Ora A. Holcomb

Ora A. Holcomb

2002 PhD - Plant Physiology - Washington State University

Keene State College

Biology & Chemistry


Mentor: Aaron B. Margolin, Ph.D. - Associate Professor of Microbiology

Anti-viral Phytochemicals

Certain natural plant products which exhibit antiviral activity have been identified. Several phytochemicals with inhibitory action have been isolated. A class of proteins, SCRIPS (Single Chain Ribosome Inactivating Proteins), present in a number of natural plant products have been the center of much of the research. The purpose of the proposed experimental procedures is to identify the active constituents from extracts taken from three plants: Phytolacca americana, Chelidonium majus and Hypericum perforatum, which have been used in traditional herbal medicine. Anti-viral activity will be determined through bioassay using poliovirus as a model virus.

Traditional extractions in the form of six week ethanol tinctures are used for the initial phytochemical separations. Upon removal of the ethanol, the residue is passed through solvents in a polarity series. Further fractionation determined upon bioassay activity. Water based extraction with acid ethanol precipitation and affinity chromatography are used for isolation of proteins. Protein determination by spectrometry and HPLC (size exclusion). Quantification by BSA STD curve Bradford Assay.

Previous studies indicate that some SCRIPS inhibit protein synthesis by reversibly binding with poliovirus which then facilitates its transport into the cell. These proteins enzymically inactivate the 60 S ribosomal unit. Fractions are therefore mixed with poliovirus and incubated for 30 minutes, prior to the innoculation in a dilution series. A decrease in PFU (replication of infectious virus) will indicate viral inhibition.

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