Rare diseases caused by single-gene mutations affect almost one million Canadians. According to the Online Mendelian Inheritance in Man database, ~4,500 rare monogenic diseases have a known cause; but less than 5% of patients have access to disease-modifying drugs. The dearth of accessible drugs for patients suffering from rare genetic diseases is partly due to the astronomical costs of traditional drug development which, when combined with the small target population, make rare disease therapeutics unattractive ventures for the pharmaceutical establishment. The paucity of cost-effective treatments for rare diseases has resulted in the promotion of clinic-ready drug repurposing as a tenable strategy for rare disease therapeutics. To identify repurposed candidates for rare neurogenetic diseases, I conducted a transcriptome-wide drug screen in mouse primary cerebrocortical cultures. RNA sequencing was used to develop a database of transcriptome-wide differential expression for 218 clinic-tested drugs. The “Neuron Screen” database was queried to identify drugs that upregulate ~60 rare neurogenetic disease genes (type I hits). Gene set enrichment pathway analysis by Ingenuity Pathway Analysis (IPA) was used to identify network associated drug-gene interactions (type II hits). Both types of drug-gene hits were further assessed in vitro and in vivo by qRT-PCR and western blot analysis. This analysis showed that the IPA-based network-associated approach reduces the false positive rate when identifying differentially expressed genes in transcriptome-wide data-sets. The analysis also identified two drug-gene interactions with genes that cause rare neurogenetic disease, thyroid hormone-Pmp22 and dexamethasone-Mfsd2a, that merit further investigation. This work proves the utility of the Neuron Screen database to connect rare disease genes with transcript-modulating drugs and provides a starting point to understand the transcriptional effects of pharmacologic agents on the mammalian brain.

Indiana University-Purdue University Indianapolis (IUPUI) / Background: Alzheimer’s disease (AD) is the third leading cause of death for the older demographic in the United States, just after heart disease and cancer. However, unlike heart disease and cancer, the death rates for AD are increasing. Despite extensive research, the cause or origin of AD remains unclear and there is no existing cure. However, with the improvement of single-cell RNA-sequencing (scRNA-seq) technologies and drug repurposing tools, we can further our knowledge of AD and its pathogenesis. Method: Our primary aim was to identify repurposable drug and compound candidates for AD treatment and identify significant cell types and signaling pathways using two scRNA-seq datasets from cortex samples of AD patients and controls. To achieve this aim, we generated differential gene expression profiles, calculated log fold-changes, and estimated standard errors to make pairwise comparisons between the diseased and healthy samples. We used the 21,304 drugs/compounds with response gene expression profiles in 98 cell lines from the LINCS L1000 project to detect consistent differentially expressed genes (DEGs), that were either i) up-regulated in cells of diseased samples and down-regulated in cells with treatment, or ii) down-regulated in cells from diseased samples but up-regulated in cells with treatment. To evaluate these identified drugs, we compared the p-value, false discovery rate (FDR) and A Single-cell Guided Pipeline to Aid Repurposing of Drugs (ASGARD) drug score for each cell type. We further annotated and assessed doublet cell types within the Grubman et al. dataset using cell type proportions. Result: The analysis provided several potential therapeutic treatments for AD and its target genes and pathways as well as important cell type interactions. Notably, we identified an interaction between endothelial cells and microglia, and further identified drug candidates to target this interaction. Conclusion: We identified repurposable drugs/compounds candidates in each dataset which were also identified in literature. We further identified doublet cell type interactions of interest and drugs that target this interaction.

