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1.
Int J Nanomedicine ; 19: 1287-1301, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38348174

RESUMO

Introduction: Interleukin-10 (IL-10) is a key anti-inflammatory mediator in protecting host from over-exuberant responses to pathogens and play important roles in wound healing, autoimmunity, cancer, and homeostasis. However, its application as a therapeutic agent for biomedical applications has been limited due to its short biological half-life. Therefore, it is important to prolong the half-life of IL-10 to replace the current therapeutic application, which relies on administering large and repeated dosages. Therefore, not a cost-effective approach. Thus, studies that aim to address this type of challenges are always in need. Methods: Recombinant IL-10 was encapsulated in biodegradable nanoparticles (Poly-(Lactic-co-Glycolic Acid) and Chitosan)) by the double emulsion method and then characterized for size, surface charge, thermal stability, cytotoxicity, in vitro release, UV-visible spectroscopy, and Fourier Transform-Infrared Spectroscopy as well as evaluated for its anti-inflammatory effects. Bioactivity of encapsulated IL-10 was evaluated in vitro using J774A.1 macrophage cell-line and in vivo using BALB/c mice. Inflammatory cytokines (IL-6 and TNF-α) were quantified from culture supernatants using specific enzyme-linked immunosorbent assay (ELISA), and significance was analyzed using ANOVA. Results: We obtained a high 96% encapsulation efficiency with smooth encapsulated IL-10 nanoparticles of ~100-150 nm size and release from nanoparticles as measurable to 22 days. Our result demonstrated that encapsulated IL-10 was biocompatible and functional by reducing the inflammatory responses induced by LPS in macrophages. Of significance, we also proved the functionality of encapsulated IL-10 by its capacity to reduce inflammation in BALB/c mice as provoked by Chlamydia trachomatis, an inflammatory sexually transmitted infectious bacterium. Discussion: Collectively, our results show the successful IL-10 encapsulation, slow release to prolong its biological half-life and reduce inflammatory cytokines IL-6 and TNF production in vitro and in mice. Our results serve as proof of concept to further explore the therapeutic prospective of encapsulated IL-10 for biomedical applications, including inflammatory diseases.


Assuntos
Quitosana , Nanopartículas , Camundongos , Animais , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Interleucina-10 , Ácido Láctico/química , Quitosana/química , Ácido Poliglicólico/química , Interleucina-6 , Citocinas , Nanopartículas/química , Inflamação/tratamento farmacológico , Chlamydia trachomatis , Anti-Inflamatórios/farmacologia
2.
Indian J Otolaryngol Head Neck Surg ; 75(4): 3602-3609, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37974827

RESUMO

As the cases of COVID-19 have declined, the number of patients who have recovered from the dreaded disease is reporting for elective or emergency surgeries. Surgical planning in patients who have recovered from COVD-19 requires special considerations because of the morbidity and mortality associated with the infection and its devastating after-effects. There is a distinct paucity of literature on guidelines and protocols to follow in the perioperative management of these patients. With the help of experience gained over the past 2 years of the 'COVID-19 era', we have been able to establish important recommendations, guidelines and useful protocols during perioperative management of COVID-recovered patients. These protocols include important anesthetic and surgical considerations, which are both practical as well as implementable and are also in cognizance with government-laid down advisories. Although SARS-CoV-2 infection primarily affects the pulmonary and cardiac systems, it has the potential for serious and severely affect multiple organs and various other body systems in erratic and unpredictable manner. All of these factors can have significant implications that make the perioperative management of post-COVID-19 patients, difficult and challenging. Considering the far-reaching and long-lasting effects of this infection on the human body, the protocols and recommendations presented in this article can serve as a valuable guide for clinicians to effectively manage the surgical patient and help reduce perioperative complications attributable to COVID-19 infection.

