RESUMEN
Repurposing drugs and adjuvants is an attractive choice of present therapy that reduces the substantial costs, chances of failure, and systemic toxicity. Mycobacterium indicus pranii was originally developed as a leprosy vaccine but later has been found effective against Leishmania donovani infection. To extend our earlier study, here we reported the immunotherapeutic modulation of the splenic and circulatory neutrophils in favour of hosts as neutrophils actually serve as the pro-parasitic portable shelter to extend the Leishmania infection specifically during the early entry into the hosts' circulation. We targeted to disrupt this early pro-parasitic incidence by the therapeutic combination of M. indicus pranii and heat-induced promastigotes against antimony-resistant L. donovani infection. The combination therapy induced the functional expansion of CD11b+Ly6CintLy6Ghi neutrophils both in the post-infected spleen, and also in the circulation of post-treated animals followed by the immediate Leishmania infection. More importantly, the enhanced expression of MHC-II, phagocytic uptake of the parasites by the circulatory neutrophils as well as the oxidative burst were induced that limited the chances of the very early establishment of the infection. The enhanced expression of pro-inflammatory cytokines, like IL-1α and TNF-α indicated resistance to the parasite-mediated takeover of the neutrophils, as these cytokines are critical for the activation of T cell-mediated immunity and host-protective responses. Additionally, the induction of essential transcription factors and cytokines for early granulocytic lineage commitment suggests that the strategy not only contributed to the peripheral activation of the neutrophils but also promoted granulopoiesis in the bone marrow.
Asunto(s)
Antimonio , Leishmania donovani , Leishmaniasis Visceral , Neutrófilos , Leishmania donovani/inmunología , Animales , Neutrófilos/inmunología , Leishmaniasis Visceral/inmunología , Leishmaniasis Visceral/tratamiento farmacológico , Ratones , Antimonio/farmacología , Mycobacterium/inmunología , Activación Neutrófila/inmunología , Bazo/inmunología , Calor , Citocinas/metabolismo , Ratones Endogámicos BALB C , Resistencia a MedicamentosRESUMEN
PURPOSE: In the present perspective, emergence of resistant strains of Leishmania donovani and severe side effects resulting from the use of conventional anti-leishmanial therapies present an urgent need for developing novel agents against this parasite. We have explored the effectiveness of secondary plant metabolites as alternative choices in the treatment for visceral leishmaniasis (vl). METHODS: The plant Parthenium hysterophorus L. (Asteraceae) was collected from the West Bengal State University Campus, Barasat, West Bengal, India. The leaves of this plant were extracted by different solvents, such as ethyl acetate, water, petroleum ether and hexane. Gas chromatography-mass spectrometry (GC-MS) analysis was also carried out for the identification of compounds in the hexane soluble fraction (PHFd) with substantial anti-leishmanial activities. The antipromastigote activity and cytotoxicity of this fraction were evaluated by the tetrazolium MTT assay. Other biochemical and physiological parameters were studied by microscopic observation and flow cytometric analyses. RESULTS: PHFd showed considerable activity against L. donovani promastigotes (IC50: 20 µg/ml). The PHFd also inhibited in vitro growth of L. major LV39 promastigotes dose dependently with an IC50 of 40 µg/ml. The GC-MS studies of this particular fraction revealed the presence of four major compounds with different retention times (RT) of 26.08, 33.11, 36.41, and 41.20 min. In this study, we also established that PHFd could induce DNA damage and subsequent apoptosis of L. donovani promastigotes with a concomitant increase in generations of reactive oxygen species (ROS) in a time-dependent manner. This fraction was also found to be effective in nitric oxide-mediated inhibition of intracellular amastigotes (IC50:12.5 µg/ml) without any noticeable cytotoxicity towards murine splenocytes in vitro. CONCLUSION: This study provides the basis for additional phytochemical and pharmacological studies on the antiprotozoal applications of P. hysterophorus.
