Anti-viral effects of aqueous extracts of Aloe ferox and Withania somnifera on herpes simplex virus type 1 in cell culture

Aloe ferox and Withania somnifera are among southern African plants commonly used for the treatment of sexually transmitted infections (STIs). Aqueous extracts from both species, together with aloin, isolated from A. ferox, were evaluated for antiviral activity against herpes simplex virus type 1 (HSV-1) in vitro. The aqueous extracts showed detectable activity at a concentration of 1000 µg/ml against the virus in monolayers of the Vero African green monkey cell cultures, whereas aloin showed significant activity at 62 µg/ml. HSV-1 is usually associated with mucocutaneous infections of the oropharynx but can also cause genital herpes. Herpes simplex virus type 2 (HSV-2) is the classical genital herpes pathogen, but with current sexual habits, can give rise to both oral and genito-anal infections. Our results indicate that the use of these two plant species for the treatment of STIs could have a scientific rationale.