Anti-leishmanial activity of Eleutherine plicata Herb. and predictions of isoeleutherin and its analogues.

Introduction: Leishmaniasis is caused by protozoa of the genus Leishmania, classified as tegumentary and visceral. The disease treatment is still a serious problem, due to the toxic effects of available drugs, the costly treatment and reports of parasitic resistance, making the search for therapeutic alternatives urgent. This study assessed the in vitro anti-leishmanial potential of the extract, fractions, and isoeleutherin from Eleutherine plicata, as well as the in silico interactions of isoeleutherin and its analogs with Trypanothione Reductase (TR), in addition to predicting pharmacokinetic parameters. Methods: From the ethanolic extract of E. plicata (EEEp) the dichloromethane fraction (FDEp) was obtained, and isoeleutherin isolated. All samples were tested against promastigotes, and parasite viability was evaluated. Isoeleutherin analogues were selected based on similarity in databases (ZINK and eMolecules) to verify the impact on structural change. Results and Discussion: The extract and its fractions were not active against the promastigote form (IC50 > 200 µg/mL), while isoeleutherin was active (IC50 = 25 µg/mL). All analogues have high intestinal absorption (HIA), cell permeability was moderate in Caco2 and low to moderate in MDCK. Structural changes interfered with plasma protein binding and blood-brain barrier permeability. Regarding metabolism, all molecules appear to be CYP3A4 metabolized and inhibited 2-3 CYPs. Molecular docking and molecular dynamics assessed the interactions between the most stable configurations of isoeleutherin, analogue compound 17, and quinacrine (control drug). Molecular dynamics simulations demonstrated stability and favorable interactions with TR. In summary, fractionation contributed to antileishmanial activity and isoleutherin seems to be promising. Structural alterations did not contribute to improve pharmacokinetic aspects and analogue 17 proved to be more promising than isoeleutherin, presenting better stabilization in TR.

Cytotoxicity and Genotoxicity Evaluation of Zanthoxylum rhoifolium Lam and In Silico Studies of Its Alkaloids.

The alkaloids isolated from Zanthoxylum rhoifolium have demonstrated great pharmacological potential; however, the toxic profiles of these extracts and fractions are still not well elucidated. This study evaluated the toxicity of the ethanol extract (EEZR) and neutral (FNZR) and alkaloid (FAZR) fractions. Chemical characterization was performed by chromatographic methods: thin-layer chromatography (TLC) and high-performance liquid chromatography coupled with diode array detection (HPLC-DAD). The cytotoxicity of the samples was evaluated in human hepatocellular carcinoma (HepG2) cells using the cell viability method (MTT) and mutagenicity by the Allium cepa assay (ACA). Alkaloids isolated from the species were selected for toxicity prediction using preADMET and PROTOX. The molecular docking of the topoisomerase II protein (TOPOII) was used to investigate the mechanism of cell damage. In the EEZR, FNZR, and FAZR, the presence of alkaloids was detected in TCL and HPLC-DAD analyses. These samples showed a 50% inhibitory concentration (IC50) greater than 400 µg/mL in HepG2 cells. In ACA, time- and concentration-dependent changes were observed, with a significant reduction in the mitotic index and an increase in chromosomal aberrations for all samples. Nuclear sprouts and a micronucleus of the positive control (PC) were observed at 10 µg/mL and in the FAZR at 30 µg/mL; a chromosomal bridge in FNZR was observed at 105 µg/mL, CP at a concentration of 40 µg/mL, and nuclear bud and mitotic abnormalities in the EEZR were observed at 170 µg/mL. The alkaloids with a benzophenanthridine were selected for the in silico study, as structural alterations demonstrated certain toxic effects. Molecular docking with topo II demonstrated that all alkaloids bind to the protein. In summary, the fractionation of Z. rhoifolium did not interfere with toxicity; it seems that alkaloids with a benzophenanthridine nucleus may be involved in this toxicity.

Study of Genotoxicity, Activities on Caspase 8 and on the Stabilization of the Topoisomerase Complex of Isoeleutherin and Analogues.

