Purification, antitumour and immunomodulatory activity of water-extractable and alkali-extractable polysaccharides from Solanum nigrum L

Solanum nigrum L. in COVID-19 and post-COVID complications: a propitious candidate

COVID-19 is caused by severe acute respiratory syndrome coronavirus-2, SARS-CoV-2. COVID-19 has changed the world scenario and caused mortality around the globe. Patients who recovered from COVID-19 have shown neurological, psychological, renal, cardiovascular, pulmonary, and hematological complications. In some patients, complications lasted more than 6 months. However, significantly less attention has been given to post-COVID complications. Currently available drugs are used to tackle the complications, but new interventions must address the problem. Phytochemicals from natural sources have been evaluated in recent times to cure or alleviate COVID-19 symptoms. An edible plant, Solanum nigrum, could be therapeutic in treating COVID-19 as the AYUSH ministry of India prescribes it during the pandemic. S. nigrum demonstrates anti-inflammatory, immunomodulatory, and antiviral action to treat the SARS-CoV-2 infection and its post-complications. Different parts of the plant represent a reduction in proinflammatory cytokines and prevent multi-organ failure by protecting various organs (liver, kidney, heart, neuro, and lung). The review proposes the possible role of the plant S. nigrum in managing the symptoms of COVID-19 and its post-COVID complications based on in silico docking and pharmacological studies. Further systematic and experimental studies are required to validate our hypothesis.

Solanum nigrum Linn.: An Insight into Current Research on Traditional Uses, Phytochemistry, and Pharmacology

Solanum nigrum Linn., is a common edible medicinal herb of the Solanaceae family which is native to Southeast Asia and is now widely distributed in temperate to tropical regions of Europe, Asia, and America. Traditionally, it has been used to treat various cancers, acute nephritis, urethritis, leucorrhea, sore throat, toothache, dermatitis, eczema, carbuncles, and furuncles. Up to now, 188 chemical constituents have been identified from S. nigrum. Among them, steroidal saponins, alkaloids, phenols, and polysaccharides are the major bioactive constituents. Investigations of pharmacological activities of S. nigrum revealed that this edible medicinal herb exhibits a wide range of therapeutic potential, including antitumor, anti-inflammatory, antioxidant, antibacterial, and neuroprotective activities both in vivo and in vitro. This article presents a comprehensive and systematic overview of the botanical, traditional uses, phytochemical compositions, pharmacological properties, clinical trials, and toxicity of S. nigrum to provide the latest information for further exploitation and applications of S. nigrum in functional foods and medicines.

Kigelia africana fruit biofibre polysaccharide extraction and biofibre development by silane chemical treatment

Silane-treated natural cellulosic Kigelia africana fruit fibre (KAF) was experimentally established to have strong strength after removing hydrophilic materials. Silane treatment makes it compatible with hydrophobic biopolymeric materials than existing non-grafted KA fibre. In this work, the polysaccharide was extracted from the KAF and found to have all the essential compounds. KA fruit-based cellulosic fibre was extracted and treated with different concentrations of silane solution. Silane-treated (13%) KAF has a cellulose content of about 76.86%. The peak found at 1734 cm^-1 shows the hemicellulose in untreated fibres, and its intensity decreased after silane treatment, as confirmed by FTIR. X-ray diffraction investigation indicated that silane-treated (5%) KAF has a crystallinity index of 70.22%. After treatment, the tensile strength of 5% silane-treated KAF shows a tensile strength of 490.77 MPa, giving more viability to biofibre reinforcement.

Research advances in bioactive components and health benefits of jujube (Ziziphus jujuba Mill.) fruit

Jujube (Ziziphus jujuba Mill.), a highly nutritious and functional fruit, is reported to have various health benefits and has been extensively planted worldwide, especially in China. Many studies have shown that bioactive components derived from jujube fruit have significant nutritional and potential biological effects. In this paper, the latest progress in research on major bioactive compounds obtained from jujube is reviewed, and the potential biological functions of jujube fruit resources are discussed. As a dietary supplement, jujube fruit is well recognized as a healthy food which contains a variety of bioactive substances, such as polysaccharides, polyphenols, amino acids, nucleotides, fatty acids, dietary fiber, alkaloids, and other nutrients. These nutrients and non-nutritive phytochemicals obtained from jujube fruit have physiological functions including anticancer, antioxidant, anti-inflammatory, anti-hyperlipidemic, anti-hyperglycemic, immunoregulatory, neuroprotective, sedative, and antiviral functions. Of note is that new constituents, including alkaloids, dietary fiber, and other bioactive substances, as well as the antiviral, hypoglycemic, lipid-lowering, and neuroprotective effects of jujube fruit, are systematically reviewed here for the first time. Meanwhile, problems affecting the exploitation of jujube fruit resources are discussed and further research directions proposed. Therefore, this review provides a useful bibliography for the future development of jujube-based products and the utilization of jujube nutritional components in functional foods.

