Isolation, purification, immunological and anti-tumor activities of polysaccharides from Gymnema sylvestre

Structural characterization, anti-tumor and immunomodulatory activity of intracellular polysaccharide from Armillaria luteo-virens

Armillaria luteo-virens (A. luteo-virens) is a kind of edible fungus mainly exists in Qinghai-Tibet of China, but at present only very few studies focus on the bioactivities of its polysaccharides. This study aimed to purify and characterize the structure features of a novel intracellular polysaccharide (ALP-A) derived from A. luteo-virens and explore its potential anti-tumor and immunomodulatory activities. Through systematic separation and purification, we obtained a homogeneous ALP-A with an average molecular weight of 23693Da. Structural analysis indicated that ALP-A was mainly composed of glucose and mannose with a molar ratio of 6.02:1. The repeating unit of ALP-A was →4) -α-D-Glcp-(1→ backbone with α-Glcp-(1→ and α-Manp-(6→ side chains which branched at O-2 position. The anti-tumor assays in vivo suggested that ALP-A could effectively restrain S180 solid tumor growth, protect immune organs and promote the secretion of cytokines (IL2, IL6 and TNF-α) in serum. Besides, in vitro immunomodulatory assays indicated that ALP-A could improve proliferation, phagocytic capacity and raise the level of NO and cytokines in Raw264.7 cells. These results demonstrate that ALP-A which possess potential antitumor and immunomodulatory abilities can be developed as a new functional food.

Microwave-ultrasonic technique development coupled with natural deep eutectic solvents in anthocyanin extraction from perilla leaves (Perilla frutescens var. Acuta)

BACKGROUND

As potent antioxidants, anthocyanins can protect the body from free radicals. However, the traditional solvent extraction method has the disadvantages of requiring a high extraction temperature and long extraction time, so it is necessary to develop an efficient extraction method for anthocyanins.

RESULTS

In this study, the technique of natural deep eutectic solvents (DESs) was applied to extract anthocyanins from purple perilla leaves with the aid of microwave-ultrasonic assisted extraction (MUAE). The response surface methodology (RSM), based on the Box-Behnken design (BBD), predicted the maximum extraction yield of anthocyanins to be 619.62 mg (100 g)^-1 under the following conditions: x₁ (ultrasonic extraction power) = 357.25 W, x₂ (time) = 25.62 min, and x₃ (temperature) = 57.80 °C. The biological activity of the extract obtained was evaluated by examining its radical-scavenging effect on 1,1-diphenyl-2-picrylhydrazyl, hydroxyl radical, and superoxide anion radicals. Its bacteriostatic impact was investigated on four typical bacteria: Shewanella putrefaciens (S. putrefaciens), Pseudomonas fluorescens (P. fluorescens), Escherichia coli (E. coli), and Staphylococcus aureus (S. aureus).

CONCLUSION

The integrated extraction method of DESs with MUAE was efficient, energy-saving, green, and sustainable. © 2022 Society of Chemical Industry.

Triterpenoid saponins and C21 steroidal glycosides from Gymnema tingens and their glucose uptake activities

Four new triterpenoid saponins, tigensides A-D (1-4), and one new C21 steroid, tipregnane A(9), together with six known compounds were isolated from the EtOAc fraction of the roots and stems of Gymnema tingens. The chemical structures of the new compounds were determined based on their spectroscopic data, including IR, UV, NMR, and mass spectrometric analysis. All compounds were isolated for the first time. Compounds 1-11 promoted glucose uptake in the range of 1.12 to 2.52 fold, respectively. Compound 2 showed the most potent glucose uptake, with 2.52 fold enhancement. Additionally, compound 2 showed a medium effect on the GLUT4 translocation activity in L6 cells in further study.

