Schinus terebinthifolius Raddi: A potential agent against HSV-1

Herpes simplex virus type 1 (HSV-1) is normally associated with orofacial, pharyngeal, and ocular infections and transmitted by contact with contaminated secretions. Acyclovir is the most commonly used agent in the treatment of HSV infection, but high rates of resistance to this drug have been shown, mainly among immunocompromised patients. Because of this problem, several efforts have been made to discover anti-HSV-1 drugs. Schinus terebinthifolius Raddi, popularly known as Aroeira, is used in folk medicine to treat several illnesses, including in the skin and mucous membranes. Preliminary in vitro studies showed anti-HSV-1 activity of the crude hydroethanolic extract (CHE) of S. terebinthifolius, and bioguided fractionation demonstrated that the CHE has more effective antiviral effects than fractions of S. terebinthifolius and low cytotoxicity. To elucidate the mechanism of action of the effect of the CHE on HSV-1 replication in Vero cells, different experimental strategies were developed using the sulforhodamine B colorimetric method. The CHE was not able to inhibit the proliferation of HSV-1 in Vero cells when the cells were treated 1 and 24h before and after virus entry. However, cell culture protection was observed when the cells were treated during the early stages of HSV-1 entry into cells. Apparently, the CHE also exerts virucidal effects, but more accurate experiments are needed to confirm and elucidate these results. The evidence of the effectiveness and safety of the CHE from Aroeira could contribute to the validation of its use in the topical treatment of skin and mucous diseases caused by HSV-1.