Anti-herpes simplex virus activities of crude water extracts of Thai medicinal plants.
Yoosook C., Bunyapraphatsara N., Boonyakiat Y., Kantasuk C.
Author Affiliation: Department of Microbiology, Faculty of Science, Mahidol University, Bangkok, Thailand.
Phytomedicine 6 : 411-419
Abstract : A number of Thai medicinal plants, recommended as remedies for herpesvirus infection and used in primary health care were investigated for their intracellular activities against herpes simplex viruses (HSV). Centella asiatica, Maclura cochinchinensis and Mangifera indica showed both anti-HSV-1 and -2 activities, as determined by the plaque inhibition assay. An inhibition of the production of infectious HSV-2 virions from infected Vero cells could also be demonstrated. Combinations of each of these reconstituted extracts with 9-(2-hydroxyethoxymethyl) guanosine (acyclovir; ACV) resulted either in subadditive, additive, or synergistic interaction, against HSV-2, depending on the dose of ACV used; a mixture of C. asiatica and M. indica exerted an additive effect in a similar assay. Furthermore, the inhibitory effects of these plant extracts were also substantiated by flow cytometric analysis of virus-specific antigens in the infected cells. The active constituent present in C. asiatica extract was determined to be asiaticoside while in M. indica it was mangiferin.