Determination of the speed of action of new hits against asexual forms of P. falciparum in vitro

• Grant number: 21/12162-1
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: November 01, 2021
• End date: October 31, 2022
• Field of knowledge: Biological Sciences - Parasitology - Protozoology of Parasites
• Principal Investigator: Anna Caroline Campos Aguiar
• Grantee: Caio Silva Moura
• Host Institution: Instituto de Saúde e Sociedade (ISS). Universidade Federal de São Paulo (UNIFESP). Campus Baixada Santista. Santos , SP, Brazil
• Associated research grant: 19/19708-0 - Identification of new antimalarial compounds: a multidisciplinary strategy aimed to search for potent chemical classes against new molecular targets and different stages of life of Plasmodium spp, AP.JP

Abstract

The search for new drugs to treat human malaria continues in highlighted in the fight against this disease and represents a constant challenge, as the parasites can adapt and develop resistance, making them less sensitive to the latest medicines. Resistance to artemisinin derivatives, characterized by delayed elimination of parasites, is a recent example of how the parasites manage to develop resistance to antimalarials. In this sense, the development of new compounds to combat the spread of drug-resistant malaria is urgent. In this context, the search for new candidates with a fast action mode will ensure rapid symptom relief for the patient, in addition to rapidly reducing parasitemia, which could minimize the occurrence of mutations that lead to new mechanisms of resistance to antimalarials. Recently, our group, in collaboration with the MMV team, developed a new method to provide information on the speed of action of new compounds (data in the Publication). This method uses the SYBR Green technique, where culture plates with the test compounds will be incubated during different times (24h, 48h, and 72h). Furthermore, because it uses DNA marking, the evaluation of the morphology of parasites from optical microscopy is conducted in parallel, which aims to eliminate results false due to the marking of non-viable parasites by the SYBR technique. This test will be applied in this project and aims to identify compounds with fast-acting mode still in the early stages of drug development. In this sense, hit compounds, belonging to the chemical classes of Pseudokeratidine and hydrazinobenzimidazole will be evaluated in vitro for their mode of action against the asexual stage of P. falciparum (3D7 strain). Other compounds belonging to the backup classes of CIBFar and to the new series may be included in this project. In addition, with this project we will standardize the evaluation of morphology using the high content screening (HCS) technique, which is a simple and fast assay that uses classic DNA markers (SYBR Green I), aiming at comparison with optical microscopy. The two types of tests allow evaluating the evolution of the parasites comparing the morphology with the untreated group. The development of this project will allow the characterization of the mode of action of new candidates aiming at the identification of compounds with the fast mode of action for the development of new drugs.(AU)