Regulation of Inflammatory Gene Expression in PBMCs by Immunostimulatory Botanicals

Karen L Denzler,Bertram L Jacobs,Yvan Rochon,Robert Waters,Jeffrey O Langland,Jörn Coers

doi:10.1371/journal.pone.0012561

Abstract

Many hundreds of botanicals are used in complementary and alternative medicine for therapeutic use as antimicrobials and immune stimulators. While there exists many centuries of anecdotal evidence and few clinical studies on the activity and efficacy of these botanicals, limited scientific evidence exists on the ability of these botanicals to modulate the immune and inflammatory responses. Using botanogenomics (or herbogenomics), this study provides novel insight into inflammatory genes which are induced in peripheral blood mononuclear cells following treatment with immunomodulatory botanical extracts. These results may suggest putative genes involved in the physiological responses thought to occur following administration of these botanical extracts. Using extracts from immunostimulatory herbs (Astragalus membranaceus, Sambucus cerulea, Andrographis paniculata) and an immunosuppressive herb (Urtica dioica), the data presented supports previous cytokine studies on these herbs as well as identifying additional genes which may be involved in immune cell activation and migration and various inflammatory responses, including wound healing, angiogenesis, and blood pressure modulation. Additionally, we report the presence of lipopolysaccharide in medicinally prepared extracts of these herbs which is theorized to be a natural and active component of the immunostimulatory herbal extracts. The data presented provides a more extensive picture on how these herbs may be mediating their biological effects on the immune and inflammatory responses.

Highlights

Many complementary and alternative medicine (CAM) approaches and interventions are thought to exert activities by enhancing immune function
As a mixed population of T-lymphocytes, B-lymphocytes, natural killer cells, monocytes, macrophages and dendritic cells, Peripheral blood mononuclear cells (PBMCs) represent key cells involved in the genetic expression of cytokines leading to innate and adaptive immune and inflammatory responses
To investigate the cytokine response induced by immuno-stimulatory herbal extracts, PBMCs were treated with an herbal extract followed by microarray analysis on isolated cellular RNA

Summary

Introduction

Many complementary and alternative medicine (CAM) approaches and interventions are thought to exert activities by enhancing immune function. In 1985, the World Health Organization estimated that perhaps 80% of the world population relied on herbs for primary health care needs [2,3,4,5]. This widespread use of herbal medicines is not restricted to developing countries, as it has been estimated that 12-31% of patients in European countries utilize herbal medicines [2,3,4,5,6]. The Journal of the American Medical Association reported that between 1990 and 1997 the prevalence of herbal remedy use increased 380% in the United States [7]. Even with the widespread use and acceptance, a complete understanding of the biochemistry and mechanisms of action regarding herbal remedies has remained largely unknown [21,22]

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