Abstract
This study examined the anti-herpes simplex virus type I activity of the major constituents
of several essential oils. Plaque reduction assays were performed to evaluate anti-herpes
simplex virus type I activity. Thymol and carvacrol both possessed significant antiviral
activity with an IC50 of 7 µM, and herpes simplex virus type I was 90 % inactivated within 1 hr. The mode
of antiviral action was shown to affect the virion directly. Evidence was also observed
by electron microscopy. Evaluation of the structural requirements for antiviral activity
of thymol-related monoterpenoids revealed that aliphatic side chains had a minor effect,
while a hydrophilic group on the benzene ring was sufficient for activity. Our results
suggest that thymol and carvacrol are potential candidates for topical therapeutic
application to reduce herpes simplex virus transmission.
Key words
monoterpenoids - antiviral - herpes simplex virus type 1 - thymol - carvacrol