The number of known monogenic rare diseases (~7000) exceeds the number of effective treatments (~500) by more than an order of magnitude underlining the pressing need for generalizable therapeutic approaches for this class of conditions. In this regard, the majority of recessive and x-linked recessive disorders are caused by missense mutations encoding proteins that frequently have residual function but are rapidly degraded by the 26S proteasome. Bortezomib is a small molecule that inhibits the 26S proteasome and has been approved for use in patients for an unrelated condition; multiple myeloma. Previous work has shown that, for a small number of disorders, bortezomib can inhibit the degradation of the mutant protein, thereby increasing the protein level and activity, holding out the promise of a beneficial therapeutic effect by the repurposing of this agent. We present here a high level western blot based survey of nine recessive disorders to characterize the general effectiveness of such an approach. Thirteen patient fibroblast cell lines comprising 9 different diseases with 19 known mutations were selected on the basis of missense mutations protein expression data when available. The cell lines were incubated with bortezomib (10 nM and 50 nM; 24 hrs) and levels of the mutated protein were quantified by western blot. Unfortunately, no consistent, appreciable increase was observed for any of the conditions tested. The general therapeutic value of re-purposing bortezomib for recessive and x-linked diseases appears limited at best. The few reported cases of bortezomib successfully working in increasing mutated protein levels appear to be the exceptions and not the norm. Moreover successes are more often limited to cell lines carrying a transgene expressing the mutated protein rather than endogenous mutated protein in patient cell lines.

Chronic obstructive pulmonary disease (COPD) is a progressive lung disease characterized by breathlessness due to airflow obstruction. COPD is the third leading cause of death worldwide. So far, none of the existing pharmacological treatments for COPD can stop the progressive decline in lung function. Drug repurposing is the application of existing approved therapeutic compounds for new disease indications, which may reduce the cost and time of new drug development. So far, there is not any systematic multi-omics data integration for drug repurposing in COPD. The goal of this project is to develop a systems biology pipeline for the identification of biological-relevant gene targets with drug repurposing potential for COPD treatment using multi-omics integration. Here we implemented a computational methodology to identify drug repurposing targets for COPD. We integrated multi-omics COPD data including, genome, transcriptome, proteome, metabolome, interactome data, and drug-target information. A distance-based network model was created to rank the potential candidate genes. Fifty genes were prioritized as COPD signature genes for their overall proximity to signature genes identified at all omics levels. Forty of them may be considered as “druggable” targets. Literature search reported CRCX4 – Plerixafor as one prioritized targets-gene pair for drug repurposing. The bone marrow stimulant Plerixafor is currently being evaluated for COPD treatment in clinical trials, suggesting that our pipeline is finding promising drug repurposing targets. Our work, for the first time, applied a systematic approach integrating multiple omics data to find drug repurposing targets for COPD. / Pharmaceutical Sciences

Aspergillus fumigatus is a globally present pathogen capable of inflicting debilitating and life-threatening opportunistic infections in individuals, primarily those who are immunocompromised. Diagnosing A. fumigatus infections is often difficult, leading to a delay in treatment which can greatly impact patient outcomes. Furthermore, our lessening of antifungal development combined with increasing resistance generates a feasible scenario where only last resort options are viable. This has prompted the World Health Organization (WHO) to declare this pathogen a "critical priority" due to increased resistance and rising mortality rates. Azoles are utilized as primary treatment options for Aspergillus fumigatus infections such as voriconazole (VRC), itraconazole (ITC), and posaconazole (POS) with a reserve of Amphotericin B (AmB). In the past two decades, the emergence of resistance to azoles has contributed to a 90% mortality rate in resistant cases globally. In this report, we investigated the MedChem Express (MCE) Drug Repurposing Compound Library (4,226 compounds) in conjunction with itraconazole at 0.06 µg/mL against A. fumigatus CDC #738. After the initial screening, we identified compounds known to be antifungals or antiseptics and deselected them. The remaining thirty selected compounds were evaluated through published literature and clinical trial data to determine those candidates with favorable characteristics/properties. Criteria for