Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 20
Filtrar
Mais filtros











Base de dados
Intervalo de ano de publicação
1.
J Minim Access Surg ; 2024 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-38289034

RESUMO

ABSTRACT: Liver cysts often have no symptoms, are benign and are usually encountered during routine abdominal imaging for other conditions. Giant cysts have a higher risk of complications. Recurrence is common, and most research papers support laparoscopic deroofing as the initial management modality even in the recurrent cases as it avoids the morbidity of laparotomy and gives better short- and long-term post-operative outcomes. Here, we present a case of a 68-year-old female who presented to the outpatient department with complaints of right-sided dull-aching abdominal pain, heaviness, early satiety and significant weight loss for the past 2 months. A laparoscopic drainage and deroofing were done, and histopathological examination of the cystic wall was consistent with benign pathology. The patient has been doing well for the past year.

2.
J Minim Access Surg ; 2023 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-37706415

RESUMO

Peritoneal encapsulation (PE) is a rare congenital disorder described as an accessory peritoneal lining covering a part or whole of the small bowel. Some theorise the encapsulation is due to the formation of adhesion between the physiological hernia and the caudal duodenum. While others have stated it is a defect in the reduction of the physiological hernia. Patients usually present at different stages of intestinal obstruction at any point of time during life. There are also reports on post-humous diagnosis on autopsy. PE is a rare surgical entity, hence not much evidences are available on how to tackle this condition by minimally invasive approach. Here, we report a case of PE in a 43-year-old male who presented with features of intermittent sub-acute intestinal obstruction and was managed by laparoscopic surgery at our institute.

3.
Sci Transl Med ; 14(667): eabo7219, 2022 10 19.
Artigo em Inglês | MEDLINE | ID: mdl-36260689

RESUMO

Compounds acting on multiple targets are critical to combating antimalarial drug resistance. Here, we report that the human "mammalian target of rapamycin" (mTOR) inhibitor sapanisertib has potent prophylactic liver stage activity, in vitro and in vivo asexual blood stage (ABS) activity, and transmission-blocking activity against the protozoan parasite Plasmodium spp. Chemoproteomics studies revealed multiple potential Plasmodium kinase targets, and potent inhibition of Plasmodium phosphatidylinositol 4-kinase type III beta (PI4Kß) and cyclic guanosine monophosphate-dependent protein kinase (PKG) was confirmed in vitro. Conditional knockdown of PI4Kß in ABS cultures modulated parasite sensitivity to sapanisertib, and laboratory-generated P. falciparum sapanisertib resistance was mediated by mutations in PI4Kß. Parasite metabolomic perturbation profiles associated with sapanisertib and other known PI4Kß and/or PKG inhibitors revealed similarities and differences between chemotypes, potentially caused by sapanisertib targeting multiple parasite kinases. The multistage activity of sapanisertib and its in vivo antimalarial efficacy, coupled with potent inhibition of at least two promising drug targets, provides an opportunity to reposition this pyrazolopyrimidine for malaria.


Assuntos
Antimaláricos , Plasmodium , Animais , Humanos , Antimaláricos/farmacologia , Antimaláricos/uso terapêutico , Plasmodium falciparum , Inibidores de MTOR , 1-Fosfatidilinositol 4-Quinase , Guanosina Monofosfato , Estágios do Ciclo de Vida , Serina-Treonina Quinases TOR , Sirolimo , Mamíferos
4.
Science ; 376(6597): 1074-1079, 2022 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-35653481

RESUMO

Aminoacyl transfer RNA (tRNA) synthetases (aaRSs) are attractive drug targets, and we present class I and II aaRSs as previously unrecognized targets for adenosine 5'-monophosphate-mimicking nucleoside sulfamates. The target enzyme catalyzes the formation of an inhibitory amino acid-sulfamate conjugate through a reaction-hijacking mechanism. We identified adenosine 5'-sulfamate as a broad-specificity compound that hijacks a range of aaRSs and ML901 as a specific reagent a specific reagent that hijacks a single aaRS in the malaria parasite Plasmodium falciparum, namely tyrosine RS (PfYRS). ML901 exerts whole-life-cycle-killing activity with low nanomolar potency and single-dose efficacy in a mouse model of malaria. X-ray crystallographic studies of plasmodium and human YRSs reveal differential flexibility of a loop over the catalytic site that underpins differential susceptibility to reaction hijacking by ML901.


Assuntos
Antimaláricos , Malária Falciparum , Terapia de Alvo Molecular , Plasmodium falciparum , Biossíntese de Proteínas , Proteínas de Protozoários , Tirosina-tRNA Ligase , Adenosina/análogos & derivados , Animais , Antimaláricos/química , Antimaláricos/farmacologia , Antimaláricos/uso terapêutico , Cristalografia por Raios X , Humanos , Malária Falciparum/tratamento farmacológico , Malária Falciparum/parasitologia , Camundongos , Plasmodium falciparum/efeitos dos fármacos , Plasmodium falciparum/enzimologia , Biossíntese de Proteínas/efeitos dos fármacos , Conformação Proteica , Proteínas de Protozoários/química , Proteínas de Protozoários/metabolismo , Ácidos Sulfônicos/química , Tirosina-tRNA Ligase/química , Tirosina-tRNA Ligase/metabolismo
5.
Comb Chem High Throughput Screen ; 25(3): 414-428, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34077341

