Characterization and antitumor activity of pollen polysaccharide

Relative abundance of saccharides, free amino acids, and other compounds in specific pollen species for source profiling of atmospheric aerosol

Though studies in bioaerosols are being conducted with increasing frequency over the past decade, the total breadth of knowledge on bioaerosols and their role in atmospheric processes is still minimal. In order to better characterize the chemical composition of fresh biological aerosol for purposes of source apportionment and tracing in the atmosphere, several plant pollen species were selected for detailed chemical analyses. For this purpose, different pollen species were purchased and collected around Reno, Nevada, USA, for further extraction and detailed chemical analysis. These species included aspen, corn, pecan, ragweed, eastern cottonwood, paper mulberry, rabbitbrush, bitterbrush, lodgepole pine, and Jeffrey pine. Saccharides, free amino acids, and various other polar compounds (e.g., anhydrosugars and resin acids) were quantitatively analyzed using gas chromatography and ultra-high performance liquid chromatography coupled with mass spectrometry techniques (GC-MS and UPLC-MS), with the purpose to identify differences and nuances in chemical composition of specific pollen species. The saccharides β-d-fructose, α-d-glucose, and β-d-glucose were ubiquitously found across all pollen samples (10), and sucrose was found in five samples. d-galactose was also found in pine species. Total saccharides were 4.0 to 29% of total dry weight across all samples. Total free amino acids were 0.29% to 15% of total dry weight across all samples, with the most common amino acid being proline. Chemical profiles (including both saccharides and amino acids) of surface-deposited aerosol in the Lake Tahoe area correlated most closely with pine pollen than other analyzed pollen species, indicating that chemical profiles of pollen can be used to infer its contribution to local aerosols.

Isolation, Characterization and Antitumor Effect on DU145 Cells of a Main Polysaccharide in Pollen of Chinese Wolfberry

Modern studies have shown that pollen has a certain role in the treatment of prostate-related diseases. In the present study, pollen polysaccharides from Chinese wolfberry (WPPs) were extracted by hot-water extraction and ethanol precipitation, further purified by chromatography on a DEAE-cellulose column and Sephadex G-100 column. Homogeneous polysaccharide CF1 of WPPS was obtained, the molecular weight of which was estimated to be 1540.10 ± 48.78 kDa by HPGPC-ELSD. HPLC with PMP derivatization analysis indicated that the monosaccharide compositions of CF1 were mannose, glucuronic acid, galacturonic acid, xylose, galactose, arabinose, and trehalose, in a molar ratio of 0.68:0.59:0.27:0.24:0.22:0.67:0.08. The antitumor effects of CF1 upon MTT, Tunel assay and flow cytometry assay were investigated in vitro. The results showed that CF1 exhibited a dose-dependent antiproliferative effect, with an IC50 value of 374.11 μg/mL against DU145 prostate cancer cells. Tunel assay and flow cytometry assay showed that the antitumor activity of CF1 was related to apoptosis in vitro. The present study suggested that the CF1 of WPPs might be a potential source of antitumor functional food or agent.

Pollen-derived nonallergenic substances enhance Th2-induced IgE production in B cells

BACKGROUND

B cells play a central role in IgE-mediated allergies. In damaged airway epithelium, they are exposed directly to aeroallergens. We aimed to assess whether direct exposure of B cells to pollen constituents affects allergic sensitization.

METHODS

B cells from murine splenocytes and from blood samples of healthy donors were incubated for 8 days under Th2-like conditions with aqueous ragweed pollen extracts (Amb-APE) or its constituents. Secreted total IgM, IgG, and IgE was quantified by ELISA. Additionally, birch, grass, or pine-pollen extracts were tested. The number of viable cells was evaluated by ATP measurements. B-cell proliferation was measured by CFSE staining. IgE class switch was analyzed by quantitation of class switch transcripts. In an OVA/Alum i.p.-sensitization mouse model, Amb-APE was intranasally instilled for 11 consecutive days.

RESULTS

Upon Th2 priming of murine B cells, ragweed pollen extract caused a dose-dependent increase in IgE production, while IgG and IgM were not affected. The low-molecular-weight fraction and phytoprostane E1 (PPE1) increased IgE production, while Amb a 1 did not. PPE1 enhanced IgE also in human memory B cells. Under Th1 conditions, Amb-APE did not influence immunoglobulin secretion. The IgE elevation was not ragweed specific. It correlated with proliferation of viable B cells, but not with IgE class switch. In vivo, Amb-APE increased total IgE and showed adjuvant activity in allergic airway inflammation.