candidate selection consisted of evaluating the compounds; plasma concentration peak, the time to reach peak, protein binding, oral availability, and drug class. Six candidates were ranked the highest of the previous round –surprisingly 50% of those compounds were HIV drugs, cobicistat, elvitegravir, lopinavir. The remaining three selected compounds are penfluridol, rilapladib, and rolapitant. The combination of itraconazole (ITC), posaconazole (POS), and voriconazole (VRC), with the identified compounds demonstrated promising amounts of synergy, in resistant and susceptible isolates. Further investigation revealed novel properties of ITC and POS when in combination with our compounds of interest. Rilapladib was able to reverse POS, ITC, and VRC resistant strain(s) to a sensitive profile. Growth kinetic assays demonstrate potent anti-germination properties not seen before in the sub-inhibitory doses of azoles. This work demonstrates that high-throughput screening as a viable technique to identify robust antifungal synergizers, allowing for tenable translation to a clinical setting. / Master of Science / Aspergillus fumigatus is a worldwide fungal organism capable of causing disease, particularly in immunocompromised individuals. Infections primarily occur when individuals inhale spores that can remain dormant until the person's immune system is weakened, via disease, cancer, or prescribed drug for surgery. When the immune system is weakened, the spores are more effective at lung colonization. Aspergillus fumigatus infections can be combatted with voriconazole (VRC), itraconazole (ITC), or posaconazole (POS). However, in the past two decades, some fungi have started to develop resistance to azoles, necessitating the use of amphotericin B (AmB), a highly intolerable and final treatment option. In this report, we challenged A. fumigatus CDC isolate #738 with compounds from the MedChem Express (MCE) Drug Repurposing Compound Library (4,226 compounds) with itraconazole at 0.06 µg/mL, an ineffective concentration. We selected combinations and compounds that negated 90% of fungal growth those combinations that contained a known antifungal or antiseptic agent; once identified we deselected any known antifungal or antiseptic agents. The remaining selected compounds were evaluated for favorable drug properties, by reviewing published literature and clinical reports to determine those candidates with favorable characteristics/properties. The combination of ITC, POS, and VRC with the identified compounds demonstrated antifungal enhancement in resistant and susceptible isolates. We observed the reversal of resistance to POS, ITC, and VRC in several isolates when the drug combinations were applied. This demonstrates the importance of evaluating approved and under current review drugs to identify novel properties to aid our dwindling number of effective antifungals. This study provides promising combinational therapies for further evaluation in combating resistant A. fumigatus infections.

Neisseria gonorrhoeae, the causative agent of gonorrhea, is the second most prevalent sexually transmitted infection that leads to substantial morbidity and economic burden worldwide. Improperly treated or untreated gonorrhea can lead to severe and life-threatening complications, including abortion, infertility, pelvic pain, and maternal death. Neisseria gonorrhoeae has developed resistance to the formally and currently used antibiotics. The Centers for Disease Control and Prevention (CDC) have listed multi-drug resistant N. gonorrhoeae as an urgent threat that promptly requires the development of novel therapeutic agents. Traditional drug discovery and development is a time-consuming and costly process associated with high risks. To address the dire need to replenish the dry pipeline of anti-gonorrhea medications, drug repurposing is a promising approach. In this study, an FDA-approved drug library was screened, and 14 drugs were found to exhibit promising anti-gonococcal activity. Interestingly, three extremely potent and narrow-spectrum novel candidates, itraconazole, isavuconazole, and ravuconazole, are azole antifungals, and their activities were further investigated in vitro. Of the three azoles, ravuconazole displayed the most potent activity against N. gonorrhoeae clinical isolates. The time-kill assay revealed that the three azoles showed bactericidal activity. All three azole drugs showed a low frequency of resistance. Besides, isavuconazole and ravuconazole have a longer post-antibiotic effect than azithromycin. All three azoles cleared the burden of intracellular N. gonorrhoeae completely, which is superior to ceftriaxone. In conclusion, itraconazole, isavuconazole, and ravuconazole merit future investigation for the development of anti-gonorrheal therapeutics. This study provided unexplored avenues and promising opportunities that can be further evaluated to combat N. gonorrhoeae infection. / Master of Science / Neisseria gonorrhoeae, the causative agent of gonorrhea, is the second most