The effects of Gymnema Sylvestre supplementation on lipid profile, glycemic control, blood pressure, and anthropometric indices in adults: A systematic review and meta-analysis

There is a growing interest in the considerable health benefits of Gymnema Sylvestre (GS) supplementation, as some studies have reported that it may improve cardiometabolic risk factors. However, the widespread impact of GS supplementation on the parameters mentioned above is not fully resolved. Consequently, this study aimed to examine the effects of GS supplementation on lipid profile, glycemic control, blood pressure, and anthropometric indices in adults. Eligible randomized controlled trials (RCT), published up to November 2021, were identified through PubMed, Scopus, and ISI Web of Science databases. Six studies were included and analyzed using a random-effects model to calculate weighted mean differences (WMDs) with 95% confidence intervals (CI). All studies were conducted in adults that used a GC supplement (>1 week) and assessed our selected cardiovascular risk factors. Outcomes revealed that GS supplementation significantly decreased triglyceride (p < .001), total cholesterol (p < .001), low-density lipoprotein (p < .001), fasting blood sugar (p < .001), and diastolic blood pressure (p = .003). Some limitations, including notable heterogeneity, low quality of studies, and lack of diversity among research participants, should be considered when interpreting our results. Our outcomes suggest that GS supplementation may improve cardiovascular risk factors. Future large-high-quality RCTs with longer duration and various populations are needed to firmly establish the clinical efficacy of the plant.

Quaternary Ammonium Salt Strategy and Molecular Docking Studies of Novel 5-Acyl-8-(Arylamino)-Quinolines by Acetyl and Methanesulfonyl Chloride for Dual Evaluation Bioactivity

Six quinoline derivatives containing quaternary ammonium salts and acyl chloride groups were synthesized from ethyl 8-chloro-[1,3]dioxolo[4,5-g]quinoline-7-carboxylate in several step. With berberine as the positive control, three human cancer cell lines (HCT-116, Hela and A549) and human normal liver L-02 cell lines were used to evaluate the cytotoxicity of the newly synthesized compounds in vitro. Compound (V-X) showed good antitumor activity, and the test result of compound (VII) was better than that of positive control group. In terms of antibacterial activity, compound (V-X) has obvious inhibitory effect on Staphylococcus aureus (ATCC 29213) and Escherichia coli (ATCC 8739), and its antibacterial activity is about 1-4 times that of positive control amoxicillin and 1-2 times that of ciprofloxacin. Among them, the most effective compounds (VII) and (X) have 4-fold the antibacterial activity of amoxicillin and 2-fold the antibacterial activity of ciprofloxacin.

Supplementary Information

The online version contains supplementary material available at 10.1134/S1068162023020097.

Recent developments made in the assessment of the antidiabetic potential of gymnema species - From 2016 to 2020

BACKGROUND

In traditional herbal medicine, the Gymnema species has been well known for various therapeutic activities such as anti-diabetic, anti-inflammatory, anti-bacterial, anti-arthritic, anti-hyperlipidemic, cytotoxic, and immunostimulatory activities. This review is an effort to analyse all the recent studies done to explore the anti-diabetic potential of traditional Gymnema species. Gymnema sylvestre (Retz.) R.Br. ex Sm. is an important member of the Apocynaceae family that has been used to treat a variety of diseases, the most studied of which is diabetes. This action is mostly due to the pharmacologically active phytoconstituents present in its extract, which include gymnemic acids, triterpenoid saponin glycosides, and so on. Numerous other Gymnema species have also demonstrated a similar pharmacological action.

INTRODUCTION

The goal of this study is to give a critical overview of the available data on Gymnema species that are used to treat diabetes. The major goal of this study is to give up-to-date knowledge on ethnopharmacology, botany, pharmacology, and structure-activity relationships of Gymnemaspecies from 2016 to 2020, as well as potential future research. The potential of using medicinal plants for alleviating symptoms of diabetes is recently being recognized. This review aims to summarize the available data and highlight both the potential and shortcomings of using Gymnema therapeutically. This knowledge can further be used to develop more therapeutically effective drugs derived from Gymnema.

