Outlining the Molecules Tested In Vivo for Chagas Disease, Malaria, and Schistosomiasis Over the Last Six Years - A Literature Review Focused on New Synthetic Drug Identities and Repurposing Strategies.

BACKGROUND: COVID-19 disrupted NTD programs in 60% of countries, impairing public health goals. Thus, boosting NTD's research knowledge is demanding, and in vivo screening of candidates allows for the prospect of promising options based on their overall profile. OBJECTIVE: In this work, we highlighted the relevant research done between 2015-2021 in the fields of synthetic and repurposed drugs that were tested in vivo for Chagas disease, malaria, and schistosomiasis. METHODS: MEDLINE, PUBMED, CAPES PERIODIC, and ELSEVIER databases were used for a comprehensive literature review of the last 6 years of research on each area/disease. RESULTS: Overall, research focused on nitro heterocyclic, aromatic nitro, nucleoside, and metal-based scaffolds for analogue-based drug generation. Repurposing was widely assessed, mainly with heterocyclic drugs, their analogues, and in combinations with current treatments. Several drug targets were aimed for Chagas treatment, specific ones such as iron superoxide dismutase, and more general ones, such as mitochondrial dysfunction. For malaria, hemozoin is still popular, and for schistosomiasis, more general structural damage and/or reproduction impairment were aimed at in vitro analysis of the mechanism of action. CONCLUSION: Latest in vivo results outlined trends for each disease - for Chagas Disease, heterocyclics as thiazoles were successfully explored; for Malaria, quinoline derivatives are still relevant, and for schistosomiasis, repurposed drugs from different classes outstood in comparison to synthetic compounds. This study uprises the continuous development of Chagas disease, malaria, and schistosomiasis drugs, providing researchers with tools and information to address such unmet therapeutic needs.

Identification of Novel Zika Virus Inhibitors: A Screening using Thiosemicarbazones and Thiazoles Templates.

BACKGROUND: Zika virus (ZIKV) remains an important cause of congenital infection, fetal microcephaly, and Guillain-Barré syndrome in the population. In 2016, WHO declared a cluster of microcephaly cases and other neurological disorders reported as a global public health emergency in Brazil. There is still no specific treatment for Zika virus fever, only palliative care. Therefore, there is a need for new therapies against this disease. According to the literature, thiosemicarbazone, phthalimide and thiazole are privileged structures with several biological activities, including antiviral activity against various viruses. OBJECTIVE: Based on this, this work presents an antiviral screening using previously synthesized compounds derived from thiosemicarbazone, phthalimide, and thiazole as new hits active against ZIKV. METHODS: After synthesis and characterization, all compounds were submitted to Cytotoxicity by MTT and Antiviral activity against ZIKV assays. RESULTS: Compounds 63, 64, 65, and 73 exhibited major reductions in the ZIKV title from this evaluation. Compounds 63 (99.74%), 64 (99.77%), 65 (99.92%), and 73 (99.21%) showed a higher inhibition than the standard 6MMPr (98.74%) at the CC20 dose. These results revealed new chemical entities with anti-ZIKV activity. CONCLUSION: These derivatives are promising candidates for further assays. In addition, the current approach brings a new privileged scaffolding, which may drive future drug discovery for ZIKV.

Synthesis, ADMET Prediction, and Antitumor Profile of Phenoxyhydrazine- 1,3-thiazoles Derivatives.

BACKGROUND: Cancer is one of the most important barriers to increasing life expectancy in all countries in the 21st century. Investigations of new anti-cancer drugs with low side effects are an urgent demand for medicinal chemists. Considering the known antitumor and immunomodulatory activity of thiazoles, this work presents the synthesis and antineoplastic activity of new thiazoles. METHODS: The 22 new compounds (2a-v) were synthesized from different thiosemicarbazones and 2-bromoacetophenone. The compounds were evaluated on: MOLT-4, HL-60, HL-60/MX1, MM1S, SKMEL-28, DU145, MCF-7, and T47d. RESULTS: Compound 2b induced cellular viability on MOLT-4 (37.1%), DU145 (41.5%), and HL- 60/MX1 (58.8%) cells. On MOLT-4 cells, compound 2b exhibited an IC50 of 8.03 µM, and against DU145 cells, an IC50 of 6.04µM. Besides, at IC50 and fold of IC50, 20% to 30% of dead cells were found, most due to necrosis/late apoptosis. Most compounds no showed cytotoxicity against fibroblast cells L929 at the concentrations tested. The compound did not alter the cell cycle of DU145 cells when compared to the negative control. Therefore, compound 2b stands out against DU145 and MOLT-4 cells. CONCLUSION: Our study reinforced the importance of 1,3-thiazoles nuclei in antitumor activity. In addition, derivative 2b stands out against DU145 and MOLT-4 cells and could be a starting point for developing new antineoplastic agents.