3.
Indian J Otolaryngol Head Neck Surg ; 75(2): 1193-1195, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37275029

RESUMO

Moebius Syndrome is a rare congenital neurological condition characterized by paralysis of several cranial nerves, commonly the VI(Abducens) and VII(Facial) cranial nerves which causes lateral gaze strabismus and internal strabismus & classical mask like appearance respectively. Other cranial nerves such as V, VII, IX, X, XI, XII are rarely affected. Von Graefe and German neurologist Moebius (1888), after whom the syndrome was eventually named, provided the earliest descriptions of it. Although the etiopathogenesis is unknown, it appears to occur sporadically in the majority of cases, and some documented cases show hereditary predisposition. This paper presents a rare instance of trigeminal neuralgia associated with Moebius syndrome. According to the author's research, this is the first case of Poland Moebius syndrome with trigeminal neuralgia documented from India.

4.
Indian J Otolaryngol Head Neck Surg ; 74(Suppl 3): 4096-4099, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36742617

RESUMO

Mandible fractures are regularly encountered by maxillofacial surgeons and various treatment protocols are available for the management of these fractures. The aim of study compares the efficacy of open reduction and internal fixation of mandibular fractures with and without use of intra-operative inter-maxillary fixation. Twenty patients between age group ranging l8-65 years who reported with single mandibular fracture in Dental college in India, during Oct 2012-March 2015 were the study subjects. These patients were divided into two groups. In one group fracture reduction was done by using inter-maxillary fixation and miniplate fixation was done. In other group fracture reduction was done manually and then fractured fragments were held in position by the assistant and miniplate fixation was done. Post-operatively patients were evaluated for occlusion, bone alignment and soft tissue/hard tissue infection at 1st, 4th, 8th, 12th weeks in both the groups. Statistics done by using Spearman's Rank correlation coefficient and Mann-Whitney U test. It was observed thatthere was no statistically significant difference seen in both the groups in terms of post-operative occlusion, radiological alignment and soft/hard tissue infection. Statistically significant difference was seen when the mean operating time was compared. The Group A showed mean difference of 35.50 min more time than Group B. The results of our study suggested that, use of intra-operative IMF does not show any advantages in terms of post-operative occlusion, bone alignment and soft/hard tissue infection. We have concluded from the study that the increased intra-operative time for the placement of IMF increases the cost of the surgery in regard to equipment and theatre time. There is no benefit in terms of radiographic and clinical outcome. Hence use of intra-operative IMF can be avoided for ORIF of single mandibular fracture.

5.
Curr Top Med Chem ; 21(31): 2800-2813, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34477520

RESUMO

Breast cancer (BC) is the second most commonly diagnosed cancer in the world. BC develops due to dysregulation of transcriptional profiles, substantial interpatient variations, genetic mutations, and dysregulation of signaling pathways in breast cells. These events are regulated by many genes such as BRCA1/2, PTEN, TP53, mTOR, TERT, AKT, PI3K and others genes. Treatment options for BC remain a hurdle, which warrants a comprehensive understanding that establishes an interlinking connection between these genes in BC tumorigenesis. Consequently, there is an increasing demand for alternative treatment approaches and the design of more effective treatments. In this regard, it is crucial to build the corresponding transcriptional regulatory networks governing BC by using advanced genetic tools and techniques. In the past, several molecular editing technologies have been used to edit genes with several limitations. Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/CRISPR Associated Protein 9 (CRISPR/Cas9) recently received wise attention due to its potential in biomedical and therapeutic applications. Here, we review the role of various molecular signalling pathways dysregulated in BC development such as PTEN/PI3K/AKT/mTOR as well as BRCA1/BRCA2/TP53/TERT and their interplay between the related gene networks in BC initiation, progression and development of resistance against available targeted therapeutic agents. Use of CRISPR/Cas9 gene-editing technology to generate BC gene-specific transgenic cell lines and animal models to decipher their role and interactions with other gene products has been employed successfully. Moreover, the significance of using CRISPR/Cas9 technology to develop early BC diagnostic tools and treatments is discussed here.


