Defensive effects of a fucoidan from brown alga Undaria pinnatifida against herpes simplex virus infection

Int Immunopharmacol. 2008 Jan;8(1):109-16. doi: 10.1016/j.intimp.2007.10.017. Epub 2007 Nov 20.


Fucoidan, a sulfated polysaccharide isolated from an edible brown alga Undaria pinnatifida, was previously shown to be a potent inhibitor of the in vitro replication of herpes simplex virus type 1 (HSV-1). HSV-1 is a member of herpes viruses that cause infections ranging from trivial mucosal ulcers to life-threatening disorders in immunocompromised hosts. In the in vivo conditions, the replication of HSV-1 is controlled under the immunoresponse coordinated by both the innate and adaptive immune systems. In the present study, the effects of the fucoidan were examined on in vivo viral replication and the host's immune defense system. Oral administration of the fucoidan protected mice from infection with HSV-1 as judged from the survival rate and lesion scores. Phagocytic activity of macrophages and B cell blastogenesis in vitro were significantly stimulated by the fucoidan, while no significant change in the release of NO(2)(-) by macrophages was observed. In in vivo studies, oral administration of the fucoidan produced the augmentation of NK activity in HSV-1-infected mice immunosuppressed by 5-fluorouracil treatment. CTL activity in HSV-1-infected mice was also enhanced by oral administration of the fucoidan. The production of neutralizing antibodies in the mice inoculated with HSV-1 was significantly promoted during the oral administration of the fucoidan for 3 weeks. These results suggested that oral intake of the fucoidan might take the protective effects through direct inhibition of viral replication and stimulation of both innate and adaptive immune defense functions.

MeSH terms

  • Administration, Oral
  • Animals
  • Antibodies, Viral / biosynthesis
  • Antiviral Agents / administration & dosage
  • Antiviral Agents / therapeutic use
  • Cell Proliferation / drug effects
  • Dose-Response Relationship, Immunologic
  • Female
  • Fucose
  • Herpes Simplex / immunology
  • Herpes Simplex / prevention & control*
  • Herpes Simplex / virology
  • Herpesvirus 1, Human / drug effects
  • Herpesvirus 1, Human / immunology*
  • Immunity, Cellular / drug effects
  • Immunity, Innate / drug effects
  • Lymphocyte Activation / drug effects
  • Lymphocyte Activation / immunology
  • Macrophages, Peritoneal / drug effects
  • Macrophages, Peritoneal / immunology
  • Male
  • Mice
  • Mice, Inbred BALB C
  • Mice, Inbred C3H
  • Polysaccharides / administration & dosage
  • Polysaccharides / therapeutic use*
  • Sulfuric Acid Esters / administration & dosage
  • Sulfuric Acid Esters / therapeutic use
  • Undaria / immunology*


  • Antibodies, Viral
  • Antiviral Agents
  • Polysaccharides
  • Sulfuric Acid Esters
  • Fucose
  • fucoidan