Anticancer polysaccharides from natural resources: a review of recent research

Therapeutics Role of Azadirachta indica (Neem) and Their Active Constituents in Diseases Prevention and Treatment

Neem (Azadirachta indica) is a member of the Meliaceae family and its role as health-promoting effect is attributed because it is rich source of antioxidant. It has been widely used in Chinese, Ayurvedic, and Unani medicines worldwide especially in Indian Subcontinent in the treatment and prevention of various diseases. Earlier finding confirmed that neem and its constituents play role in the scavenging of free radical generation and prevention of disease pathogenesis. The studies based on animal model established that neem and its chief constituents play pivotal role in anticancer management through the modulation of various molecular pathways including p53, pTEN, NF-κB, PI3K/Akt, Bcl-2, and VEGF. It is considered as safe medicinal plants and modulates the numerous biological processes without any adverse effect. In this review, I summarize the role of Azadirachta indica in the prevention and treatment of diseases via the regulation of various biological and physiological pathways.

TLR-4 may mediate signaling pathways of Astragalus polysaccharide RAP induced cytokine expression of RAW264.7 cells

ETHNOPHARMACOLOGICAL RELEVANCE

Polysaccharides of Radix Astragali (Astragalus membranaceus (Fisch) Bge.; Huangqi) are able to induce cytokine production of macrophages and are considered the main active ingredient for the immune-enhancing effect of this commonly used medicinal herb.

AIM OF STUDY

To investigate the molecular mechanism of immunomodulating activities of a reported Astragalus polysaccharide, RAP, which is a hyperbranched heteroglycan with average molecular weight of 1334kDa.

MATERIALS AND METHODS

The cytokine production of RAW264.7 cells were analyzed by using ELISA assays while cell viability was assessed by MTT method. Western blot analysis was used for determining protein contents of mitogen-activated protein kinases (MAPKs). In addition, the level of IL-6, iNOS, and TNF-α mRNA was determined by RT-PCR.

RESULTS

It has been found that RAP itself did not have any cytotoxic effect on mouse mammary carcinoma 4T1 cells, but it significantly enhanced cytotoxicity of the supernatant of RAW264.7cells on 4T1 cells. Furthermore, RAP enhanced the production of NO and cytokines in RAW264.7 cells, and significantly up-regulated gene expressions of TNF-α, IL-6, iNOS. All these bioactivities were blocked by the inhibitor of TLR4 (Toll-like receptor 4), suggesting that TLR4 is a receptor of RAP and mediates its immunomodulating activity. Further analyses demonstrated that RAP rapidly activated TLR4-related MAPKs, including phosphorylated ERK, phosphorylated JNK, and phosphorylated p38, and induced translocation of NF-κB as well as degradation of IκB-α. These results are helpful to better understand the immunomodulating effects of Radix Astragali.

CONCLUSIONS

RAP may induce cytokine production of RAW264.7 cells through TLR4-mediated activation of MAPKs and NF-κB.

Anti-hepatoma activity of the stiff branched β-d-glucan and effects of molecular weight

The water soluble β-d-glucan AF1 with short branches isolated from Auricularia auricula-judae exhibited significant anti-hepatoma activities, and it was confirmed that AF1 had stiff chains and could induce cancer cell apoptosis and anti-angiogenesis through activating immune responses.

The antioxidative effects of acidic-, alkalic-, and enzymatic-extractable mycelium zinc polysaccharides by Pleurotus djamor on liver and kidney of streptozocin-induced diabetic mice

BACKGROUND

Edible mushrooms, especially the genus of Pleurotus, have been well studied for their nutrition as well as non-toxic medicinal properties. Recently, much attention has been paid to the therapeutic values of mushrooms in genus of Pleurotus with diabetes mellitus (DM), which was a complex metabolic disorder that induced by increased oxidative stress and characterized by hyperglycemia. However, scare attention has been paid to polysaccharides from P. djamor. Meanwhile, zinc is an essential trace element in the human body and it participates in various pathways of metabolism. Therefore, the objective of present study was aimed to evaluate the protective effects of the three extractable mycelium zinc polysaccharides (MZPS), including acidic-MZPS (Ac-MZPS), alkalic-MZPS (Al-MZPS) and enzymatic-MZPS (En-MZPS), on the liver and kidneys in diabetic mice induced by streptozocin (STZ) aiming to better understand the possible hypoglycemic mechanisms and their health benefits.

