Pharmacological and pharmaceutical properties

Abstract

Abstract Aqueous extracts from eight species of Hong Kong marine algae were tested for their antiviral activity against Herpes simplex viruses type 1 (HSV-1) and type 2 (HSV-2). These extracts were tested for their cytotoxicity by examining their effects on the Vero cells. Their potential anti-HSV activity was evaluated using cytopathogenic effect (CPE) inhibition assay. Among the extracts tested, five (from Caulerpa sp., Corallina sp., Hypnea charoides, Padina arborescens and Sargassum patens) showed some potential activities with very low cytotoxicity to Vero cells and three (from Laurencia japonica, Galaxaura oblongata and Sargassum siliquastrum) had no activity against HSV-1 and HSV-2. The extracts of Sargassum patens and Caulerpa sp. were found to be the most promising with very low ECso, namely 25 µg/ ml against HSV-1 and 12.5 µg/ml against HSV-2. The extract of Sargassum patens was precipitated with ethanol. The dark brown precipitated fraction (designated as SP) showed more potent antiviral activities with EC50 against HSV-1 and HSV-2 clinical strains, being 12.5 µg/ml and 4.7 µg/ml respectively in Vero cells. This SP inhibited CPE formation of both HSV clinical and laboratory strains in Vero cells and HEp-2 cells. This SP also showed good antiviral activity against an HSV-1 acyclovir resistant strain. These results indicate that the extract from Sargassum patens is a promising source of natural antiviral agent against herpes virus.