Evaluating the Genotoxicity of Hydroxychloroquine: An In Vitro and In Vivo Study

Background: Hydroxychloroquine (HCQ) is a drug used to treat malarial parasites and it was extensively used during the initial phase of COVID-19. However, HCQ demonstrated certain serious effects when administered to patients. Hence, this study intends to determine its toxicity by exposing it to human peripheral blood and the fly model.Methods: In the present experimental study, HCQ (200 mg) was tested in different volumes (62.5 μl - 500 μl) on human blood samples (in vitro) and Drosophila melanogaster (in vivo). Hemolytic assay, trypan blue assay, mitotic index, chromosomal aberration, and DNA fragmentation assay were used to assess the sublethal effects of HCQ.Results: The results implied that HCQ, at its highest concentration (500 μl), showed maximum lysis in the hemolytic assay, and an increased number of dead cells were observed with increasing concentration in trypan blue assay. Also, the percent mitotic index decreased with increasing concentration of HCQ. Chromosomal aberrations, including breaks, centromeric disruption, dicentrics, and pulverized chromosomes, were observed on exposure to HCQ. The number of fragments in agarose gel electrophoresis revealed damage to DNA. Therefore, these results provide evidence and prove the cytotoxicity and genotoxicity of HCQ.Conclusion: HCQ is found to have cytotoxic and genotoxic effects. These results imply that further examinations must be conducted before prescribing HCQ to treat various diseases.