CONCLUSIONS

Aqueous pollen extracts, the protein-free fraction of Amb-APE, and the pollen-contained substance PPE1 specifically enhance IgE production in Th2-primed B cells. Thus, pollen-derived nonallergenic substances might be responsible for B-cell-dependent aggravation of IgE-mediated allergies.

In Vitro Anti-tumor Effects of Chemically Modified Polysaccharides from Cherokee Rose Fruit

Cherokee rose fruit (CRF) is a Chinese traditional herb which has been used in medicine for hundreds of years. The anti-tumor activity of CRF polysaccharides (CRFPs) has not yet been evaluated. To study the in vitro anti-tumor effects of CRFP and its derivatives, native CRFP was isolated from CRF by hot water extraction, and its molecular weight analyzed with gel filtration chromatography was 227,000 Da. Native CRFP was sulfated with ClSO3H-DMF and carboxymethylated with monochloroacetic acid in alkaline aqueous medium. The resulting derivatives were isolated and labeled as SF-CRFP and CM-CRFP, respectively. The in vitro inhibition rates of CRFP and its derivatives for tumor cells SKVO (human ovarian cancer cell), HepG2 (human hepatoma cell), and LoVo (human colon cancer cell) were evaluated, the result showed that native CRFP exhibited no significant inhibition effect on the three tumor cells even at a concentration of 50 μg/ml, but sulfation and carboxymethylation substantially enhanced the anti-tumor activities of CRFP in a dose-dependent way. SF-CRFP at the dose of 50 μg/ml displayed a significant inhibitory effect on SKVO, HepG2, and LoVo, with the viability rates of 33.6%, 44.8%, and 43.2%, respectively. It has a dosage-dependence inhibition on tumor growth in this model, with IC50 for SKVO, HepG 2, and LoVo being 21 μg/ml, 36 μg/ml, and 49 μg/ml, respectively. CM-CRFP showed a specific inhibition on HepG2 with a viability rate of 12.2%, with an IC50 of 17 μg/ml, while it had hardly any anti-tumor effect on SKVO cells. Thus, chemical modifications of CRFPs by sulfation and carboxymethylation effectively improved their anti-tumor properties.

Characterization of chemical composition of bee pollen in China

Bee pollen has been praised for its good nutrition and therapeutic values. China is the largest producer in the world. Twelve common varieties of monofloral bee pollen collected from China's main producing regions were selected for nutritional composition analysis, including proximate contents, dietary fibers, amino acid distribution, fatty acid composition, and mineral elements. The proximate compositions mostly met the specifications regulating pollen load quality of China. Proline and glutamic acids were found to be the predominant amino acids in the form of both total amino and free amino acids. Lysine was the relative limiting amino acid. The percentage of total essential amino acids (TEAA) to total amino acids (TAA) reached the nutrition recommendation of the Food and Agricultural Organization (FAO). The major fatty acids, presented as mean values, were C18:3 (25.1%), C16:0 (19.6%), C18:1 (17.3%), C18:2 (8.78%), C22:0 (4.07%), and C18:0 (2.96%) acids. The proportions of C18:3 were generally higher than those of C18:2, and the ratio of total unsaturated fatty acids (TUS) to total saturated fatty acids (TS) was >1.0, except for Nelumbo nucifera Gaertn. pollen for the characteristic absence of C18:3 acids. High levels of beneficial elements such as K, Ca, Mg, Zn, Fe, Mn. and Cu were observed in pollen samples. The contents of detrimental trace elements of Cd, Pb, and Hg were primarily lower or not detected. However, more attention should be paid to a large amount of Al, with a concentration of >100 mg/kg DW in most samples. There were some significant differences between samples. On the whole, the Chinese bee pollen was evaluated as a good complement to diet.