METHODS

The Ac-, Al-, and En-MZPS were extracted with hydrochloric acid (1 M), sodium hydroxide (1 M) and snailase (4 %) from P. djamor zinc-enriched mycelium, respectively. The diabetic mice were induced by injection of STZ. Besides the histopathological analyses of liver and kidney, the following biochemical analysis were processed to investigate the antioxidative effects, including activities of superoxide dismutase (SOD), GSH peroxide (GSH-Px) and catalase (CAT), and contents of malondialdehyde (MDA) in liver and kidney homogenate; activities of alamine aminotransferase (ALT) and aspertate aminotransferase (AST), and levels of urea nitrogen (BUN), creatinine (CRE), total cholesterol (TC), albumin (ALB), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) and very low-density lipoprotein cholesterol (VLDL-C) in serum.

RESULTS

Results showed that the activities of SOD, GSH-Px and CAT were significantly increased, the MDA contents remarkably reduced, and the values of ALT, AST, BUN, CRE, TC, LDL-C and HDL-C observably mitigated in the liver, kidneys and serum of diabetic mice by these three polysaccharides treatment. Biochemical and histopathological analyses also showed that MZPS could alleviate liver and kidneys injury.

CONCLUSION

These results demonstrated that Ac-, Al-, and En-MZPS possessed potent antioxidant activities, and could be used as a potentially functional food for the prevention of diabetes and its complications induced by STZ.

Immunomodulatory activity on macrophage of a purified polysaccharide extracted from Laminaria japonica

In this work, a novel water-soluble homogeneous polysaccharide (LJP-31) with a molecular mass of 2.24 × 10(6) Da was isolated and purified from Laminaria japonica using DEAE-cellulose and Sephacryl S500 chromatography. Results showed that LJP-31 mainly consists of arabinose, mannose, glucose and galactose in a molar ratio of 1.0:7.8:6.6:0.8. LJP-31 exhibited significant stimulation on macrophages and enhanced the production of NO, TNF-α, IL-1β, IL-6 and IL-10 as well as the up-regulation of their gene expressions. Western blot analysis suggested that LJP-31 has the positive effects on the translocation of NF-κB p65 from cytoplasm to nucleus and the phosphorylation of IκBα, ERK1/2, JNK1/2 and P38 in macrophages. Flow cytometric and confocal laser-scanning microscopy analysis indicated that toll-like receptor 4 (TLR4) was at least one of the recognition receptors of LJP-31 on the plasma membrane of macrophages. Taken together, LJP-31 may exert its immunostimulating potency via TLR4 activation of MAPK and NF-κB signaling pathways.

Ultrasound-Assisted Extraction, Antioxidant and Anticancer Activities of the Polysaccharides from Rhynchosia minima Root

Box-Behnken design (BBD), one of the most common response surface methodology (RSM) methods, was used to optimize the experimental conditions for ultrasound-assisted extraction of polysaccharides from Rhynchosia minima root (PRM). The antioxidant abilities and anticancer activity of purified polysaccharide fractions were also measured. The results showed that optimal extraction parameters were as follows: ultrasound exposure time, 21 min; ratio of water to material, 46 mL/g; ultrasound extraction temperature, 63 °C. Under these conditions, the maximum yield of PRM was 16.95% ± 0.07%. Furthermore, the main monosaccharides of purified fractions were Ara and Gal. PRM3 and PRM5 exhibited remarkable DPPH radical scavenging activities and reducing power in vitro. PRM3 showed strong inhibitory activities on the growth of MCF-7 cells in vitro. The above results indicate that polysaccharides from R. minima root have the potential to be developed as natural antioxidants and anticancer ingredients for the food and pharmaceutical industries.

