Fucoidan has been shown to be an effective antiviral ingredient. Maritech® Undaria pinnatifida Extract produced by Marinova has inhibitory effects against 40 different strains of HSV-I and HSV-II, of which half were acyclovir (ACV) resistant. The mechanism of inhibition was via blocking the receptor used by the viruses to enter cells rather than disabling the virus itself. This mechanism of viral inhibition by large anionic molecules, such as fucoidan, does not generate resistant strains to the same degree as ACV-type drugs (which inhibit viral replication) and the inhibition covers a wide spectrum of viral strains. For instance, Maritech® Undaria pinnatifida Extract has also inhibited EBV, HSC and human immunodeficiency virus (HIV). Fucoidan has also been shown to inhibit prion-mediated disease. Many researchers postulate that if viral inhibitory molecules, such as fucoidan, can supplement conventional therapies, considerable scope may exist for reductions in both the use of prescription drugs and the emergence of resistant strains. Applications of these viral inhibitory properties include lotions or gels to reduce the spread of herpetic lesions in skin or ocular surfaces.
For examples of fucoidan activity in this area, refer to the following journal articles:
Cooper R, Dragar C, Elliot K, et al. GFS, a preparation of Tasmanian Undaria pinnatifida is associated with healing and inhibition of reactivation of Herpes. BMC Complement Altern Med. 2002;2(1):11.
Thompson KD, Dragar C. Antiviral activity of Undaria pinnatifida against herpes simplex virus. Phytother Res. 2004;18(7):551-555.
Witvrouw M, De Clercq E. Sulfated polysaccharides extracted from sea algae as potential antiviral drugs. Gen Pharmacol. 1997;29(4):297-511.