Structural characterization and immunomodulatory activity of exopolysaccharide from Aureobasidium pullulans CGMCC 23063

Structural elucidation and anti-psoriasis activity of a novel polysaccharide from Saussurea Costus

PSCP, a novel water-soluble polysaccharide, was extracted from the root of Saussurea costus and subsequently purified using DEAE-52 cellulose and Sephadax G-50 columns. The elucidation of its structure involved various techniques including HPGPC, FT-IR, HPLC-ELSD, GC-MS, NMR, AFM, and SEM. The results show that PSCP was a homogeneous heteropoly saccharide having molecular weight of 4131 Da and mainly composed of 1-α-D-Glcp-(-2-β-D-Fruf-1-)23-2-β-D-Fruf. The anti-psoriasis activity of PSCP was evaluated in imiquimod-induced psoriasis in Balb/C mice. This study revealed that treatment with PSCP resulted in a significant improvement in the pathological morphology of the skin and a reduction in the PASI score. Analysis of liver RNA-Seq data indicated that the MAPK signaling pathway may play a crucial role in the ability of PSCP to ameliorate psoriasis. PSCP was found to effectively inhibit the phosphorylation of JNK, ERK, and p38, as well as down-regulate the expression of the transcription factor AP-1 (c-fos and c-jun) in the nucleus, thereby reducing the expression of inflammatory factors. These findings suggest that PSCP holds promise as a novel therapeutic approach for the treatment of psoriasis.

Microbial exopolysaccharides: Unveiling the pharmacological aspects for therapeutic advancements

Microbial exopolysaccharides (EPSs) have emerged as a fascinating area of research in the field of pharmacology due to their diverse and potent biological activities. This review paper aims to provide a comprehensive overview of the pharmacological properties exhibited by EPSs, shedding light on their potential applications in various therapeutic areas. The review begins by introducing EPSs, exploring their various sources, significance in microbial growth and survival, and their applications across different industries. Subsequently, a thorough examination of the pharmaceutical properties of microbial EPSs unveils their antioxidant, immunomodulatory, antimicrobial, antidepressant, antidiabetic, antiviral, antihyperlipidemic, hepatoprotective, anti-inflammatory, and anticancer activities. Mechanistic insights into how different EPSs exert these therapeutic effects have also been discussed in this review. The review also provides comprehensive information about the monosaccharide composition, backbone, branches, glycosidic bonds, and molecular weight of pharmacologically active EPSs from various microbial sources. Furthermore, the factors that can affect the pharmacological activities of EPSs and approaches to improve the EPSs' pharmacological activity have also been discussed. In conclusion, this review illuminates the immense pharmaceutical promise of microbial EPS as versatile bioactive compounds with wide-ranging therapeutic applications. By elucidating their structural features, biological activities, and potential applications, this review aims to catalyze further research and development efforts in leveraging the pharmaceutical potential of microbial EPS for the advancement of human health and well-being, while also contributing to sustainable and environmentally friendly practices in the pharmaceutical industry.

Effects of different steaming times on the composition, structure and immune activity of Polygonatum Polysaccharide

ETHNOPHARMACOLOGICAL RELEVANCE

As a commonly used traditional Chinese herbal medicine, Polygonati Rhizoma has high medicinal value, it can enhance the immune capacity of the body, regulate the metabolism of blood glucose and lipids, treat weakness of the stomach and intestines and physical fatigue, and so on. There are three plant varieties of Polygonati Rhizoma recorded in Chinese Pharmacopoeia, including Polygonatum sibiricum Red., Polygonatum kingianum Coll. et Hemsl. and Polygonatum cyrtonema Hua, compared with the first two, Polygonatum cyrtonema Hua is less studied. Polygonatum cyrtonema Hua is one of the basal plants of the Chinese herb Polygonati Rhizoma, that strengthens the spleen, moistens the lungs, and benefits the kidneys. Polygonatum polysaccharide is the main active substance of Polygonatum cyrtonema Hua, which has various biological effects of regulating immune system, anti-inflammatory, anti-antidepressant, antioxidant and other effects.

