Planta Med 2001; 67(8): 737-742
DOI: 10.1055/s-2001-18358
Original Paper
Natural Product Chemistry
© Georg Thieme Verlag Stuttgart · New York

Isolation of Three High Molecular Weight Polysaccharide Preparations with Potent Immunostimulatory Activity from Spirulina platensis, Aphanizomenon flos-aquae and Chlorella pyrenoidosa

Nirmal Pugh1 , Samir A. Ross1, 2 , Hala N. ElSohly2 , Mahmoud A. ElSohly2, 3 , David S. Pasco*, 1, 2
  • 1 Department of Pharmacognosy, School of Pharmacy, University of Mississippi, University, Mississippi, USA
  • 2 National Center for Natural Products Research, School of Pharmacy, University of Mississippi, University, Mississippi, USA
  • 3 Department of Pharmaceutics, Research Institute of Pharmaceutical Sciences, School of Pharmacy, University of Mississippi, University, Mississippi, USA
Further Information

Publication History

October 6, 2000

March 11, 2001

Publication Date:
09 November 2001 (online)


This research describes the identification of three new high molecular weight polysaccharide preparations isolated from food-grade microalgae that are potent activators of human monocytes/macrophages: ”Immulina” 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 microalgal dry weight.

Immunostimulatory activity was measured using a 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 microalgal 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-1β (IL-1β) and tumor necrosis factor-α (TNF-α). These polysaccharides are between one hundred and one thousand times more active for in vitro monocyte activation than polysaccharide preparations that are currently used clinically for cancer immunotherapy.


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Dr. David S. Pasco

National Center for Natural Products Research

Research Institute of Pharmaceutical Sciences

School of Pharmacy

The University of Mississippi


MS 38677



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