Sulfated polysaccharides as multi target molecules to fight COVID 19 and comorbidities

Harnessing traditional Chinese medicine polysaccharides for combatting COVID-19

With the global spread of COVID-19 posing ongoing challenges to public health systems, there is an ever-increasing demand for effective therapeutics that can mitigate both viral transmission and disease severity. This review surveys the landscape of polysaccharides derived from traditional Chinese medicine, acclaimed for their medicinal properties and potential to contribute to the COVID-19 response. We specifically focus on the capability of these polysaccharides to thwart SARS-CoV-2 entry into host cells, a pivotal step in the viral life cycle that informs transmission and pathogenicity. Moreover, we delve into the concept of trained immunity, an innate immune system feature that polysaccharides may potentiate, offering an avenue for a more moderated yet efficacious immune response against various pathogens, including SARS-CoV-2. Our comprehensive overview aims to bolster understanding of the possible integration of these substances within anti-COVID-19 measures, emphasizing the need for rigorous investigation into their potential applications and underlying mechanisms. The insights provided here strongly support ongoing investigations into the adjunctive use of polysaccharides in the management of COVID-19, with the anticipation that such findings could lead to a deeper appreciation and clearer elucidation of the antiviral potentials inherent in complex Chinese herbal remedies.

Sulfated polysaccharides of Laetiporus sulphureus fruiting bodies exhibit anti-breast cancer activity through cell cycle arrest, apoptosis induction, and inhibiting cell migration

ETHNOPHARMACOLOGICAL RELEVANCE

Laetiporus sulphureus has long been used as an edible and medicinal mushroom in Asia, America, and Europe. Its fruiting bodies are widely used in folk medicine for treating cancer, gastric diseases, cough, and rheumatism. Polysaccharides are an important bioactive component of mushrooms. In nature, sulfated polysaccharides have never been reported in mushrooms. Furthermore, there is no information on differences in physicochemical properties and anti-breast cancer activities between polysaccharides (PS) and sulfated polysaccharides (SPS) of L. sulphureus.

AIM OF THE STUDY

This study aimed to investigate the physicochemical properties of PS and SPS isolated from fruiting bodies of L. sulphureus and examine their anti-proliferative effects and mechanism(s) of action on MDA-MB-231 breast cancer cells.

METHODS

Polysaccharides (PS) were isolated using hot water and ethanol precipitation methods. Sulfated polysaccharides (SPS) were isolated by the papain-assisted hydrolysis method. Physicochemical properties comprising sugar, protein, uronic acid, and sulfate contents, and molecular weight, monosaccharide composition, and structural conformation were analyzed on PS and SPS. In the anti-cancer study, a triple-negative breast cancer cell line (MDA-MB-231) and a normal human mammary epithelial cell line (H184B5F5/M10) were used to evaluate the anti-proliferative activity of PS and SPS, and their mechanism(s) of action.

RESULTS

The results showed that SPS, which had higher sulfate and protein contents and diversified monosaccharide composition, exhibited more potent anti-proliferative activity against MDA-MB-231 cells than PS. Furthermore, it had a selective cytotoxic effect on breast cancer cells but not the normal cells. SPS induced cell cycle arrest at G0/G1 phase via down-regulating CDK4 and cyclin D1 and up-regulating p21 protein expression. Breast cancer cell apoptosis was not observed until 72 h after SPS treatment. In addition, SPS also markedly inhibited breast cancer cell migration.

CONCLUSION

This study demonstrates that SPS exhibited selective cytotoxicity and was more potent than PS in inhibiting MDA-MB-231 cell proliferation. The contents of sulfate and protein, and monosaccharide composition could be the main factors affecting the anti-breast cancer activity of L. sulphureus SPS.

Fucoidan-based antibody-free magnetic nanoparticle for on-site detection of waterborne SARS-CoV-2

The portable and sensitive point-of-care-test (POCT) method is in urgent need to detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) for ensuring public health and safety. However, detection of trace number of pathogens in real water sample from the environment still faces challenges, because complex environment disruptors can rapidly degrade targets. Herein, magnetic beads coated with fucoidan and polydopamine (Fuc-PDA-MBs) were introduced as the capture carrier for pretreatment of samples. Fucoidan, a sulfated polysaccharide, can recognize the SARS-CoV-2 spike (S1) protein receptor-binding domain (S1 RBD) and was chosen for replacement of antibody in enrichment. Environmental water seeded with SARS-CoV-2 spike pseudovirus was applied to test performance of Fuc-PDA-MBs method. Under optimal conditions, the use of Fuc-PDA-MBs showed average 76 % capture efficiency at SARS-CoV-2 spike pseudovirus concentration ranging from 107.62 to 104.34 gene copies (gc)/L. Compared with Electronegative filtration (ENF), Fuc-PDA-MBs showed better virion sorption effectiveness. Fuc-PDA-MBs also validated by raw contaminated urban wastewater and showed high recovery results for SARS-CoV-2 variants. To rapidly detect virus in POCT, nucleic acid extraction-free Loop-Mediated Isothermal Amplification (LAMP) was used for simplifying experimental process. The Fuc-PDA-MBs-LAMP assay showed the quantitation limit of sample (LOQ) was 105.49 gc/L. The whole procedure could be completed within 90 min, including 30 min for virus pre-enrichment, 10 min nucleic acid release and 45 min LAMP analysis. Compared with regular antibody-based immunodetection, this integrated system provides broad-spectrum, economic way to detect SARS-CoV-2 mutants in complex environments and also adaptable for high throughput test, which might be used for on-site early warning of SARS-CoV-2 outbreaks in developing area.