Effect of gamma irradiation on mistletoe (Viscum album) lectin-mediated toxicity and immunomodulatory activity

This study evaluated the effect of gamma irradiation on the reduction of the toxicity of mistletoe lectin using both in vitro and in vivo models. To extract the lectin from mistletoe, an (NH4)2SO4 precipitation method was employed and the precipitant purified using a Sepharose 4B column to obtain the pure lectin fraction. Purified lectin was then gamma-irradiated at doses of 0, 5, 10, 15, and 20 kGy, or heated at 100 °C for 30 min. Toxic effects of non-irradiated, irradiated, and heat-treated lectins were tested using hemagglutination assays, cytotoxicity assays, hepatotoxicity, and a mouse survival test and immunological response was tested using cytokine production activity. Hemagglutination of lectin was remarkably decreased (P < 0.05) by irradiation at doses exceeding 10 kGy and with heat treatment. However, lectin irradiated with 5 kGy maintained its hemagglutination activity. The cytotoxicity of lectin was decreased by irradiation at doses over 5 kGy and with heat treatment. In experiments using mouse model, glutamate oxaloacetate transaminase (GOT) and glutamic pyruvic transaminase (GPT) levels were decreased in the group treated with the 5 kGy irradiated and heat-treated lectins as compared to the intact lectin, and it was also shown that 5 kGy irradiated and heat-treated lectins did not cause damage in liver tissue or mortality. In the result of immunological response, tumor necrosis factor (TNF-α) and interleukin (IL-6) levels were significantly (P < 0.05) increased in the 5 kGy gamma-irradiated lectin treated group. These results indicate that 5 kGy irradiated lectin still maintained the immunological response with reduction of toxicity. Therefore, gamma-irradiation may be an effective method for reducing the toxicity of lectin maintaining the immune response.

A polysaccharide from the fungi of Huaier exhibits anti-tumor potential and immunomodulatory effects

A neutral water-soluble polysaccharide (W-NTRP), with a molecular weight of 2.5 × 10(4)Da, was isolated from the fruit bodies of Trametes robiniophila (Huaier). Gas chromatography (GC) results indicated that W-NTRP was determined to be galactose (Gal), arabinose (Ara) and glucose (Glc), with a relative molar ratio of 4.2:2.5:0.7. Its antitumor and immunomodulatory activity were evaluated in vitro. W-NTRP showed remarkable inhibitory effect on three human cholangiocarcinoma cell lines (QBC939, Sk-ChA-1 and MZ-ChA-1), with respective IC(50) values of 47.8, 75.9, and 43.7 μg/mL, but had no cytotoxicity to L-929 normal cells. Furthermore, W-NTRP had proliferation promoting effect on mouse splenocytes with or without concanavalin A (ConA) or lipopolysaccharide (LPS) in a bell-shaped dose-response manner. In addition, W-NTRP could prominently stimulate macrophages to produce nitric oxide (NO) through the up-regulation of inducible NO synthase (iNOS) activity. These results suggest that W-NTRP could be explored as a potential antitumor agent for cholangiocarcinoma.

Anticancer polysaccharides from natural resources: a review of recent research

Taking into account the rising trend of the incidence of cancers of various organs, effective therapies are urgently needed to control human malignancies. However, almost all of the chemotherapy drugs currently on the market cause serious side effects. Fortunately, several previous studies have shown that some non-toxic biological macromolecules, including polysaccharides and polysaccharide-protein complexes, possess anti-cancer activities or can increase the efficacy of conventional chemotherapy drugs. Based on these encouraging observations, a great deal of effort has been focused on discovering anti-cancer polysaccharides and complexes for the development of effective therapeutics for various human cancers. This review focuses on the advancements in the anti-cancer efficacy of various natural polysaccharides and polysaccharide complexes in the past 5 years. Most polysaccharides were tested using model systems, while several involved clinical trials.

Enhancement of cyclophosphamide-induced antitumor effect by a novel polysaccharide from Ganoderma atrum in sarcoma 180-bearing mice

The aim of this study was to investigate the enhancement of Ganoderma atrum polysaccharide (PSG-1) on cyclophosphamide (CTX)-induced antitumor effect in sarcoma 180 (S-180)-bearing mice. Results showed that both CTX and PSG-1 delayed tumor growth and resulted in tumor apoptosis. The combined regimen was superior to either modality alone. Moreover, the combined treatment-induced apoptosis was mediated via mitochondrial pathway, as evidenced by alterations of Bcl-2 family proteins, loss of mitochondrial membrane potential (Δψ(m)), cytochrome c release, and caspases activation. Our results also showed that thymus and spleen indexes, lymphocytes proliferation, and concentrations of cytokine in the CTX group were decreased, which were alleviated by PSG-1. Additionally, the combined treatment ameliorated oxidative stress as compared with CTX alone. Taken together, we conclude that PSG-1 improved the antitumor effect of CTX, possibly in part mediated by enhancing the induction of apoptosis via mitochondrial pathways, activating host immune function, and modifying the redox system in S-180-bearing mice.

