In vitro effect of oral antiseptics on human immunodeficiency virus-1 and herpes simplex virus type 1

Abstract

Aim: The antiviral effectiveness of widely used commercial mouthrinses has not been well studied. A project was undertaken to evaluate and compare the in vitro antiviral effectiveness of essential oil-containing mouthrinses (LA & TLA) and chlorhexidine mouthrinses (PX & CHX) on 2 different enveloped viruses, human immunodeficiency virus (HIV-1) and Herpes simplex virus (HSV-1) McIntyre strain.

Method: HIV-1(89.6) (1x10(5)/ml) and HSV-1 (1x10(6)/ml) in RPMI-1640 medium were treated with two commercially available forms of LA & TLA (tartar control LA), and 2 formulations of chlorhexidine [(PX), 0.12% chlorhexidine & (CHX), 0.2% chlorhexidine] for 30 sec. The antiviral effect was estimated by inhibition of the syncytia formation or the cytopathic effect (CPE) for HIV-1 on MT-2 cells and by inhibition of the plaque formation for HSV-1 on Vero cell monolayers.

Results: Undiluted LA, TLA, PX and CHX completely inhibited both HIV-189.6 and HSV-1 McIntyre strain. PX and CHX inhibited HIV-1 up to 1:4 dilution, whereas, LA and TLA inhibited HSV-1 up to 1:2 dilution. The antiviral effects of LA and TLA were found to be similar and also the antiviral effect of PX and CHX were also found to be comparable.

Conclusions: The methods used in this investigation allow easy and reproducible evaluations of antiviral efficacy. The anti-HIV-1 and anti-HSV-1 effects of LA, TLA, PX and CHX as evidenced in our in vitro study suggest that we should investigate potential in vivo effects during the use of essential oil-containing or chlorhexidine containing products when used by patients as mouthrinses. If the clinical studies confirm the in vitro data, pre-procedural use by clinicians may be beneficial in reducing viral contamination of bio-aerosols during the delivery of dental care.