prevalent sexually transmitted infection that leads to substantial morbidity and economic burden worldwide. Improperly treated or untreated gonorrhea can lead to severe and life-threatening complications, including abortion, infertility, pelvic pain, and maternal death. Due to the increasing prevalence of drug resistance against the formally and currently used antibiotics, the Centers for Disease Control and Prevention (CDC) have classified multi-drug resistant N. gonorrhoeae as an urgent-threat pathogen. Therefore, the discovery of new anti-gonorrheal therapeutics is an urgent need. Drug repurposing is the process of discovering new therapeutic uses for approved or investigational drugs that go beyond the original medical indication. To address the dire need to replenish the dry pipeline of anti-gonorrheal drugs, repurposing FDA-approved drugs is a promising approach as it significantly reduces the time and expense associated with traditional drug development. By screening an FDA-approved drug library, 14 drugs were found to display promising anti-gonococcal activity. Interestingly, three (itraconazole, isavuconazole, and ravuconazole) out of 14 identified drugs were azole antifungal drugs, and their activities were further investigated in vitro. All three azole drugs showed bactericidal activity, meaning that they killed bacteria, had a low propensity to develop resistance, and completely cleared the burden of intracellular N. gonorrhoeae. Besides, our findings suggested that isavuconazole and ravuconazole possessed exceptional activity in the suppression of bacterial growth following brief antibiotic exposure. In conclusion, the three azole drugs exhibited potent anti-gonococcal activity and merited further investigation. This study provided unexplored avenues and promising opportunities that can be further evaluated to combat multidrug-resistant N. gonorrhoeae. Neisseria gonorrhoeae, the causative agent of gonorrhea, is the second most prevalent sexually transmitted infection that leads to substantial morbidity and economic burden worldwide. Improperly treated or untreated gonorrhea can lead to severe and life-threatening complications, including abortion, infertility, pelvic pain, and maternal death. Due to the increasing prevalence of drug resistance against the formally and currently used antibiotics, the Centers for Disease Control and Prevention (CDC) have classified multi-drug resistant N. gonorrhoeae as an urgent-threat pathogen. Therefore, the discovery of new anti-gonorrheal therapeutics is an urgent need. Drug repurposing is the process of discovering new therapeutic uses for approved or investigational drugs that go beyond the original medical indication. To address the dire need to replenish the dry pipeline of anti-gonorrheal drugs, repurposing FDA-approved drugs is a promising approach as it significantly reduces the time and expense associated with traditional drug development. By screening an FDA-approved drug library, 14 drugs were found to display promising anti-gonococcal activity. Interestingly, three (itraconazole, isavuconazole, and ravuconazole) out of 14 identified drugs were azole antifungal drugs, and their activities were further investigated in vitro. All three azole drugs showed bactericidal activity, meaning that they killed bacteria, had a low propensity to develop resistance, and completely cleared the burden of intracellular N. gonorrhoeae. Besides, our findings suggested that isavuconazole and ravuconazole possessed exceptional activity in the suppression of bacterial growth following brief antibiotic exposure. In conclusion, the three azole drugs exhibited potent anti-gonococcal activity and merited further investigation. This study provided unexplored avenues and promising opportunities that can be further evaluated to combat multidrug-resistant N. gonorrhoeae.

京都大学 / 0048 / 新制・課程博士 / 博士(薬科学) / 甲第22752号 / 薬科博第126号 / 新制||薬科||14(附属図書館) / 京都大学大学院薬学研究科薬科学専攻 / (主査)教授 金子 周司, 教授 土居 雅夫, 教授 竹島 浩 / 学位規則第4条第1項該当 / Doctor of Pharmaceutical Sciences / Kyoto University / DFAM

A quimioterapia disponível para o tratamento das leishmanioses conta com um número reduzido de fármacos, com efeitos adversos severos e progressivo aumento de resistência. O reposicionamento de fármacos oferece uma grande oportunidade para introdução de novas terapias. Antidepressivos orais têm demonstrado eficácia tanto in vitro quanto in vivo contra espécies de Leishmania spp. Neste estudo, o antidepressivo sertralina (SRT), e o fármaco ciclobenzaprina (CBP), um relaxante muscular de estrutura tricíclica análoga a antidepressivos, foram avaliados quanto a atividade contra Leishmania (L.) infantum. Estudos metabolômicos não dirigidos utilizando multiplataforma analítica, foram combinados a análises de parâmetros celulares, essenciais para obtenção de uma ampla descrição dos mecanismos de ação. A CBP mostrou uma atividade leishmanicida in vitro, com valor de CE50 de 4,3 ?M contra formas promastigotas e 8,6 ?M contra formas amastigotas intracelulares. O fármaco apresentou uma