Cell proliferative effect of polyxyloses extracted from the rhizomes of wild turmeric, Curcuma aromatica

Hot water-soluble crude polysaccharides were extracted from the rhizomes of wild turmeric, Curcuma aromatica Salisb. (Zingiberaceae), using dry grinding, boiling water extraction, and then ethanol precipitation. The crude polysaccharide extract was then fractionated by DEAE-cellulose ion exchange column chromatography, and subsequently further purified by Superdex G-200 gel filtration column chromatography, giving two relatively abundant polysaccharide fractions, called P11 and P21, and a much less common fraction P22 obtained in insufficient amounts for further analysis. The two main polysaccharide fractions were evaluated for monosaccharide composition by acid hydrolysis and high performance liquid chromatography (HPLC), whilst the molecular weight and functional groups were determined by gel permeable chromatography (GPC) and FT-IR, respectively. Fractions P11 and P21 were found to be polyxyloses with molecular weight-averages of 469,171 and 157,665 Da, respectively. P11 (100 microg/mL) could significantly induce human gingival fibroblast cells proliferation by 30%, while P21 (100 microg/mL) could significantly inhibit gingival fibroblast cells proliferation by 92%. The in vitro human primary gingival fibroblast cell proliferation in cell culture at a concentration of 100 microg/mL.

Isolation, purification and immunobiological activity of a new water-soluble bee pollen polysaccharide from Crataegus pinnatifida Bge

A novel water-soluble polysaccharide was obtained from bee pollen of Crataegus pinnatifida Bge. Two fractions of this polysaccharide, CPP-1 and CPP-2, were first extracted by hot-water and purified. The average molecular weight of CPP-1 and CPP-2 were approximately 3.7 × 10⁵ Da and 7.8 × 10⁴ Da, and their chemical structures were studied by gas chromatography (GC), Fourier transform-infrared (FT-IR) spectroscopy, methylation analysis. We evaluated the effects of CPP-1 and CPP-2 on the basis of phagocytosis of macrophage assay, natural killer cells cytotoxicity assay and spleen lymphocyte proliferation assay. The results showed CPP-1 and CPP-2 significantly induced phagocytic rates and phagocytic indexes by peritoneal macrophages. Moreover, these two fractions caused a significant stimulation of rat spleen cell proliferation. At 50 μg/mL, CPP-2 activated NK cells more significantly than CPP-1. These findings suggest that they should be explored as a novel potential immunostimulants.

Characterization and free radical scavenging activity of rapeseed meal polysaccharides WPS-1 and APS-2

Two major polysaccharide fractions, WPS-1 and APS-2, were isolated from water-soluble and alkali-soluble extracts of Huaza No. 4 rapeseed meal with a stepwise procedure of D3520 macroporous adsorption resin column chromatography, ethanol precipitation, and DE-52 cellulose column chromatography. Physicochemical properties of the polysaccharides were determined by chemical methods, high -performance liquid chromatography (HPLC), gel permeation chromatography (GPC), and Fourier transform infrared spectrometry (FT-IR). The chemiluminescence (CL) method was used to investigate the free radical scavenging activity of the polysaccharide fractions. The polysaccharides were primarily polymers of arabinose, galactose, and glucose, associated with protein portions consisting of 13 different amino acids. The average molecular masses of WPS-1 and APS-2 were 7.20 x 10(5) and 1.61 x 10(5) Da, respectively. Compared with APS-2, WPS-1 was more effective at scavenging superoxide radical (O(2)(*-)) and hydroxyl radical (HO(*)), but less effective at scavenging hydrogen peroxide (H(2)O(2)). In decreasing order, the free radical scavenging activity of WPS-1 and APS-2 toward reactive oxygen species (ROS) was H(2)O(2) > HO(*) > O(2)(*-).