Plantago asiatica L. polysaccharides: Physiochemical properties, structural characteristics, biological activity and application prospects: A review.

Plantago asiatica L. (PAL), a traditional herb, has been used in East Asia for thousands of years. In recent years, polysaccharides extracted from PAL have garnered increased attention due to their outstanding pharmacological and biological properties. Previous research has established that PAL-derived polysaccharides exhibit antioxidant, anti-inflammatory, antidiabetic, antitumor, antimicrobial, immune-regulatory, intestinal health-promoting, antiviral, and other effects. Nevertheless, a comprehensive summary of the research related to Plantago asiatica L. polysaccharides (PALP) has not been reported to date. In this paper, we review the methods for isolation and purification, physiochemical properties, structural features, and biological activities of PALP. To provide a foundation for research and application in the fields of medicine and food, this review also outlines the future development prospects of plantain polysaccharides.

Huaier Polysaccharide Interrupts PRV Infection via Reducing Virus Adsorption and Entry.

A pseudorabies virus (PRV) novel virulent variant outbreak occurred in China in 2011. However, little is known about PRV prevention and treatment. Huaier polysaccharide has been used to treat some solid cancers, although its antiviral activity has not been reported. Our study confirmed that the polysaccharide can effectively inhibit infection of PRV XJ5 in PK15 cells. It acted in a dose-dependent manner when blocking virus adsorption and entry into PK15 cells. Moreover, it suppressed PRV replication in PK15 cells. In addition, the results suggest that Huaier polysaccharide plays a role in treating PRV XJ5 infection by directly inactivating PRV XJ5. In conclusion, Huaier polysaccharide might be a novel therapeutic agent for preventing and controlling PRV infection.

Epigallocatechin-3-Gallate, the Main Polyphenol in Green Tea, Inhibits Porcine Epidemic Diarrhea Virus In Vitro.

There are currently no licensed drugs against porcine epidemic diarrhea virus (PEDV), but vaccines are available. We identified a natural molecule, epigallocatechin-3-gallate (EGCG), the main polyphenol in green tea, which is effective against infection with PEDV. We used a variety of methods to test its effects on PEDV in Vero cells. Our experiments show that EGCG can effectively inhibit PEDV infections (with HLJBY and CV777 strains) at different time points in the infection using western blot analysis. We found that EGCG inhibited PEDV infection in a dose-dependent manner 24 h after the infection commenced using western blotting, plaque formation assays, immunofluorescence assays (IFAs), and quantitative reverse-transcriptase PCR (qRT-PCR). We discovered that EGCG treatment of Vero cells decreased PEDV attachment and entry into them by the same method analysis. Western blotting also showed that PEDV replication was inhibited by EGCG treatment. Whereas EGCG treatment was found to inhibit PEDV assembly, it had no effect on PEDV release. In summary, EGCG acts against PEDV infection by inhibiting PEDV attachment, entry, replication, and assembly.