citotoxicidade (CC50) de 70,6 ?M em células NCTC, e um índice de seletividade similar a miltefosina. Os estudos de mecanismo de ação, sugeriram que a CBP se difunde pela membrana plasmática, causando diminuição do ??p e no interior citoplasmático, parece induzir um estresse do RE com liberação de Ca+2; concomitantemente, induz um desacoplamento brando da cadeia respiratória mitocondrial e depleção dos níveis de ATP. Com o efeito prolongado, a liberação de Ca+2 parece ativar a autofagia, e seu influxo para a mitocôndria potencializar os efeitos deletérios, diminuindo o ??m e aumentando a produção de ROS. A longo prazo, o CBP induz uma extensa alteração metabólica, caracterizada aumento dos níveis da maioria dos metabólitos identificados e atividade desregulada de transportadores de membrana, gerando alto gasto energético associado a condições insuficientes de produção de energia mitocondrial, resultando em morte celular. A sertralina também apresentou atividade leishmanicida in vitro, com valor de CE50 de 2 ?M contra formas promastigotas e 3,9 ?M contra formas amastigotas intracelulares. Sua toxicidade em células NCTC foi de 19,6 ?M, resultando em um índice de seletividade similar a miltefosina. Nossos estudos confirmaram a mitocôndria de Leishmania como alvo primário e, o efeito de desacoplamento da cadeia respiratória associado ao colapso energético, estresse oxidativo seguido da despolarização do ??m como a possível origem desta disfunção mitocondrial. Estudos metabolômicos evidenciaram que a extensão do desarranjo metabólico, abrange diminuição da capacidade de detoxificação do metabolismo tiol-redox, uma severa depleção do pool intracelular de aminoácidos e poliaminas, evidenciando uma completa deterioração do metabolismo energético, por meio de um mecanismo multialvo direcionado a vias metabólicas essências do parasita. Finalmente, este estudo descreve a atividade anti-Leishmania de dois fármacos orais aprovados, com mecanismos de ação letais e irreversíveis no parasita, encorajando o prosseguimento para futuros estudos pré-clínicos na leishmaniose visceral americana / The available chemotherapy for the treatment of leishmaniasis has a reduced number of drugs, with severe adverse effects and progressive increase of resistance. The drug repurposing offers a great opportunity for the introduction of new therapies. Oral antidepressants have been demonstrated efficacy both in vitro and in vivo against Leishmania spp. In this study, the antidepressant sertraline (SRT), and the drug cyclobenzaprine (CBP), a muscle relaxant with tricyclic structure analogous to antidepressants, were evaluated against Leishmania (L.) infantum. Untargeted metabolomic studies using multiplataform analysis were combined to cellular parameters to a broad description of the mechanisms of action. Cyclobenzaprine showed an in vitro leishmanicidal activity with an EC50 value of 4.3 ?M against promastigotes and 8.6 ?M against intracellular amastigote forms. The drug showed a cytotoxicity (CC50) of 70.6 ?M in NCTC cells, and a selectivity index similar to miltefosine. Mechanism of action studies suggested that CBP diffuses through the plasma membrane, causing a decrease of the ??p and inside the cytoplasm, the drug seems to induce an ER stress, with release of Ca+2; concomitantly, it induces a mild decoupling of the mitochondrial respiratory chain and depletion of ATP levels. With the prolonged effect, a release of Ca+ 2 appears to activate an autophagy, and its mitochondrial influx results in a potentiation of deleterious effects as decreasing of ??m and increasing ROS production. In long term, CBP induces an extensive metabolic alteration, characterized increased levels of most of the identified metabolites and unregulated activity of membrane transporters. These generates a high energy expenditure associated to limited conditions of mitochondrial energy production, resulting in the cellular death. Sertraline also showed in vitro leishmanicidal activity, with an EC50 value of 2 ?M against promastigotes and 3.9 ?M against intracellular amastigote forms. Its toxicity in NCTC cells was 19.6 ?M, resulting in a selectivity index similar to miltefosine. Our studies confirmed the mitochondria of Leishmania as the primary target, and the uncoupling of the respiratory chain associated with energy collapse, oxidative stress, and the depolarization of ??m as the possible origin of this mitochondrial dysfunction. Metabolomics evidenced an extended metabolic disarray caused by SRT encompassing a decrease in the scavenging capacity of the thiol-redox metabolism and a severe depletion of the intracellular pool of amino acids and polyamines. The complete deterioration of energetic metabolism was evident through a multi-target mechanism, affecting the main metabolic pathways of the parasite. Finally, this study describes an anti-Leishmania activity of two approved oral drugs with lethal and irreversible mechanisms of action in the parasite, encouraging future preclinical studies in American visceral leishmaniasis.

