Preparation methods, structural characteristics, and biological activity of polysaccharides from Platycodon grandiflorus

Polysaccharides isolated from shufeng jiedu capsules by cross-flow ultrafiltration show anti-inflammatory effects on LPS-stimulated RAW264.7 cells and zebrafish inflammatory models

ETHNOPHARMACOLOGICAL RELEVANCE

Shufeng Jiedu Capsules (SFJDC) is a traditional Chinese patent medicine comprising eight traditional Chinese medicines (TCM). SFJDC is known for its anti-inflammatory and antipyretic effects and is mainly used in clinics to treat upper respiratory tract infections. Currently, studies on the active ingredients of the SFJDC all focus on small-molecule compounds. In contrast, bio-macromolecules, such as the anti-inflammatory activities of polysaccharides in SFJDC, have not been studied, and the composition of the polysaccharides in SFJDC is also unclear.

AIM OF THE STUDY

This study aimed to isolate active polysaccharides from Shufeng Jiedu capsules and determine their structural properties and anti-inflammatory activities.

MATERIALS AND METHODS

The polysaccharides with different molecular weights were prepared by organic solvent extraction, alcohol precipitation, dialysis, and cross-flow ultrafiltration. The structural characterization of polysaccharides was clarified by high-performance size exclusion chromatography (HPGPC), ion chromatography (IC), and Fourier transform infrared spectroscopy (FT-IR). Enzyme-linked immunosorbent assay (ELISA) and quantitative real-time PCR (qRT-PCR) assay were used to investigate the anti-inflammatory effects of polysaccharides on Lipopolysaccharides (LPS)-stimulated RAW264.7 cells. The in vivo study was employed on the CuSO4-induced and LPS-stimulated zebrafish inflammatory models, and the survival analysis, observation of neutrophil migration, hematoxylin-eosin (H&E) staining, and qRT-PCR assays were used to investigate the in vivo anti-inflammatory effect of polysaccharides.

RESULTS

The crude polysaccharides SFJDC-CP were obtained from the mixed aqueous extract of SFJDC with a yield of 38.72 %. Both SFJDC and SFJDC-CP dose-dependently inhibited the secretion of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and IL-1β in LPS-stimulated RAW264.7 cells, and SFJDC-CP was more effective at a lower dosage. SFJDC-CP was further separated into three fractions, SFJDC-CP1-CP3, by cross-flow ultrafiltration apparatus with nominal molecular weight cut-offs of 100 kDa, 50 kDa, and 10 kDa membrane cassettes, and the yields were approximately 58.19 %, 10.88 %, and 30.94 %, respectively. The MWs of the SFJDC-CP and its SFJDC-CP1-CP3 were 35.7 kDa, 149.1 kDa, 34.5 kDa, and 15.1 kDa, respectively. The four polysaccharides were composed of rhamnose, arabinose, galactose, glucose, and galacturonic acid in different molar ratios. Non-toxic concentrations of the four polysaccharides ranged from 12.5 to 200 μg/mL. The four polysaccharides significantly reduced the mRNA expression levels and release of IL-1β, IL-6, and TNF-α (P < 0.0001) in LPS-stimulated RAW264.7 cells. Polysaccharides also decreased inflammatory cell infiltration and neutrophil migration (P < 0.05 or P < 0.001) in both CuSO4-induced and LPS-microinjected zebrafish inflammatory models. Additionally, they effectively inhibited the mRNA levels of IL-6 and TNF-α in LPS-infected zebrafish (P < 0.01 or P < 0.001).

CONCLUSIONS

Polysaccharides isolated from Shufeng Jiedu capsules have demonstrated anti-inflammatory effects on LPS-stimulated RAW264.7 cells and zebrafish inflammatory models. This study provided preliminary evidence that polysaccharides are one of the main anti-inflammatory ingredients of Shufeng Jiedu capsules. Additionally, it may provide valuable perspectives for investigating polysaccharides in other TCM formulations, particularly those obtained through aqueous extraction methods.

Distribution Patterns of Platycodon grandiflorus From the Last Interglacial Period to the Future by Ecological Niche Modeling

