Immunomodulatory activity of acidic polysaccharides isolated from Tanacetum vulgare L.

Tanacetum vulgare L. (Tansy) has been extensively used in folk medicine for treatment of a variety of medical disorders. In the present study, we isolated and purified four acidic polysaccharide fractions (designated T-I to T-IV) from Tansy florets by the sequential use of hot-water extraction, ethanol precipitation, ultra-filtration, anion-exchange, and size-exclusion chromatography. The average M, of fractions T-I through T-IV was estimated to be 326, 151, 64 and 9 kDa, respectively, as determined by high performance size-exclusion chromatography analysis. Sugar composition analysis revealed that Tansy polysaccharides consisted primarily of galacturonic acid, galactose, arabinose, and rhamnose. Fractions T-II through T-IV contained an arabinogalactan type 11 structure, as determined by reaction with Yariv reagent. High M, fractions T-I and T-II exhibited potent macrophage/monocyte-activating activity, enhancing production of reactive oxygen species (ROS), nitric oxide (NO), and tumor necrosis factor (X (TNF-alpha) by J774.A1 murine macrophages, and activating nuclear factor kappa B (NF-kappa B) in THP-1 human monocytes. In addition, Tansy polysaccharides stimulated human neutrophil function by greatly enhancing neutrophil myeloperoxidase (MPO) release. Furthermore, the low M, fraction T-IV had potent complement-fixing activity, which may also contribute to the anti-inflammatory and would-healing properties of Tansy extracts. Taken together, our results provide a molecular basis to explain at least part of the beneficial therapeutic effects of Tansy extracts, and support the concept of using Tansy polysaccharides as an immunotherapeutic adjuvant. (c) 2007 Elsevier B.V. All rights reserved.