Drugs exert their (therapeutic) effects via molecular-level interactions with proteins and other biomolecules. Computational prediction of drug-protein interactions plays a significant role in the effort to improve our current and limited knowledge of these interactions. The use of the putative drug-protein interactions could facilitate the discovery of novel applications of drugs, assist in cataloging their targets, and help to explain the details of medicinal efficacy and side-effects of drugs. We investigate current studies related to the computational prediction of drug-protein interactions and categorize them into protein structure-based and similarity-based methods. We evaluate three representative structure-based predictors and develop a Protein-Drug Interaction Database (PDID) that includes the putative drug targets generated by these three methods for the entire structural human proteome. To address the fact that only a limited set of proteins has known structures, we study the similarity-based methods that do not require this information. We review a comprehensive set of 35 high-impact similarity-based predictors and develop a novel, high-quality benchmark database. We group these predictors based on three types of similarities and their combinations that they use. We discuss and compare key architectural aspects of these methods including their source databases, internal databases and predictive models. Using our novel benchmark database, we perform comparative empirical analysis of predictive performance of seven types of representative predictors that utilize each type of similarity individually or in all possible combinations. We assess predictive quality at the database-wide drug-protein interaction level and we are the first to also include evaluation across individual drugs. Our comprehensive analysis shows that predictors that use more similarity types outperform methods that employ fewer similarities, and that the model combining all three types of similarities secures AUC of 0.93. We offer a first-of-its-kind analysis of sensitivity of predictive performance to intrinsic and extrinsic characteristics of the considered predictors. We find that predictive performance is sensitive to low levels of similarities between sequences of the drug targets and several extrinsic properties of the input drug structures, drug profiles and drug targets.

A quimioterapia disponível para o tratamento das leishmanioses conta com um número reduzido de fármacos, com efeitos adversos severos e progressivo aumento de resistência. O reposicionamento de fármacos oferece uma grande oportunidade para introdução de novas terapias. Antidepressivos orais têm demonstrado eficácia tanto in vitro quanto in vivo contra espécies de Leishmania spp. Neste estudo, o antidepressivo sertralina (SRT), e o fármaco ciclobenzaprina (CBP), um relaxante muscular de estrutura tricíclica análoga a antidepressivos, foram avaliados quanto a atividade contra Leishmania (L.) infantum. Estudos metabolômicos não dirigidos utilizando multiplataforma analítica, foram combinados a análises de parâmetros celulares, essenciais para obtenção de uma ampla descrição dos mecanismos de ação. A CBP mostrou uma atividade leishmanicida in vitro, com valor de CE50 de 4,3 ?M contra formas promastigotas e 8,6 ?M contra formas amastigotas intracelulares. O fármaco apresentou uma citotoxicidade (CC50) de 70,6 ?M em células NCTC, e um índice de seletividade similar a miltefosina. Os estudos de mecanismo de ação, sugeriram que a CBP se difunde pela membrana plasmática, causando diminuição do ??p e no interior citoplasmático, parece induzir um estresse do RE com liberação de Ca+2; concomitantemente, induz um desacoplamento brando da cadeia respiratória mitocondrial e depleção dos níveis de ATP. Com o efeito prolongado, a liberação de Ca+2 parece ativar a autofagia, e seu influxo para a mitocôndria potencializar os efeitos deletérios, diminuindo o ??m e aumentando a produção de ROS. A longo prazo, o CBP induz uma extensa alteração metabólica, caracterizada aumento dos níveis da maioria dos metabólitos identificados e atividade desregulada de transportadores de membrana, gerando alto gasto energético