Structural Characterization of Pectic Polysaccharides in the Cell Wall of Stevens Variety Cranberry Using Highly Specific Pectin-Hydrolyzing Enzymes

The potential of poly- and oligosaccharides as functional ingredients depends on the type and glycosidic linkages of their monosaccharide residues, which determine their techno-functional properties, their digestibility and their fermentability. To isolate the pectic polysaccharides of cranberry, alcohol insoluble solids were first obtained from pomace. A sequential extraction with hot phosphate buffer, chelating agents (CH), diluted (DA) and concentrated sodium hydroxide was then carried out. Pectic polysaccharides present in CH and DA extracts were purified by anion exchange and gel filtration chromatography, then sequentially exposed to commercially available pectin-degrading enzymes (endo-polygalacturonase, pectin lyase and endo-arabinanase/endo-galactanase/both). The composition and linkages of the generated fragments revealed important characteristic features, including the presence of homogalacturonan with varied methyl esterification extent, branched type I arabinogalactan and pectic galactan. The presence of arabinan with galactose branches was suggested upon the analysis of the fragments by LC-MS.

Therapeutic opportunities of edible antiviral plants for COVID-19

The pandemic of Serious Acute Respiratory Syndrome Corona Virus-2 (SARS-CoV-2) that produces corona virus disease (COVID-19) has challenged the entire mankind by rapidly spreading globally in 210 countries affecting over 25 million people and about 1 million deaths worldwide. It continues to spread, afflicting the health system globally. So far there is no remedy for the ailment and the available antiviral regimens have been unsatisfactory for the clinical outcomes and the mode of treatment has been mainly supportive for the prevention of COVID-19-induced morbidity and mortality. From the time immortal the traditional plant-based ethno-medicines have provided the leads for the treatment of infectious diseases. Phytopharmaceuticals have provided potential and less toxic antiviral drugs as compared to conventional modern therapeutics which are associated with severe toxicities. The ethnopharmacological knowledge about plants has provided food supplements and nutraceuticals as a promise for prevention and treatment of the current pandemic. In this review article, we have attempted to comprehend the information about the edible medicinal plant materials with potential antiviral activity specifically against RNA virus which additionally possess property to improve immunity along with external and internal respiration and exhibit anti-inflammatory properties for the prevention and treatment of the disease. This will open an arena for the development of novel nutraceutical herbal formulations as an alternative therapy that can be used for the prevention and treatment of COVID-19.

Anticancer and Immunomodulatory Effects of Polysaccharides

Cancer is one of the leading causes of death and one of the most important public health problems in the world. And every year, millions of new cancers and hundreds of thousands of cancer-related deaths are reported worldwide. In recent decades, a number of biologically active polysaccharides and polysaccharide-protein complexes have been isolated from plants, lichen, algae, yeast, fungi and mushroom, and due to their antitumor and immunomodulatory properties, these compounds have received considerable attention. Overall, the two key mechanisms by which polysaccharides act on tumor cells are direct action (inhibition of cancer cell growth and induction of programmed cell death/apoptosis) and indirect action (stimulation of immunity). Immunosuppressive effects are recognizable in both cancer patients and tumor bearing animals, suggesting that the immune system plays an important role in the immune surveillance of cancer cells. Thus, enhancement of the host immune response has been evaluated as a possible way of inhibiting tumor growth without damaging the host. In addition to their therapeutic and prophylactic properties, the polysaccharides are effective and less toxic than chemotherapy. The anticancer activity and immunomodulatory effects of most polysaccharides have shown the promising and real potential for the benefits of human health.