Assuntos
Neoplasias da Mama/genética , Neoplasias da Mama/terapia , Sistemas CRISPR-Cas/genética , Edição de Genes , Regulação Neoplásica da Expressão Gênica , Redes Reguladoras de Genes , Oncogenes/genética , Animais , Carcinogênese/genética , Humanos
6.
Nanomedicine ; 29: 102257, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32610072

RESUMO

Vaccine developmental strategies are utilizing antigens encapsulated in biodegradable polymeric nanoparticles. Here, we developed a Chlamydia nanovaccine (PLGA-rMOMP) by encapsulating its recombinant major outer membrane protein (rMOMP) in the extended-releasing and self-adjuvanting PLGA [poly (D, L-lactide-co-glycolide) (85:15)] nanoparticles. PLGA-rMOMP was small (nanometer size), round and smooth, thermally stable, and exhibited a sustained release of rMOMP. Stimulation of mouse primary dendritic cells (DCs) with PLGA-rMOMP augmented endosome processing, induced Th1 cytokines (IL-6 and IL-12p40), and expression of MHC-II and co-stimulatory (CD40, CD80, and CD86) molecules. BALB/c mice immunized with PLGA-rMOMP produced enhanced CD4+ T-cells-derived memory (CD44high CD62Lhigh), and effector (CD44high CD62Llow) phenotypes and functional antigen-specific serum IgG antibodies. In vivo biodistribution of PLGA-rMOMP revealed its localization within lymph nodes, suggesting migration from the injection site via DCs. Our data provide evidence that the PLGA (85:15) nanovaccine activates DCs and augments Chlamydia-specific rMOMP adaptive immune responses that are worthy of efficacy testing.


Assuntos
Imunidade Adaptativa/genética , Proteínas da Membrana Bacteriana Externa/genética , Nanopartículas/química , Vacinas/imunologia , Imunidade Adaptativa/imunologia , Animais , Proteínas da Membrana Bacteriana Externa/imunologia , Antígenos CD4/química , Antígenos CD4/imunologia , Chlamydia/genética , Chlamydia/imunologia , Chlamydia/patogenicidade , Células Dendríticas/imunologia , Antígenos de Histocompatibilidade Classe II/genética , Humanos , Receptores de Hialuronatos/química , Receptores de Hialuronatos/imunologia , Subunidade p40 da Interleucina-12/genética , Subunidade p40 da Interleucina-12/imunologia , Interleucina-6/genética , Interleucina-6/imunologia , Selectina L/química , Selectina L/imunologia , Camundongos , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/imunologia , Linfócitos T/imunologia , Vacinas/genética
7.
Mediators Inflamm ; 2020: 7461742, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32684836

RESUMO

The immunopathology of chlamydial diseases is exacerbated by a broad-spectrum of inflammatory mediators, which we reported are inhibited by IL-10 in macrophages. However, the chlamydial protein moiety that induces the inflammatory mediators and the mechanisms by which IL-10 inhibits them are unknown. We hypothesized that Chlamydia major outer membrane protein (MOMP) mediates its disease pathogenesis, and the suppressor of cytokine signaling (SOCS)1 and SOCS3 proteins are mediators of the IL-10 inhibitory actions. Our hypothesis was tested by exposing mouse J774 macrophages to chlamydial stimulants (live Chlamydia muridarum and MOMP) with and without IL-10. MOMP significantly induced several inflammatory mediators (IL-6, IL-12p40, CCL5, CXCL10), which were dose-dependently inhibited by IL-10. Chlamydial stimulants induced the mRNA gene transcripts and protein expression of SOCS1 and SOCS3, with more SOCS3 expression. Notably, IL-10 reciprocally regulated their expression by reducing SOCS1 and increasing SOCS3. Specific inhibitions of MAPK pathways revealed that p38, JNK, and MEK1/2 are required for inducing inflammatory mediators as well as SOCS1 and SOCS3. Chlamydial stimulants triggered an M1 pro-inflammatory phenotype evidently by an enhanced nos2 (M1 marker) expression, which was skewed by IL-10 towards a more M2 anti-inflammatory phenotype by the increased expression of mrc1 and arg1 (M2 markers) and the reduced SOCS1/SOCS3 ratios. Neutralization of endogenously produced IL-10 augmented the secretion of inflammatory mediators, reduced SOCS3 expression, and skewed the chlamydial M1 to an M2 phenotype. Inhibition of proteasome degradation increased TNF but decreased IL-10, CCL5, and CXCL10 secretion by suppressing SOCS1 and SOCS3 expressions and dysregulating their STAT1 and STAT3 transcription factors. Our data show that SOCS1 and SOCS3 are regulators of IL-10 inhibitory actions, and underscore SOCS proteins as therapeutic targets for IL-10 control of inflammation for Chlamydia and other bacterial inflammatory diseases.


