Abstract
Since their introduction, nucleoside analogues such as acyclovir are considered to be effective antiviral drugs against viral infections caused by herpes simplex. However, with the emergence of acyclovir-resistance, there is a growing need to develop an alternative antiherpetic drug. Within such context, snake venom could serve as a potential lead. In this study, the antiviral properties of Naja haje haje (N. haje) venom was evaluated against herpes simplex virus types 1 and 2 (HSV-1, 2) in vitro. HSV-infected Vero cells and cell-free virus suspensions were treated with N. haje crude venom phospholipase A2 (PLA2) as well as 3 different fractions, and the virus yield and infectivity were then quantified by direct plaque assay. The results of the present study showed that N. haje venom at a concentration of 1 mu g/ml resulted in 72.1% inhibition of plaque of HSV-1 and 67.5% inhibition against HSV-2, while PLA2 and fraction 1 at a concentration of 25 mu g/ml caused 18.4 and 56.3% inhibition against HSV-1 and 15.2 and 52.2 % against HSV-2, respectively. On the other hand, fraction 3 at a concentration of 150 mu g/ml resulted in 61.1% inhibition against HSV-1 and 65.9% plaque inhibition against HSV-2. N. hale venom inhibited both HSV-1 and 2 and showed some virucidal activity. These properties suggest that this venom could provide advantages as a topical prophylactic/therapeutic agent for HSV infections.