A tumor-targeted nanoplatform with stimuli-responsive cascaded activities for multiple model tumor therapy

Herein, a rambutan-like nanocomplex (PDA-SNO-GA-HA-DOX, PSGHD for short) was designed to enable effective and accurate tumor therapy. The PSGHD nanocomplex consists of an S-nitrosothiol-functionalized polydopamine (PDA-SNO) core and a gambogic acid-derivatized hyaluronic acid (HA-GA) shell with doxorubicin (DOX) as the cargo. Due to the HA section, the PSGHD nanocomplex can be rapidly and selectively internalized by tumor cells instead of healthy cells in 12 h of co-incubation. After that, the internalized PSGHD nanocomplex is able to gradually release both DOX (agent for chemotherapy) and GA (agent for enhancing thermal damage) under different tumor-specific physiological conditions (low pH and rich HAase). When 808 nm NIR radiation was employed, the PSGHD nanocomplex further demonstrated excellent photothermal conversion to increase the local temperature over 43 °C and convert SNO to nitric oxide (NO, an agent for decreasing drug-efflux). Based on the synergistic effects of NO/DOX and GA/heat, the PSGHD nanocomplex simultaneously achieved tumor-specific low-drug-efflux chemotherapy and low-temperature photothermal therapy, resulting in an eight-fold apoptosis of tumor cells over normal cells under NIR radiation. In vivo data from mouse models further showed that the PSGHD nanocomplex can completely inhibit tumor growth and significantly prolong the survival rate of tumor bearing mice in 50 days, demonstrating the high efficiency of the PSGHD nanocomplex for tumor therapy.

Awareness and current knowledge of epilepsy

Epilepsy is a severe neural disorder that affects approximately fifty million individuals globally. Despite the fact that for most of the people with epilepsy, convulsions are better controlled by current accessible antiepileptic medicines, yet there are more than 30% of individuals affected with medically intractable epilepsy and around 30-40% of all patients with epilepsy affected by many adverse reactions and convulsion resistance to the present antiepileptic drugs. Consequently, various scientists attempt to develop new strategies to treat epilepsy, for instance, to find out novel antiepileptic ingredients from traditional medicines. This work aims to present a complete summary of natural medicines prescribed as antiepileptic agents all over the world by ethnic groups and different tribes. We undertook an extensive bibliographic analysis by searching peer reviewed papers and classical textbooks and further consulting well accepted worldwide scientific databases. We carried out PubMed, EMbase and CENTRAL searches by means of terms such as "antiepileptic" and "anti-convulsant" activity of plants. Medicinal plants have been prescribed to treat epilepsy and have been recognized as antiepileptic medicines. In this review, a variety of herbs have been reviewed for thorough studies such as Cuminum cyminum, Butea monosperma, Solanum americanum, Anacyclus pyrethrum, Leonotis leonurus, Elaeocarpus ganitrus and Angelica archangelica. This paper shows that it was high time experimental studies are increased to obtain novel potential active principles from medicinal plants. Plant extracts and their chemical constituents should be further evaluated to clarify their mechanisms of action. This paper provides a solid base upon which to further investigate the clinical efficacy of medicinal plants that are both currently prescribed by physicians as traditional antiepileptic agents, but also could be effective as an antiepileptic drug with further research and study.

Physicochemical Characterization and Immunomodulatory Activity of a Novel Acid Polysaccharide from Solanum muricatum

To investigate the structure and immunomodulatory activity of polysaccharide from Solanum muricatum, a novel acid polysaccharide named SMP-3a was purified from Solanum muricatum pulp through DEAE-52 cellulose column and Sephadex G-200 chromatography. Monosaccharide composition analysis showed that SMP-3a was mainly composed of rhamnose, arabinose, galactose, and galacturonic acid with the molar ratio of 1.09:2.64:1.54:1. The average molecular weight was found to be 227 kDa by high performance gel permeation chromatography (HPGPC). Thermal studies revealed the SMP-3a was a thermally stable polymer. Based on the results of methylation and NMR analysis, the backbone chain of SMP-3a was composed of →2)-α-l-Rhap-(1→, →4)-α-d-GalpA-(1→ and →4)-α-d-Galp-(1→. The side chain was consisted of α-l-Araf-(1→ and →5)-α-l-Araf-(1→. Immunomodulatory assay indicated that SMP-3a could significantly promote the proliferation of macrophages and stimulate the secretion of cytokines, including TNF-α, IL-1β, and IL-6. Our results suggested that SMP-3a could be used as a novel potential immunomodulatory agent in functional food.