Reviews on Mechanisms of In Vitro Antioxidant Activity of Polysaccharides

It is widely acknowledged that the excessive reactive oxygen species (ROS) or reactive nitrogen species (RNS) induced oxidative stress will cause significant damage to cell structure and biomolecular function, directly or indirectly leading to a number of diseases. The overproduction of ROS/RNS will be balanced by nonenzymatic antioxidants and antioxidant enzymes. Polysaccharide or glycoconjugates derived from natural products are of considerable interest from the viewpoint of potent in vivo and in vitro antioxidant activities recently. Particularly, with regard to the in vitro antioxidant systems, polysaccharides are considered as effective free radical scavenger, reducing agent, and ferrous chelator in most of the reports. However, the underlying mechanisms of these antioxidant actions have not been illustrated systematically and sometimes controversial results appeared among various literatures. To address this issue, we summarized the latest discoveries and advancements in the study of antioxidative polysaccharides and gave a detailed description of the possible mechanisms.

Cytotoxicity and antimicrobial activity of marine macro algae (Dictyotaceae and Ulvaceae) from the Persian Gulf

Pharmaceutical industry now accept the worlds ocean which contains a vast array of organisms with unique biological properties, as a major frontier for medical investigation. Bioactive compounds with different modes of action, such as, antiproliferative, antioxidant, antimicrotubule, have been isolated from marine sources, specifically macro and micro algae, and cyanobacteria. The aim of this work was to investigate antimicrobial and cytotoxic activities of the extracts of marine macro algae Ulva flexuosa, Padina antillarum and Padina boergeseni from the northern coasts of the Persian Gulf, Qeshm Island, Iran, against three cell lines including MCF7, HeLa and Vero, as well as their inhibitory effects against a wide array (i.e. n = 11) of pathogenic bacteria and fungi. Antimicrobial activity of the marine macro algal extracts was assessed using a disc diffusion method; an MTT cytotoxicity assay was employed to test the effects of the extracts on each cancer cell line. The algal extracts showed considerable antimicrobial activity against the majority of the tested bacteria and fungi. Both ethyl acetate and methanol extracts at the highest concentration (100 µg/ml) caused cell death, with the IC50 values calculated for each cell type and each algal extracts. Results are exhibited a higher decrease in the viability of the cells treated at the highest concentration of marine macro algal ethyl acetate extracts compared to the methanol extracts (78.9 % death in Vero cells by ethyl acetate extracts from U. flexuosa). Despite, the ethyl acetate extracts with lower dose- response of cells, exhibited better cytotoxic activity than methanol extracts (IC50: 55.26 μg/ml in Vero cells by ethyl acetate extracts from U. flexuosa). Based on the findings, it is concluded that the marine macro algal extracts from the Persian Gulf possess antibacterial and cytotoxic potential, which could be considered for future applications in medicine and identifying novel drugs from the marine resources.

Present and future medical applications of microbial exopolysaccharides

Microbial exopolysaccharides (EPS) have found outstanding medical applications since the mid-20th century, with the first clinical trials on dextran solutions as plasma expanders. Other EPS entered medicine firstly as conventional pharmaceutical excipients (e.g., xanthan - as suspension stabilizer, or pullulan - in capsules and oral care products). Polysaccharides, initially obtained from plant or animal sources, became easily available for a wide range of applications, especially when they were commercially produced by microbial fermentation. Alginates are used as anti-reflux, dental impressions, or as matrix for tablets. Hyaluronic acid and derivatives are used in surgery, arthritis treatment, or wound healing. Bacterial cellulose is applied in wound dressings or scaffolds for tissue engineering. The development of drug controlled-release systems and of micro- and nanoparticulated ones, has opened a new era of medical applications for biopolymers. EPS and their derivatives are well-suited potentially non-toxic, biodegradable drug carriers. Such systems concern rating and targeting of controlled release. Their large area of applications is explained by the available manifold series of derivatives, whose useful properties can be thereby controlled. From matrix inclusion to conjugates, different systems have been designed to solubilize, and to assure stable transport in the body, target accumulation and variable rate-release of a drug substance. From controlled drug delivery, EPS potential applications expanded to vaccine adjuvants and diagnostic imaging systems. Other potential applications are related to the bioactive (immunomodulator, antitumor, antiviral) characteristics of EPS. The numerous potential applications still wait to be developed into commercial pharmaceuticals and medical devices. Based on previous and recent results in important medical-pharmaceutical domains, one can undoubtedly state that EPS medical applications have a broad future ahead.