Asunto(s)
Antiprotozoarios , Asteraceae , Leishmania donovani , Leishmaniasis Visceral , Animales , Antiprotozoarios/farmacología , Antiprotozoarios/uso terapéutico , Humanos , Leishmaniasis Visceral/tratamiento farmacológico , Ratones , Hojas de la PlantaRESUMEN
The anti-leishmanial effect of the 'carbohydrate-fraction', isolated from an edible mushroom Astraeus hygrometricus, was evaluated against Leishmania donovani infection both in vitro and in vivo. Ahf-Car induced the expression of inducible nitric oxide synthase 2 (iNOS2) and pro-inflammatory cytokines like TNF-α and IL-12, with subsequent downregulation of the anti-inflammatory cytokines as TGF-ß and IL-10, in vitro and in vivo along with a remarkable increase in the expressions of IL-6, IL-1ß, IFN-γ and IRFs, IRF-7 and IRF-8 in vivo. Ahf-Car also reduced the parasite burden in the spleen and liver dose-dependently with a simultaneous proliferation of Ly6C+ cells in the bone marrow of Leishmania-infected experimental animals. It also increased the monocyte population dose-dependently and the expression of the myeloid transcription factor PU.1, in vivo, which presumably signifies the expansion of protective macrophages. Thus, Ahf-Car might be a potent anti-leishmanial lead with unique and effective adjuvant capacity.
Asunto(s)
Basidiomycota/química , Productos Biológicos/uso terapéutico , Leishmania donovani , Leishmaniasis Visceral/prevención & control , Adyuvantes Inmunológicos/farmacología , Animales , Productos Biológicos/aislamiento & purificación , Citocinas/inmunología , Interleucina-12/inmunología , Leishmania donovani/inmunología , Leishmaniasis Visceral/inmunología , Hígado/parasitología , Macrófagos/inmunología , Masculino , Ratones , Ratones Endogámicos BALB C , Bazo/inmunología , Bazo/parasitología , Factor de Necrosis Tumoral alfa/inmunologíaRESUMEN
Since inception, the magic bullets developed against leishmaniasis traveled a certain path and then dropped down due to either toxicity or the emergence of resistance. The route of administration is also an important concern. We developed a series of water-soluble ferrocenylquinoline derivatives, targeting Leishmania donovani, among which CQFC1 showed the highest efficacy even in comparison to other drugs, in use or used, both in oral and intramuscular routes. It did not induce any toxicity to splenocytes and on hematopoiesis, induced protective cytokines, and did not hamper the drug-metabolizing enzymes in hosts. It acts through the reduction and the inhibition of parasites' survival enzyme trypanothione reductase of replicating amastigotes in hosts' reticuloendothelial tissues. Unlike conventional drugs, this molecule did not induce the resistance-conferring genes in laboratory-maintained resistant L. donovani lines. Experimentally, this easily bioavailable preclinical drug candidate overcame all of the limitations causing the discontinuation of the other conventional antileishmanial drugs.
Asunto(s)
Antiprotozoarios/química , Leishmania donovani/enzimología , NADH NADPH Oxidorreductasas/antagonistas & inhibidores , Proteínas Protozoarias/antagonistas & inhibidores , Quinolinas/química , Administración Oral , Animales , Antiprotozoarios/metabolismo , Antiprotozoarios/farmacología , Antiprotozoarios/uso terapéutico , Sitios de Unión , Modelos Animales de Enfermedad , Diseño de Fármacos , Resistencia a Medicamentos/efectos de los fármacos , Compuestos Ferrosos/química , Semivida , Leishmania donovani/efectos de los fármacos , Leishmaniasis Visceral/tratamiento farmacológico , Metalocenos/química , Ratones , Simulación del Acoplamiento Molecular , Sistema Mononuclear Fagocítico/metabolismo , Sistema Mononuclear Fagocítico/parasitología , NADH NADPH Oxidorreductasas/metabolismo , Proteínas Protozoarias/metabolismo , Quinolinas/metabolismo , Quinolinas/farmacología , Quinolinas/uso terapéutico , Especies Reactivas de Oxígeno/metabolismo , Solubilidad , Relación Estructura-ActividadRESUMEN
