Jun-Yi Yin

Chemical characteristics and antioxidant activities of polysaccharide purified from the seeds of Plantago asiatica L.

BACKGROUND A water-soluble polysaccharide from the seeds of Plantago asiatica L. (P. asiatica L. polysaccharide, PLP) was extracted with hot water and purified by gel filtration chromatography. The chemical characteristics of PLP were determined by high-performance gel permeation chromatography (HPGPC) and Fourier transform infrared (FTIR) spectroscopy. In addition, the antioxidant activities of PLP in vitro were evaluated using various test systems, including scavenging of 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radicals, scavenging of superoxide radicals generated by 1,2,3-phentriol autoxidation, scavenging of hydroxyl radicals and inhibition of lipid peroxidation. RESULTS The molecular weight of PLP was determined by HPGPC to be about 1894 kDa. PLP contained 29.2 g kg(-1) protein and 145.8 g kg(-1) uronic acid. The FTIR spectrum of PLP also revealed typical characteristics of a polysaccharide containing protein and uronic acid. Moreover, the results showed that PLP possessed antioxidant activities, but lower than those of ascorbic acid. CONCLUSION PLP is an acid protein-bound polysaccharide of high molecular weight, but its structure needs further study. The present results suggest that PLP could potentially be used as a natural antioxidant.

Immunomodulatory activity of the seeds of Plantago asiatica L.

ETHNOPHARMACOLOGICAL RELEVANCE The seeds of Plantago asiatica L. were often used as a traditional Chinese medicine for some immunologically weak patients suffering from chronic illness. These uses could be related to immunomodulatory properties of the plant. AIM OF THE STUDY In this study, effects of extract of the seeds of Plantago asiatica L. (ES-PL) were investigated on the maturation of dendritic cells (DCs), which play significant role in primary immune system. MATERIALS AND METHODS The phenotypes of DCs were analyzed by using flow cytometry while phagocytosis was assessed by the uptake of FITC-dextran. Antigen presenting ability to allogeneically naïve or syngeneically primed T lymphocytes was examined by the lymphocyte proliferation of mixed lymphocyte reaction (MLR). In addition, the level of chemokine receptor CCR7 mRNA was determined by RT-PCR. RESULTS DCs treated with ES-PL expressed higher levels of MHC class II molecules and major costimulatory molecules such as CD80 and CD86. Functional maturation of DCs treated with ES-PL was confirmed by decreased mannose receptor-mediated endocytosis and increased antigen presenting abilities to allogeneically naïve or syngeneically primed T lymphocytes. The CCR7 mRNA expression in DCs treated with ES-PL was also enhanced. CONCLUSIONS These results indicated that ES-PL could induce the maturation of murine DCs.

Simultaneous analysis of 18 mineral elements in Cyclocarya paliurus polysaccharide by ICP-AES

The contents of 18 kinds of mineral elements in Cyclocarya paliurus polysaccharide samples were determined by ICP-AES. The limits of detection (LOD) of the method for 18 elements were in the range of 0.01-3.80 mg/kg. The average recoveries obtained by the standard addition method were found between 94.34% and 105.69% (RSD, 1.01-4.23%). The results showed that C. paliurus polysaccharides were abundant in major and trace elements which are healthy for human body. The contents of Ca, Al, Mg, K, Fe, Mn and P were very high, ranging from 274.5±10.3 to 5980.0±102.7 mg/kg, while the contents of Zn, Na, Se, Cr, Pb, Cu and As ranged from 0.9±0.1 to 37.1±4.2 mg/kg. Finally, the levels of Ni, Cd, V and Co were not detected in the samples. ICP-AES is a simple, precise and efficient method for the determination of many mineral elements in polysaccharide samples simultaneously.

Mechanism of Interactions between Calcium and Viscous Polysaccharide from the Seeds of Plantago asiatica L.

