Isolation of Three High Molecular Weight Polysaccharide Preparations with Potent Immunostimulatory Activity from Spirulina platensis, Aphanizomenon flos-aquae and Chlorella pyrenoidosa
Planta Med 67 (2001) 737-742
Author(s): Nirmal Pugh, Samir A. Ross, Hala N. Elsohly, Mahmoun A. ElSohly, David S. Pasco
This research describes the identification of three new high molecular weight polysaccharide preparations isolated from food-grade micro algae that are potent activators of human monocytes/macrophages: "immuline" from Spirulina platensis "Immunon" from Aphanizomenon flos-aquae; and "Immurella" from Chlorella pyrenoidosa. These polysaccharides are structurally complex and have estimated molecular weights above ten million Daltons. All three polysaccharides are highly water soluble and comprise between 0.5% and 2.0% of micro algal dry weight. Immunostimulatory activity was measured using transcription factor-based bioassay for nuclear factor kappa B (NF-kappa B) activation in THP-1 human monocytes/macrophages. Using this system the EC50 values for these micro algal polysaccharides are between 20 and 110 ng/ml (about 10pM). THP-1 activation was confirmed by measuring immune cytokine mRNA induction using reverse transcriptase-polymerase chain reaction (RT-PCR). Each polysaccharide substantially increased mRNA levels of interleukin and tumor necrosis factor-a (TNF-a). The polysaccharides are between one hundred and one thousand times more active for in vitro monocyte activation than polysaccharides preparation that are currently used clinically for cancer immunotherapy.