The major issues in available therapeutic modalities against leishmaniasis are cost, toxicity, and the emergence of drug resistance. The aim of this work was to develop a successful therapeutic adjuvant against drug-resistant Leishmania donovani infection by means of combining Mycobacterium indicus pranii with heat-induced promastigotes (HIP). One-month postinfected BALB/c mice were administered subcutaneously with M. indicus pranii (108 cells) and HIP (100 µg) for 5 days. Spleens were harvested for flow cytometric and reverse transcriptase PCR analysis. The antileishmanial effect of the combination strategy was associated with induction of a disease-resolving Th1 and Th17 response with simultaneous downregulation of CD4+ CD25+ Foxp3+ (nTreg) cells and CD4+ CD25- Foxp3- (Tr1) cells in the spleen. The significant expansion of CD4+ TCM (CD4+ CD44hi CD11ahi CD62Lhi) cells was a further interesting outcome of this therapeutic strategy in the context of long-term protection of hosts against secondary infection. Toll-like receptor 2 (TLR2) was also found instrumental in this antiparasitic therapy. Induced interleukin-6 (IL-6) production from expanded CD11c+ CD8α+ (cDC1) and CD11c+ CD11b+ (cDC2) dendritic cells (DCs) but not from the CD11b+ Ly6c+ inflammatory monocytes (iMOs), was found critical in the protective expansion of Th17 as evidenced by an in vivo IL-6 neutralization assay. It also promoted the hematopoietic conversion toward DC progenitors (pre-DCs) from common dendritic cell progenitors (CDPs), the immediate precursors, in bone marrow. This novel combinational strategy demonstrated that expansion of Th17 by IL-6 released from CD11c+ classical DCs is crucial, together with the conventional Th1 response, to control drug-resistant infection.
Asunto(s)
Proteínas de Choque Térmico/administración & dosificación , Leishmania donovani , Leishmaniasis Visceral/parasitología , Leishmaniasis Visceral/terapia , Mycobacterium/fisiología , Proteínas Protozoarias/administración & dosificación , Animales , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD4-Positivos/metabolismo , Diferenciación Celular , Terapia Combinada , Células Dendríticas/citología , Células Dendríticas/inmunología , Células Dendríticas/metabolismo , Resistencia a Medicamentos , Calor , Memoria Inmunológica , Inmunofenotipificación , Mediadores de Inflamación , Interleucina-6/biosíntesis , Leishmania donovani/efectos de los fármacos , Leishmania donovani/inmunología , Leishmaniasis Visceral/inmunología , Leishmaniasis Visceral/metabolismo , Ratones , Mycobacterium/inmunología , Bazo/inmunología , Bazo/metabolismo , Bazo/patología , Subgrupos de Linfocitos T/inmunología , Subgrupos de Linfocitos T/metabolismoRESUMEN
The current study was designed to assess the anti-leishmanial effect of a semi-purified fraction of wild mushroom Grifola frondosa against Leishmania donovani, in vitro. A total of five extracts from three wild mushrooms [Grifola frondosa (family, Meripilaceae) Laetiporus sulphurous (family, Polyporaceae) and Meripilus giganteus (family, Meripilaceae) were explored for novel anti-leishmanial leads against promastigotes. The ethanol extract of G. frondosa was selected as the most efficient against L. donovani promastigotes (IC50: 93.9⯵g/mL). A semi-purified fraction was obtained from an active ethanol extract of G. frondosa and found to inhibit the survival of promastigotes of L. donovani (MHOM/IN/83/AG83) significantly (IC50: 20.37⯵g/mL) and it also had some effect against L. major LV39 (MRHO/Sv/59/P strain) and L. tropica WR683 (MHOM/SU/58/OD) strains at higher concentrations (IC50: 46.08⯵g/mL and 53.79⯵g/mL respectively). The semi-purified fraction also interfered in lipid biosynthesis, altered parasite morphology and induced apoptosis in L. donovani promastigotes. The semi-purified fraction was also effective against intracellular amastigotes in infected macrophages and enhanced the release of nitric oxide and pro-inflammatory cytokines, in vitro. Interestingly, the 50% inhibitory concentration of the semi-purified fraction against the intracellular amastigotes (IC50: 2.48⯵g/mL) was much lower in comparison to promastigotes (IC50: 20.37⯵g/mL). The semi-purified fraction was found to inhibit the intracellular amastigotes slightly more efficiently in comparison to conventional anti-leishmanial drugs; sodium antimony gluconate, amphotericin B, miltefosine and paromomycin and noticeably non-toxic towards host splenocytes. The findings of the present study established that G. frondosa might be a natural resource for development of a new anti-leishmanial lead.
