CUR - The Council on Undergraduate Research

Molecular Mechanism of Anti-Inflammatory Activity of Prairie Turnip (Psoralea esculenta), Extract Treated Human Macrophages

Faith Harvey, Grace Bybee, Megan O’Gara, Dr. Paul Weber and Dr. Daniel Jung, Departments of Biology and Chemistry, Briar Cliff University, 3303 Rebecca St, Sioux City IA 51103

Prairie turnip (Psoralea esculenta), abundant in Siouxland prairies, has been used as a food source by Native Americans. Previous studies show that prairie turnip extracts exhibited antioxidant activity and the reduction of inflammation. This is important in the immune response to resolve infection or physical trauma. The reduction of inflammation may be mediated via IDO (Indoleamine dioxygenase) expression. Currently, unreported results in the lab demonstrated that IDO expression was increased by a regulator protein called Aryl hydrocarbon receptor (AhR). The goal of this research was to uncover the molecular and immunological mechanism of IDO expression by the prairie turnip extract in human macrophage cells. The cytokines IL-10 and IL-21 are key anti-inflammatory cytokines. Previous studies showed that these cytokines are involved in increasing AhR expression. Thus, we hypothesized that treatment of prairie turnip extracts may induce the expression of IL-10 and/or IL-21. To test this, RNA was isolated from the following treated macrophages: Interferon + Tumor Necrosis Factor alpha (this treatment is known to increase IDO expression), prairie turnip extract treated and a control group. cDNA was synthesized from the isolated RNA. Subsequently, Real Time PCR analysis using IL-10 and IL-21 primers was performed. The results were inconclusive for IL-10 gene expression, but IL-21 was upregulated. We propose a possible mechanism that IL-21 may increase the AhR expression and in turn increase the expression of Indoleamine dioxygenase.

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