This study evaluated the genotoxicity of Ethanol Extract (EEEp), Dichloromethane Fraction (FDCMEp) and isoeleutherin isolated from Eleutherine plicata, using the micronucleus test and the impact of structural alterations on toxicity and molecular docking (topoisomerase II and DNA complex). The extract was obtained by maceration and fractionation in a chromatography column. The genotoxicity was evaluated by the micronucleus test in human hepatoma cells (HepG2). Isoeleutherin was the starting molecule in the search for analogues by structural similarity, using the ZINC and e-Molecules databases. Isoeleutherin and analogues were subjected to in silico toxicity prediction, and compounds free of toxicological risks (CP13, CP14, CP17 and isoeleutherin) were selected for molecular docking in Topoisomerase II (PDB: 1ZXM). In the micronucleus test, isoeleutherin was less genotoxic. Among the 22 isoeleutherin analogues there were variations in the toxicity profile. Molecular docking studies showed that the compounds have good complementarity in the active site with important hydrogens bonds. Therefore, the structural changes of isoeleutherin led to the obtaining of a molecule with a lower mutagenic potential, and the CP13 can be considered a prototype compound for the development of new molecules with pharmacological potential.

Toxicity evaluation of Eleutherine plicata Herb. extracts and possible cell death mechanism.

Eleutherine plicata has been shown to be a promising medicinal plant, and its activity has been associated with naphthoquinones. The present study aimed at evaluating the cytotoxicity, genotoxicity, and oral toxicity of the ethanol extract (EEEp), dichloromethane fraction (FDMEp) of E. plicata, and isoeleutherin. For the cytotoxicity evaluation, the viability test (MTT) was used. Genotoxicity was accessed through the Comet assay (alkaline version), acute and subacute oral toxicities were also evaluated. The antioxidant capacity of the samples in the wells where the cells were treated with E. plicata was evaluated. Furthermore, the participation of caspase-8 in the possible mechanism of action of isoeleutherin, eleutherin, and eleutherol was also investigated through a docking study. FDMEp and isoeleutherin were cytotoxic, with higher rates of DNA fragmentation observed for FDMEp and isoeleutherin, and all samples displayed higher antioxidant potential than the control. In the acute oral toxicity test, EEEp, FDMEp, and isoeleutherin did not cause significant clinical changes. In the subacute toxicity assay, EEEp and FDMEp also did not cause clinical, hematological, or biochemical changes. The three compounds bound similarly to caspase-8. Despite the results of cytotoxicity, in vitro studies demonstrated that the use of EEEp appears to be safe and cell death may involve its binding to caspase-8.

Flavopereirine-An Alkaloid Derived from Geissospermum vellosii-Presents Leishmanicidal Activity In Vitro.

Chemotherapy is limited in the treatment of leishmaniasis due to the toxic effects of drugs, low efficacy of alternative treatments, and resistance of the parasite. This work assesses the in vitro activity of flavopereirine on promastigote cultures of Leishmania amazonensis. In addition, an in silico evaluation of the physicochemical characteristics of this alkaloid is performed. The extract and fractions were characterized by thin-layer chromatography and HPLC-DAD, yielding an alkaloid identified by NMR. The antileishmanial activity and cytotoxicity were assayed by cell viability test (MTT). The theoretical molecular properties were calculated on the Molinspiration website. The fractionation made it possible to isolate a beta-carboline alkaloid (flavopereirine) in the alkaloid fraction. Moreover, it led to obtaining a fraction with greater antileishmanial activity, since flavopereirine is very active. Regarding the exposure time, a greater inhibitory effect of flavopereirine was observed at 24 h and 72 h (IC50 of 0.23 and 0.15 µg/mL, respectively). The extract, fractions, and flavopereirine presented low toxicity, with high selectivity for the alkaloid. Furthermore, flavopereirine showed no violation of Lipinski's rule of five, showing even better results than the known inhibitor of oligopeptidase B, antipain, with three violations. Flavopereirine also interacted with residue Tyr-499 of oligopeptidase B during the molecular dynamics simulations, giving a few insights of a possible favorable mechanism of interaction and a possible inhibitory pathway. Flavopereirine proved to be a promising molecule for its antileishmanial activity.

Brazilian Amazon Traditional Medicine and the Treatment of Difficult to Heal Leishmaniasis Wounds with Copaifera.

