Abstract:
The purpose of this study was to screen for antiviral activity of seventeen Thai medicinal plant extracts against herpes simplex virus type 2 (HSV-2) strain Baylor 186 compared with that of acyclovir using plaque reduction assay (PRA) including inactivation, pre-treatment andpost-treatment. In this study, most of crude extracts (79 of 90 fractions), of the selected plant exhibited positive activity [median effective dose (ED(subscript 50)) ˂ median cytotoxic dose (CD(subscript 50))]. The most successful treatment in PRA has inactivation. The efficacy of anti-HSV-activity was evaluated by using selective index (Sl). Based on the Sl ˃ 10, there were 28 fractions, 11 plant including Barleria lupulina, F1 (ethanol fraction), F2 (hexane fraction) Nephelium lappaceum F3 (aqueous-ethanol fraction), F4 (ethyl acetate fraction), F5 (aqueous-ethyl acetate fraction); Clinacanthus siamensis, F1, F3, F4; Vitis vinifera, F1, F3, F5; Thunbergia lanurifolia, F1, F5; Phyllanthus amarus, F3, F4, F5; Orthosiphon aristatus, F2, F3, F5; Costus speciosus, F1, F3, F4; Bridelia ovate, F3, F4, F5; Clinacanthus nutans, F4; and Cissus quadrangularis, F1, F5.