MATERIALS AND METHODS

Data for Gymnema species was obtained using a mix of several search terms from online databases such as PubMed, SCOPUS, and Europe PMC. Other literature surveys relevant to traditional knowledge, phytochemistry, pharmacology, or structure-activity relationship activity were also used as reference. Several methods by which Gymnema species extracts exert their effects have been investigated, and a summary of the newly discovered chemicals isolated from the plant in the previous five years has been provided.

RESULTS

SAR based evaluation has been carried out for a total of 27 pharmacologically active compounds belonging to three species of Gymnema genus (Gymnema sylvestre, Gymnema latifolium, and Gymnema inodorum).These compounds demonstrated the critical significance of plant medicines for diabetes management. Numerous heterocyclic compounds have anti-diabetic action and may serve as a starting point for the design and identification of new diabetes inhibitors.

CONCLUSIONS

This study aims to provide researchers with a better understanding of the antidiabetic potential Gymnema species, as well as an outline of prospective future developments. It was concluded after studying the evaluation done in the last 5 years that although extracts of Gymnema have shown good antidiabetic potential, further modifications in the structures could result in the development of more potent and safer compounds.

Antitumor activity and immunomodulation mechanism of a novel polysaccharide extracted from Polygala tenuifolia Willd. evaluated by S180 cells and S180 tumor-bearing mice

We recently isolated a polysaccharide from Polygala tenuifolia Willd. (PTP) and reported that such a PTP could induce cell apoptosis with FAS/FAS-L-mediated death receptor pathway in human lung cancer cells. Herein, we indicate antitumor activity and immunoregulation of PTP for S180 sarcoma cells by in vitro and in vivo targeting. In vitro, S180 cells took on prominent characteristics of apoptosis under-treated with PTP in follow-up antitumor activity studies, including irregular shrinkage and fragmentation nuclear, apoptotic bodies formation, and reduction of mitochondrial membrane potential (MMP). Additionally, flow cytometry indicated that the number of normal cells (FITC^-/PI^-) gradually decreased from 98.08% to 16.31%, while the number of apoptotic cells (FITC⁺/PI^- or FITC⁺/PI⁺) increased from 0.87% to 54.84%. The ratio of BAX and Bcl-2 increased, which promoted the release of Cytochrome C (CytC), and it further maximized the expression of activated-caspase-9/-3. Additionally, the PTP revised the immune organ indexes, the activities of NK cells and lymphocytes, and induced the secretion of IL-2 (7.34-16.17%), IFN-γ (14.34-20.85%) and TNF-α (12.32-22.58%) in vivo. Thus, PTP can induce cell apoptosis and activate the immunoregulation mechanism thereby exhibiting biological activity.

Metabolic differentiation and quantification of gymnemic acid in Gymnema sylvestre (Retz.) R.Br. ex Sm. leaf extract and its fermented products

INTRODUCTION

Gymnemagenin is the bioactive metabolite found in Gymnema sylvestre leaves and possesses different therapeutic potential. Due to its lower abundance and higher market potential, gymnemagenin was obtained from chemical conversion and bacterial biotransformation.

OBJECTIVE

To obtain the probiotic-based fermentative conversion of gymnemic acid-enriched G. sylvestre leaf extract to gymnemagenin-containing nutraceuticals and its metabolites based chromatographic comparison.

MATERIAL AND METHODS

Gymnema sylvestre leaves were extracted through soxhalation, and the extract was prepared and characterised. Gymnemic acid was fermented, separately, by Lactobacillus casei, Lactobacillus rhamnosus, Bifidobacterium bifidum, and by their mix co-culture. The fermented materials were analysed for their gymnemagenin content, antioxidant potential, antidiabetic potential, and metabolomics analysis.

RESULTS

Extraction yielded about 35% w/w of raw plant material, and 8.5% was found to be as total saponin content. Extract at higher concentration (≥ 5%, w/v) significantly altered the growth behaviour of probiotics. High-performance thin-layer chromatography (HPTLC) based quantification of gymnemagenin revealed that a maximum increase of 95.5% gymnemagenin was found in extract incubated with B. bifidum followed by mix co-culture containing (B. bifidum, L. casei, and L. rhamnosus), L. casei, and L. rhamnosus. However, liquid chromatography mass spectrometry (LC-MS) analysis resulted in the identification of a total of 56 metabolites.