Assuntos
Proteínas da Membrana Bacteriana Externa/toxicidade , Chlamydia muridarum/patogenicidade , Inflamação/metabolismo , Interleucina-10/metabolismo , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Proteína 1 Supressora da Sinalização de Citocina/metabolismo , Proteína 3 Supressora da Sinalização de Citocinas/metabolismo , Animais , Linhagem Celular , Citometria de Fluxo , Camundongos , Microscopia de Fluorescência , Proteína 1 Supressora da Sinalização de Citocina/genética , Proteína 3 Supressora da Sinalização de Citocinas/genética
8.
Molecules ; 24(4)2019 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-30795572

RESUMO

Bioassay-guided fractionation of an EtOAc extract of the broth of the endophytic fungus Nemania sp. UM10M (Xylariaceae) isolated from a diseased Torreya taxifolia leaf afforded three known cytochalasins, 19,20-epoxycytochalasins C (1) and D (2), and 18-deoxy-19,20-epoxy-cytochalasin C (3). All three compounds showed potent in vitro antiplasmodial activity and phytotoxicity with no cytotoxicity to Vero cells. These compounds exhibited moderate to weak cytotoxicity to some of the cell lines of a panel of solid tumor (SK-MEL, KB, BT-549, and SK-OV-3) and kidney epithelial cells (LLC-PK11). Evaluation of in vivo antimalarial activity of 19,20-epoxycytochalasin C (1) in a mouse model at 100 mg/kg dose showed that this compound had weak suppressive antiplasmodial activity and was toxic to animals.


Assuntos
Antineoplásicos/farmacologia , Antiprotozoários/farmacologia , Citocalasinas/farmacologia , Malária/tratamento farmacológico , Taxaceae/microbiologia , Xylariales/química , Animais , Antineoplásicos/química , Antineoplásicos/isolamento & purificação , Antiprotozoários/química , Antiprotozoários/isolamento & purificação , Linhagem Celular , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Chlorocebus aethiops , Citocalasinas/química , Citocalasinas/isolamento & purificação , Endófitos/química , Células Epiteliais/citologia , Células Epiteliais/efeitos dos fármacos , Humanos , Malária/mortalidade , Malária/parasitologia , Masculino , Camundongos , Folhas de Planta/microbiologia , Plasmodium berghei/efeitos dos fármacos , Plasmodium berghei/crescimento & desenvolvimento , Análise de Sobrevida , Células Vero
9.
J Biomater Appl ; 33(7): 924-934, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30472917

