Anti-HBV Activities of Polysaccharides from Thais clavigera (Küster) by In Vitro and In Vivo Study

Abstract

Hepatitis B virus (HBV) infection remains a major global health problem. It is therefore imperative to develop drugs for anti-hepatitis B with high-efficiency and low toxicity. Attracted by the observations and evidence that the symptoms of some patients from the Southern Fujian, China, suffering from hepatitis B were alleviated after daily eating an edible marine mollusk, Thais clavigera (Küster 1860) (TCK). Water-soluble polysaccharide from TCK (TCKP1) was isolated and characterized. The anti-HBV activity of TCKP1 and its regulatory pathway were investigated on both HepG2.2.15 cell line and HBV transgenic mice. The data obtained from in vitro studies showed that TCKP1 significantly enhanced the production of IFN-α, and reduced the level of HBV antigens and HBV DNA in the supernatants of HepG2.2.15 cells in a dose-dependent manner with low cytotoxicity. The result of the study on the HBV transgenic mice further revealed that TCKP1 significantly decreased the level of transaminases, HBsAg, HBeAg, and HBV DNA in the serum, as well as HBsAg, HBeAg, HBV DNA, and HBV RNA in the liver of HBV transgenic (HBV-Tg) mice. Furthermore, TCKP1 exhibited equivalent inhibitory effect with the positive control tenofovir alafenamide (TAF) on the markers above except for HBV DNA even in low dosage in a mouse model. However, the TCKP1 high-dose group displayed stronger inhibition of transaminases and liver HBsAg, HBeAg, and HBV RNA when compared with those of TAF. Meanwhile, inflammation of the liver was, by pathological observation, relieved in a dose-dependent manner after being treated with TCKP1. In addition, elevated levels of interleukin-12 (IL-12) and interferon γ (IFN-γ), and reduced level of interleukin-4 (IL-4) in the serum were observed, indicating that the anti-HBV effect of TCKP1 was achieved by potentiating immunocyte function and regulating the balance of Th1/Th2 cytokines.

Portulaca oleracea L. Polysaccharide Inhibits Porcine Rotavirus In Vitro

“…Crude polysaccharides from seaweed and abalone viscera have antiviral activity against SARS-CoV-2 [45]. Polysaccharides from Thais clavigera (Küster) show significant anti-hepatitis B virus activity by enhancing immune cell function [46]. Isatis indigotica polysaccharide effectively inhibits the expression of IP-10, IL-6, MIG, and CCL-5 induced by human influenza virus (PR8/H1N1) and avian influenza virus (H9N2) [47].…”

Polysaccharides and Their Derivatives as Potential Antiviral Molecules

“…Woo et al isolated polysaccharides from Korean edible clams with virus-cell fusion inhibitory activity against HIV infection [88]. In 2021, Fei Tang et al reported significant anti-hepatitis B virus activity with low toxicity, associated with the polysaccharides from Thais clavigera [133].…”

Advances in Research on Antiviral Activities of Sulfated Polysaccharides from Seaweeds

“…In addition, their high yields, low production costs, broad-spectrum antiviral activities, and unique antiviral mechanisms suggest that sulfated polysaccharides from seaweeds are promising antiviral drugs. It should be noted that the source of marine polysaccharides is not limited to seaweed but also includes a large number of marine animals and marine microorganisms, such as Thais clavigera [ 135 ], Sepia pharaonis [ 136 ], sea cucumbers [ 137 ], Haliotis discus hannai [ 138 ], and Celtodoryxgirardae [ 139 ].…”