CONCLUSION

Chromatographically profiled, and probiotic-based fermented G. sylvestre leaves can be used as a potent nutraceutical for diabetes and other metabolic disorders.

Purification, structural elucidation and physicochemical properties of a polysaccharide from Abelmoschus esculentus L (okra) flowers

Abelmoschus esculentus L (okra) is widely used as a healthy vegetable and favourable source of dietary medicine. Okra flowers which are by-products of okra, are rich in polysaccharide, polyphenols and trace elements etc., however, except a few for health tea, most of them were discarded as the waste of resources. In this study, a polysaccharide named AEFP22 was extracted, purified and identified from okra flowers, and its physicochemical property and antioxidant activity were also elucidated. AEFP22, with a molecular weight of 2.741 × 10⁵ Da, was composed of Rha, GalA and Gal in the ratio of 1: 1.02: 0.86. The methylation and nuclear magnetic resonance (NMR) analysis indicated AEFP22 was composed of [2)-α-D-Rhap-(1 → 4)-α-D-GalpA-(1 → 2,4)-α-D-Rhap-(1 → 4)-α-D-GalpA-(1] with branch of terminal T-α-D-Galp pointed at C4 of 1,2,4-α-D-Rhap. The Conge-red test, Atomic force microscope (AFM) and Scanning electron microscope (SEM) further revealed the triple-helical conformation, irregular sheet structure with molecule aggregations of AEFP22. The physicochemical property analysis indicated AEFP22 possessed stable thermal property and exhibited shear-thinning and normal Newtonian fluid in different concentrations, -7.04 mV zeta potential and polymerization phenomenon existed in AEFP22 solution. AEFP22 exhibited good 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging ability. These results indicated potential utilization of AEFP22 in nutritional food and material application.

Comprehensive Review on Phytochemicals, Pharmacological and Clinical Potentials of Gymnema sylvestre

Gymnema sylvestre is a plant included in Apocynaceae family and is located in many regions of Asia, Africa and Australia. This plant is widely used as a traditional therapy for different purposes. Even now it is being used as a dietary supplement due to its numerous therapeutic uses. It is known to have blood glucose lowering potential and, thus, is widely used in traditional and Ayurvedic systems of medicine. It renders glucose lowering activity due to the presence of phytochemicals, such as gurmarin, gymnemic acid as well as gymnemasaponins. Gymnema sylvestre is also known to have anti-oxidant, antibiotic, anti-inflammatory, antiviral, gastro and hepatoprotective, anticancer and lipid-lowering activities. This review discusses in details on different pharmacological and clinical potentials of Gymnema sylvestre and its chemical constituents associated with its therapeutic potentials.

Optimization of Ultrasound-Assisted Extraction and Structural Characterization of the Polysaccharide from Pumpkin (Cucurbita moschata) Seeds

In the present study, ultrasound-assisted extraction (UAE) of crude polysaccharides (PSP) from pumpkin seeds was optimized by response surface method (RSM). The polysaccharide yield (2.29 ± 0.14%), which agreed closely with the theoretical predicted value 2.40%, was obtained under the optimal extraction conditions: extraction time 24 min, extraction temperature 50 °C, ultrasonic power 347 W, and liquid to solid ratio 23 mL/g. After further purification by two-step column chromatography, a novel polysaccharide (PSP-1) was isolated from pumpkin seeds. PSP-1 was composed of mannose, glucose, and galactose in a molar ratio of 1.00:4.26:5.78 with molecular weight of 3728 g/mol. 1D and 2D NMR spectroscopy analysis revealed that the backbone of PSP-1 was mainly formed by β→6)-β-d-Galp-(1→, →6)-α-d-Glcp-(1→, and →3,6)-β-d-Manp-(1→ with branching at O-3 and O-6 of →3,6)-β-d-Manp-(1→. Branch linkages were composed of α-d-Glcp-(1→ and →4)-α-d-Galp-(1→.

