Background: The emergence of different viral infections calls for the development of new, effective, and safe antiviral drugs. Glycyrrhiza glabra is a well-known herbal remedy possessing antiviral properties. Objective: The objective of our research was to evaluate the effectiveness of a newly developed combination of the probiotics Lactobacillus acidophilus and G. glabra root extract against two viral models, namely the DNA virus Herpes simplex virus-1 (HSV-1) and the RNA virus Vesicular Stomatitis Virus (VSV), with regards to their antiviral properties. Methodology: To examine the antiviral impacts of various treatments, we employed the MTT assay and real-time PCR methodology. Results: The findings of our study indicate that the co-administration of L. acidophilus and G. glabra resulted in a significant improvement in the survival rate of Vero cells, while also leading to a reduction in the titers of Herpes Simplex Virus Type 1 (HSV-1) and Vesicular Stomatitis Virus (VSV) in comparison to cells that were not treated. Additionally, an investigation was conducted on glycyrrhizin, the primary constituent of G. glabra extract, utilizing molecular docking techniques. The results indicated that glycyrrhizin exhibited a greater binding energy score for HSV-1 polymerase (− 22.45 kcal/mol) and VSV nucleocapsid (− 19.77 kcal/mol) in comparison to the cocrystallized ligand (− 13.31 and − 11.44 kcal/mol, respectively). Conclusions: The combination of L. acidophilus and G. glabra extract can be used to develop a new, natural antiviral agent that is safe and effective.

Purpose: There is an immense need to develop new antiviral compounds that are effective and have little side effects. Natural compounds provide a good candidate that is gaining popularity. Probiotics as Lactiplantibacillus plantarum and plant-derived medicines as star anise extract have been investigated to treat viral diseases, cancer, and inflammation. This work aimed to investigate the antiviral effect of probiotics ( Lactiplantibacillus plantarum ) and (star anise) against Herpes simplex virus type 1(HSV-1) and Vesicular stomatitis virus (VSV). Patients and methods: Lactiplantibacillus plantarum and star anise extract had been prepared and tested against vero cell lines for cytotoxicity assay. The antiviral effect of L. plantarum and star anise against HSV-1 and VSV was evaluated by titration calculation (TCID50). The expression of MX genes were measured in infected cells before and after treatment with L. plantarum and star anise. Results: We found that L. planterum is more effective against HSV-1 and caused 2.5 log reduction in virus titre while star anise extract is more effective against VSV and caused 1.25 log reduction in virus titre. Evaluation of MX genes expression revealed higher expression in HSV-1 infected cell treated with L. planterum and VSV infected cells treated with star anise extract. Conclusion: L. planterum and star anise could be useful antiviral natural compounds that have minimal side effects Plain language Summary: Both Herpes simplex virus type 1(HSV-1) and Vesicular stomatitis virus (VSV) caused infection characterized by lytic lesions. Lactiplantibacillus plantarum and star anise had shown promising antiviral effects. So, we investigated the antiproliferative effect of L. plantarum and star anise against HSV-1 and VSV by assessment of virus titre before and after treatment and assessment of MX gene coding for antiviral proteins. We found that L. plantarum and star anise could inhibit proliferation of HSV-1 and VSV and increase expression of MX gene. L. plantarum and star anise could be good antiviral candidate.