A Water-Soluble Polysaccharide from the Fruit Bodies of Bulgaria inquinans (Fries) and Its Anti-Malarial Activity

Purification, Chemical Characterization and Immunomodulatory Activity of a Sulfated Polysaccharide from Marine Brown Algae Durvillaea antarctica

An immunomodulatory polysaccharide (DAP4) was extracted, purified, and characterized from Durvillaea antarctica. The results of chemical and spectroscopic analyses demonstrated that the polysaccharide was a fucoidan, and was mainly composed of (1→3)-α-l-Fucp and (1→4)-α-l-Fucp residues with a small degree of branching at C-3 of (1→4)-α-l-Fucp residues. Sulfate groups were at C-4 of (1→3)-α-l-Fucp, C-2 of (1→4)-α-l-Fucp and minor C-6 of (1→4)-β-d-Galp. Small amounts of xylose and galactose exist in the forms of β-d-Xylp-(1→ and β-d-Gal-(1→. The immunomodulatory activity of DAP4 was measured on RAW 264.7 cells, the results proved that DAP4 exhibited excellent immunomodulatory activities, such as promoted the proliferation of spleen lymphocytes, increased NO production, as well as enhanced phagocytic of macrophages. Besides, DAP4 could also produce better enhancement on the vitality of NK cells. For the high immunomodulatory activity, DAP4 might be a potential source of immunomodulatory fucoidan with a novel structure.

Mushroom Bulgaria inquinans Modulates Host Immunological Response and Gut Microbiota in Mice

We aimed to determine the prebiotic impact of Mushroom Bulgaria inquinans (BI) on the host immune response and gut microbiota. Male C57BL/6 mice were fed a diet supplemented with 0, 1, or 2% BI for 4 wks. Compared to mice fed with a control diet (0% BI), mice fed with 1 or 2% BI had an increase of T cell proliferation from the spleen, but such change was not found between 1 and 2% BI treated mice. Also, BI at 2% increased the production of IL-2 of splenocytes stimulated with T-cell mitogens, but BI at 1 and 2% did not affect productions of other splenic-T cell cytokines including IL-4, IL-10, and IFN-γ. Interestingly, BI at 1 or 2% inhibited T cell proliferation of mesenteric lymph node (mLN) but this effect was not found between 1 and 2% BI treated mice. Furthermore, BI inhibited the production of IL-2 in anti-CD3/CD28-stimulated T cells from mLN in a dose-dependent manner. Meanwhile, BI at 2%, not 1% inhibited the production of IL-4, IL-10, and IFN-γ of mLN. Since BI at 2% produced a more significant effect on the immune response, we further used BI at 2% to evaluate the effect of BI on gut microbiota. Of note, BI reduced the diversity of gut microbiota and resulted in an increase of Faecalibaculum and Parabacteroides abundance and the decrease of Allobaculum, Candidatus_Saccharimonas, and Rikenella abundance at the genus level. Finally, the correlation was observed between specific bacteria genera and the productions of T-cell cytokines from mesenteric lymphocytes: Rikenella and Candidatus_Saccharimonas correlated positively with IL-2, IL-4, IL-10, and IFN-γ; Bacteroides and Parabacteroides correlated negatively with IL-2 and IL-4; Faecalibaculum correlated negatively with IFN-γ and IL-4 and Bacteroides and Bifidobacterium correlated negatively with IFN-γ. The specific role of each intestinal microbiota observed is still unclear, but BI might exert a prebiotic effect on gut microbiota by increasing the abundance of potentially beneficial bacteria (Faecalibaculum). This is helpful for further demonstrating the healthy-promotion mechanism of B. inquinans.

Antiplasmodial Activity of the n-Hexane Extract from Pleurotus ostreatus (Jacq. ex. Fr) P. Kumm

Objectives

Several mushrooms species have been reported to be nematophagous and antiprotozoan. This study reported the antiplasmodial and cytotoxic properties of the n-hexane extract from the edible mushroom Pleurotus ostreatus and the isolation of a sterol from the extract.

Materials and Methods

Antiplasmodial and cytotoxicity assays were done in vitro using the plasmodium lactate dehydrogenase assay and human HeLa cervical cell lines, respectively. The structure of the isolated compound from the n-hexane extract was elucidated using spectroscopic techniques.

Results

The n-hexane extract (yield: 0.93% w/w) showed dose dependent antiplasmodial activity with the trend in parasite inhibition of: chloroquine (IC₅₀=0.016 μg/mL) > n-hexane extract (IC₅₀=25.18 μg/mL). It also showed mild cytotoxicity (IC₅₀>100 μg/mL; selectivity index >4) compared to the reference drug emetine (IC₅₀=0.013 μg/mL). The known sterol, ergostan-5,7,22-trien-3-ol, was isolated and characterized from the extract.

Conclusion

This study reporting for the first time the antiplasmodial activity of P. ostreatus revealed its nutraceutical potential in the management of malaria.