AIM OF THE STUDY

In order to analyze the necessity and scientificity of multiple cycles of steaming during the traditional nine-steaming and nine-drying process of the concoction of Polygonatum, we investigated the changes in the composition and structure of polysaccharides, and explored its immunomodulatory activity and molecular biological mechanism.

METHODS

The structural characterization and molecular weight of polysaccharides were studied by scanning electron microscope (SEM), high-performance size exclusion chromatography-evaporative light scattering detector (HPSEC-ELSD) and Matrix.assisted laser resolutionu ionization time-of-flight mass spectrometry (MALDI-TOF-MS). The composition and proportion of monosaccharides were determined by PMP-HPLC method. A mouse immunosuppression model was established by intraperitoneal injection of cyclophosphamide to compare the immunomodulatory effects and mechanisms of different steaming times of Polygonatum, The changes of body mass and immune organ indices of mice were measured; the secretion levels of interleukin-2 (IL-2), interferon γ (IFN-γ) and the expression levels of immunoglobulin M (IgM) and immunoglobulin A (IgA) in serum were determined by enzyme-linked immunosorbent assay; and then flow cytometry was used to detect T-lymphocyte subpopulations to evaluate the differences of immunomodulatory effects of polysaccharides during the processing and preparation of Polygonatum. Finally, the Illumina MiSeq high-throughput sequencing platform was used to analyze short-chain fatty acids and to investigate the effects of different steaming times of Polygonatum polysaccharides on immune function and intestinal flora in immunosuppressed mice.

RESULTS

The structure of the Polygonatum polysaccharide with different steaming times changed significantly, the relative molecular weight of Polygonatum polysaccharide decreased significantly, and the monosaccharide composition of Polygonatum cyrtonema Hua with different steaming times was the same but the content was different. The immunomodulatory activity of the Polygonatum polysaccharide was enhanced after concoction, which significantly increased the spleen index and thymus index, and increased the expression of IL-2, IFN-γ, IgA and IgM. The CD4+/CD8+ ratio of Polygonatum polysaccharide also increased gradually with different steaming times, indicating enhanced immune function and significant immunomodulatory effect. The content of short-chain fatty acids in the feces of mice in both six steaming six sun-drying of Polygonatum polysaccharides (SYWPP) and nine steaming nine sun-drying of Polygonatum polysaccharides (NYWPP) groups increased significantly, including the content of propionic acid, isobutyric acid, valeric acid, and isovaleric acid, and also had a good effect on the regulation and improvement of microbial community abundance and diversity, SYWPP and NYWPP increased the relative abundance of Bacteroides and the ratio of Bacteroides and Firmicutes (B:F), while SYWPP significantly increased the abundance of Bacteroides, Alistipes and norank_f__Lachnospiraceae, but the effect of raw Polygonatum polysaccharides (RPP) and NYWPP was not significant than SYWPP.

CONCLUSION

Overall, both SYWPP and NYWPP could significantly enhance the immune activity of the organism, improve the imbalance of intestinal flora in immunosuppressed mice, and increase the content of intestinal short chain fatty acids (SCFAs), it is noteworthy that SYWPP has a better effect on the improvement of the immune activity of the organism. These findings can explore the stage of the concoction process of Polygonatum cyrtonema Hua to achieve the best effect, provide a reference basis for the development of quality standards, and at the same time promote the application of new therapeutic agents and health foods in raw and different steaming times of Polygonatum polysaccharide.

Rhizoctonia solani AG1 IA extracellular polysaccharides: Structural characterization and induced resistance to rice sheath blight

Sheath blight, caused by Rhizoctonia solani (R. solani), is one of the most serious diseases of rice. Extracellular polysaccharides (EPS) are complex polysaccharides secreted by microbes that have a pivotal role in the plant-microbe interaction. At present, many studies have been carried out on R. solani, but it is not very clear whether the EPS is secreted by R. solani exists. Therefore, we isolated and extracted the EPS from R. solani, two kinds of EPS (EW-I and ES-I) were obtained by DEAE-cellulose 52 and Sephacryl S-300HR column further purification, and their structures were characterized by FT-IR, UV, GC, and NMR analysis. The results showed that EW-I and ES-I had similar monosaccharide composition but different molar ratio, they were composed of fucose, arabinose, galactose, glucose, and mannose with a ratio of 7.49: 27.72: 2.98: 6.66: 55.15 and 3.81: 12.98: 6.15: 10.83: 66.23, and their backbone may be composed of →2)-α-Manp-(1→ residues, beside ES-I was highly branched compared to EW-I. The exogenous application of EW-I and ES-I had no effect on the growth of R. solani AG1 IA itself, but their pretreatment of rice induced plant defense through activation of the salicylic acid pathway, resulting in enhanced resistance to sheath blight.