A water-soluble polysaccharide from Grifola frondosa induced macrophages activation via TLR4-MyD88-IKKβ-NF-κB p65 pathways

Here, the immunomodulatory effects of water-soluble polysaccharide from Grifola frondosa on RAW264.7 macrophages and its molecular mechanisms were investigated. G. frondosa polysaccharide could obviously enhance immunostimulatory activity such as the release of nitric oxide and cytokine production. Western blotting results showed that G. frondosa polysaccharide elevated the TLR4, which might act as an upstream regulator of MyD88 induced G. frondosa polysaccharide. MyD88 promoted IKKβ in endochylema and translocate NF-κB p65 subunit into the nucleus which increased the NO production and cytokine/chemokines level. The results suggested that G. frondosa polysaccharide activated macrophages through TLR4-MyD88-IKKβ-NF-κBp65 signaling pathways.

Extraction, Purification and Primary Characterization of Polysaccharides from Defatted Peanut (Arachis hypogaea) Cakes

The hot-water extraction, purification and characterization of polysaccharides from defatted peanut cake (PPC) were investigated in this study. A Box-Behnken factorial design (BBD) was used to investigate the effects of three independent variables, namely extraction temperature (X₁), extraction time (X₂) and ratio of water to raw material (X₃). The optimum conditions were 85 °C, 3 h and 20:1 (mL/g) respectively. Regression analysis was done to reveal the experimental results which include 34.97% extraction rate while the value verified under these conditions was 34.49%. The crude PPC was sequentially further purified by Sephadex G-100 chromatography, and one purified fraction was obtained. The PPC purified fraction was characterized by FT-IR, HPAEC; SEC-MALLS. The average molecular weight of the PPC purified fraction was 2.383 × 10⁵ Da. The polysaccharide was mainly composed of glucose, galactose, arabinose and xylose. The PPC have the typical absorption of polysaccharide.

Immunomodulatory Effect of Gymnema sylvestre (R.Br.) Leaf Extract: An In Vitro Study in Rat Model

Gymnema sylvestre Wild R.Br (family: Asclepidaceae) is a valuable medicinal plant used in folk medicine to treat diabetes, obesity, asthma etc. in India for antiquity. Diabetes mellitus is a syndrome characterized immunologically by lymphocyte apoptosis and reduced cell-mediated and humoral immunity. Modulation of immune responses to alleviate diseases has been of interest, and traditional herbal medicines may play an important role in this regard. In this study, we aim to evaluate the immunomodulatory potential of methanolic extract of G. sylvestre leaf using rat model. HPLC analysis of leaf extract was carried out for gymnemic acid. The method involves the initial hydrolysis of gymnemic acids, the active ingredients, to a common aglycone followed by the quantitative estimation of gymnemagenin, using gymnemagenin as reference standard. Gymnemic acid content was 2.40% (w/w) in G. sylvestre leaf extract. In vitro immunomodulatory activity of the methanolic extract of G. sylvestre leaf (1-200μg/ml) was evaluated by gauging its effects on nitroblue tetrazolium reduction and nitrite release in rat peritoneal macrophages and on mitogen (ConA, PHA and LPS) induced splenic lymphocyte proliferation. G. sylvestre leaf extract showed significant (<0.05) enhancement in NO and ROS generation in macrophages and in proliferation of lymphocytes in dose dependent manner. EC50 value was 3.10, 3.75 and 2.68 μg/ml for NBT reduction, nitrite release and lymphoproliferation, respectively. Potential effect was observed at 100 μg/ml in NO and ROS generation in macrophages and 20 μg/ml in lymphocyte proliferation. G. sylvestre leaf extract stimulates macrophage reactivity, increasing the level of activity even higher when combined with PMA or LPS. These findings suggest the presence of active compounds, gymnemic acid, in methanolic extract of G. sylvestre leaf that stimulates both myeloid and lymphoid components of immune system, and therefore can restore the innate immune function. Through this study, the traditional knowledge of anti-diabetic property of G. sylvestre is scientifically supplemented with its immunomodulatory properties.