Therapeutic value of steroidal alkaloids in cancer: Current trends and future perspectives

Discovery and development of new potentially selective anticancer agents are necessary to prevent a global cancer health crisis. Currently, alternative medicinal agents derived from plants have been extensively investigated to develop anticancer drugs with fewer adverse effects. Among them, steroidal alkaloids are conventional secondary metabolites that comprise an important class of natural products found in plants, marine organisms and invertebrates, and constitute a judicious choice as potential anti-cancer leads. Traditional medicine and modern science have shown that representatives from this compound group possess potential antimicrobial, analgesic, anticancer and anti-inflammatory effects. Therefore, systematic and recapitulated information about the bioactivity of these compounds, with special emphasis on the molecular or cellular mechanisms, is of high interest. In this review, we methodically discuss the in vitro and in vivo potential of the anticancer activity of natural steroidal alkaloids and their synthetic and semi-synthetic derivatives. This review focuses on cumulative and comprehensive molecular mechanisms, which will help researchers understand the molecular pathways involving steroid alkaloids to generate a selective and safe new lead compound with improved therapeutic applications for cancer prevention and therapy. In vitro and in vivo studies provide evidence about the promising therapeutic potential of steroidal alkaloids in various cancer cell lines, but advanced pharmacokinetic and clinical experiments are required to develop more selective and safe drugs for cancer treatment.

Structural characterization and immunomodulating activities of a novel polysaccharide from Nervilia fordii

Nervilia fordii (Hance) Schltr. has been widely used as a medicinal and edible herb in Southwest China and Southeast Asia. In this study, NFP-1, a new water-soluble polysaccharidewith a purity of 97.8%, was purified from water extract of Nervilia fordii by DEAE-cellulose and Sephadex G-100 chromatography. NFP-1 has a relative molecular weight of 950 kDa determined by high performance gel-permeation chromatography (HPGPC). Its monosaccharide compositions were analyzed by high performance liquid chromatography (HPLC) after pre-column derivatizing its hydrolysate with 1-phenyl-3-methyl-5-pyrazolone (PMP). NFP-1 mainly consists of galactose, arabinose, rhamnose, and galacturonic acid. Based on FT-IR, methylation and GC–MS analysis, and NMR, the structure unit of NFP-1 was established as →4)-α-Rhap-(2→ 4)-α-GalpA-(1→2)-α-Rhap-(1→2)-α-Rhap-(4→1)-β-Galp-T containing two branch chains of →2,4)-α-Rhap-(1→5)-α-Araf-(1→3)-α-Araf-(1→, and →2,4)-α-Rhap-(1→4)-β-Galp-(1→. The immunomodulatory assays revealed the dual-functionalities of NFP-1. NFP-1 could significantly induce the secretion of nitric oxide (NO), and promote the secretions of TNF-α, IL-6, and IL-1β in RAW264.7 macrophages. NFP-1 could also significantly inhibit the production of NO, depress the secretions of TNF-α, IL-6 and IL-1β in RAW264.7 macrophages activated by lipopolysaccharide (LPS), and promote the production of IL-10 meanwhile. Our study suggested that Nervilia fordii could be an ideal medicinal or functional food due to its dual immunomodulatory activities.

The Antioxidative, Antiaging, and Hepatoprotective Effects of Alkali-Extractable Polysaccharides by Agaricus bisporus

The aim of this work was designed to investigate the antioxidant, antiaging, and hepatoprotective effects of alkali-extractable polysaccharides (AlAPS) and their three purified fractions (AlAPS-1, AlAPS-2, and AlAPS-3) from Agaricus bisporus in D-galactose induced aging mice. For in vitro antioxidant analysis, both AlAPS and its fractions exhibited moderate reducing power, Fe²⁺-chelating activities, and potent scavenging activities on hydroxyl and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals. The in vivo results demonstrated that the polysaccharides, especially AlAPS-2, showed potential antiaging and hepatoprotective effects by enhancing the antioxidant status, decreasing serum hepatic enzyme activities, and improving the lipid metabolism. This study suggested that the polysaccharides extracted and purified from A. bisporus could be exploited as a potent dietary supplement to attenuate aging and prevent age-related diseases.

Purification, characterization and immunoregulatory activity of a polysaccharide isolated from Hibiscus sabdariffa L

BACKGROUND

Hibiscus sabdariffa L. is not only used traditionally as a component of herbal drinks, beverages and flavoring agents but also as a herbal medicine in the drug industry. Bioactive polysaccharides are important constituents of H. sabdariffa that may contribute to the plant's beneficial effects. This study was designed to investigate the structural characteristics of a water-soluble polysaccharide from H. sabdariffa, HSP41, and its immunoregulatory activity on RAW264.7 cells.

