Abstract :
Aims: To determine the anti-HSV 2 properties and mechanism of action of two important medicinal plants Sericostoma pauciflorum Stocks exWight (Boraginaceae) and Lepidagathis trinervis Nees (Acanthaceae).
Methods and Results: To identify natural products with anti-HSV-2 activity, the aqueous and 50% ethanolic extracts were prepared from whole plants of S. pauciflorum and L. trinervis. Cytotoxicity assay using Vero cells as target revealed CC50 values of these extracts ranging from 301.8 to 436.8 µg ml-1. Extracts from both the plants showed dose dependent inhibition of HSV-2 infection using Plaque Reduction Assay. Among the tested extracts, 50% ethanolic extract of L. trinervis showed lowest IC50 value of 6.86
µg ml-1. To study the possible mode of antiviral action, all the extracts showed 50 to 97% reduction in the formation of plaques in the attachment assay. Extracts prepared from L. trinervis also inhibited the HSV-2 penetration in a time and dose dependent manner. In post-attachment assay, both the extracts from S. pauciflorum as well as 50% ethanolic extract from L. trinervis showed significant inhibition in HSV-2 infection.
Conclusions: These studies document anti-HSV-2 activity of the two commonly used medicinal plants that will have implications in the development of an alternate remedy for HSV-2 infection.
Keyword :
Sericostoma pauciflorum, Lepidagathis trinervis, anti HSV 2 activity, Attachment assay, Penetration assay, Post attachment assay 3