associado a condições insuficientes de produção de energia mitocondrial, resultando em morte celular. A sertralina também apresentou atividade leishmanicida in vitro, com valor de CE50 de 2 ?M contra formas promastigotas e 3,9 ?M contra formas amastigotas intracelulares. Sua toxicidade em células NCTC foi de 19,6 ?M, resultando em um índice de seletividade similar a miltefosina. Nossos estudos confirmaram a mitocôndria de Leishmania como alvo primário e, o efeito de desacoplamento da cadeia respiratória associado ao colapso energético, estresse oxidativo seguido da despolarização do ??m como a possível origem desta disfunção mitocondrial. Estudos metabolômicos evidenciaram que a extensão do desarranjo metabólico, abrange diminuição da capacidade de detoxificação do metabolismo tiol-redox, uma severa depleção do pool intracelular de aminoácidos e poliaminas, evidenciando uma completa deterioração do metabolismo energético, por meio de um mecanismo multialvo direcionado a vias metabólicas essências do parasita. Finalmente, este estudo descreve a atividade anti-Leishmania de dois fármacos orais aprovados, com mecanismos de ação letais e irreversíveis no parasita, encorajando o prosseguimento para futuros estudos pré-clínicos na leishmaniose visceral americana / The available chemotherapy for the treatment of leishmaniasis has a reduced number of drugs, with severe adverse effects and progressive increase of resistance. The drug repurposing offers a great opportunity for the introduction of new therapies. Oral antidepressants have been demonstrated efficacy both in vitro and in vivo against Leishmania spp. In this study, the antidepressant sertraline (SRT), and the drug cyclobenzaprine (CBP), a muscle relaxant with tricyclic structure analogous to antidepressants, were evaluated against Leishmania (L.) infantum. Untargeted metabolomic studies using multiplataform analysis were combined to cellular parameters to a broad description of the mechanisms of action. Cyclobenzaprine showed an in vitro leishmanicidal activity with an EC50 value of 4.3 ?M against promastigotes and 8.6 ?M against intracellular amastigote forms. The drug showed a cytotoxicity (CC50) of 70.6 ?M in NCTC cells, and a selectivity index similar to miltefosine. Mechanism of action studies suggested that CBP diffuses through the plasma membrane, causing a decrease of the ??p and inside the cytoplasm, the drug seems to induce an ER stress, with release of Ca+2; concomitantly, it induces a mild decoupling of the mitochondrial respiratory chain and depletion of ATP levels. With the prolonged effect, a release of Ca+ 2 appears to activate an autophagy, and its mitochondrial influx results in a potentiation of deleterious effects as decreasing of ??m and increasing ROS production. In long term, CBP induces an extensive metabolic alteration, characterized increased levels of most of the identified metabolites and unregulated activity of membrane transporters. These generates a high energy expenditure associated to limited conditions of mitochondrial energy production, resulting in the cellular death. Sertraline also showed in vitro leishmanicidal activity, with an EC50 value of 2 ?M against promastigotes and 3.9 ?M against intracellular amastigote forms. Its toxicity in NCTC cells was 19.6 ?M, resulting in a selectivity index similar to miltefosine. Our studies confirmed the mitochondria of Leishmania as the primary target, and the uncoupling of the respiratory chain associated with energy collapse, oxidative stress, and the depolarization of ??m as the possible origin of this mitochondrial dysfunction. Metabolomics evidenced an extended metabolic disarray caused by SRT encompassing a decrease in the scavenging capacity of the thiol-redox metabolism and a severe depletion of the intracellular pool of amino acids and polyamines. The complete deterioration of energetic metabolism was evident through a multi-target mechanism, affecting the main metabolic pathways of the parasite. Finally, this study describes an anti-Leishmania activity of two approved oral drugs with lethal and irreversible mechanisms of action in the parasite, encouraging future preclinical studies in American visceral leishmaniasis.