RESULTS

HSP41 was mainly composed of arabinose, xylose and mannose at a molar ratio of 1:1.34:15.6, with an average molecular weight of 3.3 × 10⁵  Da. Fourier transform infrared (FTIR) spectra exhibited absorption peaks characteristic of HSP41. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) revealed the amorphous form and aggregation conformation of HSP41 respectively. HSP41 significantly induced interleukin 1β (IL-1β) and inducible nitric oxide synthase (iNOS) expression in RAW264.7 cells in vitro, promoting an increase in nuclear factor kB p65 (NF-kB p65) levels in the nucleus.

CONCLUSION

The results indicated that HSP41 up-regulated the immune response by stimulating RAW264.7 cell activity. HSP41, a promising immunoregulator, possibly contributes to the health benefits of H. sabdariffa and might have potential applications in health food or medicine. © 2016 Society of Chemical Industry.

Characterization of Polysaccharides with Antioxidant and Hepatoprotective Activities from the Edible Mushroom Oudemansiella radicata

The preliminary structure, in vitro antioxidant and in vivo hepatoprotective activities of water-soluble polysaccharides (ORWP) and alkali-soluble polysaccharides (ORAP), prepared from the mushroom Oudemansiella radicata, were investigated. Both ORWP and ORAP were heteropolysaccharides with mannose, glucose and galactose being the main monosaccharide components. Regarding the antioxidant activities, ORWP and ORAP showed effective 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, hydrogen peroxide scavenging activity and lipid peroxidation inhibitory effects, as well as moderate reducing power and Fe²⁺ chelating activity. For the hepatoprotective activity, administration of ORWP and ORAP prevented the increase in serum alanine aminotransferase and aspartate aminotransferase activities in a carbon tetrachloride-induced acute liver damage model, suppressed hepatic malondialdehyde formation and stimulated the activities of hepatic superoxide dismutase and glutathione peroxidase. Thus, we speculate that ORWP and ORAP may protect the liver from CCl₄-induced hepatic damage via antioxidant mechanisms.

Cytotoxic, Antitumor and Immunomodulatory Effects of the Water-Soluble Polysaccharides from Lotus (Nelumbo nucifera Gaertn.) Seeds

Lotus is an edible and medicinal plant, and the extracts from its different parts exhibit various bioactivities. In the present study, the hot water-soluble polysaccharides from lotus seeds (LSPS) were evaluated for their cancer cell cytotoxicity, immunomodulatory and antitumor activities. LSPS showed significant inhibitory effects on the mouse gastric cancer MFC cells, human liver cancer HuH-7 cells and mouse hepatocarcinoma H22 cells. The animal studies showed that LSPS inhibited tumor growth in H22 tumor-bearing mice with the highest inhibition rate of 45.36%, which is comparable to that induced by cyclophosphamide (30 mg/kg) treatment (50.79%). The concentrations of white blood cells were significantly reduced in cyclophosphamide-treated groups (p < 0.01), while LSPS showed much fewer side effects according to the hematology analysis. LSPS improved the immune response in H22 tumor-bearing mice by enhancing the spleen and thymus indexes, and increasing the levels of serum cytokines including tumor necrosis factor-α and interleukin-2. Moreover, LSPS also showed in vivo antioxidant activity by increasing superoxide dismutase activity, thus reducing the malondialdehyde level in the liver tissue. These results suggested that LSPS can be used as an antitumor and immunomodulatory agent.

Immunomodulatory and Antioxidant Effects of Polysaccharides from Gynostemma pentaphyllum Makino in Immunosuppressed Mice

The immunomodulatory and antioxidant activities of crude polysaccharides extracted from Gynostemma pentaphyllum Makino (GPMPP) were investigated. GPMPP was composed of rhamnose, arabinose, xylose, mannose, glucose and galactose in the molar ratio of 1.39:3.76:1.00:1.64:4.98:5.88. In vivo studies showed GPMPP significantly increased the spleen and thymus indices, activated the macrophage phagocytosis and NK cells, and exhibited activity on none or Con A/LPS-stimulated splenocytes in a dose-dependent manner in C57BL/6 mice. Moreover, GPMPP elevated CD4⁺ T lymphocyte counts as well as the CD4⁺/CD8⁺ ratio dose-dependently, and it increased IL-2 level in the sera and spleen of Cy-immunosuppressed mice. Furthermore, GPMPP significantly increased the SOD, GSH-Px, T-AOC, GSH and CAT level, and decreased the MDA level. The results showed that GPMPP might play an important role in prevention of oxidative damage in immunological system. These findings indicate GPMPP has immunomodulatory activity in vivo and seems to be an effective natural immunomodulatory agent.

