Date of Project


Document Type

Honors Thesis

School Name

College of Arts and Sciences



Major Advisor

Dr. Savita chaurasia, Thesis advisor

Second Advisor

Dr. Joanne Dobbins, Academic advisor

Third Advisor

Dr. Josef Jareczek, Thesis reader


Xanthorhiza simplicissima is a plant that is steeped in medical history. It has been used for hundreds of years by the Native Americans, and later by the Europeans, of Appalachia for its medicinal properties. One of the most useful medical applications of this plant are its antibiotic properties, as typified by its use as a tea that was consumed to treat mouth sores. These antibiotic properties can be attributed to some of its secondary alkaloids such as berberine, liriodenine, oxyacanthine, and magnoflorine. These compounds have been studied in other systems; however, oxyacanthine and magnoflorine have not been researched in tandem with the use of efflux pump inhibitors. Neither has the X. simplicissima extract itself. Efflux pumps allow bacteria to exude antibiotics and other cytotoxic molecules out of their cells. The disabling of these pumps has been shown to greatly increase the effectiveness of antibiotics and antimicrobial compounds. This study examines the effect of efflux pump inhibitor reserpine on the antimicrobial effectiveness of magnoflorine, oxyacanthine, and the X simplicissima extract against Staphylococcus aureus, with norfloxacin as the control antibiotic. The Yellowroot extract and its two secondary alkaloids have been found to inhibit S. aureus growth. Reserpine alone did not show good inhibitory against S. aureus. However, reserpine being an efflux pump inhibitor, exhibited great synergistic effects with oxyacanthine, magnoflorine, and the yellowroot extract, either halving their minimum inhibitory concentrations or making them more effective at lower concentrations.

Available for download on Tuesday, April 15, 2025