Immolina, a High-Molecular-Weight Polysaccharide Fraction of Spirulina, Enhances Chemokine Expression in Human Monocytic THP-1 Cells

J Altern Complement Med. 2006 Jun;12(5):429-35. doi: 10.1089/acm.2006.12.429.

Abstract

Introduction: Spirulina (Spirulina platensis) is a dietary supplement valued for its immune-enhancing properties. We previously reported that the immunostimulatory effect of spirulina can be traced to a high-molecular- weight polysaccharide fraction. This fraction, labeled Immolina, activates nuclear factor kappa-B in human monocytic THP-1 cells and increases expression of proinflammatory cytokines.

Objective: To characterize further the immunostimulatory effects of Immolina on THP-1 cells, we evaluated its effect on genes encoding the chemokines interleukin (IL)-8, MCP-1, MIP-1alpha, MIP-1beta, IP-10, the cytokines tumor necrosis factor (TNF)-alpha, IL-1beta, and the enzyme cyclo-oxygenase-2 (COX-2).

Methods: THP-1 cells were exposed to concentrations of Immolina ranging from 1 ng/mL to 100 microg/mL and changes in gene expression were assessed by reverse transcriptase-polymerase chain reaction (RT-PCR). For comparison, THP-1 cells were activated with 1 ng/mL of TNF-alpha, 10 ng/mL of IL-1beta, or 10 ng/mL of lipopolysaccharide using the same assay conditions. To assess the response of THP-1 cells to Immolina at the protein level, we probed culture supernatants using a cytokine array immunoblot assay.

Results: RT-PCR analysis revealed that Immolina dose-dependently increased the expression of all 5 chemokines tested as well as the expression of TNF-alpha, IL-1beta, and COX-2. The cytokine array immunoblot assay revealed an increase in the chemokines IL-8 and MIP-1beta. Thymidine uptake experiments verified that Immolina did not affect the viability and growth rate of THP-1 cells.

Conclusions: The results of the experiments demonstrate that Immolina activates THP-1 cells in a manner that is consistent with the recruitment of diverse populations of leukocytes in response to inflammatory and infectious signals.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Chemokines / metabolism*
  • Dose-Response Relationship, Drug
  • Inflammation Mediators / pharmacology
  • Monocytes / drug effects*
  • Monocytes / metabolism
  • Plant Extracts / pharmacology*
  • Polysaccharides / pharmacology*
  • Receptors, Chemokine / drug effects*
  • Receptors, Chemokine / metabolism
  • Reverse Transcriptase Polymerase Chain Reaction
  • Spirulina
  • Tumor Cells, Cultured

Substances

  • Chemokines
  • Inflammation Mediators
  • Plant Extracts
  • Polysaccharides
  • Receptors, Chemokine
  • immolina