Characterization and antihyperglycemic activity of a polysaccharide from Dioscorea opposita Thunb roots

A polysaccharide DOTP-80 from Dioscorea opposita Thunb was obtained by using the method of acid water-extraction and ethanol-precipitation. After being purified by chromatography, the structure characteristics of DOTP-80 were established. Based on the calibration curve obtained with standard dextrans, the molecular weight of the polysaccharide fraction DOTP-80 was calculated to be 123 kDa. The results of Infrared spectrum (FT-IR) indicated that the polysaccharide contained the α-configuration of sugar units. GC-MS analysis revealed that DOTP-80 was mainly composed of mannose and glucose. Alloxan-induced diabetic rats and mice models were developed to evaluate the in vivo hypoglycemic activity of the polysaccharide. The results indicated that a high dose DOTP-80 (400 mg/kg) had strong hypoglycemic activity. Moreover, DOTP-80 could increase the level of antioxidant enzymes (SOD) activity in alloxan-induced diabetic mice and stimulate an increase in glucose disposal in diabetic rats. Therefore, the polysaccharide DOTP-80 should be evaluated as a candidate for future studies on diabetes mellitus.

Anti-tumor activity of a polysaccharide from blueberry

Blueberries (Vaccinium spp.) are rich in bioactive compounds. However, the biological activity of polysaccharides from blueberry has not been reported so far. This study evaluated the anti-tumor and immunological activities of a polysaccharide (BBP3-1) from blueberry in S180-bearing mice. The experimental results indicated that BBP3-1 (100 mg·kg⁻¹·d⁻¹) inhibited the tumor growth rate by 73.4%. Moreover, this group, compared with the model control, had shown an effect of increasing both the spleen and thymus indices (p < 0.05), increasing phagocytosis by macrophages (p < 0.05), boosting the proliferation and transformation of lymphocytes (p < 0.01), promoting the secretion of TNF-α, IFN-γ, and IL-2 (p < 0.05) and improving NK cell activity (p < 0.01). From this study, we could easily conclude that BBP3-1 has the ability to inhibit tumor progression and could act as a good immunomodulator.

Cheonggukjang polysaccharides enhance immune activities and prevent cyclophosphamide-induced immunosuppression

Cheonggukjang is a traditional Korean fermentation product prepared from soybean that is reported to have various biological functions. We previously reported that the polysaccharides from Cheonggukjang (PSCJ) have immunostimulatory activities in RAW 264.7 macrophages and primary cultured splenocytes. In this study, the immunostimulatory activities of the PSCJ were investigated further using various experimental models such as in vitro, ex vivo, and in vivo. The PSCJ was able to stimulate the complement system (ITCH50: 30.6%). In primary cultured mouse peritoneal macrophages, the PSCJ was found to significantly increase nitric oxide and immunostimulatory cytokines (IL-6 and IL-12) production in a concentration-dependent manner (1-100 μg/mL). In the normal mice model, the oral administration of the PSCJ increased the weight of spleen (p < 0.05 at 100 and 200 mg/kg) and improved the phagocytic rates of peritoneal macrophages (p < 0.05 at 200 mg/kg) and lymphocytes proliferation (p < 0.05 at 100 and 200 mg/kg). Similarly, the PSCJ markedly restored the decreased lymphocytes proliferation (p < 0.01 at 200 mg/kg), natural killer cell activity (p < 0.01 at 200mg/kg), and white blood cell count (p<0.01 at 100 and 200 mg/kg) in the cyclophosphamide-induced immunosuppressed mice model. These results suggest that the PSCJ could be utilized as an effective immunostimulatory agent.

