Extract of algae for use as an immunomodulator agent

1. A method for stimulating the immune response in a human being or an animal, the method comprising administering to a human being or an animal an effective dose of an extract of an algae from the family of Ulvaceae, comprising sulfated and non-sulfated polyanionic polysaccharides, wherein all of the sulfated and non-sulfated polyanionic polysaccharides have a size less than or equal to 50 kDa.

2. The method according to claim 1 , wherein the polysaccharides comprise mannose, arabinose or a combination thereof.

3. The method according to claim 2 , wherein the polysaccharides comprise at least 0.005% of mannose, at least 0.005% of arabinose, by weight based on the weight of the total dry material of the algae extract.

4. The method according to claim 3 , wherein the polysaccharides comprise mannose in an amount ranging from 0.01 to 0.50%, arabinose in an amount ranging from 0.01 to 0.5% or a combination thereof, by weight based on the weight of the total dry material of the algae extract.

5. The method according to claim 2 , wherein the polysaccharides further comprise:

galactose;

glucose;

rhamnose;

xylose; and

glucuronic acid.

6. The method according to claim 5 , wherein the polysaccharides comprise:

from 0.05 to 0.5% of galactose;

from 0.005 to 0.5% of glucose;

from 2 to 15% of rhamnose;

from 0.1 to 1% of xylose; and

from 1 to 7% of glucuronic acid;

by weight based on the weight of the total dry material of the algae extract.

7. The method according to claim 2 , wherein the polysaccharides comprise mannose.

8. The method according to claim 1 , wherein the algae extract induces expression of adhesion molecules and of chemokines.

9. The method according to claim 8 , wherein the adhesion molecules and chemokines comprise IL-8, IL-1α, IL1-β, IL-6, TNF-α, CCL20 or a combination thereof.

10. The method according to claim 1 , wherein the algae extract is a supplement to vaccination.

11. The method according to claim 1 for treating infectious pathologies, preventing infectious pathologies, or a combination thereof.

12. The method according to claim 11 , wherein the infectious pathologies comprise porcine infectious pathologies selection from the group consisting of parvovirus disease, Erysipela Rhusiopathiae, infectious rhinitis, influenza, porcine circovirus disease, mycoplasma and colibacillosis; avian infectious pathologies selected from: Marek's disease, Newcastle's disease, infectious bronchitis, Gumboro's disease, fowlpox, mycoplasma, avian infectious anemia, infectious laryngotracheitis, EDS and avian influenza; bovine infectious pathologies selected from: BVD (bovine viral diarrheas), enzootic bronchopneumonia, IBR, herpes virus disease, clostridial disease, colibacillosis, bluetongue disease, coronavirus disease, rotavirus disease and rhinotracheitis; and aquaculture infectious pathologies selected from: hematopoietic necrosis, vibriosis, furunculosis, infectious pancreatic necrosis and infectious anemia.

13. The method according to claim 1 , wherein the algae extract is comprised in a pharmaceutical composition.

14. The method according to claim 1 , wherein the algae extract is comprised in a food composition.

15. The method according to claim 1 , wherein the algae extract is administered at a dose in humans comprised between 0.1 and 100 mg/kg or at a dose in animals comprised between 1 and 200 mg/kg.

16. The method according to claim 1 , wherein the sulfated and non-sulfated polyanionic polysaccharides have a size of less than or equal to 15 kDa.

17. The method according to claim 1 , wherein the extract is of green algae of the Ulva type.

18. The method according to claim 1 , wherein stimulating the immune response in a human being or animal comprises stimulating an intestinal immune system.