Antiviral activity against Zika virus of a new formulation of curcumin in poly lactic-co-glycolic acid nanoparticles.

OBJECTIVES: In the search of an effective antiviral formulation, the natural product curcumin (CUR) was encapsulated into poly(lactic-co-glycolic acid) nanoparticles, a non-toxic bioresorbable and biocompatible copolymer. The resulting CUR containing particles (PLGA-CUR NPs) were characterized and analysed for antiviral activity against Zika virus (ZIKV) infection. METHODS: The PLGA-CUR NPs were characterized by Fourier transform infrared, differential scanning calorimetry, dynamic light scattering, scanning electron microscopy and thermogravimetric analysis and release profile. Cytotoxicity of PLGA-CUR and the antiviral activity against ZIKV were determined in Vero cells. The effect of PLGA-CUR NPs on viral RNA synthesis and protein expression was analysed by RT-qPCR and immunofluorescence staining, respectively. KEY FINDINGS: The PLGA-CUR NPs showed an appropriate in vitro drug release profile. Our studies of the antiviral activity of PLGA-CUR NPs and CUR against ZIKV by virus yield reduction as well as viral RNA synthesis and protein expression have shown that PLGA-CUR formulation is more effective than free CUR to inhibit ZIKV infection of Vero cells. CONCLUSIONS: Our results demonstrate for the first time the antiviral activity against ZIKV of PLGA nanoparticles charged with CUR, suggesting that PLGA-CUR NPs are promising candidates for a drug formulation against human pathogenic flaviviruses.

Identifying Restriction Factors for Hemorrhagic Fever Viruses: Dengue and Junín.

Host restriction factors are cellular components that interfere with viral multiplication. They are up-regulated and expressed upon viral infection and in consequence their activity is specific. So far several important restriction factors have been described against diverse viruses. The cellular antiviral mechanisms defined include proteins with the ability to interfere with early steps of viral replication and others that have been shown to block viral morphogenesis. However, other strategies by which the antiviral action is exerted still remain elusive. An additional interesting matter is how viruses also developed ways to by-pass these host-specific obstacles. Thus, unusual cell localization or re-localization represents a frequent virus choice to evade the cellular surveillance. In the present chapter, we summarize methods to identify cell restriction factors, their antiviral activity, and possible subcellular locations where their activity can take place.