Asunto(s)
Grifola/química , Leishmania donovani/efectos de los fármacos , Animales , Cromatografía en Gel , Citocinas/genética , Citocinas/metabolismo , Cromatografía de Gases y Espectrometría de Masas , Concentración 50 Inhibidora , Leishmania donovani/patogenicidad , Leishmania donovani/ultraestructura , Leishmania major/patogenicidad , Macrófagos/parasitología , Ratones , Ratones Endogámicos BALB C , Microscopía Electrónica de Rastreo , Polyporaceae/química , Polyporales/química , Bazo/citología , Bazo/efectos de los fármacos , VirulenciaRESUMEN
The devastating appearance of numerous drug-unresponsive strains of Leishmania donovani and severe toxic side effects of conventional antileishmanial therapy necessitates the search for novel leads, to treat visceral leishmaniasis efficiently. The current study deals with the synthesis and biological evaluation of a unique C-5 functionalized oxindole based polyphenol to ascertain its activities against L. donovani infection, in vitro. The polyhydroxylated oxindole derivative (1) was generated by coupling styrene derivatives with 5-bromo bis-arylidene oxindole using Heck coupling reaction. The synthesized molecule 1 was tested for its antileishmanial activity using both promastigote and amastigote stages of L. donovani. Molecule 1 showed promising anti-promastigote and anti-amastigote activities with IC50 values 15⯵M and 1⯵M, respectively, with no cytotoxicity towards host splenocytes. The results revealed that this compound induced parasite death by promoting oxidative stress, thereby triggering apoptosis.
Asunto(s)
Antiprotozoarios/farmacología , Indoles/farmacología , Leishmania donovani/efectos de los fármacos , Antiprotozoarios/síntesis química , Antiprotozoarios/química , Relación Dosis-Respuesta a Droga , Hidroxilación , Indoles/síntesis química , Indoles/química , Microscopía Confocal , Estructura Molecular , Oxindoles , Pruebas de Sensibilidad Parasitaria , Programas Informáticos , Relación Estructura-ActividadRESUMEN
The emergence of resistance against existing antileishmanial drugs necessitates the search for new classes of antileishmanial compounds. Herein a series of structurally diverse ferrocenylquinolines have been synthesized and evaluated for in vitro antileishmanial activity against Leishmania donovani using the MTT assay. Thirteen (M2-M14) substituted ferrocenylquinoline congeners possessing triazole rings were generated by palladium mediated Suzuki-Miyaura coupling reaction of 5-iodoferrocenylquinolinetriazole and substituted arylboronic acids. All the synthesized compounds were tested for its antileishmanial activity using both promastigote and amastigote stages of L. donovani. Among them, three compounds (M4, M7 and M9) exhibited promising anti-promastigote activity, with an IC50 value of 28.7 µM, 22.1 µM and 28 µM, respectively, and no cytotoxicity toward host splenocytes. These three compounds are equally effective against the intracellular amastigote stage of L. donovani showing the IC50 values of 16 µM (M4), 8 µM (M7) and 16 µM (M9), respectively, with consistent nitric oxide generation as required for parasite clearance. From the battery of tests conducted in this study, it appears that these compounds induce parasite death by promoting cell cycle arrest and triggering apoptosis.