RESUMO

OBJECTIVE: To investigate the toxicity and antibacterial application of antimicrobial peptide-functionalized silver-coated carbon nanotubes against Staphylococcus infection using a full thickness human three-dimensional skin model. MATERIALS AND METHODS: The three-dimensional skin formation on the scaffolds was characterized by electron microscopy and investigation of several skin cell markers by real time-reverse transcriptase polymerase chain reaction. Functionalized silver-coated carbon nanotubes were prepared using carboxylated silver-coated carbon nanotubes with antimicrobial peptides such as TP359, TP226 and TP557. Following the characterization and toxicity evaluation, the antibacterial activity of functionalized silver-coated carbon nanotubes against Staphylococcus aureus was investigated using a bacterial enumeration assay and scanning electron microscopy. For this purpose, a scar on the human three-dimensional skin grown on Alvetex scaffold using keratinocytes and fibroblasts cells was created by taking precaution not to break the scaffold beneath, followed by incubation with 5 µg/mL of functionalized silver-coated carbon nanotubes re-suspended in minimum essential medium for 2 h. Post 2-h incubation, 200 µL of minimum essential medium containing 1 × 104 colony forming units of Staphylococcus aureus were incubated for 2 h. After incubation with bacteria, the colony forming unit/gram (cfu/g) of skin tissue were counted using the plate count assay and the samples were processed for scanning electron microscopy analysis. RESULTS: MTT assay revealed no toxicity of functionalized silver-coated carbon nanotubes to the skin cells such as keratinocytes and fibroblasts at 5 µg/mL with 98% cell viability. The bacterial count increased from 104 to 108 cfu/g in the non-treated skin model, whereas skin treated with functionalized silver-coated carbon nanotubes showed only a small increase from 104 to 105 cfu/g (1000-fold viable cfu difference). Scanning electron microscopy analysis showed the presence of Staphylococcus aureus on the non-treated skin as opposed to the treated skin. CONCLUSION: Thus, our results showed that functionalized silver-coated carbon nanotubes are not only non-toxic, but also help reduce the infection due to their antibacterial activity. These findings will aid in the development of novel antibacterial skin substitutes.


Assuntos
Antibacterianos/farmacologia , Peptídeos/farmacologia , Prata/farmacologia , Pele/microbiologia , Infecções Estafilocócicas/tratamento farmacológico , Staphylococcus aureus/efeitos dos fármacos , Antibacterianos/química , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Linhagem Celular , Humanos , Nanotubos de Carbono/química , Peptídeos/química , Prata/química , Pele/efeitos dos fármacos , Pele/ultraestrutura
10.
Front Immunol ; 9: 2369, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30374357

RESUMO

Recently, we reported that our PPM chlamydial nanovaccine [a biodegradable co-polymeric PLA-PEG (poly(lactic acid)-poly(ethylene glycol))-encapsulated M278 peptide (derived from the major outer membrane protein (MOMP) of Chlamydia)] exploits the caveolin-mediated endocytosis pathway for endosomal processing and MHC class II presentation to immune-potentiate Chlamydia-specific CD4+ T-cell immune effector responses. In the present study, we employed the Chlamydia muridarum mouse infection model to evaluate the protective efficacy of PPM against a genital tract challenge. Our results show that mice immunized with PPM were significantly protected against a homologous genital tract challenge evidently by reduced vaginal bacterial loads. Protection of mice correlated with enhanced Chlamydia-specific adaptive immune responses predominated by IFN-γ along with CD4+ T-cells proliferation and their differentiation to CD4+ memory (CD44high CD62Lhigh) and effector (CD44high CD62Llow) T-cell phenotypes. We observed the elevation of M278- and MOMP-specific serum antibodies with high avidity in the ascending order IgG1 > IgG2b > IgG2a. A key finding was the elevated mucosal IgG1 and IgA antibody titers followed by an increase in MOMP-specific IgA after the challenge. The Th1/Th2 antibody titer ratios (IgG2a/IgG1 and IgG2b/IgG1) revealed that PPM evoked a Th2-directed response, which skewed to a Th1-dominated antibody response after the bacterial challenge of mice. In addition, PPM immune sera neutralized the infectivity of C. muridarum in McCoy cells, suggesting the triggering of functional neutralizing antibodies. Herein, we reveal for the first time that subcutaneous immunization with the self-adjuvanting biodegradable co-polymeric PPM nanovaccine immune-potentiated robust CD4+ T cell-mediated immune effector responses; a mixed Th1 and Th2 antibody response and local mucosal IgA to protect mice against a chlamydial genital tract challenge.


