Integrative Multi-Kinase Approach for the Identification of Potent Antiplasmodial Hits

Malaria is a tropical infectious disease that affects over 219 million people worldwide. Due to the constant emergence of parasitic resistance to the current antimalarial drugs, the discovery of new antimalarial drugs is a global health priority. Multi-target drug discovery is a promising and innovative strategy for drug discovery and it is currently regarded as one of the best strategies to face drug resistance. Aiming to identify new multi-target antimalarial drug candidates, we developed an integrative computational approach to select multi-kinase inhibitors for Plasmodium falciparum calcium-dependent protein kinases 1 and 4 (CDPK1 and CDPK4) and protein kinase 6 (PK6). For this purpose, we developed and validated shape-based and machine learning models to prioritize compounds for experimental evaluation. Then, we applied the best models for virtual screening of a large commercial database of drug-like molecules. Ten computational hits were experimentally evaluated against asexual blood stages of both sensitive and multi-drug resistant P. falciparum strains. Among them, LabMol-171, LabMol-172, and LabMol-181 showed potent antiplasmodial activity at nanomolar concentrations (EC₅₀ ≤ 700 nM) and selectivity indices >15 folds. In addition, LabMol-171 and LabMol-181 showed good in vitro inhibition of P. berghei ookinete formation and therefore represent promising transmission-blocking scaffolds. Finally, docking studies with protein kinases CDPK1, CDPK4, and PK6 showed structural insights for further hit-to-lead optimization studies.

Chalcones as a basis for computer-aided drug design: innovative approaches to tackle malaria

Aim: Computer-aided drug design approaches were applied to identify chalcones with antiplasmodial activity. Methodology: The virtual screening was performed as follows: structural standardization of in-house database of chalcones; identification of potential Plasmodium falciparum protein targets for the chalcones; homology modeling of the predicted P. falciparum targets; molecular docking studies; and in vitro experimental validation. Results: Using these models, we prioritized 16 chalcones with potential antiplasmodial activity, for further experimental evaluation. Among them, LabMol-86 and LabMol-87 showed potent in vitro antiplasmodial activity against P. falciparum, while LabMol-63 and LabMol-73 were potent inhibitors of Plasmodium berghei progression into mosquito stages. Conclusion: Our results encourage the exploration of chalcones in hit-to-lead optimization studies for tackling malaria.

[Use of amitriptyline in attention deficit hyperactivity disorder]

We studied the action of amitriptyline (AMI) in the attention deficit hyperactivity disorder (ADHD). Twenty-five children who came to consultation for ADHD were analyzed, in two groups: the group which used AMI (n = 18) at 1.6 mg/kg/day and the group which used placebo (n = 7). Both groups were submitted to two assessments in a 30 days interval, which consisted of the evolutive neurological evolution examination (ENE) and the WISC scale subtests on numbers, drawings to be completed and the code. The results showed that the AMI produced an improvement in performance in the motor persistence tests.

[Performance of literacy and cortical brain functions in a sample of first grade students of Porto Alegre, Brazil]

Cortical brain functions are the basis of the learning process and evolutionary neurological examination (ENE) provides the level of development of the brain. The purpose of this work was to study by means of the ENE the brain functions in a representative sample of first grade students of Porto Alegre, to investigate the learning performance. An observation, analytical and transversal delineated study was performed. The random sample had 484 children. It was observed: sex, age, race, weight, height, neurological examination, ENE, performance in the number sub-tests, completing figures and codes from WISC scale and literacy learning. The items of ENE were below the expected for the age in 11.4% and 38.2% of the children: the most affected ones were the sensitivity activity and gnosias (38.2%) and the least one was motor persistence (11.4%). In psychometric tests, 40.5% of the subjects had their development in numbers below the espected, 39.0% in accomplishing figures, 71.5% in codes. Concerning literacy, 94.4% of the children learned to read and write. The neuropsychological dysfunction and malestablished laterality were a risk factor for the learning process.