The present study aimed at investigating the mechanism of interactions between calcium and the psyllium polysaccharide. Plantago asiatica L. crude polysaccharide (PLCP) was subjected to ethylenediaminetetraacetic acid (EDTA) to yield calcium-depleted polysaccharide named PLCP-E. There was essentially no difference in the structure between PLCP-E and PLCP. However, PLCP-E exhibited a much lower apparent viscosity compared to that of PLCP. PLCP was treated with sodium hydroxide to deplete ferulic acid. The resultant material was named PLCP-FAS, which also exhibited lower viscosity. Adding Ca(2+) could both increase apparent viscosity of PLCP-E and PLCP-FAS, but only PLCP-E could keep the high viscosity when dialysis was carried out to remove free Ca(2+) in the solution. Thermal analysis showed that the thermal stability of the polysaccharide was reduced after EDTA chelation. Scanning electron microscopy (SEM) analysis showed that PLCP-E was flaky and curly aggregation, while PLCP was mostly filamentous in appearance. The results suggested that there are strong interactions between Ca(2+) and the polysaccharide. The interactions contributed to the high viscosity, weak gelling property, and thermal stability of the polysaccharide.

Effect of calcium on solution and conformational characteristics of polysaccharide from seeds of Plantago asiatica L.

Polysaccharide from seeds of Plantago asiatica L. is rich in calcium, which is important for keeping viscous and weak gelling properties of the polysaccharide. However, few studies reported effect of calcium on solution and conformational characteristics of the polysaccharide. In this study, polysaccharide was prepared from seeds of P. asiatica L. and named as PLCP. PLCP was treated with EDTA to remove calcium ion to get PLCP-E. PLCP and PLCP-E were characterized by Ubbelohde capillary viscometer, light scattering and HPSEC with refractive index, light scattering and viscometric detectors. The results showed that PLCP had much higher intrinsic viscosity, hydrodynamic radius (Rh), radius of gyration (Rg) and molecular weight than that of PLCP-E when measured in the same solvent. PLCP and PLCP-E were in random coil conformation in aqueous solutions according to light scattering and HPSEC measurements. HPSEC data showed PLCP-E had lower intrinsic viscosity than that of PLCP with the same molecular weight. Persistence length of Lp was 2.5nm for PLCP and 2.3nm for PLCP-E, respectively. In conclusion, PLCP exhibited higher intrinsic viscosity and molecular weight, and stiffer conformation than that of PLCP-E, which could explain the reason of higher viscosity of PLCP.

Lactobacillus plantarum NCU116 Attenuates Cyclophosphamide-Induced Immunosuppression and Regulates Th17/Treg Cell Immune Responses in Mice

The balance of T helper cells 17 (Th17)/regulatory T cells (Treg) plays a key role in maintaining a normal immune response. It is well-known that cyclophosphamide (CTX) applied at high dose often damages the immune system by inhibiting immune cell proliferation. In this study, the immunomodulating effects of Lactobacillus plantarum NCU116 in CTX-induced immunosuppression mice were investigated. Results showed that the levels of cytokines interleukin (IL)-17 and IL-21 were significantly increased after 10 days of treatment with a high dose of NCU116 (46.92 ± 4.28 and 119.92 ± 10.89, respectively) compared with the model group (36.20 ± 2.63, 61.00 ± 6.92, respectively), and the levels of cytokines IL-23 and TGF-β3 of the three NCU116 treatment groups were significantly higher than that of the model group (90.48 ± 6.33 and 140.45 ± 14.30, respectively) (p < 0.05) and close to 62 and 69% of the normal groups level (140.98 ± 14.74 and 266.95 ± 23.11, respectively) at 10 days. The bacterium was also found to increase the expression levels of Th17 immune response and Treg immune response specific transcription factors RORγt and Foxp3. In addition, the bacterium significantly increased the number of CD4(+)T cells and dendrtic cells (DCs) and up-regulated mRNA expression of Toll-like receptors (TLRs). These findings demonstrated that NCU116 has the potential ability to enhance intestinal mucosa immunity and regulate the Th17/Treg balance, which may be attributed to the TLR pathway in DCs.

Fractionation, physicochemical property and immunological activity of polysaccharides from Cassia obtusifolia.