Purification, characterization, and antitumor activity of a novel glucan from the fruiting bodies of Coriolus Versicolor

Cancer is one of the most common causes of deaths worldwide. Herein, we report an efficient natural anticancer glucan (CVG) extracted from Coriolus Versicolar (CV). CVG was extracted by the hot water extraction method followed by ethanol precipitation and purified using gas exclusion chromatography. Structural analysis revealed that CVG has a linear α-glucan chain composed of only (1→ 6)-α-D-Glcp. The antitumor activity of CVG on Sarcoma-180 cells was investigated in vitro and in vivo. Mice were treated with three doses of CVG (40, 100, 200 mg/kg body weight) for 9 days. Tumor weight, relative spleen, thymus weight, and lymphocyte proliferation were studied. A significant increase (P< 0.01) in relative spleen and thymus weight and a decrease (P< 0.01) in tumor weight at the doses of 100 and 200 mg/kg were observed. The results obtained demonstrate CVG has antitumor activity towards Sarcoma-180 cells by its immunomodulation activity.

Ethnomedicinal and phytochemical review of Pakistani medicinal plants used as antibacterial agents against Escherichia coli

Medicinal plants have always been part of human culture and have the potential to cure different diseases caused by microorganisms. In Pakistan, biologists are mainly focusing on plants’ antimicrobial activities against Escherichia coli due to its increasing resistance to antibiotics. In total, extracts from 34 ethnomedicinally valuable Pakistani plants were reported for in-vitro anti-E. coli activities. Mostly methanolic extracts of medicinal plants were used in different studies, which have shown comparatively higher inhibitory activities against E. coli than n-hexane and aqueous extracts. It has been found that increasing concentration (mg/ml) of methanolic extract can significantly increase (p < 0.01) anti-E. coli activities. Not all medicinal plants are extracted in solvents others than above, which should also be tested against E. coli. Moreover, medicinal plant species must be fully explored phytochemically, which may lead to the development of new drugs.

Structures of (1→6)-β-D-glucans from Bulgaria inquinans (Fries) and their immunological activities

In previous study, an unbranched (1→6)-β-D-glucan with Mw 2.6kDa was isolated from fruit bodies of Bulgaria inquinans (Fries). In present paper, three branched (1→6)-β-D-glucans were obtained from the water-extracted residues by a sequential KOH-extraction, namely BIK2, BIK10 and BIK30. Their molecular weights were determined to be 37.5kDa (BIK2), 288.9kDa (BIK10) and 175.5kDa (BIK30). Structural analysis indicated that their backbones were substituted by single glucosyls at C-3 positions, the branching ratios were 0.01 (BIK2), 0.17 (BIK10), 0.25 (BIK30). Immunological tests showed that all the four β-D-glucans could significantly increase the ConA or LPS-induced lymphocytes proliferation in vivo. Moreover, branched (1→6)-β-D-glucans have more significantly lymphocytes proliferation activities than unbranched (1→6)-β-D-glucan, and the effect of (1→6)-β-D-glucans on lymphocytes proliferation increases along with molecular weights. The present results well enrich the structure-activity relationships of (1→6)-β-D-glucan, and indicate (1→6)-β-D-glucans from B. inquinans (Fries) are potential immunostimulating agents.

Purification and in vitro anti-proliferative effect of novel neutral polysaccharides from Lentinus edodes

A (1→6)-β-D-glucan (WPLE-N-1) and two mannogalactoglucans (WPLE-N-2 and WPLE-N-3) were isolated from the basidiocarps of Lentinus edodes by hot water extraction, ethanol precipitation, anion exchange chromatography, and further purified by gel-permeation chromatography (GPC). Their structural features were investigated by high performance liquid chromatography (HPLC), high performance gel-permeation chromatography (HPGPC), methylation analysis, periodate oxidation-Smith degradation, Fourier transform-infrared (FT-IR) and NMR spectroscopy, including two-dimensional (2D) NMR. HPLC analysis revealed that WPLE-N-1 was mainly composed of glucose (92%) with small amount of galactose (3.9%) and mannose (4.1%), WPLE-N-2 and WPLE-N-3 contained mannose-galactose-glucose in the molar ratio of 10:27:63 and 5:12:83, respectively. GPC and HPGPC showed that WPLE-N-1, WPLE-N-2 and WPLE-N-3 are homogeneous fractions and their molecular weights were estimated to be 757.5 kDa, 20.9 kDa and 4.7 kDa, respectively. Chemical and spectroscopic studies indicated that WPLE-N-1 consisted of (1→6)-β-D-glucopyranosyl residues; while WPLE-N-2 and WPLE-N-3 were found to contain (1→6)-, (1→4)- and (1→3)-α-D-glucopyranosyl residues, (1→6)-α-D-galactopyranosyl residues, (1→3,6)- and (1→2,4)-α-D-mannopyranosyl residues and terminal residues of D-glucopyranosyl residues. On a preliminary bioactivity test, these three polysaccharides exhibited antitumor activity against Sarcoma S-180, Carcinoma HCT-116 and HT-29 in vitro. This finding suggests that mannogalactoglucan should be explored as potential antitumor agents and utilized as tumor cell growth inhibitors for food and pharmaceutical industries.