An Overview of Leishmania In Vitro Cultivation and Implications for Antileishmanial Screenings against Promastigotes

The quest for new drug candidates targeting neglected parasitic diseases has become increasingly urgent over the past decades. Advancements in formulating and optimizing drug delivery systems begin with basic research, including direct assays to evaluate the activity of molecules against parasitic stages maintained in laboratories; i.e., promastigotes. In the context of leishmaniasis, an endemic disease worldwide, the cultivation of Leishmania parasites can vary significantly across different laboratories. Factors such as culture media composition, pH, supplementation, and temperature can lead to varied drug responses in in vitro activity assays. This study aims to compile the parameters used in Leishmania spp. promastigotes cultivation protocols described in scientific articles published in indexed journals over the past ten years. The data reveal a lack of uniformity among Leishmania culture protocols, suggesting a potential bottleneck in comparing the leishmanicidal potential of in vitro drug candidates reported by different research groups. This condition is crucial to consider, because viability/inhibition assays should begin with fully-grown, healthy promastigote cultures capable of homogeneous division, thereby producing more reproducible results.