Investigation of antiviral efficacy of some antibacterial and antiparasitic drugs used in humans and animals against human DNA and RNA viruses.

The limited availability of active ingredients used in antiviral treatment against viral infections and the long time it takes to develop new antivirals have made it necessary to try drugs that are not in the antiviral class, as seen in the COVID-19 pandemic. In these treatment trials, the potential of some antibiotics, antiparasitics and antioxidants to provide effective results in antiviral treatment has been observed. In this study, in addition to the active ingredients of ivermectin (IVM) (Although it is mainly used in veterinary medicine, it is also used in humans.) and selamectin (SLM), which are antiparasitics used in veterinary medicine, and enrofloxacin and tulathromycin, which are antibiotics; the antiviral activities of azithromycin, which is used in both human and veterinary medicine, on some viruses causing infection in humans (Human HSV-1, Human Adenovirus and Human Poliovirus) and Bovine coronavirus from the Coronaviridae family were investigated in-vitro. For this purpose, the viability rates of the active substances in cell cultures were first determined and then three different methods were used for antiviral activity. In Method 1, the virus and the active substance were contacted for one hour and then the virus-active substance mixture was added to the cell. In Method 2, virus was added to the cell, and after one hour of incubation, the active substance was added to the cell. In Method 3, the active substance was added to the cell and contacted for one hour, after which the active substance was removed and virus was added to the cell. The test results were evaluated by observing the cytopathic effects (CPE) in the cells and the results were calculated according to the Sperman-Karber method. Each assay was performed in four replicates and according to the reductions in mean TCID50 log. values; the efficacy of ivermectin was found to be the highest in method 2 antiviral efficacy for HAdV (mean 4.25 log inhibition). In the method 1 antiviral efficacy assay for HSV-1, IVM and SLM were found to be the most effective (Mean 6 log inhibition). In the method 2 antiviral efficacy assay for Human Poliovirus, AZM was found to be the most effective (Mean 3.75 log inhibition). For BCoV, only in the method 1 antiviral efficacy test, all drugs caused a maximum of 1.25 log inhibition. In new pandemics such as the COVID-19 pandemic or when antivirals are insufficient, the active ingredients of these drugs, which are commercially sold and used in veterinary medicine, should be considered for human medicine and used in R&D studies.