Arabinoxylan from Mucilage of Tomatoes (Solanum lycopersicum L.): Structure and Antinociceptive Effect in Mouse Models

Tomato is a known functional food due to its content of bioactive compounds. Herein, polysaccharides were extracted from mucilage of tomatoes, and a purified fraction (PTOK) was analyzed by sugar composition, methylation, and NMR spectroscopy analysis. The results showed the presence of an arabinoxylan, having (1→4)-linked β-d-Xylp units in the main chain, which carried a low proportion of branching (∼5.6%), at O-2 and O-3 position, with side chains constituted by single Araf or Xylp units. Intraperitoneal administration of the arabinoxylan in mice significantly reduced the number of abdominal constrictions induced by 0.6% acetic acid and the inflammatory phase of nociception induced by 2.5% formalin, indicating that it had an antinociceptive effect on inflammatory pain models, amplifying the biological role displayed by arabinoxylans in the diet. Furthermore, this study reports the presence of an arabinoxylan in a dicotyledon plant, and also it is the first study of polysaccharides from mucilage of tomatoes.

Antitumor efficacy in H22 tumor bearing mice and immunoregulatory activity on RAW 264.7 macrophages of polysaccharides from Talinum triangulare

The aim of this paper was to study the antitumor and immunoregulatory activities of a polysaccharide (TTP) from Talinum triangulare. The molecular weight of TTP-IV was 49.9 kDa. The monosaccharide composition analysis of TTP-IV revealed that it was a heteropolysaccharide consisting of rhamnose, arabinose, mannose and galactose with a molar ratio of 1.22 : 1.00 : 1.05 : 1.51. The results of the in vivo study showed that TTP (200 mg per kg bw) significantly inhibited the growth of tumor by 49.07% in H22-bearing Kunming mice. In vitro, the growth of primary murine macrophages was promoted by TTP in a dose- and time-dependent manner significantly. Besides, RAW 264.7 cells were activated by TTP to produce NO and the toxicity of RAW 264.7 supernatant was markedly enhanced in vitro. The levels of iNOS, TLR2, TLR4 and IL-1β were obviously increased by TTP. Therefore, it is suggested that TTP can be utilized as a potent antitumor and immunoenhancing material in functional food.

Therapeutic Potential of Steroidal Alkaloids in Cancer and Other Diseases

Steroidal alkaloids are a class of secondary metabolites isolated from plants, amphibians, and marine invertebrates. Evidence accumulated in the recent two decades demonstrates that steroidal alkaloids have a wide range of bioactivities including anticancer, antimicrobial, anti-inflammatory, antinociceptive, etc., suggesting their great potential for application. It is therefore necessary to comprehensively summarize the bioactivities, especially anticancer activities and mechanisms of steroidal alkaloids. Here we systematically highlight the anticancer profiles both in vitro and in vivo of steroidal alkaloids such as dendrogenin, solanidine, solasodine, tomatidine, cyclopamine, and their derivatives. Furthermore, other bioactivities of steroidal alkaloids are also discussed. The integrated molecular mechanisms in this review can increase our understanding on the utilization of steroidal alkaloids and contribute to the development of new drug candidates. Although the therapeutic potentials of steroidal alkaloids look promising in the preclinical and clinical studies, further pharmacokinetic and clinical studies are mandated to define their efficacy and safety in cancer and other diseases.

Evaluation of antitumor property of extracts and steroidal alkaloids from the cultivated Bulbus Fritillariae ussuriensis and preliminary investigation of its mechanism of action

BACKGROUND

Cancer is well known as a leading cause of death in the world. At present, it is the very active area to search for anticancer drugs from natural products. In this study, we evaluated the antitumor property of chloroform extract (CE), n-hexane extract (HE), water extract (WE) and steroidal alkaloids from the cultivated Bulbus Fritillariae ussuriensis (BFU) and its preliminary mechanism for its action was investigated.

METHODS

Firstly, cytotoxicity of the different extracts from BFU against Lewis lung carcinoma cell line (LLC), Human ovarian cancer cell line (A2780), human hepatocellular carcinoma cell line (HepG2), human lung carcinoma cell line (A549) was measured by MTT assay. Then, we identified the compounds from the active extract of BFU by bioassay guided isolation, determined their antitumor activity in vitro, and detected cell cycle distribution using flow cytometry. Moreover, the extract of BFU which showed remarked anti-proliferative activity in vitro was further evaluated using S180 and LLC tumor models. Additionally, a preliminary investigation of the mechanism of the action was carried out by using histological and immunohistochemical staining technique.

