Hepatitis C and Dengue viruses belong to the family of Flaviviridae. Viruses in this family are enveloped, have positive-sense RNA and are responsible for a variety of life threatening diseases. Hepatitis C virus is the major etiological agent of post-transfusion hepatitis worldwide. An estimated 3 % of the world's population is infected with HCV according to the World Health Organization. Infection with HCV will most regularly result in chronic hepatitis, which leads to liver cirrhosis, hepatocellular carcinoma and liver failure. Dengue is currently the most important viral disease transmitted by mosquitoes afflicting humans the world context. Clinical symptoms range from mild fevers to a severe haemorrhagic disease. To date neither specific antiviral treatments exist nor are there any vaccines available for both infections. Thus there is an urgent need for new therapies.