasound. Results showed that ultrasound treatment at different ultrasonic intensities decreased the intrinsic viscosity and molecular weight of PL-N, as well as narrowed the molecular weight distribution. A larger reduction in intrinsic viscosity and molecular weight was caused by a higher ultrasonic intensity. The degradation kinetics model was fitted to (1/Mt-1/M0)=k·t, and the reaction rate constant (k) increased with increasing ultrasonic intensity. Ultrasound degradation did not change the primary structure of PL-N, and scanning electron microscopy analysis indicated that the morphology of the original PL-N was different from that of degraded PL-N fractions. Antioxidant activity assays in vitro indicated that the degraded PL-N fraction with low molecular weight had stronger hydroxyl radical scavenging capacity and higher TEAC and FRAP values.

Structure and antioxidative property of a polysaccharide from an ammonium oxalate extract of Phellinus linteus.

In this paper, the novel polysaccharide PL-A11 was purified from an ammonium oxalate extract of Phellinus linteus mycelia. Its physicochemical properties, structural characteristics, and antioxidant activities were investigated. Results showed that PL-A11 had a weight-average molecular weight (Mw) of 13.8kDa and was mainly composed of arabinose, xylose, mannose, and glucose in a molar ratio of 1.1:1.3:1.0:6.6. The backbone of PL-A11 was composed of (1→4)-α-d-glucopyranosyl, (1→2)-α-d-xylopyranosyl, and (1→3)-α-d-arabinofuranosyl residues, whereas the (1→6)-α-d-mannopyranosyl residues formed branches at the O-2 position with 1-linked-α-d-glucopyranosyl terminal residues. From the antioxidative activity tests in vivo, the administration of PL-A11 obviously enhanced the activity of antioxidant enzymes and significantly reduced the level of malondiadehyde (MDA) in the serum and liver of d-galactose-treated aging mice in a dose-dependent manner, as well as effectively stimulated the immune system of aging mice. These findings implied that PL-A11 could be developed as a potential antioxidant for applications in the functional food, pharmaceutical, cosmetic or nutraceutical industries.

A novel chemo-enzymatic synthesis of hydrophilic phytosterol derivatives.

In this study, a novel method was developed for chemo-enzymatic synthesis of hydrophilic phytosterol derivatives, phytosteryl polyethylene glycol succinate (PPGS), through an intermediate phytosteryl hemisuccinate (PSHS), which was first chemically prepared and subsequently coupled with polyethylene glycol (PEG) through lipase-catalyzed esterification. The chemical structure of intermediate and goal product were finally confirmed to be PSHS and PPGS by FT-IR, MS and NMR, suggesting that hydrophilic phytosterol derivatives were successfully synthesized. The effects of various parameters on the conversion of PSHS to PPGS were investigated and the highest conversion (>78%) was obtained under the selected conditions: 75 mmol/L PSHS, 1:2M ratio of PSHS to PEG, 50 g/L Novozym 435, 120 g/L 3 Å molecular sieves in tert-butanol, 55 °C, 96 h and 200 rpm. The solubility of phytosterols in water was significantly improved by coupling with PEG, facilitating the incorporation into a variety of foods containing water.

[Study on anti-cancer components of Fig residues with supper critical fluid CO2 extracting technique].

OBJECTIVE: To optimize Supper Critical CO2 extracting technical (SFE-CO2) methods for extraction of anti-cancer active components of Fig Residues and to investigate the anti-cancer effect of the extract in vitro and in vivo. METHOD: The anti-cancer activity of extracted compound was measured on U937,95D and AGS cancer cells in vitro by MTT method. The anti-cancer effect of the extraction of Fig Residues was studied on mice transplant liver cancer in vivo. RESULT: The SFE-CO2 condition for extraction of the anti-cancer components of Fig Residues was optimized as follows: granularity was 100, the extraction pressure was 30 MPa, the extraction temperature was 45 degrees C, the extraction time was 6 h and the CO2 flux was 12 L x h(-1); The IC50 of anti-cancer active components of Fig Residues on U937, 95D and AGS cells were 70.125 microg x mL(-1), 127.957 microg x mL(-1), 116.000 microg x mL(-1); The anti-cancer active components of Fig Residues inhibited 49.3% of the transplanted liver cancer in the mice. CONCLUSION: The method for extracting the anticancer active components of Fig Residues is stable and reasonable, and the extract from Fig Residues is of the anticancer effect.

Purification, characterization and antitumor activity of polysaccharides extracted from Phellinus igniarius mycelia.