Immunoregulation on Mice of Low Immunity and Effects on Five Kinds of Human Cancer Cells of Panax japonicus Polysaccharide

The goal of this study is to investigate the immunoregulative effects of Panax japonicus polysaccharide (PJPS) on mice of low immunity. An orthogonal experiment was designed to determine the best extraction process for PJPS. By the tests of macrophages swallow chicken red blood cells, Delayed-type hypersensitivity (DTH), and serum hemolysin value, we studied the immune adjustment ability of PJPS. MTT was employed to detect the effects of different concentrations of PJPS, respectively, in 24 h, 48 h, and 72 h on five kinds of human cancer cells. The results show that the best extraction process for PJPS was as follows: ratio of solvent consumption to raw material 40, extraction temperature 100°C, re-extracted two times, each extraction time 4 hours. PJPS can significantly improve the immune function of mice processed by cyclophosphamide and PJPS did not work on the above five cancer cells.

Structure-function relationships of immunostimulatory polysaccharides: A review

Immunostimulatory polysaccharides are compounds capable of interacting with the immune system and enhance specific mechanisms of the host response. Glucans, mannans, pectic polysaccharides, arabinogalactans, fucoidans, galactans, hyaluronans, fructans, and xylans are polysaccharides with reported immunostimulatory activity. The structural features that have been related with such activity are the monosaccharide and glycosidic-linkage composition, conformation, molecular weight, functional groups, and branching characteristics. However, the establishment of structure-function relationships is possible only if purified and characterized polysaccharides are used and selective structural modifications performed. Aiming at contributing to the definition of the structure-function relationships necessary to design immunostimulatory polysaccharides with potential for preventive or therapeutical purposes or to be recognized as health-improving ingredients in functional foods, this review introduces basic immunological concepts required to understand the mechanisms that rule the potential claimed immunostimulatory activity of polysaccharides and critically presents a literature survey on the structural features of the polysaccharides and reported immunostimulatory activity.

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

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

Modulating the SDF-1/CXCL12-induced cancer cell growth and adhesion by sulfated K5 polysaccharides in vitro

Stromal cell-derived factor-1 (SDF-1)/chemokine (CXC motif) ligand 12 (CXCL12) is involved in the process of tumor progression. Sulfated K5 polysaccharides have shown anti-cancer activity by acting on multiple targets, though it remains unclear whether sulfated K5 polysaccharides would disrupt SDF-1/CXCL12-stimulated cancer biology. This study aimed to investigate the effects of sulfated K5 polysaccharides on cell growth, adhesion in murine B16 melanoma cells and the underlying mechanism by targeting SDF-1/CXCL12. Results indicated that K5-NS,OS inhibited the proliferation of B16 melanoma cells, induced the cell cycle arrest mainly at the G0/G1 phase, and suppressed cancer cell proliferation or adhesion induced by SDF-1/CXCL12. It was possible that K5-NS,OS appeared to interact with CXCL12 and block the subsequent biological functions. This work suggests that the existence of O- and N-sulfate groups is more effective in targeting CXCL12 and exhibiting anti-cancer activity.

Fungus Cerrena unicolor as an effective source of new antiviral, immunomodulatory, and anticancer compounds

In the report, three bioactive fractions from Cerrena unicolor: laccase (LAC), endopolysaccharides (c-EPL), and low molecular weight (ex-LMS) were tested for the first time towards their antiviral, immunostimulatory, cytotoxic and antiproliferative effect. The immunomodulatory activity was studied by means of THP-1-derived macrophages able to synthesize and secrete IL-6 and TNF-α. We used cervical carcinoma cell lines SiHa (ATCC, HTB-35) and CaSki (ATCC, CRL 1550) to determine antitumor activity and human skin fibroblasts (HSF) as a control. SiHa and L929 cell lines were used in the antiviral activity assay to propagate HHV-1 and EMCV, respectively. LAC was the most active against HSV at an early stage of viral replication, whereas the activity of laccase against EMCV was evident after incubation of the virus with LAC before and after the adsorption step. Moreover, the investigations showed that the fungal c-EPL fraction stimulated the production and secretion of TNF-α and IL-6 by THP-1-derived macrophages up to a level of 2000 pg/ml and 400 pg/ml, respectively. It was indicated for the first time that the LAC and ex-LMS fractions exhibited anticancer activity. This resulted from their cytotoxic or antiproliferative action against the investigated tumor cells at concentrations above 250 μg/ml and 10 μg/ml, respectively.