RESULTS

The results showed that CE and the purified total alkaloids of BFU (TAFU) exhibited stronger cytotoxic activity than the others (WE and HE). We further isolated the four main steroidal alkaloids from TAFU, and found all alkaloids showed significant cytotoxicity, and peimisine induced G0/G1 phase arrest and increased apoptosis. The results showed that TAFU had significant antitumor activity and low toxicity in vivo. Additionally, the immunohistochemical examinations signified that TAFU remarkably increased caspase-3 expression and reduced microvessel density (MVD) in tumor tissues of transplantable S180 and LLC tumor models.

CONCLUSIONS

These results achieved suggested that the steroidal alkaloids could hold a good potential for use as an antitumor drug. Notably, our finding is the first report on the antitumor activity of extracts and steroidal alkaloids from the cultivated BFU in vitro and in vivo and its mechanisms.

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.

Characterization of polysaccharides with antioxidant and hepatoprotective activities from the wild edible mushroom Russula vinosa Lindblad

The aim of the present study was to investigate the antioxidant and hepatoprotective effects of water-soluble polysaccharides (RVLWP) and alkali-soluble polysaccharides (RVLAP) from Russula vinosa on carbon tetrachloride (CCl4)-induced acute liver damage in mice. For the in vitro antioxidant activities, RVLWP and RVLAP exhibited potent 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity (IC50 = 1.55 ± 0.04 and 3.37 ± 0.21 mg/mL, respectively), hydrogen peroxide scavenging activity (IC50 = 6.07 ± 0.24 and 9.23 ± 0.54 mg/mL, respectively), lipid peroxidation inhibitory effect (IC50 = 0.52 ± 0.095 and 0.86 ± 0.043 mg/mL, respectively), and moderate reducing power and Fe(2+) chelating activity (IC50 = 1.86 ± 0.0036 and 0.22 ± 0.0057 mg/mL, respectively). Ascorbic acid was employed as the standard antioxidant in the present study. For the in vivo hepatoprotective activity, administration of RVLWP and RVLAP (200 mg/kg) significantly prevented the elevation in serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities in acute liver damage induced by CCl4 and suppressed hepatic malondialdehyde (MDA) formation. Mice treated with RVLWP and RVLAP demonstrated a better profile of antioxidants with augmented activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in the liver. The results suggest that RVLWP and RVLAP protect the liver from CCl4-induced hepatic damage via antioxidant mechanisms.

Screening and comparison of antioxidant activities of polysaccharides from Coriolus versicolor

Six polysaccharide fractions (Coriolus versicolor polysaccharides: CVPS-1, CVPS-2, CVPS-3, CVPS-4, CVPS-5 and CVPS-6) were isolated and purified from the fruiting bodies of C. versicolor by ion exchange chromatography and gel chromatography. Their chemical and physical characteristics were determined by chemical methods, high performance liquid chromatography, and high-performance gel-permeation chromatography. Finally, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical assay, superoxide radical assay, and hydroxyl radical assay were carried out to test the antioxidant activities of CVPS in vitro. The results indicated that the six CVPS fractions were acidic heteropolysaccharides, composed of mannose, rhamnose, glucuronic acid, glucose and fructose with different ratios. The molecular weights of CVPS-1, CVPS-2, CVPS-3, CVPS-4, CVPS-5 and CVPS-6 were 1740, 1480, 568, 880, 1260 and 1840kDa and the protein contents were 4.2%, 6.4%, 8.5%, 7.8%, 6.5% and 3.9%, respectively. Among the six fractions, CVPS with lower molecular weight, higher protein content and larger uronic acid amount, basically exhibited higher radical scavenging effects at the same concentration. Compared with other fractions, CVPS-3 exhibited the highest antioxidant activities. The effects of the molecular weight, protein content and uronic acid amount of the polysaccharides appeared to be significant on the improvement of the bioactivities.