Water-soluble intracellular polysaccharides (IPS) were extracted from cultured mycelia of Phellinus igniarius. The IPS were purified by ethanol fractional precipitation, ion-exchange and size exclusion chromatography in that order. Homogeneous polysaccharide IPSW-1, IPSW-2, IPSW-3, and IPSW-4 were obtained, which molecular characteristics were examined using multiangle laser-light scattering and refractive index detector system. The average molecular weights of them were 34.1, 17.7, 15.1, 21.7kDa, respectively. GC analysis indicated that IPSW-1, IPSW-2 and IPSW-3 all only contained glucose, while IPSW-4 was composed of rhamnose, xylose, mannose, glucose and galactose in a molar ratio of 1.29:1.21:1:43.86:1.86. UV and IR analysis suggested they belonged to α-type of the pyran group and didn't contain protein. These homogeneous polysaccharides could inhibit the growth of SW480 and HepG2 cells to a certain extent in a dose-dependent manner. So they could be beneficial for the further development of a natural carcinoma preventive agent and functional food.

Effects of ultrasound on molecular properties, structure, chain conformation and degradation kinetics of carboxylic curdlan.

In this study, high-intensity ultrasound (20 kHz), a simple, effective and without any additive method, was used to the degradation of carboxylic curdlan (Cc) produced by 4-acetamido-TEMPO-mediated oxidation. The effects of ultrasound on molecular properties, structure and chain conformations of Cc were investigated by viscometry, size-exclusion chromatography with multiangle laser-light scattering (SEC-MALLS) analysis, as well as FTIR and NMR spectroscopies. The results indicated that the intrinsic viscosity [η] and the weight-average molecular weight (Mw) of Cc decreased obviously after ultrasound, and a uniform and narrow distribution of degradation product was obtained. The z-average radius of gyrations (Rg) firstly increased and then decreased as the sonication time prolonged. Ultrasound destroyed the hydrogen bonds resulting in the transition from compact random coil conformation to more flexible and even shorter extended chains. Ultrasonic treatment could not alter the primary chemical structure of Cc molecules according to the structural analysis by FTIR and NMR spectroscopies. Degradation kinetics based on Schmid model was applied to estimate the degradation rate constant k. It was found that the k value of Cc decreased with increasing the polymer concentration from 0.05 to 0.2% (w/v).

Structural features and antitumor activity of a novel polysaccharide from alkaline extract of Phellinus linteus mycelia.

A novel high molecular weight polysaccharide (PL-N1) was isolated from alkaline extract of the cultured Phellinus linteus mycelia. The weight average molecular weight (Mw) of PL-N1 was estimated at 343,000kDa. PL-N1 comprised arabinose, xylose, glucose, and galactose in the molar ratio of 4.0:6.7:1.3:1.0. The chemical structure of PL-N1 was investigated by FTIR and NMR spectroscopies and methylation analysis. The results showed that the backbone of PL-N1 comprised (1→4)-linked ß-D-xylopyranosyl residues, (1→2)-linked α-D-xylopyranosyl residues, (1→4)-linked α-D-glucopyranosyl residues, (1→5)-linked ß-D-arabinofuranosyl residues, (1→4)-linked ß-D-xylopyranosyl residues which branched at O-2, and (1→4)-linked ß-D-galactopyranosyl residues which branched at O-6. The branches consisted of (1→)-linked α-D-arabinofuranosyl residues. Antitumor activity assay in vitro showed that PL-N1 could inhibit the growth of HepG2 cells to a certain extent in a dose-dependent manner. Thus, PL-N1 may be developed as a potential, natural antitumor agent and functional food.

Highly selective and sensitive nucleic acid detection based on polysaccharide-functionalized silver nanoparticles.

Polysaccharide-functionalized silver nanoparticles (Oc-AgNPs) with a mean diameter of 15 nm were utilized as a novel and effective fluorescence-sensing platform for nucleic acid detection. Tests on the oligonucleotide sequences associated with the human immunodeficiency virus as a model system showed that the Oc-AgNPs effectively absorbed and quenched dye-labeled single-stranded DNA through strong hydrogen bonding interactions and slight electrostatic attractive interactions. The proposed system efficiently differentiated between complementary and mismatched nucleic acid sequences with high selectivity and good reproducibility at room temperature.

Self-aggregated nanoparticles of carboxylic curdlan-deoxycholic acid conjugates as a carrier of doxorubicin.

In this study, a new non-toxic, biodegradable, biocompatible and water-soluble carboxylic curdlan bearing the dissociable COOH group in 100% purity, which was prepared by 4-acetamido-TEMPO-mediated oxidation, was hydrophobically modified by deoxycholic acid (DOCA) to attain novel amphiphilic curdlan derivatives (CCDs) for the preparation of nano-carriers for antitumor drug doxorubicin (DOX). Under the effect of ultrasonication, the carboxylic curdlan derivatives in water were self-aggregated into spherical nanoparticles with diameters ranging from 214 nm to 380 nm. The critical aggregation concentrations decreased from 0.047 mg/mL to 0.016 mg/mL with increasing DS of DOCA. DOX-loaded CCD nanoparticles were prepared in an aqueous medium with dialysis method. The DOX-CCD nanoparticles exhibited pH- and dose-dependent drug release profiles during in vitro release experiments. Moreover, the drug transport mechanism was Fickian diffusion according to the Ritger-Peppas model. The CCD nanoparticles might be explored as potential carriers for hydrophobic drugs with controlled release and delivery functions.