Global climate change may represent a significant threat to the distribution and quality of medicinal plants, altering cultivation areas and compromising the quality of medical materials. Platycodon grandiflorus, a traditional Chinese medicinal herb, has a millennia-long medicinal and culinary use history in East Asia. Given its escalating demand, accurately evaluating the changes under different climate scenarios and predicting its potential distribution are imperative for ensuring its conservation and sustainable utilization. By integrating MaxEnt with ArcGIS, this study advances previous approaches by incorporating historical, present, and future climate data to model the distribution dynamics of P. grandiflorus across China. The results indicated: (1) The species' distribution strongly correlates with environmental variables, particularly bio13, prec07, prec09, and tmin07, whose cumulative value of percent contribution was 78.5%; (2) The centroids of potential geographic distribution during the LIG, LGM, and MH periods were situated further westward compared to the present distribution, with substantial contraction observed in highly suitable habitats throughout these historical periods; (3) Under present climatic conditions, the overall suitable habitat encompasses 4,185,964 km2, with highly suitable habitats constituting one-third of this expanse, predominantly concentrated in central, southern, and northeastern China; (4) Future climate change scenarios predict that the total suitable habitat will expand to varying degrees (7% increase on average), albeit with potential reductions in highly suitable areas (3% decrease on average); and (5) The distribution of P. grandiflorus is likely to move toward higher latitudes in the future due to climate changes. Our findings fill a critical knowledge gap by quantifying the impact of climate change on the distribution of P. grandiflorus. These results offer crucial insights for developing effective conservation strategies, promoting sustainable utilization, and establishing standardized cultivation protocols for P. grandiflorus resources.

Antiviral and Immune Enhancement Effect of Platycodon grandiflorus in Viral Diseases: A Potential Broad-Spectrum Antiviral Drug

BACKGROUND

Traditional Chinese medicine offers potential therapeutic options for viral infections. Platycodon grandiflorus (PG) is a perennial herb known for its efficacy in treating respiratory infections, including asthma, cough, and bronchitis, making it a key focus in antiviral drug research. The purpose of the study is to provide a basis for functional studies on PG and generate new insights for treating viral diseases.

METHODS

Research articles from 1990 to 2024 related to PG and viruses were obtained from databases, such as PubMed, Web of Science, and Science Direct, and systematically analysed.

RESULTS

PG demonstrates inhibitory effects on viruses such as severe acute respiratory syndrome coronavirus and porcine reproductive and respiratory syndrome virus by blocking various stages of viral proliferation or activating the host immune system. It also reduces inflammation through NF-κB, PI3K/AKT, MAPK, and other signalling pathways, enhancing T cell and macrophage function and increasing host immunity. PG exhibits diverse pharmacological effects with promising clinical applications for antiviral and immune modulation. Given its medicinal significance, PG holds substantial potential for further exploration and development.

CONCLUSION

PG, due to its antiviral, anti-inflammatory, and immune-boosting properties, can be used as an antiviral drug.

Neutral Polysaccharide from Platycodonis Radix-Ameliorated PM2.5-Induced Lung Injury by Inhibiting the TLR4/NF-κB p65 Pathway and Regulating the Lung and Gut Microbiome

Platycodonis radix (PR) has been reported to play a protective role in lung injury. However, much less is known about the protective effect and mechanism of its main component PR polysaccharides (PRPs) in particulate matter (PM2.5)-induced lung injury. Here, a neutral polysaccharide (MW: 244.56 kDa) was isolated from PR, mainly composed of Rha, Ara, Gal, Glc, Xyl, and Man. PRPs significantly improved PM2.5-induced pulmonary edema, oxidative damage, and cell apoptosis and downregulated inflammatory factor levels in bronchoalveolar lavage fluid. Mechanistically, PRPs reduced intestinal mucosal barrier damage, thereby lowering serum lipopolysaccharide levels and inhibiting the overactivation of the TLR4/NF-κB signaling pathway in the lung tissue. Notably, PRPs could optimize the composition of pulmonary and intestinal microbiota. Oral administration of PRPs resulted in enrichment of short-chain fatty acid (SCFA)-producing bacteria, thereby upregulating the levels of acetate, butyrate, and isovalerate. Taken together, PRPs have great potential in preventing and repairing the lung injury caused by PM2.5.

Antitumor immunostimulatory activity of the traditional Chinese medicine polysaccharide on hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a prevalent malignancy, often associated with compromised immune function in affected patients. This can be attributed to the secretion of specific factors by liver cancer cells, which hinder the immune response and lead to a state of immune suppression. Polysaccharides derived from traditional Chinese medicine (TCM) are valuable constituents known for their immunomodulatory properties. This review aims to look into the immunomodulatory effects of TCM polysaccharides on HCC. The immunomodulatory effects of TCM polysaccharides are primarily manifested through the activation of effector T lymphocytes, dendritic cells, NK cells, and macrophages against hepatocellular carcinoma (HCC) both in vivo and in vitro settings. Furthermore, TCM polysaccharides have demonstrated remarkable adjuvant antitumor immunomodulatory effects on HCC in clinical settings. Therefore, the utilization of TCM polysaccharides holds promising potential for the development of novel therapeutic agents or adjuvants with advantageous immunomodulatory properties for HCC.