Lactobacillus crispatus and Human Herpes Simplex Virus-2, an In Vitro Study

Introduction: Genital infections have motivated researchers to explore the role of probiotics in the prevention and treatment of these infections. Aim: Development of a new potent and non-invasive way to prevent HSV-2 by probiotics. Methods: The anti-HSV-2 properties of culture cell-free supernatant (CFS) and cell body of Lactobacillus crispatus were evaluated by plaque assay method. The cytotoxicity and adhesion potential to HeLa cells were also evaluated. Finally, the composition of cell-free supernatant was characterized by chromatography-coupled mass spectrometry (GC-MS). Results: Assay showed a significant decrease in viability of HeLa cells upon exposure to a concentration of 10 8 CFU mL –1 as compared to 10 7 CFU mL –1 and other concentration of L. crispatus. Significant antiviral effects were recorded in the pre-treated Hela cells in both cell body form and CFS of L. crispatus. Similar results were obtained in the case of the L. crispatus ATCC 33820 strain. Carbohydrates (19.64%), unknown substances (18.89%), alcohols (14.79%), acids (11.90%), and peptides (11.89%) were the main ingredients of CFS. Conclusion: In this study, the potential of L. crispatus was assessed against HSV-2. L. crispatus significantly decreased infectivity of HSV-2. Coincidence or post-infection presence of L. crispatus showed almost no effect on HSV-2. These results support the hypothesis on the contribution of CFS of L. crispatus at initial virus-host interactions such as binding. Adhesion may be disturbed by lactobacilli through neutralizing virus particles. Both forms of L. crispatus could inhibit the virus even at neutral pH.