Table 1.

Fucoidan fractions and inhibition of influenza viruses in vitro and in vivo.

Fucoidan Type	Study Focus	Description	Dose	Reference
Undaria pinnatifida Unfractionated	H1N1 Deep lung influenza PR8	Lung damage limited by oral intake of fucoidan in treatment and prevention models. Not correlated to viral titre.	3.52 or 7.04 mg/day	[23]
Undaria pinnatifida Discrete fraction 9kDa	H1N1 (A/NWS/33)	Virus yield in the mucosa of immunocompetent and compromised mice was reduced and stimulated mucosal immunoresponse.	IC50- 15 µg/mL, 5 mg/day post infection	[20]
Undaria pinnatifida Discrete fraction 9 kDa	Avian influenza viruses (H5N3 and H7N2)	Suppressed virus yields and increased antibody production.	1 mg or 5 mg/day	[21]
Kjellmaniella crassifolia Unfractionated536 kDa	PR8 (H1D1), Cal09 (H1N1), Minnesota (H2N2) and TXD09 (H1N1)	Inhibits virus replication in vitro and has low risk of inducing drug resistance.	IC50 34 µg/mL 10 or 20 μg/day intranasal	[28]
Undaria pinnatifida Unfractionated	Response to vaccine containing A/Brisbane/59/2007, A/Uruguay/716/2007, B/Brisbane/60/2008	Clinical. Enhanced immune responses to seasonal influenza vaccine in the elderly.	300 mg/day 4 weeks pre and 19 weeks post inoculation	[22]