Synthesis and biological evaluation of 4-hydroxy-methylpiperidinyl-N-benzyl-acylarylhydrazone hybrids designed as novel multifunctional drug candidates for Alzheimer's disease.

The search for new drug candidates against Alzheimer's disease (AD) remains a complex challenge for medicinal chemists due to its multifactorial pathogenesis and incompletely understood physiopathology. In this context, we have explored the molecular hybridization of pharmacophore structural fragments from known bioactive molecules, aiming to obtain a novel molecular architecture in new chemical entities capable of concomitantly interacting with multiple targets in a so-called multi-target directed ligands (MTDLs) approach. This work describes the synthesis of 4-hydroxymethyl)piperidine-N-benzyl-acyl-hydrazone derivatives 5a-l, designed as novel MTDLs, showing improved multifunctional properties compared to the previously reported parent series of N-benzyl-(3-hydroxy)piperidine-acyl-hydrazone derivatives 4. The new improved derivatives were studied in silico, regarding their mode of interaction with AChE enzyme, and in vitro, for evaluation of their effects on the selective inhibition of cholinesterases, cellular antioxidant, and neuroprotective activities as their cytotoxicity in human neuroblastoma (SH-SY5Y) cells. Overall, compound PQM-181 (5 k) showed the best balanced selective and non-competitive inhibition of AChE (IC50 = 5.9 µM, SI > 5.1), with an additional antioxidant activity (IC50 = 7.45 µM) against neuronal t-BOOH-induced oxidative stress and neuroprotective ability against neurotoxicity elicited by both t-BOOH and OAß1-42, and a moderate ability to interfere in Aß1-42 aggregates, with low cytotoxicity and good predictive druggability properties, suggesting a multifunctional pharmacological profile suitable for further drug development against AD.

Live Cell Imaging Supports a Key Role for Histone Deacetylase as a Molecular Target during Glioblastoma Malignancy Downgrade through Tumor Competence Modulation.

Glioblastoma (GBM) is the most aggressive tumor of the central nervous system, and the identification of the mechanisms underlying the biological basis of GBM aggressiveness is essential to develop new therapies. Due to the low prognosis of GBM treatment, different clinical studies are in course to test the use of histone deacetylase inhibitors (iHDACs) in anticancer cocktails. Here, we seek to investigate the impact of HDAC activity on GBM cell behavior and plasticity by live cell imaging. We pharmacologically knock down HDAC activity using two different inhibitors (TSA and SAHA) in two different tumor cell types: a commercial GBM cell line (U87-MG) and primary tumor (GBM011). Upon 72 hours of in vitro iHDAC treatment, GBM cells presented a very unusual elongated cell shape due to tunneling tube formation and independent on TGF-ß signaling epithelial to mesenchymal transition. Live cell imaging revealed that voltage-sensitive Ca++ signaling was disrupted upon HDAC activity blockade. This behavior was coupled to vimentin and connexin 43 gene expression downregulation, suggesting that HDAC activity blockade downgrades GBM aggressiveness mostly due to tumor cell competence and plasticity modulation in vitro. To test this hypothesis and access whether iHDACs would modulate tumor cell behavior and plasticity to properly respond to environmental cues in vivo, we xenografted GBM oncospheres in the chick developing the neural tube. Remarkably, upon 5 days in the developing neural tube, iHDAC-treated GBM cells ectopically expressed HNK-1, a tumor-suppressor marker tightly correlated to increased survivor of patients. These results describe, for the first time in the literature, the relevance of iHDACs for in vivo tumor cell morphology and competence to properly respond to environmental cues. Ultimately, our results highlight the relevance of chromatin remodeling for tumor cell plasticity and shed light on clinical perspectives aiming the epigenome as a relevant therapeutic target for GBM therapy.

Estudo etnofarmacognóstico da saracuramirá (Ampelozizyphus amazonicus Ducke), uma planta medicinal usada por comunidades quilombolas do Município de Oriximiná-PA, Brasil

In an ethnobotanical survey conducted within "Quilombola" communities of Oriximiná, Pará State, "saracuramirá" (SAR), Ampelozizyphus amazonicus Ducke, stood out as one of the most cited species with wide popular use, especially for malaria, as tonic and depurative. The aim of this paper was to carry out an ethnopharmacognostic study of SAR in these communities. Quantitative ethnobotanical analysis of the data showed that SAR stands out as one of the 10 most versatile species with a high relative importance (1,3); it remains among the five species with the greatest cultural importance, demonstrated by the high salience index (0,311), being the species with the highest major use agreement to malaria (85,7%). Analysis of the foam and hemolysis indexes of SAR shows the presence of saponins with high foam index (833) and low hemolytic activity (HD50 2,6 mg mL-1). In order to analyze SAR saponin aglycones, the drink was prepared by the traditional quilombola method (BMT), was hydrolyzed, and analyzed by gas chromatography after reaction with diazomethane. Two major peaks were characterized by mass spectrometry, one referring to a dammarane triterpene skeleton, characteristic from the SAR saponins, and the other identified as the methyl ester of betulinic acid. Owing to the popular usage of SAR, its in vitro acetylcholinesterase inhibitory activity was evaluated, but with negative results. However, it is possible to suggest that the indications of this plant as a tonic and for treating malaria may be related to an adaptogen and immunostimulant effect due to the presence of saponins and betulinic acid in BMT.

Um levantamento etnobotânico realizado em comunidades quilombolas de Oriximiná, Pará, destacou a saracuramirá (SAR), Ampelozizyphus amazonicus Ducke, com vasto uso popular no tratamento da malária, como tônica e depurativa. Por este motivo, o presente trabalho objetivou realizar um estudo etnofarmacognóstico da SAR nas respectivas comunidades. Por meio de uma análise etnobotânica quantitativa, foi verificado que SAR apresentou-se dentre as 10 espécies mais versáteis pela elevada importância relativa (1,3), dentre as cinco espécies com maior importância cultural pelo elevado índice de saliência (0,311) e a espécie com maior concordância de uso principal para malária (85,7%). Uma análise do índice de espuma e do índice de hemólise para SAR demonstra a presença de saponinas com elevado índice de espuma (833) e uma baixa atividade hemolítica (CH50 2,6 mg mL-1). Para realizar uma análise das agliconas das saponinas de SAR, a bebida preparada pelo método tradicional quilombola (BMT) foi hidrolisada e, após reação com diazometano, foi analisada por cromatografia gasosa. Dois sinais majoritários foram caracterizados por espectrometria de massas, um referente a um triterpeno de esqueleto damarânico, característico das saponinas da SAR, e outro referente ao éster metílico do ácido betulínico. Partindo das informações de uso popular da SAR, foi avaliada in vitro a atividade inibidora da acetilcolinesterase. Apesar de BMT não ter mostrado atividade neste ensaio, é possível supor que as indicações de uso desta planta pelos quilombolas como fortificante e contra malária podem estar relacionadas a uma possível atividade adaptógena e imunoestimulante, dada à presença das saponinas e do ácido betulínico em BMT.