Assuntos
Proteínas da Membrana Bacteriana Externa/imunologia , Vacinas Bacterianas/imunologia , Infecções por Chlamydia/imunologia , Infecções por Chlamydia/microbiologia , Chlamydia muridarum/imunologia , Imunidade nas Mucosas , Adjuvantes Imunológicos , Animais , Anticorpos Antibacterianos/imunologia , Anticorpos Neutralizantes/imunologia , Antígenos/imunologia , Vacinas Bacterianas/administração & dosagem , Citocinas/metabolismo , Modelos Animais de Doenças , Feminino , Imunização , Imunoglobulina G/imunologia , Memória Imunológica , Lactatos , Camundongos , Testes de Neutralização , Polietilenoglicóis , Linfócitos T/imunologia , Linfócitos T/metabolismo , Vagina/imunologia , Vagina/microbiologia
11.
Biomaterials ; 159: 130-145, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29324305

RESUMO

We previously developed a Chlamydia trachomatis nanovaccine (PPM) by encapsulating a chlamydial M278 peptide within poly(lactic acid)-poly(ethylene glycol) biodegradable nanoparticles that immunopotentiated Chlamydia-specific immune effector responses in mice. Herein, we investigated the mechanistic interactions of PPM with mouse bone marrow-derived dendritic cells (DCs) for its uptake, trafficking, and T cell activation. Our results reveal that PPM triggered enhanced expression of effector cytokines and chemokines, surface activation markers (Cd1d2, Fcgr1), pathogen-sensing receptors (TLR2, Nod1), co-stimulatory (CD40, CD80, CD86) and MHC class I and II molecules. Co-culturing of PPM-primed DCs with T cells from C. muridarum vaccinated mice yielded an increase in Chlamydia-specific immune effector responses including CD3+ lymphoproliferation, CD3+CD4+ IFN-γ-secreting cells along with CD3+CD4+ memory (CD44high and CD62Lhigh) and effector (CD44high and CD62Llow) phenotypes. Intracellular trafficking analyses revealed an intense expression and colocalization of PPM predominantly in endosomes. PPM also upregulated the transcriptional and protein expression of the endocytic mediator, caveolin-1 in DCs. More importantly, the specific inhibition of caveolin-1 led to decreased expression of PPM-induced cytokines and co-stimulatory molecules. Our investigation shows that PPM provided enhancement of uptake, probably by exploiting the caveolin-mediated endocytosis pathway, endosomal processing, and MHC II presentation to immunopotentiate Chlamydia-specific immune effector responses mediated by CD4+ T cells.


Assuntos
Endocitose/fisiologia , Lactatos/química , Nanopartículas/química , Polietilenoglicóis/química , Animais , Linfócitos T CD4-Positivos , Caveolinas/metabolismo , Proliferação de Células/fisiologia , Chlamydia muridarum/imunologia , Células Dendríticas/imunologia , Ensaio de Imunoadsorção Enzimática , Feminino , Camundongos , Camundongos Endogâmicos BALB C
12.
J Biol Eng ; 11: 49, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29255480

RESUMO

The repair or replacement of damaged skins is still an important, challenging public health problem. Immune acceptance and long-term survival of skin grafts represent the major problem to overcome in grafting given that in most situations autografts cannot be used. The emergence of artificial skin substitutes provides alternative treatment with the capacity to reduce the dependency on the increasing demand of cadaver skin grafts. Over the years, considerable research efforts have focused on strategies for skin repair or permanent skin graft transplantations. Available skin substitutes include pre- or post-transplantation treatments of donor cells, stem cell-based therapies, and skin equivalents composed of bio-engineered acellular or cellular skin substitutes. However, skin substitutes are still prone to immunological rejection, and as such, there is currently no skin substitute available to overcome this phenomenon. This review focuses on the mechanisms of skin rejection and tolerance induction and outlines in detail current available strategies and alternatives that may allow achieving full-thickness skin replacement and repair.

