It was also used to definitely inhibit the replication of human immunodeficiency virus (HIV-1) in lineages of monocytes and lymphocytes [12] and lineages of H9 cells [13]. Furthermore, CLQ has been used to inhibit Kunjin virus replication in cells of nonhuman primates (Vero) [14]. Dengue viruses replicate well in C6/36 cells and in other mosquito lines, they are presently used as sensitive assays for virus isolation from patients, and Vero are also permissive cell lines [15]. In the present study, we observed that in experiments carried out with C6/36 cells infected with DENV-2 and treated with CLQ did not reduce the viral load. In 1981, Coombs et al. [16] observed also that CLQ did not reduce the viral load in experiments carried out with the Sindbis virus in cells of the mosquito Aedes albopictus.

Hernandez et al. [17] obtained similar results when they used CLQ to inhibit replication of the Sindbis virus. Two explanations are possible for these findings: (i) CLQ does not block endosome acidification in the cells of the mosquito Aedes albopictus, or (ii) CLQ blocks endosome acidification but not the infection of mosquito cells with the Sindbis virus. These facts suggest that the replication of DENV-2 used in our experiments in Aedes albopictus cells occurs possibly by a pathway of intracytoplasmic penetration other than the endosomal one, which was not blocked by CLQ. Taken together with the data obtained in these studies, our results suggest that CLQ interferes in DENV-2 virus replication in Vero cells culture but not in C6/36 cells.

Thus, as chloroquine is considered a safe and effective drug, used to treatment many diseases, including malaria, their therapeutic use is promising because it was shown in this study that the drug has significant antiviral effect on the replication of dengue-2 virus in cells culture.Conflict of InterestsAll authors declare that they have no conflict of interests.AcknowledgmentsThis study was supported by FAPESP (S?o Paulo Foundation for Research) (Grant no. 05/04450-4). K. J. S. Farias was supported by a FAPESP fellowship (Grant no. 04/03635-8).
Understanding the relationship between phenotype and genotype is a fundamental problem in genetics. Of particular interest, Drug_discovery the identification of genetic risk factors underlying human inherited diseases has long been a goal in human and medical genetics. Since genetic variation is believed to be the major factor that stimulates the diversity between individuals [1], considerable efforts have been taken to understand associations between human genetic variants and their phenotypic effects [2].