Herpes antidote from marine algae
doi:10.1038/nindia.2011.165 Published online 14 November 2011
New research has shown that polysaccharides isolated from a marine alga can block the herpes simplex virus (HSV) from entering host cells. These polysaccharides might therefore yield drugs for curing herpes.
HSV-1 is the main cause of herpes infections that affect the mouth and lips, with symptoms such as cold sores and fever blisters. The viruses lie dormant in nerve cells and infection recurs. Antiviral drugs do not provide a complete cure.
To find a novel and effective antidote for herpes, the researchers isolated two polysaccharides — alginic acid and xylogalactofucan — from a marine alga (Laminaria angustata) collected from the Okha coast of Gujarat. They then converted these polysaccharides into sulphated polysaccharides using sulphuric acid.
The researchers studied the efficacy of their sulphated polysaccharides for inhibiting herpes infection using cultured African monkey kidney cells and HSV-1. They also compared the efficacy of the sulphated polysaccharides to acyclovir, an anti-viral drug.
When the host kidney cells were treated with polysaccharides prior to infection, the polysaccharides and acyclovir showed no significant effect on viral infection. However, pre-treatment of HSV-1 with the polysaccharides and drug for one hour prior to infection caused a significant reduction in viral growth.
The study revealed that the polysaccharides failed to reduce viral growth when added to the culture medium after the viruses had penetrated into the host cells. The study also showed that the polysaccharides exhibited anti-HSV-1 activity by preventing the viruses from attaching to host cells.
The sulphated xylogalactofucan has a higher potency than the sulphated form of alginic acid. The researchers say that the sulphated polysaccharides may provide a new therapeutic option for treating herpes infection.
The authors of this work are from: Natural Products Laboratory, Department of Chemistry, The University of Burdwan, West Bengal, India and Department of Infectious Diseases, Virology, University of Heidelberg, Im Neuenheimer, Feld, Heidelberg, Germany.
Saha, S. et al. Sulfated polysaccharides from Laminaria angustata: structural features and in vitro antiviral activities. Carbohydr. Polymer. 87, 123-130 (2012) | Article |