The antioxidant and chemical properties of Berberis vulgaris and its cytotoxic effect on human breast carcinoma cells

In this study we evaluated the biological activity of alcoholic and aqueous extracts from the fruit of Berberis vulgaris. The total antioxidant capacity of Berberis was characterized by FRAP, DPPH, Folin-Ciocalteu while the anthocyanins content was measured by pH differential method. Cell viability and apoptotic property were determined by MTT and DNA fragmentation assays, respectively. Alcoholic extract of Berberis was richer in antioxidants and anthocyanins compared to aqueous extract. Although both extracts significantly inhibited proliferation of breast cancer cells (MCF-7); these changes were not observed in normal human breast epithelial cells (MCF10-A). The alcoholic extract was more effective in inducing apoptosis as detected by DNA fragmentation in treated cancer cells. Our results suggest that Berberis has potent antioxidant properties and cytotoxic effects that can induce apoptosis. Therefore, Berberis can potentially be exploited for the development of therapeutics to fight against human breast cancer.

Anti-tumor activity and the mechanism of SIP-S: A sulfated polysaccharide with anti-metastatic effect

Our previous studies demonstrated that SIP-S had anti-metastatic activity and inhibited the growth of metastatic foci. Here we report the anti-tumor and immunoregulatory potential of SIP-S. SIP-S could significantly inhibit tumor growth in S180-bearing mice, and the inhibition rates was 43.7% at 30 mg/kg d. Besides, SIP-S could improve the thymus and spleen indices of S180-bearing mice and the mice treated with CTX. The combination of SIP-S (15 mg/kg d) with CTX (12.5 mg/kg d) showed higher anti-tumor potency than CTX (25 mg/kg d) alone. These results indicated that SIP-S had immunoenhancing and anticancer activity, and the immunoenhancing activity might be one mechanism for its anti-tumor activity. Flow cytometry results showed that SIP-S could induce tumor cells apoptosis. Western blot analysis indicated that SIP-S could upregulate the expression of pro-apoptotic proteins, caspase-3, -8, -9 and Bax, and downregulate the expression of anti-apoptotic protein PARP-1 in tumor cells in a dose-dependent manner. In summary, SIP-S has anti-tumor activity, which may be associated with its immunostimulating and pro-apoptotic activity.

Macrophage activation induced by the polysaccharides isolated from the roots of Sanguisorba officinalis

CONTEXT

Macrophage, involved at all stages of immune response, is an important component of the host defense system. Polysaccharides exist almost ubiquitously in medical plants and most of them possess immunomodulation and macrophage activation properties.

OBJECTIVE

This study elucidates the effects on macrophage activation and molecular mechanism induced by the polysaccharides (SOPs) from the roots of Sanguisorba officinalis Linne (Rosaceae).

MATERIALS AND METHODS

Polysaccharides (SOPs) from the roots of S. officinalis were obtained by water extraction and ethanol precipitation. Physicochemical characterization of SOPs was analyzed by phenol-sulfuric acid, m-hydroxydiphenyl, Bradford method, and gas chromatography. Phagocytic capacity of RAW 264.7 macrophages incubated with SOPs (25 and 100 μg/ml) was determined by the aseptic neutral red method. Macrophages were incubated with SOPs (25 and 100 μg/ml), and the TNF-α and NO the secretion were measured using ELISA kit and Griess reagent, respectively. In addition, TNF-α and iNOS transcripts were evaluated by semi-quantitative RT-PCR, and NF-κB signaling activation was detected by Western blot assay.

RESULTS

SOPs enhanced the phagocytosis capacity of macrophages to aseptic neutral red solution and increased TNF-α and NO secretion. The amounts of TNF-α and iNOS transcript were increased significantly at the mRNA level when macrophages were exposed to SOPs. Meanwhile, the stimulation of macrophages by SOPs induced phosphorylation of p65 at serine 536 and a marked decrease of IκB expression.

DISCUSSION AND CONCLUSION

These results suggested that SOPs exhibited significant macrophage activation properties through NF-κB signaling pathway and could be considered as a new immunopotentiator.