Asunto(s)
Antiprotozoarios/síntesis química , Antiprotozoarios/farmacología , Leishmania donovani/efectos de los fármacos , Quinolinas/síntesis química , Quinolinas/farmacología , Animales , Antiprotozoarios/química , Antiprotozoarios/toxicidad , Apoptosis/efectos de los fármacos , Puntos de Control del Ciclo Celular/efectos de los fármacos , Técnicas de Química Sintética , Concentración 50 Inhibidora , Ratones , Quinolinas/química , Quinolinas/toxicidad , Bazo/citología , Relación Estructura-ActividadRESUMEN
In our previous report, we showed that astrakurkurone, a triterpene isolated from the Indian mushroom Astraeus hygrometricus (Pers.) Morgan, induced reactive oxygen species, leading to apoptosis in Leishmania donovani promastigotes, and also was effective in inhibiting intracellular amastigotes at the 50% inhibitory concentration of 2.5 µg/ml. The aim of the present study is to characterize the associated immunomodulatory potentials and cellular activation provided by astrakurkurone, leading to effective antileishmanial activity in vitro and in vivo Astrakurkurone-mediated antileishmanial activity was evaluated by real-time PCR and flow cytometry. The involvement of Toll-like receptor 9 (TLR9) was studied by in vitro assay in the presence of a TLR9 agonist and antagonist and by in silico modeling of a three-dimensional structure of the ectodomain of TLR9 and its interaction with astrakurkurone. Astrakurkurone caused a significant increase in TLR9 expression of L. donovani-infected macrophages along with the activation of proinflammatory responses. The involvement of TLR9 in astrakurkurone-mediated amastigote killing has been evidenced from the fact that a TLR9 agonist (CpG, ODN 1826) in combination with astrakurkurone enhanced the amastigote killing, while a TLR9 antagonist (bafilomycin A1) alone or in combination with astrakurkurone curbed the amastigote killing, which could be further justified by in silico evidence of docking between mouse TLR9 and astrakurkurone. Astrakurkurone was found to reduce the parasite burden in vivo by inducing protective cytokines, gamma interferon and interleukin 17. Moreover, astrakurkurone was nontoxic toward peripheral blood mononuclear cells of immunocompromised patients with visceral leishmaniasis. Astrakurkurone, a nontoxic antileishmanial, enhances the immune efficiency of host cells, leading to parasite clearance in vitro and in vivo.
Asunto(s)
Antiprotozoarios/uso terapéutico , Leishmaniasis Visceral/tratamiento farmacológico , Leishmaniasis Visceral/inmunología , Receptor Toll-Like 9/metabolismo , Triterpenos/uso terapéutico , Agaricales/química , Animales , Antiprotozoarios/inmunología , Western Blotting , Citometría de Flujo , Inmunidad Celular/efectos de los fármacos , Macrólidos/uso terapéutico , Macrófagos/efectos de los fármacos , Macrófagos/metabolismo , Masculino , Ratones , Ratones Endogámicos BALB C , FN-kappa B/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Reacción en Cadena en Tiempo Real de la Polimerasa , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Receptor Toll-Like 9/agonistas , Receptor Toll-Like 9/antagonistas & inhibidores , Triterpenos/inmunologíaRESUMEN
Abstract In the present context of emergence of resistance aligned with the conventional anti-leishmanial drugs and occasional treatment failure compelled us to continue the search for replaceable therapeutic leads against Leishmaniainfection. Various ginger spices of the Zingiberaceae family are widely used as spices, flavouring agents, and medicines in Southeast Asia because of their unique flavour as well as due to their medicinal properties. Zerumbone, a natural component of Zingiber zerumbet (L.) Smith, has been studied for its pharmacological potential as antiulcer, antioxidant, anticancer, and antimicrobial. In this study, we have shown that zerumbone could induce ROS mediated apoptosis in Leishmania donovani promastigotes and also found effective in reducing intracellular amastigotes in infected-macrophages. We emphasized the potential of zerumbone to be employed in the development of new therapeutic drugs against L. donovaniinfection and provided the basis for future research on the application of transitional medicinal plants.
Asunto(s)
Animales , Apoptosis/efectos de los fármacos , Leishmania donovani/efectos de los fármacos , Macrófagos/microbiología , Estrés Oxidativo/efectos de los fármacos , Sesquiterpenos/farmacología , Zingiberaceae/química , Leishmania donovani/ultraestructura , Ratones Endogámicos BALB C , Microscopía Electrónica de Rastreo , Pruebas de Sensibilidad Parasitaria , Sesquiterpenos/aislamiento & purificaciónRESUMEN
Oxygenated sterols (2-16) were synthesized by skeletal rearrangement of steroidal allylic alcohols. All the derivatives were screened for their anti-leishmanial activities. Compounds 3, 11 and 12 showed potent activities. Compound 12 was found least toxic and induced highest nitric oxide (NO) at 48 h. Least toxicity of compound 12 on splenocytes validated its best anti-amastigote effect and induction of NO.
