Spirulina

Spirulina , this is true bacteria (cyanobacterium) which is widely as a food supplements now . 

 In this study, it has been evaluated that the impact of Spirulina  ,Earthrise Nutritionals,

when administered on patients suffering from allergic rhinitis , this is an allergic response causing watery eyes, sneezing, itching,  etc . 

 by assessing the production of cytokines [interleukin (IL)-4, interferon (IFN)-γ, and IL-2] critical in regulating immunoglobulin E-mediated allergy. Food supplements from spirulina doest requires chemical and physical processing because it does not contains any cellulosic cell wall and have high protein content in it . Spirulina is an effective immune modulator. It has been well documented that Spirulina have anti-inflammatory properties, in particular, by hindering the release of histamine from mast cell-mediated  allergic reactions.

C-phycocyanin ( anti inflammatory component of spirulina )displays anti oxidative and free radical scavenging properties . 

Spirulina increasing the IgA antibody level to protect against allergic reaction.

 From studies and experiments , we have shown that in vitro culture of Spirulina extract was effective in modulating the secretion of cytokines [inter- leukin (IL)-1 , IL-4, and interferon (IFN)- ] from human peripheral blood mononuclear cells (PBMCs).

Cytokine production from unstimulated PBMCs

PBMCs cultured for 48 hours under non-stimulatory conditions (i.e., media only) did not produce any detectable level of IL-4, IFN- , and IL-2 in any groups.Cytokine production from PHA-stimulated PBMCs when cultured  in presences of a T -cell mitogen , PHA was able to induce measurable levels of cytokines in all groups. 

Although Spirulina seemed to be ineffective at modulating the secretion of Th1 cytokines (IFN-γ and IL-2), studies discovered that Spirulina, administered at 2,000 mg/day, significantly reduced IL-4 levels by 32% from PHA-stimulated cells. These results indicate that Spirulina can modulate the Th profile in patients with allergic rhinitis by suppressing the differentiation of Th2 cells mediated, in part, by inhibiting the production of IL-4. Allergic rhinitis is thought to be initiated by an allergen breaching the mucosal epithelium, where antigen-presenting cells, particularly dendritic cells, can take up, process, and present allergen peptides to type-2 T helper (Th2) cells.19 This cellular interaction stimulates Th2 cells to release cytokines that promote the IgE production, as well as the growth and activation of eosinophils, mast cells, and basophils.19–21 In particular, IL-4 is a critical cytokine involved in all aspects of inducing type I hypersensitivity reactions.

This is the first study , human being feeding on Spirulina to check its protective nature against allergic rhinitis .