Immune evasion in cancer: Mechanistic basis and therapeutic strategies

Cancer immune evasion is a major stumbling block in designing effective anticancer therapeutic strategies. Although considerable progress has been made in understanding how cancers evade destructive immunity, measures to counteract tumor escape have not kept pace. There are a number of factors that contribute to tumor persistence despite having a normal host immune system. Immune editing is one of the key aspects why tumors evade surveillance causing the tumors to lie dormant in patients for years through "equilibrium" and "senescence" before re-emerging. In addition, tumors exploit several immunological processes such as targeting the regulatory T cell function or their secretions, antigen presentation, modifying the production of immune suppressive mediators, tolerance and immune deviation. Besides these, tumor heterogeneity and metastasis also play a critical role in tumor growth. A number of potential targets like promoting Th1, NK cell, γδ T cell responses, inhibiting Treg functionality, induction of IL-12, use of drugs including phytochemicals have been designed to counter tumor progression with much success. Some natural agents and phytochemicals merit further study. For example, use of certain key polysaccharide components from mushrooms and plants have shown to possess therapeutic impact on tumor-imposed genetic instability, anti-growth signaling, replicative immortality, dysregulated metabolism etc. In this review, we will discuss the advances made toward understanding the basis of cancer immune evasion and summarize the efficacy of various therapeutic measures and targets that have been developed or are being investigated to enhance tumor rejection.

Influence of pea protein aggregates on the structure and stability of pea protein/soybean polysaccharide complex emulsions

The applications of plant proteins in the food and beverage industry have been hampered by their precipitation in acidic solution. In this study, pea protein isolate (PPI) with poor dispersibility in acidic solution was used to form complexes with soybean soluble polysaccharide (SSPS), and the effects of PPI aggregates on the structure and stability of PPI/SSPS complex emulsions were investigated. Under acidic conditions, high pressure homogenization disrupts the PPI aggregates and the electrostatic attraction between PPI and SSPS facilitates the formation of dispersible PPI/SSPS complexes. The PPI/SSPS complex emulsions prepared from the PPI containing aggregates prove to possess similar droplet structure and similar stability compared with the PPI/SSPS emulsions produced from the PPI in which the aggregates have been previously removed by centrifugation. The oil droplets are protected by PPI/SSPS complex interfacial films and SSPS surfaces. The emulsions show long-term stability against pH and NaCl concentration changes. This study demonstrates that PPI aggregates can also be used to produce stable complex emulsions, which may promote the applications of plant proteins in the food and beverage industry.

Effect of different drying methods on chemical composition and bioactivity of finger citron polysaccharides

Traditionally, people like to take dried finger citron fruits (FC) as adjuvant herbal medicines to treat a diversity of chronic diseases like asthma, hypertension and respiratory tract infections. Many healing properties are attributed to FC polysaccharides (FCPs), one of the main active ingredients of FC. Three drying methods, freeze drying (FDM), hot air drying (HDM) and vacuum drying methods (VDM) were comparatively studied on the physicochemical and antioxidant properties of FCPs. The results showed these FCPs were similar in UV and FT-IR spectrum. However, they showed significant differences (p<0.05) in yields of crude polysaccharides and contents of protein and ash. Compared with VDM and HDM, FDM resulted in the properties of FCPs with lower molecular weight distribution, higher reducing power and scavenging abilities on DPPH, OH, and O2(-). Available data obtained in vitro models suggested that FDM was an appropriate and effective treatment for obtaining crude polysaccharides from FC fruits. Hence, drying methods used for preparation of FCPs can affect physicochemical and associated functional properties.

Functional polysaccharides from medicinal mushroom Cordyceps sinensis as a potent food supplement: extraction, characterization and therapeutic potentials – a systematic review

As a rich source of novel polysaccharides, Cordyceps sinensis (CS), one of the valued traditional Chinese medicinal fungi, is a major focus of many natural products research efforts.

Structural characterization and in vitro antitumor activity of polysaccharides from Zizyphus jujuba cv. Muzao

Complete structural characterization and in vitro antitumor activity of polysaccharides from Zizyphus jujuba cv. Muzao.

Polysaccharides from Cymbopogon citratus with antitumor and immunomodulatory activity

Abstract Context: Most of the present studies on the antitumor efficiency of Cymbopogon citratus (DC.) Stapf (Gramineae) are limited to its low-mass compounds, and little information about the antitumor activity of polysaccharides from this plant is available.