The seeds of Cassia obtusifolia are widely used as a drink in Asia and an additive in food industry. Considerable amounts of water-soluble polysaccharides were found in the whole seeds, while conflicting results on structure characteristics have been reported, and few studies have been reported on physicochemical properties and immunomodulatory activities. In the present study, gradient ethanol precipitation was applied to fractionate the water-soluble polysaccharide (CP), and two sub-fractions CP-30 (30% ethanol precipitate) and CP-40 (40% ethanol precipitate) were obtained. Different rheological properties for CP-30 and CP-40 were found, indicating the differences in structure characteristics between CP-30 and CP-40. Chemical properties, including molecular weight, monosaccharide composition, and glycosidic linkage were investigated. Compared with CP-30, CP-40 had lower molecular weight and higher content of xylose. The immunomodulatory effects of CP, CP-30 and CP-40 were assessed. All of them were found to possess significant immunomodulation activities, while varied effects of them on macrophage functions were observed. The aim of the present study was to develop a simple and efficient method to purify cassia polysaccharides, and investigate their physicochemical properties and biological activities, which was meaningful for their potential use in food industry and folk medicine.

Isolation, purification and physicochemical properties of polysaccharide from fruiting body of Hericium erinaceus and its effect on colonic health of mice

Hericium erinaceus was extracted with boiling water to obtain the crude polysaccharide (HECP) and refined polysaccharide (HERP). HERP was further purified using gradual ethanol precipitation to obtain five sub-fractions. Their physicochemical properties were evaluated, including chemical components, monosaccharide composition and molecular weight. Meanwhile, the effect of HERP on colonic health of mice was investigated by oral administration at dosages of 100, 200 and 400mg/kg of body weight (mg/kgbw), comparing with that of HECP. Results showed that the gradual ethanol precipitation could remarkably increase polysaccharide purity. HERP, HECP and the five purified fractions had different monosaccharide compositions, while the main monosaccharides were Glc and Gal. They all showed similar structure with amorphous appearance. Short-chain fatty acids productions in colonic and cecum contents, and feces of mice were increased in polysaccharide treated groups. Mice administrated with HERP at 400mg/kgbw showed significant reductions in pH values while obvious increases in moisture amounts. This study suggests that gradual ethanol precipitation is available for purification of polysaccharide from Hericium erinaceus and the extracted polysaccharide could improve colonic health.

Structural Features of Alkaline Extracted Polysaccharide from the Seeds of Plantago asiatica L. and Its Rheological Properties

Polysaccharide from the seeds of Plantago asiatica L. has many bioactivities, but few papers report on the structural and rheological characteristics of the alkaline extract. The alkaline extracted polysaccharide was prepared from seeds of P. asiatica L. and named herein as alkaline extracted polysaccharide from seeds of P. asiatica L. (PLAP). Its structural and rheological properties were characterized by monosaccharide composition, methylation, GC-MS and rheometry. PLAP, as an acidic arabinoxylan, was mainly composed of 1,2,4-linked Xylp and 1,3,4-linked Xylp residues. PLAP solution showed pseudoplastic behavior, and weak gelling properties at high concentration. Sodium and especially calcium ions played a significant role in increasing the apparent viscosity and gel strength.

Enzymatic purification and structure characterization of glucuronoxylan from water extract of Cassia obtusifolia seeds

Enzymatic hydrolysis was proposed for the first time to purify the sub-fraction of water-extracted cassia polysaccharide (CP-40), and a homogeneous polysaccharide CP-40-M was obtained with relatively high yield. The structural features of CP-40-M were characterized using size-exclusion chromatography equipped with multiple detectors (SEC-MALLS), high-performance anion-exchange chromatography (HPAEC), methylation and gas chromatography-mass (GC-MS), as well as nuclear magnetic resonance (NMR) spectra. The weight-average molecular weight for CP-40-M was determined to be 0.29×105Da, and the molar ratio of xylose to glucuronic acid was 4.62. The structure of CP-40-M was elucidated to be glucuronoxylan, with glucopyranosyluronic acid group terminally attached to O-2 of the →4)-β-Xylp-(1→ backbone. It was the first time to obtain this type of xylan from the water extract of Cassia obtusifolia seeds. The structure elucidation of CP-40-M was meaningful for better understanding the natural characteristics of cassia polysaccharide and important for their potential use in food industry and folk medicine.