The present study describes the use of the traditional species Copaifera for treating wounds, such as ulcers scarring and antileishmanial wounds. It also relates phytochemical studies, evaluation of the leishmanicidal activity, and toxicity. The species of Copaifera with a higher incidence in the Amazon region are Copaifera officinalis, Copaifera reticulata, Copaifera multijuga Hayne. The copaiba oil is used in the Amazon's traditional medicine, especially as anti-inflammatory ingredient, in ulcers healing, and in scarring and for leishmaniasis. Chemical studies have shown that these oils contain diterpenes and sesquiterpenes. The copaiba oil and terpenes isolated have antiparasitic activity, more promising in the amastigote form of L. amazonensis. This activity is probably related to changes in the cell membrane and mitochondria. The oil showed low cytotoxicity and genotoxicity. Furthermore, it may interfere with immune response to infection and also has a healing effect. In summary, the copaiba oil is promising as leishmanicidal agent.

Leishmania amazonensis and Leishmania chagasi: In vitro leishmanicide activity of Virola surinamensis (rol.) warb.

Virola species have been used in traditional medicine as healing in skin infections. From V. surinanensis oil were isolated several sesquiterpene as the nerolidol which showed activity against species of Leishmania. The current study aimed to evaluate the leishmanicide activity and toxicity of extracts, fractions and surinamesin obtained from leaves of Virola surinamensis. Hexane, Ethyl Acetate, and Methanol extracts were obtained from powder of dry leaves of V. surinamensis. The hexane and ethyl acetate extracts were fractionated by silica gel column chromatography and increasingly polar gradient. The viability of L. chagasi and L. amazonensis promastigotes was assessed by tetrazolium salt assay (MTT). Peritoneal macrophages were exposed to L. amazonensis promastigotes. The treatment was performed with the extracts for 24 h. Then, the coverslips were stained and the infection index was determined. Cytotoxicity was determined in macrophage cells by peritoneum viability assay (MTT). The selectivity index was calculated as the product of cytotoxic concentration 50% and inhibitory concentration 50%. The hexane extract showed leishmanicide activity in promastigotes. The ethyl acetate, methanol extracts and fractions (C1-C6), were inactive against promastigote form of L. chagasi and L. amzazonensis. None extract showed effect on L. amazonensis amastigotes. All samples tested showed low cytotoxicity (CC50 > 500 µg/mL). The selectivity index of the hexane extract was greater than 5. The hexane extract of V. surinamensis was active against L. chagasi and L. amazonensis promastigotes. The extract fractionation did not increase significantly its antipromastigote activity. The surinamensin is probably not responsible for the activity. The extracts were inactive against amastigotes of L. amazonensis.

Psicopatologia e saúde mental: questões sobre os critérios que orientam a percepção clínica / Psychopathology and mental health: questions on the standards which guide clinical perception / Psicopatología y salud mental: pregunta sobre los criterios para la percepción de clínica / Psychopathologie et santé mentale: questions sur les normes qui guident la perception clinique

Esse estudo supõe que a formação do campo da saúde mental implicou mutações nos critérios de apreensão dos problemas mentais em relação à psicopatologia. Pode-se dizer que se trata de um deslocamento fundamental, qual seja, a loucura como patologia mental deixa de ser a questão central das disciplinas psiquiátricas e psicológicas, uma vez que se instaura um domínio científico que aborda o sofrimento psíquico como uma problemática relacionada à satisfação e à realização pessoal dos indivíduos. Desse modo, se propõe aqui um estudo sobre os fundamentos epistemológicos dos saberes e das práticas em psicopatologia, conforme a perspectiva de Canguilhem, que consiste na tese de que a especificidade da racionalidade médica é o caráter normativo da apreensão dos fenômenos vitais. Dessa forma, questionam-se os parâmetros normativos que caracterizam a psicopatologia, mais especificamente, psiquiatria e psicanálise, orientando formas de intervenções terapêuticas dos padecimentos mentais. Ressalta-se, então, que a percepção do psicopatológico é regido pelos critérios de diferenciação entre o normal e o patológico que pressupõe a irredutibilidade patológica de certos fenômenos psíquicos. Daí procura-se indicar que os desdobramentos epistemológicos constitutivos do campo da saúde mental implicam modificações do estatuto médico dos padecimentos mentais, uma vez que perde sua especificidade em relação às doenças orgânicas; reformas das estratégias de intervenção, tecnologias e políticas sociais, as quais são dissociadas dos diagnósticos e, finalmente, mudanças dos critérios de definição do objeto clínico, qual seja, a referência à polaridade normal-patológico.