Purification of exopolysaccharides from Lactobacillus rhamnosus and changes in their characteristics by regulating quorum sensing genes via polyphenols

To explore the effect of Lonicera caerulea fruit polyphenols (LCP) on caries-causing bacteria, strain RYX-01 with high production of biofilm and exopolysaccharides (EPS) was isolated from the oral cavity of caries patients and was identified as Lactobacillus rhamnosus by 16S rDNA analysis and morphology. The characteristics of EPS produced by RYX-01 (EPS-CK) and those produced by adding L. caerulea fruit polyphenols (EPS-LCP) were compared to reveal whether LCP reduced the cariogenicity of RYX-01 by influencing the structure and composition of EPS. The results showed that LCP could increase the content of galactose in EPS and destroy the original aggregation state of EPS-CK but had no significant effect on the molecular weight and functional group composition of EPS (p > 0.05). At the same time, LCP could inhibit the growth of RYX-01, reduce EPS and biofilm formation and inhibit the expression of quorum sensing (QS, luxS)- and biofilm formation (wzb)-related genes. Therefore, LCP could change the surface morphology, content and composition of RYX-01 EPS and reduce the cariogenic effect of EPS and biofilm. In conclusion, LCP can be used as a potential plaque biofilm inhibitor and QS inhibitor in drugs and functional foods.

A β-glucan from Aureobasidium pullulans enhanced the antitumor effect with rituximab against SU-DHL-8

β-Glucans affect the immune system and have antitumor activity; therefore, they are being investigated as immunomodulators and chemotherapeutic adjuvants. In this study, we investigated a specific β-glucan, exopolysaccharide (EPS-1) derived from Aureobasidium pullulans (CGMCC 20363), to investigate its impact on the efficacy of rituximab against diffuse large B cell lymphoma (SU-DHL-8 cells) in vitro and in vivo. The results show that compared to rituximab alone, EPS-1 enhanced the inhibition of SU-DHL-8, had antitumor effects in vivo, and improved the response of the immune system of the host. RNA sequencing results reveal that EPS-1 had a chemotactic effect on T cells through the JAK-STAT signaling pathway and recruited immune cells into tumor tissues. EPS-1 also played an antitumor role through the mitochondrial and death receptor Fas-related apoptotic pathways. In summary, EPS-1 may be an effective adjuvant to treat diffuse large B cell lymphoma in combination with rituximab.

Efficient biosynthesis of exopolysaccharide in Candida glabrata by a fed-batch culture

Polysaccharides are important natural biomacromolecules. In particular, microbial exopolysaccharides have received much attention. They are produced by a variety of microorganisms, and they are widely used in the food, pharmaceutical, and chemical industries. The Candida glabrata mutant 4-C10, which has the capacity to produce exopolysaccharide, was previously obtained by random mutagenesis. In this study we aimed to further enhance exopolysaccharide production by systemic fermentation optimization. By single factor optimization and orthogonal design optimization in shaking flasks, an optimal fermentation medium composition was obtained. By optimizing agitation speed, aeration rate, and fed-batch fermentation mode, 118.6 g L⁻¹ of exopolysaccharide was obtained by a constant rate feeding fermentation mode, with a glucose yield of 0.62 g g⁻¹ and a productivity of 1.24 g L⁻¹ h⁻¹. Scaling up the established fermentation mode to a 15-L fermenter led to an exopolysaccharide yield of 113.8 g L⁻¹, with a glucose yield of 0.60 g g⁻¹ and a productivity of 1.29 g L⁻¹ h⁻¹.