Potent in vitro inhibitor against dengue and Zika viruses with reverse dose response against Zika virus in vivo

QUINTANA VM; JULANDER J; DAMONTE EB; BRUNETTI, JESÚS; CASTILLA V

Buenos Aires

Congreso; Drug Discovery for Neglected Diseases International Congress 2018. 4th Scientific Meeting of Research Network of Natural Products against Neglected Diseases; 2018

Research Network of Natural Products against Neglected Diseases.

Dengue (DENV) and Zika (ZIKV) viruses are a public health concern because of their global burden and the lack ofspecific antiviral treatment [1,2,3]. Anisomycinis a natural alkaloid that inhibits protein synthesis in many types of cells andexhibits inhibitory effect against certain protozoa and fungi [4,5]. Anisomycin was also proved to suppress the infectionof Japanese encephalitis virus, another human pathogen flavivirus [6].We investigated the antiviral activity of the alkaloid anisomycin against DENV and ZIKV.We first examined the effect of anisomycin on cell viability on Vero, A549, HepG2 and U937 cell lines using a MTS assay.Then, we determined antiviral activity by a virus yield inhibition assay, in cultures treated with different concentrationsof the compound for 48 h and virus titer was assessed by a plaque assay. Protein expression was analyzed using anindirect immunofluorescence assay and RNA synthesis by qRT-PCR, at 24h post-infection.The toxicity and antiviral activity of anisomycin was evaluated in a mouse model of ZIKV morbidity and mortality [7].Mice were treated with anisomycin (4, 20, or 100 mg/kg/d) for 10 days beginning 4 h after ZIKV infection. Viremia onday 5, weight change between 0 and 21 days post-infection (dpi) and survival through 28 dpi were used as primaryendpoints.Non-cytotoxic concentrations of anisomycin caused a dose dependent inhibition of viral production in Vero cells, with50% effective concentration values of 23.2, 31.3, 24.8, 61.6 and 33.0 nM for DENV-1, DENV-2, DENV-3, DENV-4 andZIKV, respectively. Anisomycin exhibited antiviral activity against DENV-2 in all the human cell lines tested and againstDENV-2 clinical isolates. A strong inhibition of DENV-2 protein expression and viral RNA synthesis was demonstrated.Doses up to 100 mg/kg/d were well-tolerated in AG129 mice treated for 10 days with anisomycin. In the antiviral study,a more rapid mortality rate was observed associated with treatment with 100 mg/kg/d in comparison to untreatedinfected mice, while animals treated with 4 mg/kg/d of anisomycin died significantly (p