13.
J Vis Exp ; (70)2012 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-23299097

RESUMO

Leishmaniasis is one of the world's most neglected diseases, largely affecting the poorest of the poor, mainly in developing countries. Over 350 million people are considered at risk of contracting leishmaniasis, and approximately 2 million new cases occur yearly(1). Leishmania donovani is the causative agent for visceral leishmaniasis (VL), the most fatal form of the disease. The choice of drugs available to treat leishmaniasis is limited (2);current treatments provide limited efficacy and many are toxic at therapeutic doses. In addition, most of the first line treatment drugs have already lost their utility due to increasing multiple drug resistance (3). The current pipeline of anti-leishmanial drugs is also severely depleted. Sustained efforts are needed to enrich a new anti-leishmanial drug discovery pipeline, and this endeavor relies on the availability of suitable in vitro screening models. In vitro promastigotes (4) and axenic amastigotes assays(5) are primarily used for anti-leishmanial drug screening however, may not be appropriate due to significant cellular, physiological, biochemical and molecular differences in comparison to intracellular amastigotes. Assays with macrophage-amastigotes models are considered closest to the pathophysiological conditions of leishmaniasis, and are therefore the most appropriate for in vitro screening. Differentiated, non-dividing human acute monocytic leukemia cells (THP1) (make an attractive) alternative to isolated primary macrophages and can be used for assaying anti-leishmanial activity of different compounds against intracellular amastigotes. Here, we present a parasite-rescue and transformation assay with differentiated THP1 cells infected in vitro with Leishmania donovani for screening pure compounds and natural products extracts and determining the efficacy against the intracellular Leishmania amastigotes. The assay involves the following steps: (1) differentiation of THP1 cells to non-dividing macrophages, (2) infection of macrophages with L. donovani metacyclic promastigotes, (3) treatment of infected cells with test drugs, (4) controlled lysis of infected macrophages, (5) release/rescue of amastigotes and (6) transformation of live amastigotes to promastigotes. The assay was optimized using detergent treatment for controlled lysis of Leishmania-infected THP1 cells to achieve almost complete rescue of viable intracellular amastigotes with minimal effect on their ability to transform to promastigotes. Different macrophage:promastigotes ratios were tested to achieve maximum infection. Quantification of the infection was performed through transformation of live, rescued Leishmania amastigotes to promastigotes and evaluation of their growth by an alamarBlue fluorometric assay in 96-well microplates. This assay is comparable to the currently-used microscopic, transgenic reporter gene and digital-image analysis assays. This assay is robust and measures only the live intracellular amastigotes compared to reporter gene and image analysis assays, which may not differentiate between live and dead amastigotes. Also, the assay has been validated with a current panel of anti-leishmanial drugs and has been successfully applied to large-scale screening of pure compounds and a library of natural products fractions (Tekwani et al. unpublished).


Assuntos
Avaliação Pré-Clínica de Medicamentos/métodos , Leishmania donovani/efeitos dos fármacos , Leishmania donovani/crescimento & desenvolvimento , Leucemia Monocítica Aguda/parasitologia , Antiprotozoários/farmacologia , Linhagem Celular Tumoral , Humanos , Leishmaniose Visceral/tratamento farmacológico , Leishmaniose Visceral/parasitologia , Leucemia Monocítica Aguda/patologia , Macrófagos/parasitologia , Macrófagos/patologia
14.
Planta Med ; 77(14): 1639-43, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21384317

RESUMO

A new indolizidine alkaloid, named Δ¹,6-juliprosopine (1), together with previously known indolizidine analogs (2- 6), was isolated from the leaves of Prosopis glandulosa var. glandulosa, collected from Nevada, USA; while two other known indolizidines, juliprosopine (6) and juliprosine (7), were isolated from P. glandulosa leaves collected in Texas, USA. The structures of compound 1 and 7 were determined using a combination of NMR and MS techniques. Compound 7 exhibited potent antiplasmodial activity against Plasmodium falciparum D6 and W2 strains with IC (50) values of 170 and 150 ng/mL, respectively, while 1 was found to be less active (IC50 values 560 and 600 ng/mL, respectively). Both compounds were devoid of VERO cells toxicity up to a concentration of 23 800 ng/mL. The antileishmanial activity of indolizidines was evaluated against Leishmania donovani promastigotes, axenic amastigotes, and amastigotes in THP1 macrophage cultures. When tested against macrophage cultures, the tertiary bases (1, 3, 6) were found to be more potent than quaternary salts (2, 5, 7), displaying IC50 values between 0.8-1.7 µg/mL and 3.1-6.0 µg/mL, respectively. In addition, compound 7 showed potent antifungal activity against Cryptococcus neoformans and antibacterial activity against Mycobacterium intracellulare, while 1 was potent only against C. neoformans and weakly active against other organisms.


