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Medicinal plants used against malaria in Mali have previously been tested for their antiplasmodial activities using their organic solvent and water extracts. As the healers mainly use the water extracts for their treatments of malaria-patients, our aim was to study the water-soluble components from Malian plants used for treatment of malaria. Argemone mexicana (aerial parts), Sarcocephalus latifolius (root bark), Vitex doniana (leaves), and Malarial-5® (an improved traditional medicine (ITM) in tea) were the objects of our studies. Water extracts of these plants contained primarily polysaccharides. Due to this, the studies focused on the determination of the monosaccharide composition of the polymers present as well as assessing the immunomodulatory properties of the polysaccharide fractions isolated from these plants. Each plant material was extracted sequentially with dichloromethane, 80% ethanol and water at 100°C. The polysaccharides were obtained using gel filtration of the aqueous extracts and their monosaccharide compositions were determined using gas chromatography. Immunomodulatory effects were assessed using the complement fixation test and macrophage stimulation. All aqueous extracts from the four samples contained polysaccharides. The monosaccharide compositions vary between the plants. Arabinose, rhamnose, galactose, glucose and galacturonic acid were present in all samples, glucose being the main monomer. These polysaccharides showed complement fixing activity and induced nitrite oxide release from macrophages in a dose dependent manner. The polysaccharide fractions of A. mexicana (Am1) and V. doniana (Vd1) showed the most potent activities. These two fractions had an ICH50 of 2.4 and 6.3 μg/mL respectively in the complement fixation assay. The same two fractions induced a dose dependent release of nitrite oxide from macrophages. The results demonstrated that antimalarial plants contain polysaccharides with immunomodulatory properties. This preliminary work constitutes a new approach of antimalarial studies. Key words: Polysaccharides, immunomodulatory effects, antimalarial plants, Mali.

Based on previous studies about microflora regulation and immunity enhancement activities of polysaccharides from Codonopsis pilosula Nannf. var. modesta (Nannf.) L. T. Shen (CPP), there is little study on intestinal mucosal immunity, which is a possible medium for contacting microflora and immunity. In the present study, the BALB/c mice were divided into five groups (eight mice in each group), including a normal group (Con), a model control group (Model), and model groups that were administered CPP (50, 100, 200 mg/kg/d) orally each day for seven days after intraperitoneal injection of 60 mg/kg BW/d cyclophosphamide (CP) for three days. CPP recovered the spleen index and restored the levels of IFN-&gamma, IL-2, IL-10, as well as serum IgG. In addition, it elevated ileum secretory immunoglobulin A (sIgA), the number of Lactobacillus and acetic acid content in cecum. These results indicated that CPP plays an important role in the protection against immunosuppression, especially mucosa immune damage, and the inhibition of pathogenic bacteria colonization, which could be considered a potential natural source of immunoregulator.

Based on previous studies about microflora regulation and immunity enhancement activities of polysaccharides from Codonopsis pilosula Nannf. var. modesta (Nannf.) L. T. Shen (CPP), there is little study on intestinal mucosal immunity, which is a possible medium for contacting microflora and immunity. In the present study, the BALB/c mice were divided into five groups (eight mice in each group), including a normal group (Con), a model control group (Model), and model groups that were administered CPP (50, 100, 200 mg/kg/d) orally each day for seven days after intraperitoneal injection of 60 mg/kg BW/d cyclophosphamide (CP) for three days. CPP recovered the spleen index and restored the levels of IFN-γ, IL-2, IL-10, as well as serum IgG. In addition, it elevated ileum secretory immunoglobulin A (sIgA), the number of Lactobacillus and acetic acid content in cecum. These results indicated that CPP plays an important role in the protection against immunosuppression, especially mucosa immune damage, and the inhibition of pathogenic bacteria colonization, which could be considered a potential natural source of immunoregulator.

The inulin-type fructan was obtained by DEAE anion exchange chromatography from C. pilosula Nannf. var. modesta (Nannf.) L. T. Shen, after optimized extract condition, which was established by response surface methodology, designed using Box-Behnken factorial design and the optimum condition were: extracting 2.5 h with ratio of solvent to material 40 mL/g at 100 °C, twice. The maximum extraction yield was 20.6 ± 0.2%. It was confirmed as β-(2-1) linkage fructan, with terminal glucose, and with a degree of polymerization of 2–17 (DPav = 6), shown by the results of methanolysis, methylation, nuclear magnetic resonance and molecular weight determination. The prebiotic activity was proven on account of stimulation effect on Lactobacillus and pH reduction of medium in vitro. The results indicated that the inulin from C. pilosula could be used as a potential natural source of prebiotics.

Exo-polysaccharides were purified and characterized from the fermentation broth of Hypsizigus marmoreus, a popular edible mushroom consumed in Asia. Among them, B-I-I and B-II-I exhibited potent complement fixating activity, meanwhile, B-N-I, B-I-I, B-II-I and B-II-II exhibited significant macrophage stimulating activity. Molecular weights of the four exo-polysaccharides were determined to be 6.3, 120, 150 and 11 kDa respectively. Molecular characterisation showed that B-N-I is basically an α-1 → 4 glucan, with branches on C6; B-I-I is a heavily branched α-mannan with 1 → 2 linked main chain. B-II-I and B-II-II, have a backbone of rhamno-galacturonan with 1 → 2 linked l -rhamnose interspersed with 1 → 4 linked galacturonic acid. Structure–activity relationship analysis indicated that monosaccharide compositions, molecular weight, certain structural units (rhamno-galacturonan type I and arabinogalactan type II) are the principal factors responsible for potent complement fixating and macrophage-stimulating activities. Their immunomodulating activities may, at least partly, explain the health benefits of the mushroom.

Platycodon grandiflorus is a plant widely used in traditional Chinese medicine, of which polysaccharides are reported to be the main components responsible for its bio-functions. In this work, the inulin-type fructan (PGF) was obtained by DEAE anion exchange chromatography from the water extracted from P. grandifloras. Characterization was performed with methanolysis, methylation, and NMR and the results showed that PGF is a &beta, (2-1) linked fructan, with terminal glucose and with a degree of polymerization of 2&ndash, 10. In order to study its biofunctions, the prebiotic and immunomodulation properties were assayed. We found that PGF exhibited good prebiotic activity, as shown by a promotion on six strains of lactobacillus proliferation. Additionally, the PGF also displayed direct immunomodulation on intestinal epithelial cells and stimulated the expressions of anti-inflammatory factors. These results indicated that the inulin from P. grandiflorus is a potential natural source of prebiotics as well as a potential intestinal immunomodulator, which will be valuable for further studies and new applications.