Hypericum in infection: Identification of anti-viral and anti-inflammatory constituents

Abstract

The Iowa Center for Research on Botanical Dietary Supplements seeks to optimize Echinacea, Hypericum, and Prunella botanical supplements for human-health benefit, emphasizing anti-viral, anti-inflammatory, and anti-pain activities. This mini-review reports on ongoing studies on Hypericum. The Center uses the genetically diverse, well-documented Hypericum populations collected and maintained at the USDA-ARS North Central Regional Plant Introduction Station (NCRPIS), and the strength of research in synthetic chemistry at Iowa State University to tap natural diversity, to help discover key constituents and interactions among constituents that impact bioactivity and toxicity. The NCRPIS has acquired more than 180 distinct populations of Hypericum, with a focus on Hypericum perforatum L. (Hypericaceae), representing about 13% of currently recognized taxa. Center chemists have developed novel synthetic pathways for key flavones, acyl phloroglucinols, hyperolactones, and a tetralin that have been found in Hypericum, and these compounds are used as standards and for bioactivity studies. Both light-dependent and light-independent anti-viral activities have been identified by using bioactivity-guided fractionation of H. perforatum and a HIV-1 infection test system. Our Center has focused on light-independent activity, potentially due to novel chemicals, and polar fractions are undergoing further fractionation. Anti-inflammatory activity has been found to be light-independent, and fractionation of a flavonoid-rich extract revealed four compounds (amentoflavone, chlorogenic acid, pseudohypericin, and quercetin) that interacted in the light to inhibit lipopolysaccharide-induced prostaglandin E₂ activity. The Center continues to explore novel populations of H. perforatum and related species to identify constituents and interactions of constituents that contribute to potential health benefits related to infection.

Keywords::

• Hypericum
• infection
• anti-viral
• anti-inflammatory
• phloroglucinols
• flavonoids

Acknowledgements

This publication was made possible by grant number P01 ES012020 from the National Institute of Environmental Health Sciences (NIEHS) and the Office of Dietary Supplements (ODS), and by grant 95P50AT004155 from the National Center of Complementary and Alternative Medicine (NCCAM) and ODS, NIH. Portions of this paper were also supported by the Iowa Agriculture and Home Economics Experiment Station, Ames, Iowa, with funding from the Hatch Act and State of Iowa.

This article was presented at the Symposium: “Plants in the Service of Human Health: Continuing Search for Plant-based Therapies” – Society for Economic Botany 48th Annual Meeting in Chicago at Lake Forest College, June 4, 2007.

Declaration of interest: Mention of commercial brand names does not constitute an endorsement of any product by the US Department of Agriculture or cooperating agencies. The contents of this paper are the responsibility of the authors and do not necessarily represent the views of the funding agencies.