Asunto(s)
Antiprotozoarios , Leishmania donovani/metabolismo , Leishmania major/metabolismo , Leishmaniasis Cutánea , Leishmaniasis Visceral , Esteroles , Animales , Antiprotozoarios/síntesis química , Antiprotozoarios/química , Antiprotozoarios/farmacología , Leishmaniasis Cutánea/tratamiento farmacológico , Leishmaniasis Cutánea/metabolismo , Leishmaniasis Cutánea/patología , Leishmaniasis Visceral/tratamiento farmacológico , Leishmaniasis Visceral/metabolismo , Leishmaniasis Visceral/patología , Ratones , Ratones Endogámicos BALB C , Esteroles/síntesis química , Esteroles/química , Esteroles/farmacologíaRESUMEN
In the present context of emergence of resistance aligned with the conventional anti-leishmanial drugs and occasional treatment failure compelled us to continue the search for replaceable therapeutic leads against Leishmania infection. Various ginger spices of the Zingiberaceae family are widely used as spices, flavouring agents, and medicines in Southeast Asia because of their unique flavour as well as due to their medicinal properties. Zerumbone, a natural component of Zingiber zerumbet (L.) Smith, has been studied for its pharmacological potential as antiulcer, antioxidant, anticancer, and antimicrobial. In this study, we have shown that zerumbone could induce ROS mediated apoptosis in Leishmania donovani promastigotes and also found effective in reducing intracellular amastigotes in infected-macrophages. We emphasized the potential of zerumbone to be employed in the development of new therapeutic drugs against L. donovani infection and provided the basis for future research on the application of transitional medicinal plants.
Asunto(s)
Apoptosis/efectos de los fármacos , Leishmania donovani/efectos de los fármacos , Macrófagos/microbiología , Estrés Oxidativo/efectos de los fármacos , Sesquiterpenos/farmacología , Zingiberaceae/química , Animales , Leishmania donovani/ultraestructura , Ratones Endogámicos BALB C , Microscopía Electrónica de Rastreo , Pruebas de Sensibilidad Parasitaria , Sesquiterpenos/aislamiento & purificaciónRESUMEN
AIM: The effect of astrakurkurone, a novel triterpene, isolated from Indian mushroom Astraeus hygrometricus has been investigated to elucidate the mechanisms involved in selective cell death of Leishmania donovani. MATERIALS & METHODS: The hypotheses were investigated using flow-cytometry, scanning electron microscopy and confocal microscopy. RESULTS: The time dependent elevation of astrakurkurone-induced reactive oxygen species (ROS) was found intimately associated with apoptosis. The involvement of ROS in promastigote death was found confirmed as NAC and GSH could decrease the ROS level and restored the mitochondrial membrane potential (ΔΨ(m)). It also inhibited the intracellular amastigotes. CONCLUSION: We claim the present invention as substantial in depth evidences that mushroom derived active molecules can be exploited as target specific, comparatively nontoxic leads for antileishmanial therapy.
