In A549 cells, OSU-03012 was identified as a moderate inhibitor based on the SI-MTT and SI-XTT (Table 6)

In A549 cells, OSU-03012 was identified as a moderate inhibitor based on the SI-MTT and SI-XTT (Table 6). ten identified compounds by testing their activity against ZIKV. Among the ten compounds, Azaribine (SI-MTT = 146.29), AVN-944 (SI-MTT = 278.16), and Brequinar (SI-MTT = 157.42) showed potent anti-ZIKV activity in post-treatment therapeutic conditions. We also observed potent anti-ZIKV activity for Mycophenolate mofetil (SI-MTT = 20.51), Mycophenolic acid (SI-MTT = 36.33), and AVN-944 (SI-MTT = 24.51) in pre-treatment prophylactic conditions MAP2K1 and potent co-treatment inhibitory activity for Obatoclax (SI-MTT = 60.58), Azaribine (SI-MTT = 91.51), and Mycophenolate mofetil (SI-MTT = 73.26) in co-treatment conditions. Importantly, the inhibitory effect of these compounds was Tepoxalin strain independent, as they similarly inhibited ZIKV strains from both African and Asian/American lineages. Our results support the broad-spectrum antiviral activity of these ten compounds and suggest their use for the development of antiviral treatment options of ZIKV infection. [1]. ZIKV is a member of the genus Flavivirus within the family in 1948 [4]. After its discovery, ZIKV infections were only sporadically reported in Asia and Africa until 2007 [5], when an outbreak of ZIKV occurred on Yap island, in the Federated States of Micronesia, where about 73% of the residents on the island were infected [6]. In 2013, an outbreak of ZIKV occurred in French Polynesia, where 88% of infected patients reported symptomatic infections, including the development of Guillain-Barr syndrome (GBS) [7]. In 2015, local transmission of ZIKV was reported in Latin America and the Caribbean, where ZIKV outbreaks were associated with congenital microcephaly through maternal infection, and a large increase in the number of Guillain-Barr syndrome cases [8]. By May 2019, ZIKV was spread to over 84 countries and is now a Tepoxalin global health problem [9]. There is an urgent medical need for the development of prophylactic and therapeutic intervention strategies to control ZIKV infections due to its potential for re-emergence [10]. However, to date, there are currently no Food and Drug Administration (FDA)-approved vaccines (prophylactic) and/or antivirals (therapeutic) for the treatment of ZIKV Tepoxalin infection. ZIKV vaccine development has been very challenging due to existing cross-reactive anti-DENV antibodies that augment viral infections [11]. There are multiple ZIKV candidate vaccines under development with several of them in phase 2 clinical trials [12,13,14]. There have also been efforts for developing effective therapies against ZIKV [15], and a number of antivirals have been identified in vitro, but their safety and efficacy in vivo remain to be determined and none have been licensed for the treatment of ZIKV infection [9]. The process of discovery and implementation of antivirals is an extensive and complex process, which requires extensive testing for safety and efficacy. Drug repurposing offers several advantages over developing an entirely new drug for a given indication, as drug repurposing can drastically reduce the timeline and resources required to advance a candidate antiviral into the clinic. The Repurposing, Focused Rescue and Accelerated Medchem (ReFRAME) Tepoxalin collection is comprised of about 12,000 compounds [16]. Our screen of the ReFRAME library identified ten compounds with activity against the mammarenavirus lymphocytic choriomeningitis (LCMV) [16]. The identified compounds included inhibitors of adenosine triphosphate (ATP) synthesis (Antimycin A), inhibitors of dihydroorotate dehydrogenase (DHODH) that is a key enzyme of the pyrimidine biosynthesis pathway (Brequinar), inhibitors of orotidine monophosphate decarboxylase (OMPD) which catalyzes key steps in pyrimidine synthesis (Azauridine, Azaribine, and Pyrazofurin), inhibitors of inosine monophosphate dehydrogenase (IMPDH) which inhibit replication of RNA and DNA via GTP reduction (AVN-944, Mycophenolic acid, and Mycophenolate mofetil), and regulators of apoptosis (OSU-03012 and Obatoclax). We have shown that these compounds with antiviral activity against LCMV, also had inhibitory activities against influenza A and B viruses [17], identifying these compounds as broad-spectrum antiviral candidates, which led us to examine Tepoxalin their ability to inhibit ZIKV infection. The ten tested compounds had effective prophylactic and therapeutic activities against divergent strains of the African and Asian/American ZIKV lineages, further supporting their broad-spectrum antiviral activity. Our results suggest the feasibility of repurposing these compounds for the treatment of ZIKV infection. 2. Material and Methods 2.1. Cell Lines African green monkey kidney epithelial Vero (ATCC, CCL-81, Manassas, VA, USA) and human adenocarcinoma alveolar basal epithelial A549 (ATCC, CCL-185) cells were maintained in Dulbeccos modified Eagles medium (DMEM; Mediatech, Inc., Manassas, VA,.