Characterization and antitumor activity of a polysaccharide from Sarcodia ceylonensis

A water-soluble polysaccharide from Sarcodia ceylonensis was obtained by using the method of water-extraction and ethanol-precipitation. The polysaccharide was further purified by chromatography on AB-8 and ADS-7 columns, yielding a pure polysaccharide termed SCP-60. The molecular weight (Mw) of SCP-60 was calculated to be 50.0 kDa, based on the calibration curve obtained with a series of Dextran T standards. The results of FT-IR indicated that the polysaccharide contains the α-configuration of sugar units. GC-MS analysis revealed that SCP-60 was mainly composed of galactose and glucose. NMR spectroscopy revealed SCP-60 had the backbone consisting of → 6)-α-Manp-(1 →, α-D-Glcp-(1 →, → 6)-α-D-Glcp-(1 → and → 6)-α-Galp-(1 →. In order to evaluate the antitumor activity in vivo of the polysaccharide, a sarcoma 180 model was used. The results showed SCP-60 had strong antitumor ability, meanwhile, SCP-60 at a high dose (100 mg/kg) could significantly increase the thymic and splenic indices of S180 mice, and strongly promote the secretion of IL-2, TNF-α and IFN-γ, increase the SOD activities and reduce the concentrations of MDA in blood. Therefore the polysaccharide SCP-60 should be explored as a novel potential antitumor drug.

Polysaccharides from Inonotus obliquus sclerotia and cultured mycelia stimulate cytokine production of human peripheral blood mononuclear cells in vitro and their chemical characterization

Inonotus obliquus is an edible and medicinal mushroom to treat many diseases. In the present study, polysaccharides and fractions were isolated and purified by DEAE-52 and Sephadex G-200 chromatography from I. obliquus wild sclerotia, culture broth and cultured mycelia under submerged fermentation. The extracts and fractions could significantly induce the secretion of TNF-α, IFN-γ, IL-1β, and IL-2 in human peripheral blood mononuclear cells (PBMCs) and showed no toxicity to PBMCs. The stimulation effect of the six extracts and eight fractions on the four-cytokine production was dose-dependent. Sclerotial polysaccharides were more effective in the four-cytokine production at 150 μg/ml while exopolysaccharides and endopolysacchrides showed a much better effect on IL-1β production at 30 μg/ml. Purified fractions from exopolysaccharides and endopolysaccharides were more effective than the fraction from sclerotia in most cytokine production. These heteropolysaccharide-protein conjugates mainly contained glucose, galactose, and mannose. Protein content, molecular weight, monosaccharide molar ratio, and anomeric carbon configuration differed from each other and had effects on the cytokine induction activity of the polysaccharides to some extent.

Purification, characterization and immunomodulating activity of a polysaccharide from flowers of Abelmoschus esculentus

A water-soluble polysaccharide (OFPS11) was obtained from okra (Abelmoschus esculentus) flowers using aqueous extraction and purification with DEAE-52 cellulose and Sephacryl™ S-500 column. Its preliminary characterization and immunomodulating activity were investigated. Results showed that OFPS11 is mainly composed of galactose and rhamnose in a molar ratio of 2.23:1 with molecular mass of 1,700 kDa. RAW264.7 cells pretreated with OFPS11 significantly inhibited the proliferation of HepG-2 cells. Additionally, OFPS11 enhanced the phagocytic ability and induced the elevation of NO production, TNF-α and IL-1β secretion of RAW264.7 cells. Furthermore, OFPS11 promoted both the expression of iNOS protein and of iNOS and TNF-α mRNA. OFPS11 can strongly increase NF-κB levels in nucleuses, which is an important transcription factor that can modulate expressions of iNOS, NO and TNF-α. These outcomes support that OFPS11 exerts its antitumor activity by probably stimulating macrophage activities through nuclear NF-κB pathway.

In vivo anti-ulcer, anti-stress, anti-allergic, and functional properties of gymnemic acid isolated from Gymnema sylvestre R Br

BACKGROUND

Gymnema sylvestre is a highly valued ethno pharmacologically important medicinal plant used currently in many poly-herbal formulations due to its potential antidiabetic activity and other health benefits. The present study was carried out to analyze the anti-stress, anti-allergic, and antiulcer activity of the bioactive compounds present in Gymnema sylvestre leaves.