Asunto(s)
Antiprotozoarios/farmacología , Basidiomycota/química , Muerte Celular/efectos de los fármacos , Leishmania donovani/efectos de los fármacos , Estrés Oxidativo , Especies Reactivas de Oxígeno/toxicidad , Triterpenos/farmacología , Antiprotozoarios/aislamiento & purificación , Citometría de Flujo , Leishmania donovani/fisiología , Microscopía Confocal , Microscopía Electrónica de Rastreo , Factores de Tiempo , Triterpenos/aislamiento & purificaciónRESUMEN
In the present state of overwhelming emergence of drug-unresponsive phenotypes of Leishmania donovani and persistent severe toxicity in conventional anti-leishmanial therapy, in search for novel leads, the aim of this study has been fixed to identify the active extract(s) of Croton caudatus Geisel. var. tomentosus Hook effective against the parasitic protozoans in vitro and in vivo. C. caudatus Geisel. is often used by Chakma and Hmar community, the local tribes of north-east India for medicinal and veterinary purposes. Among the five semi-purified extracts tested, C. caudatus leaves, extracted in hexane and subsequently semi-purified in a column packed with silica gel (70-130 µM; mesh size 60 A°) using ethyl acetate-hexane solvent (9:1), was found to be the most effective growth inhibitor (JDHex) against the Leishmania promastigotes and amastigotes. JDHex significantly altered the biochemical parameters (protein, lipid and carbohydrates) in promastigotes followed by the morphological changes, DNA condensation and subsequent apoptosis in L. donovani. In consequent steps, it has been also proved that JDHex reduced the replication of intracellular amastigotes with concomitant release of nitric oxide and pro-inflammatory cytokines, IL-12 and TNF-α in vitro. Significantly, the 50% inhibitory concentration of JDHex was estimated much lower against the intracellular amastigotes (2.5 µg/mL) in comparison to promastigotes (10 µg/mL). JDHex was also found efficient in reducing parasite burden in spleen and liver when treated in vivo and increased the intracellular IFN-γ and decreased the IL-10 in CD4+ T cells in splenocytes of orally treated animals. The results of this study support the importance in exploration of novel anti-leishmanial leads from C. caudatus Geisel. var. tomentosus Hook. against the L. donovani (MHOM/IN/83/AG83) infection. Partial chemical characterization of JDHex revealed the presence of terpenoids. However, the further chemical investigation of JDHex is warranted.
Asunto(s)
Croton/química , Citocinas/metabolismo , Leishmania donovani/efectos de los fármacos , Leishmaniasis Visceral/prevención & control , Extractos Vegetales/uso terapéutico , Animales , Apoptosis , Citocinas/inmunología , Relación Dosis-Respuesta a Droga , Concentración 50 Inhibidora , Leishmania donovani/crecimiento & desarrollo , Leishmania donovani/ultraestructura , Leishmaniasis Visceral/tratamiento farmacológico , Leishmaniasis Visceral/inmunología , Macrófagos/efectos de los fármacos , Macrófagos/metabolismo , Macrófagos/parasitología , Masculino , Ratones , Ratones Endogámicos BALB C , Microscopía Electrónica de Rastreo , Óxido Nítrico/metabolismo , Fosfatidilserinas/metabolismo , Extractos Vegetales/farmacología , Hojas de la Planta/química , Bazo/citología , Bazo/efectos de los fármacos , Bazo/inmunologíaRESUMEN
The emergence of resistance against antileishmanial drugs in current use necessitates the search for new classes of antileishmanial compounds. Herein we report the design, synthesis, and evaluation of a novel ferrocenylquinoline for activity against Leishmania donovani. 7-Chloro-N-[2-(1H-5-ferrocenyl-1,2,3-triazol-1-yl)ethyl]quinolin-4-amine (1) was generated by coupling an iron(II) ethynylferrocene species with 4-(2-ethylazido)amino-7-chloroquinoline using click chemistry. The synthesized compound 1 was tested for its antileishmanial activity using both promastigote and amastigote stages of L.â donovani. Compound 1 showed promising anti-promastigote activity, with an IC50 value of 15.26â µM and no cytotoxicity toward host splenocytes. From the battery of tests conducted in this study, it appears that this compound induces parasite death by promoting oxidative stress and depolarizing the mitochondrial membrane potential, thereby triggering apoptosis. These results suggest that ferrocenylquinoline 1 is a suitable lead for the development of new antileishmanial drugs.