This paper relies on the assumption that the formation of the mental health field led to mutations in the criteria for apprehension of mental problems in relation to psychopathology. There is a fundamental shift, that is, madness as a mental pathology is no longer the central object of psychiatric and psychological disciplines, since a new scientific domain that approaches psychic suffering as an issue related to satisfaction and personal achievement is established. Therefore it is proposed on this paper a study on the epistemic foundations of knowledge and practice in psychopathology according to Canguilhem (1946/1995) thesis that the specificity of medical rationale is the normative basis through which vital phenomena are apprehended. Accordingly the normative parameters of psychopathology field, more specifically, psychiatry and psychoanalysis, as they determine the methods of therapeutic interventions in mental illness, are reassessed. It is noteworthy that the perception of what is psychopathological is governed by the criteria for the differentiation between what is normal and what is pathological, which implies the pathological irreducibility of certain psychic phenomena. Hence the endeavors to point out that the epistemic implications constitutive of mental health field demand modifications on the medical statute of mental illness, as it loses its specificity regarding organic sickness. They also require changes in the strategies of intervention, technologies and social policies as well as in the criteria for defining the clinical object, namely the normal-pathological polarity.

Este documento se basa en el supuesto de que la formación del campo de la salud mental dirigido a mutaciones en los criterios para la aprehensión de los problemas mentales en relación con la psicopatología. No es un cambio fundamental, es decir, la locura como una patología mental ya no es el objeto central de las disciplinas psicológicas y psiquiátricas, ya que un dominio de los nuevos conocimientos científicos que se acerca al sufrimiento psíquico una cuestión relacionada con la satisfacción y la realización personal se ha establecido. Por lo tanto, es este trabajo en el estudio propuesto sobre la base del conocimiento y la práctica epistémica en la psicopatología Según Canguilhem (1946/1995) la tesis de que la especificidad de la justificación médica es la base normativa a través de cual los fenómenos vitales son aprehendidos. En consecuencia, los parámetros normativos de la psicopatología de campo, más específicamente, la psiquiatría y el psicoanálisis, ya que determinan los métodos de las intervenciones terapéuticas en la enfermedad mental, se revisan. Es de destacar que la percepción de lo que es psicopatológico se rige por los criterios para la diferenciación entre lo que es normal y lo patológico, lo que implica la irreductibilidad de ciertos fenómenos psíquicos patológicos. Por lo tanto el punto en octubre a los esfuerzos que las consecuencias constitutivos del campo epistémico de la salud mental modificaciones de la demanda sobre el estatuto médico de enfermedad mental, ya que pierde especificidad excelente relativas a la enfermedad orgánica. Ta mbién se requieren cambios en las estrategias de intervención, las tecnologías y las políticas sociales, así como en los criterios de objeto que define el clínico, Es decir, la polaridad normal y lo patológico.

Cette étude il suppose que la formation du champ de la santé mentale a impliqué des mutations dans les critères d'appréhension des problèmes mentaux concernant à la psychopathologie. On peut dit que sur un décalage fondamental, c'est à dire, la folie comme pathologie mentale cesse d'être la question centrale des disciplines psychiatriques et psychologiques, vu que on instaure un domaine scientifique que s'approche de la suffrance psichique à la condition de problematique en rapport à la satisfation et a réalisation personnel des individus. De cette façon, la proposition ici c'est de faire une étude sur les fondements epistemológicos des savoirs et des pratiques dans psychopathologie, comme la perspective de Canguilhem (1946/1995), qu'il consiste à la thèse dont la spécificité de la rationalité médicale est le caractère normatif de l'appréhension. En conséquence, on s'interroge sur les paramètres normatifs qui caractérisent la psychopathologie, plus spécifiquement, la psychiatrie et la psychanalyse, en donnant la direction des formes d'interventions thérapeutiques des souffrances mentales. Il peut être détaché, alors, que la perception du psychopathologique est régie par les critères de différenciation entre le normal et le pathologique, lequel estime l'irréductibilité pathologique de certains phénomènes psychiques. À partir de là, il se cherche à indiquer que les dédoublages epistemológicos constitutifs du champ de la santé mentale impliquent des modifications du statut médical des souffrances mentales, vu que perd sa spécificité en rapport les maladies organiques; réformes des stratégies d'intervention, technologies et politiques sociales, qui sont dissociées des diagnostics; et, finalement, modifications de critères de définition de l'objet clinique, ce qui est, à réfèrence à la polarité normal-patologique.