Preparation and potential in vivo anti‐influenza virus activity of low molecular‐weight κ‐carrageenans and their derivatives

Abstract

Degradation of native j-carrageenan was performed using acid hydrolysis aided with microwave heating. Combined with nonofiltration membrane (cut-off molecular weight 250 Da) separation, 1. 400 Da -50 kDa low-molecular-weight (LMW) j-carrageenans were obtained. Narrow molecular weight distribution of LMW j-carrageenans could be prepared under pH 2.18 during the microwave power range investigated. The in vivo anti-influenza virus (IV) activity of three kinds of LMW j-carrageenans (3, 5, and 10 kDa), their acetylated derivatives (acetylation degree of 1.5), as well as an acetylated and sulfated derivative of 3 kDa carrageenan (acetylation degree of 1.0 and sulfation degree of 2.4), were investigated using FM1-induced pulmonary oedema model. These LMW j-carrageenans showed significant inhibition against FM1-induced pulmonary oedema as compared with the virus control, although their activities were inferior to that of positive control, Rabivirin. Introduction of acetyl groups greatly increased their anti-IV activity. The acetylated 3-kDa j-carrageenan exhibited comparative activity with Rabivirin at both doses of 6 and 30 2. mg/kgÁd, and the acetylated and sulfated derivative of 3 kDa carrageenan displayed higher activity than Rabivirin at the dose of 30 mg/kgÁd. These results disclosed that 3 kDa j-carrageenan with proper acetylation degree and sulfation degree was a potential candidate against influenza virus.

Novel Polyanions Inhibiting Replication of Influenza Viruses

“…It has been reported previously that sulfated polysaccharides derived from marine algae, mainly carrageenans (17,19,25,26,29,43,44) but also alginate, fucans, ulvan, and heparin-like structures, e.g., polymannuronic acid propyl sulfate (16,30), show strong antiviral properties; however, the exact mechanisms of action and structural determinants for these compounds are not fully elucidated. In 1987, Gonzalez et al (26) hypothesized that natural polysaccharides exert their antiviral activity by direct interaction with virus particles at an early stage of viral infection.…”

Marine Algal Antioxidants as Potential Vectors for Controlling Viral Diseases

“…The carrageenan isolated from Gigartina skottsbergii exert promising antiviral activities towards diverse strains of HSV-1 and HSV-2 during virus attachment stage [63] and against human rhinovirus (HRV) proliferation by preventing the primary phases of virus replication [64]. A recent in vivo study in mice indicated that low molecular weight carrageenans (3, 5, and 10 kDa), as well as acetylated and sulfated derivatives, were active against influenza virus and reduced the HIV activity by depolymerization and sulfation processes [65].…”

The Antiviral Activities and Mechanisms of Marine Polysaccharides: An Overview

“…Tang et al found that low molecular weight carrageenans and their derivatives showed significant inhibition effects against influenza virus FM1-induced pulmonary edema in mice, and the 3 kDa k-carrageenan with proper acetylation degree and sulfation degree possesses best antiviral activity in vivo [42]. Wang and co-workers reported that the low molecular weight carrageenan oligosaccharide KCO and their sulfated derivatives could effectively inhibit influenza A virus (IAV) replication in vitro and in vivo , and KCO mainly inhibits a replication step in IAV life cycle subsequent to viral internalization but prior to virus release [43,44].…”