Asunto(s)
Antiprotozoarios/química , Antiprotozoarios/farmacología , Compuestos Ferrosos/química , Compuestos Ferrosos/farmacología , Leishmania donovani/efectos de los fármacos , Antiprotozoarios/síntesis química , Apoptosis/efectos de los fármacos , Química Clic , Compuestos Ferrosos/síntesis química , Humanos , Concentración 50 Inhibidora , Leishmania donovani/citología , Leishmania major/citología , Leishmania major/efectos de los fármacos , Leishmaniasis Cutánea/tratamiento farmacológico , Leishmaniasis Visceral/tratamiento farmacológico , Metalocenos , Quinolinas/síntesis química , Quinolinas/química , Quinolinas/farmacología , Relación Estructura-ActividadRESUMEN
The study was intended at evaluating the anti-proliferating effect of mushrooms used in traditional folklore of Santal tribal population in India against Leishmania donovani (MHOM/IN/83/AG83). A total of eighteen extracts, three estracts from each mushroom [(80% ethanol extracted; Fa), (water-soluble polysaccharide fraction; Fb), (polyphenolic fraction; Fc)], from six wild mushrooms were obtained. These extracts were tested against the promastigotes and amastigotes for their antileishmanial capacity. Fa fractions (250 µg/mL) of Astraeus hygrometricus and Tricholoma giganteum significantly inhibited the growth of L. donovani promastigotes and interfered in lipid biosynthesis. Moreover, both fractions induced apoptosis in promastigotes. Water soluble Fb fractions of A. hygrometricus, Russula laurocerasi, Russula albonigra, Termitomyces eurhizus, Russula delica and polyphenolic Fc fraction of R. laurocerasi were found to inhibit the replication of intracellular amastigotes in macrophages dose dependently. Significantly, 50% inhibitory concentration of the active extracts against intracellular amastigotes induced release of nitric oxide and IL-12 in murine macrophages and dendritic cells assay and also found considerably non-toxic on murine splenocytes. Results of this study can be used as a basis for further phytochemical and pharmacological investigations in the effort for search of novel anti-leishmanial leads.
Asunto(s)
Agaricales/química , Mezclas Complejas/farmacología , Leishmania donovani/efectos de los fármacos , Medicina Tradicional , Animales , Apoptosis , Mezclas Complejas/toxicidad , Células Dendríticas/efectos de los fármacos , Células Dendríticas/inmunología , Interacciones Hidrofóbicas e Hidrofílicas , India , Concentración 50 Inhibidora , Interleucina-12/metabolismo , Leishmania donovani/crecimiento & desarrollo , Macrófagos Peritoneales/efectos de los fármacos , Macrófagos Peritoneales/metabolismo , Macrófagos Peritoneales/parasitología , Ratones , Ratones Endogámicos BALB C , Óxido Nítrico/metabolismo , Bazo/citología , Bazo/efectos de los fármacos , Termitomyces/química , Tricholoma/químicaRESUMEN
In our previous work we have shown that the novel synthetic chromone derivative could effectively inhibit the Leishmania donovani replication in vitro and in vivo with less cytotoxicity on murine splenocytes. The aim of the present study is to explore the possible mechanism of anti-leishmanial effect of C-(6-methyl-4-oxo-4H-1-benzopyran-3-yl)-N-(p-tolyl) nitrone (designated as NP1) in vitro and in vivo in experimental visceral leishmaniasis caused by L. donovani. The cytotoxic effect of this derivative was studied in murine peritoneal macrophages by MTT method. NP1 at a dose of 17.06 µM showed 50% inhibition on L. donovani promastigotes but found less cytotoxic to the RAW 264.7 cells. Even the higher concentration of IC50 (up to four fold) did not exert much cytotoxic effect on RAW 264.7. Interestingly, NP1 at lower concentration (8.53 µM) could inhibit 50% of intracellular amastigotes in murine peritoneal macrophages. L. donovani is known to exert its pathogenic effects mainly by the suppression of NO generation and subversion of the cellular inflammatory responses in the macrophages. NP1 was found to induce a potent host-protective immune response by enhancing NO generation and iNOS2 expression at mRNA level and by up-regulating proinflammatory cytokines such as IL-12 and IFN-γ and limiting the expression of IL-10 in vivo. The NO dependent killing was further confirmed in iNOS(-/-) mice compared to wild type. In agreement with the fact, induced synthesis of IL-12 and IFN-γ and associated down-regulation of IL-10 by the treatment of NP1 clearly indicated the possibility of novel strategy of drug development against Leishmania infection.