An Overview of the Compounds Tested In Vivo for Leishmania spp. of the Last 5 Years.

BACKGROUND: Leishmaniasis, a still important public health problem, exhibits environmental risk factors such as massive migrations, urbanization, and deforestation. WHO research for Leishmaniasis is mainly focused on the development of new tools, such as diagnostic tests, drugs, and vaccines. During the drug development strategy, only a few compounds were promising and call for further study after the in vitro and in vivo preclinical tests. OBJECTIVE: In this review, our group aimed to highlight the utmost research done during 2014 to 2019 in the fields of natural and synthetic compounds, as well as repurposed drugs and new formulations tested in vivo for Leishmania spp. METHOD: Based on the literature search, we used the databases MEDLINE, PUBMED, CAPES PERIODIC and ELSEVIER to delineate an interval of the last 5 years of research on each field. RESULTS: Among the natural compounds tested, allicin and a fraction of potato tuber extract showed the most promising antileishmanial activity. Concerning synthetic compounds, quinolines, bornyl ester, thymol, benzoxaborole and nitroimidazole derivatives exhibited encouraging results. Moreover, repositioned alternatives involved combinations with known drugs and monotherapy protocols as well. In these years, new formulations were widely assessed as drug delivery systems, such as nanoparticles, micelles and liposomes in polymer conjugations. CONCLUSION: Drug repurposing and new formulations of already-known drugs are worthwhile approaches to promptly introduce new treatment schemes to Leishmaniasis. Nevertheless, the interest in new synthetic compounds and new formulations brings light to new treatment proposals and are notable lines of research.

PA-Int5: An isatin-thiosemicarbazone derivative that exhibits anti-nociceptive and anti-inflammatory effects in Swiss mice.

Pain and inflammation are symptoms of various diseases, and they can be modulated by different pathways, thus highlighting the importance of investigating the therapeutic effects of novel compounds. Previous studies have shown that isatin-thiosemicarbazone exhibits antitumor, antifungal antibacterial and other biological properties. Based on the wide range of biological effects of these compounds, the aim of the present study was to investigate the central nervous system (CNS) performance, and the anti-nociceptive and anti-inflammatory activity of (Z)-2-(5-nitro-2-oxoindolin-3-ilidene)-N-hydroazinecarbothioamide (PA-Int5) in treated mice. Three doses of PA-Int5 were tested orally (1.0, 2.5 and 5.0 mg/kg) in the nociceptive and inflammatory animal models. Additionally, the potential sedative effects of PA-Int5 (5 mg/kg, oral gavage) were investigated using an open field and rotarod tests, to exclude any possible unspecific effects of the nociceptive assays. Anti-nociceptive activity was assessed using the acetic acid-induced abdominal contortion and formalin tests, whereas anti-inflammatory activity was assessed using a carrageenan-induced paw edema and zymosan-induced air-pouch models. PA-Int5 (5 mg/kg) induced anti-nociceptive activity in the abdominal contortion model. In the formalin test, PA-Int5 (at 2.5 and 5 mg/kg) reduced nociception in the second phase. At the higher dose tested, PA-Int5 did not affect spontaneous locomotion or motor coordination. The data revealed that at all doses tested, the compound significantly reduced paw edema following carrageenan administration. In the zymosan-induced air-pouch model, PA-Int5 potently inhibited leukocyte migration and protein levels at the site of inflammation. When combined, the results revealed, for the first time, that PA-Int5 exhibited anti-nociceptive and anti-inflammatory activities, and highlights its potential, as well that of other derivatives, as novel candidates for pain relief.