Immunomodulatory and therapeutic potentials of herbal, traditional/indigenous and ethnoveterinary medicines

Herbs/Botanical plants are considered as God's gift to human beings in the form of natural medicines, like the one well known "Sanjeevani booti" described in Hindu Mythology. The traditional and ethno-veterinary practices have been in use for centuries, transferring the knowledge from generation to generation and they are accessible, easy to prepare and administer, with little or no cost at all. Even though the modern developments in therapeutic field brought about a rapid decline in traditional medicine, the plant-based remedies are still having a crucial role as potential source of therapeutic aids in health systems all over the world for both humans and animals. Among the 21,000 medicinal plants listed by the World Health Organization (WHO), 2500 species are native to India, which stands first in the production of medicinal herbs. This innumerable treasure of medicinal herbs brings India the distinction of 'the botanical garden of the world'. Nowadays immune-based therapies are gaining more importance than monovalent approaches which are having limited benefits. Apart from the actions like treating diseases, control of ecto- and endo-parasites, fertility enhancement, bone setting and poor mothering management, an array of herbal medicines have been reported which are having immunomodulatory effects like modulation of cytokine secretion, histamine release, immunoglobulin secretion, class switching, cellular co-receptor expression, lymphocyte expression, phagocytosis and so on. The present article describes in brief few of these important ones viz., ashwagandha, amla, tulsi, arjuna, aloe vera, garlic, turmeric, ginger, shatavari, neem, guduchi, kiwifruit, tut, kamala, palashlata, kokilaksha etc. being used for human and animal health benefits.

Structure and inducing tumor cell apoptosis activity of polysaccharides isolated from Lentinus edodes

In this study, five novel polysaccharides SLNT1, SLNT2, JLNT1, JLNT2, and JLNT3 were isolated from the fruit body of Lentinus edodes. Chemical and physical analyses showed that the five polysaccharides consist of glucose with the structure of β-(1→3)-d-glucose main chains and β-(1→6)-d-glucose side chains. Moreover, all of them had triple-helical conformation and different molecular weight distributions. Animal studies further demonstrated that the antitumor effects were remarkably improved by SLNT1 and JLNT1 treatments with the inhibitory rates of 65.41% and 61.07% in H22-bearing mice, respectively. Additionally, both of them significantly increased the levels of serum IL-2 and TNF-α production and induced the tumor cell apoptosis. Taken together, our findings revealed that the involved antitumor mechanisms possibly in part were mediated not only by enhancing the immunity but also by directly killing the tumor and the induction of tumor cell apoptosis in H22-bearing mice.

The pretreatment effects on the antioxidant activity of jujube polysaccharides

Pretreatment is vital to keep the bioactivities of polysaccharides. In this paper, the effects of hot water, ultrasonic and microwave extraction, as well as the effects of protein and pigment removal steps, on the antioxidant activity of water soluble polysaccharides in jujube (WSPJ) were studied. Hydroxyl free radical (OH) scavenging activity was adopted to determine the antioxidant activity of WSPJ. The results showed that OH scavenging activity of WSPJ extracted by ultrasonic wave was higher than that extracted by hot water and by microwave. Furthermore, power parameter in both ultrasonic and microwave extraction affected the OH scavenging activity dramatically. On the other hand, Sevag reagent was better than trichloroacetic acid (TCA), TCA with 1-butanol (TCA-B) and hydrochloric acid for protein removal, and H2O2 was better than active carbon for pigment removal to keep the antioxidant activity of WSPJ.

Three sulphated polysaccharides isolated from the mucilage of mud snail, Bullacta exarata philippi: characterization and antitumour activity

Three sulphated polysaccharides, coded as BEMPA, BEMPB(1), BEMPB(2), were extracted from the mucilage of mud snail of Bullacta exarata and purified by DEAE-cellulose ion-exchange and size-exclusion chromatography. Structural analysis of purified polysaccharides by chemical and biochemical methods revealed BEMPA was a high (1→3,4)-linked mannose-containing polysaccharide with molecular weight of 22,977 Da. BEMPB(1), with molecular weight of 64,117 Da, was a high (1→3)-linked arabinose-containing polysaccharide. BEMPB(2) was mainly composed of (1→3,4)-linked mannose with molecular weight of 47,507Da. The comparison between sulphated polysaccharides and their desulphated products showed that sulphate substitutions of BEMPB(1) were deduced to be at the C-3 of (1→4)-linked mannose, while sulphate substitutions of BEMPA and BEMPB(2) were at C-4 of (1→3)-linked mannose. Furthermore, BEMPA exhibited highest inhibitory effects on growth of B-16 melanoma cells, and IC(50) were 31.1 μg/mL.

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.