METHODS

The preliminary phytochemical screening for bioactive compounds from aqueous extracts revealed the presence of alkaloids, triterpenes, flavonoids, steroids, and saponins. The antioxidant activities were investigated using DPPH radical scavenging method. The characterization of the extract was carried out using standard compound by High Performance Thin Layer Chromatography (HPTLC) and phytochemical analysis in terms of total phenol, total flavonoids, reducing power and antioxidant potentials, etc. The in vivo studies on albino mice proved the purified fraction has anti-stress/anti-allergic activity against milk induced leucocytosis/eosinophilia and able to inhibit the aspirin induced gastric ulcers.

RESULTS

The quantitative estimation for aqueous extract exhibited total antioxidant (9.13 ± 0.04 μg/g), flavonoids (125.62 ± 26.84 μg/g), tannin (111.53 ± 15.13 μg/g), total phenol content (285.23 ± 1.11 μg/g) and free radical scavenging (52.14 ± 0.32%). Further the aqueous extract was consecutively purified by TLC and silica column chromatography. The purified fractions were characterized by HPTLC and GC-MS and the component was identified as gymnemic acid. The potency of the antimicrobial activity of the extract was studied with bacteria. Pharmacological experiments clearly demonstrated that the extracts of all plants given orally showed significant gastric protection against the asprin-induced gastric ulcer model in mice. Furthermore, healing effects were also confirmed through histopathological examination.

CONCLUSIONS

The aqueous extracts of the leaves of Gymnema sylvestre possess anti ulcerogenic, Anti allergic, Anti stress, properties that may be due to cytoprotective mechanism. These results support the ethno medical uses of the plant in the treatment of gastric ulcer.

Schisandra polysaccharide evokes immunomodulatory activity through TLR 4-mediated activation of macrophages

Schisandra chinensis (Turcz.) Baill has been used in traditional Chinese medicine for centuries. Previous studies have shown that Schisandra polysaccharide (SCPP11) has robust antitumor activity in vivo. In this study, the immunomodulatory activity and mechanisms of action of SCPP11 were investigated further to reveal its mechanism of action against tumors. Results showed that SCPP11 increased the thymus and spleen indices, pinocytic activity of peritoneal macrophages, and hemolysin formation in CTX-induced immunosuppressed mice. Moreover, SCPP11 significantly increased immunoglobulin levels, cytokines levels in vivo and induced RAW264.7 cells to secrete cytokines in vitro. RAW264.7 cells pretreated with SCPP11 significantly inhibited the proliferation of HepG-2 cells. In addition, SCPP11 promoted both the expression of iNOS protein and of iNOS and TNF-α mRNA. TLR-4 is a possible receptor for SCPP11-mediated macrophage activation. Therefore, the data suggest that SCPP11 exerted its antitumor activity by improving immune system functions through TLR-4-mediated up-regulation of NO and TNF-α.

Antitumor and immunomodulatory activity of a water-soluble low molecular weight polysaccharide from Schisandra chinensis (Turcz.) Baill

A water-soluble low molecular weight polysaccharide (SCPP11) was extracted and purified using DEAE-cellulose and Sephadex G-100 column from Schisandra chinensis (Turcz.) Baill. Its in vivo and in vitro antitumor and immunomodulatory activity were investigated. The results showed that SCPP11 with a molecular weight of 3.4×10(3)Da exhibited indirect cyctotoxic activity against tumor cells in vitro, but could significantly inhibit the growth of Heps cells in vivo at dose of 50mg/kg, and its inhibition rate is higher than that in the positive group. Moreover, SCPP11 could ameliorate the hematological and biochemical parameters to almost normal and no significant changes in organ weight, and could increase the body weight. In addition, SCPP11 (at 50mg/kg) could also increased in thymus indexes as well as IL-2 and TNF-α levels in serum in vivo and significantly enhance the phagocytosis activity and the productions of NO of RAW264.7 in vitro. The results indicated that antitumor properties of SCPP11 might be achieved by improving immune response. It could be explored as a potential adjuvant against cancer used in the health food and pharmaceutical therapy.