Evaluation of extracts used in traditional Chinese medicine for antiviral potential against herpes simplex virus type 1

Abstract

Herpes Simplex Virus type 1 (HSV-1) is a common pathogen that causes disease throughout the world. The need for new methods for the control and prevention of the virus is vital to reduce the number of people affected by HSV-1. A recent review concluded that natural products represent an important source for new antiviral activity and that Traditional Chinese Medicines (TCMs) are good sources for these agents. The objective of this study was to determine if any TCM plant extracts have potential active compounds capable of antiviral activity against HSV-1, with the ultimate goal identifying anti-HSV-1 drug candidates. After performing a cytotoxicity screen for each of 140 TCM extracts, Vero cells were exposed to HSV-1 and one of the extracts simultaneously to determine antiviral potential. Antiviral potential was determined by fluorescence readings from a spectrophotometer taken after a period of virus, cell, and extract incubation. Cell viability was determined using the fluorescent dye PrestoBlue which is reduced to a fluorescent red color by viable cells. Ten extracts showed potential antiviral activity by maintaining cell viability though cells were infected with HSV-1. The most effective four extracts inhibited HSV-1 by 80% and included Mussaenda pubescens, Antirrhinum majus, Bidens biternata, and Gnetum parvifolium. Further testing will be done to isolate active compounds from these extracts.