Assuntos
Alcaloides/farmacologia , Anti-Infecciosos/farmacologia , Indolizidinas/farmacologia , Extratos Vegetais/química , Prosopis/química , Alcaloides/química , Animais , Anti-Infecciosos/química , Linhagem Celular , Chlorocebus aethiops , Cryptococcus neoformans/efeitos dos fármacos , Humanos , Indolizidinas/química , Concentração Inibidora 50 , Leishmania donovani/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Estrutura Molecular , Complexo Mycobacterium avium/efeitos dos fármacos , Folhas de Planta/química , Plantas Medicinais , Plasmodium falciparum/efeitos dos fármacos , Texas
15.
J Drug Target ; 16(9): 706-15, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18982519

RESUMO

Currently, there is a clinical need for more effective vaccine for hepatitis B that induces robust cell-mediated immune response capable of viral clearance in chronic hepatitis B infection. In the present study, hepatitis B vaccines formulations were designed by loading the hepatitis B surface antigen into liposomes adjuvanted with rough lipopolysaccharide (Re-LPS) and lpxL1 LPS using conventional rotatory evaporation method and were characterized for various parameters, such as vesicle shape and surface morphology, size and size distribution, entrapment efficiency, turbidity, and in vitro release pattern. The immunoreactivity in mice was evaluated by measuring anti-HBs IgG titer and compared with alum-adsorbed HBsAg solution, plain HBsAg, and liposomal HBsAg formulations. The formulations were also evaluated for cell-mediated immune response by HBsAg specific proliferation of spleenocytes after secondary immunization and re-stimulation in vitro with the same antigen. Simultaneous estimation of cytokines (IL-4, IFN-gamma) was also carried out. Ex vivo cellular uptake study was performed by fluorescence microscopy. Results indicate that the serum IgG titer obtained after i.m administration of Re-LPS- and lpxL1 LPS-adjuvanted liposomal HBsAg formulation was equivalent to alum-adsorbed HBsAg formulation but was more responsive, sustained, and significantly higher than the corresponding liposomal HBsAg and plain HBsAg formulations. Incorporation of lpxL1 LPS into the liposomal HBsAg increased the stimulation index (SI) 6-10 times as compared with plain HBsAg. Re-LPS- and lpxL1 LPS-adjuvanted liposomal HBsAg formulations induced stronger cellular immune response with a predominant Interferon-gamma (IFN-gamma) level than those induced by free HBsAg alone, alum-adsorbed HBsAg, and non-adjuvanted liposomal HBsAg. Probably, the possible mechanism for the enhancement of cellular immunity in addition to humoral immunity by LPS-adjuvanted liposomal HBsAg formulation is due to marked enhancement of immunological presentation and recruitment of antigen via macrophage and antigen-presenting cells (APCs).


Assuntos
Antígenos de Superfície da Hepatite B/imunologia , Lipopolissacarídeos/química , Lipopolissacarídeos/farmacologia , Lipossomos/química , Linfócitos T Auxiliares-Indutores/fisiologia , Animais , Sistemas de Liberação de Medicamentos , Feminino , Hepatite B/imunologia , Vacinas contra Hepatite B/administração & dosagem , Vacinas contra Hepatite B/imunologia , Macrófagos/metabolismo , Masculino , Camundongos , Linfócitos T Auxiliares-Indutores/efeitos dos fármacos , Fatores de Tempo
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