OBJECTIVES

This study focused on the potential antitumor and immunomodulatory activities of polysaccharides (CCPS) from C. citratus.

MATERIALS AND METHODS

CCPS was isolated using the water extraction-ethanol precipitation method. The sarcoma 180 (S180) cells-inoculated mice were intraperitoneally administrated with CCPS (30-200 mg/kg/d) for seven consecutive days. The effects of CCPS on tumor growth, thymus and spleen weights, splenocyte proliferation, and cytokine secretion in the tumor-bearing mice were measured. The cytotoxicity of CCPS (50-800 μg/mL) towards S180 cells was also studied.

RESULTS

CCPS significantly inhibited the growth of the transplanted S180 tumors, with the inhibition rates ranging from 14.8 to 37.8%. Simultaneously, CCPS dose-dependently improved the immunity of the tumor-bearing mice. With the highest dose of 200 mg/kg/d, the thymus and spleen indices were increased by 21.9 and 91.9%, respectively; ConA- and LSP-induced splenocyte proliferations were increased by 32.7 and 35.3%, respectively. The secretions of interleukin 2 (IL-2), interleukin 6 (IL-6), interleukin 2 (IL-12), and tumor necrosis factor-α (TNF-α) were increased by 103.2, 40.2, 23.6, and 26.3%, respectively. Nevertheless, almost no toxicity of CCPS towards S180 cells was observed, with the maximal inhibition rate less than 15% at the CCPS concentration of 800 μg/mL.

CONCLUSION

CCPS exhibited antitumor activity in vivo, and this activity might be achieved by immunoenhancement rather than direct cytotoxicity.

Preparation of nano/submicrometer Ganoderma tsugae and its mutagenic potencies and cytotoxicity

This study explored the feasibility of preparing nano/submicrometer particles from Ganoderma tsugae to enhance the contents of bioactive compounds and to assess its mutagenic potencies and cytotoxicity. Hot-water extract, a common product, was employed as a reference. After 3 h of media milling, almost all of the particles were smaller than 1 μm with a number-mean diameter of 0.11 μm. There were about 62% particles smaller than 0.1 μm in terms of number of particles. Scanning electron microscopy (SEM) confirmed the presence of particles at nano/submicrometer scale. The content of 1→3-β-D-glucan in nano/submicrometer G. tsugae was 3.5 times of that in hot-water extract. Both nano/submicrometer and hot-water extract G. tsugae exhibited no mutagenic potential to Salmonella Typhimurium tester strains. Cell toxicity test also confirmed the safety of both nano/submicrometer and hot-water extract G. tsugae. The effect of media milling on the structural change of hyphae was also discussed.

Response surface optimization and physicochemical properties of polysaccharides from Nelumbo nucifera leaves

Dynamic high pressure microfluidization (DHPM)-assisted extraction (DHPMAE) of lotus (Nelumbo nucifera) leaves polysaccharides (LLPs) was optimized by response surface methodology. The optimal extraction conditions were: liquid/solid ratio of 35:1 (v/m, mL/g), processing pressure of 180 MPa, processed two times, extraction temperature of 76°C, extraction time of 50 min. Under the optimal extraction conditions, DHPMAE produced a higher polysaccharides yield (6.31%) than leaching (2.95%). Scanning electron microscope (SEM) analysis revealed that DHPM could reduce the particles size and make the surface more unconsolidated. The LLPs prepared by both methods showed similar FT-IR spectrum, and were consisted of the same monosaccharides, including rhamnose, fucose, arabinose, xylose, mannose, glucose and galactose. The content of each monosaccharide in extracts, however, was quite different. The average molecular weight of LLPs prepared by DHPMAE is 550 kDa, smaller than 578 kDa obtained by leaching. The LLPs prepared by DHPMAE exhibited stronger DPPH scavenging ability (IC50 value of 0.38 mg/mL), HO scavenging ability (IC50 value of 0.61 mg/mL) and reducing power. Therefore, DHPMAE can be a promising alternative to traditional extraction techniques for polysaccharides from plants, and lotus leaves might be a potential resource of natural antioxidants.