RESUMO

BACKGROUND: Coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 infection has become a worldwide pandemic and created an utmost crisis across the globe. To mitigate the crisis, the design of vaccine is the crucial solution. The frequent mutation of the virus demands generalized vaccine candidates, which would be effective for all mutated strains at present and for the strains that would evolve due to further new mutations in the virus. OBJECTIVE: The objective of this study is to identify more frequently occurring mutated variants of SARS-CoV-2 and to suggest peptide vaccine candidates effective against the viral strains considered. METHODS: In this study, we have identified all currently prevailing mutated strains of SARS-CoV-2 through 2D Polar plot and Quotient Radius characterization descriptor. Then, by considering the top eight mutation strains, which are significant due to their frequency of occurrence, peptide regions suitable for vaccine design have been identified with the help of a mathematical model, 2D Polygon Representation, followed by the evaluation of epitope potential, ensuring that there is no case of any autoimmune threat. Lastly, in order to verify whether this entire approach is applicable for vaccine design against any other virus in general, we have made a comparative study between the peptide vaccine candidates prescribed for the Zika virus using the current approach and a list of potential vaccine candidates for the same already established in the past. RESULTS: We have finally suggested three generalized peptide regions which would be suitable as sustainable peptide vaccine candidates against SARS-CoV-2 irrespective of its currently prevailing strains as well any other variant of the same that may appear in the future. We also observed that during the comparative study using the case of E protein of Zika virus, the peptide regions suggested using the new approach that matches with the already established results. CONCLUSION: The study, therefore, illustrates an approach that would help in developing peptide vaccine against SARS-CoV-2 by suggesting those peptide regions which can be targeted irrespective of any mutated form of this virus. The consistency with which this entire approach was also able to figure out similar vaccine candidates for Zika virus with utmost accuracy proves that this protocol can be extended for peptide vaccine design against any other viruses in the future.


Assuntos
COVID-19 , Vacinas , Infecção por Zika virus , Zika virus , Vacinas contra COVID-19 , Humanos , Peptídeos , SARS-CoV-2 , Zika virus/genética
6.
J Minim Access Surg ; 15(3): 234-241, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-29737322

RESUMO

BACKGROUND: The morbidity related to radical oesophagectomy can be reduced by adopting minimally invasive techniques. Over 250 thoraco-laparoscopic oesophagectomy (TLE) was done in our centre over the last 15 years, before adopting robotic surgery as the latest innovation in the field of minimally invasive surgery. Here, we share our initial experience of robotic-assisted minimally invasive oesophagectomy (RAMIE) for carcinoma oesophagus. METHODS: A prospective observational study conducted from February to December 2017. A total of 15 patients underwent RAMIE in this period. Data regarding demography, clinical characteristics, investigations, operating techniques, and post-operative outcome were collected in detail. RESULTS: There were 10 (66.7%) male patients and the median age of all patients was 62.9 (range 36-78) years. The median body mass index was 24.4 (range 15-32.8) kg/m2. Twelve (80.0%) patients had squamous cell carcinoma (SCC) of the oesophagus and 3 (20%) patients had adenocarcinoma (AC). Five (33.3%) patients received neoadjuvant therapy. All 15 patients underwent RAMIE. Patients with SCC underwent McKeown's procedure, and those with AC underwent Ivor Lewis procedure. Extended two-field lymphadenectomy (including total mediastinal lymphadenectomy) was done for all the patients. The median operating time was 558 (range 390-690) min and median blood loss was 145 (range 90-230) ml. There were no intra-operative adverse events, and none of them required conversion to open or total thoracolaparoscopic procedure. The most common post-operative complications were recurrent laryngeal nerve paresis (3 patients, 20.0%) and pneumonia (2 patients, 13.3%). The median hospital stay was 9 (range 7-33) days. In total, 9 (60%) patients required adjuvant treatment. CONCLUSION: Adequate experience in TLE can help minimally invasive surgeons in easy adoption of RAMIE with satisfactory outcome.

7.
Curr Top Med Chem ; 18(26): 2202-2208, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30417788

RESUMO

We briefly review the situations arising out of epidemics that erupt rather suddenly, threatening life and livelihoods of humans. Ebola, Zika and the Nipah virus outbreaks are recent examples where the viral epidemics have led to considerably high degree of fatalities or debilitating consequences. The problems are accentuated by a lack of drugs or vaccines effective against the new and emergent viruses, and the inordinate amount of temporal and financial resources that are required to combat the novel pathogens. Progress in computational, biological and informational sciences have made it possible to consider design of synthetic vaccines that can be rapidly developed and deployed to help stem the damages. In this review, we consider the pros and cons of this new paradigm and suggest a new system where the manufacturing process can be decentralized to provide more targeted vaccines to meet the urgent needs of protection in case of a rampaging epidemic.


Assuntos
Doença pelo Vírus Ebola/epidemiologia , Infecções por Henipavirus/epidemiologia , Peptídeos/imunologia , Vacinas Virais/imunologia , Infecção por Zika virus/epidemiologia , Animais , Doença pelo Vírus Ebola/imunologia , Doença pelo Vírus Ebola/prevenção & controle , Doença pelo Vírus Ebola/virologia , Infecções por Henipavirus/imunologia , Infecções por Henipavirus/prevenção & controle , Humanos , Vírus Nipah/imunologia , Infecção por Zika virus/imunologia , Infecção por Zika virus/prevenção & controle , Infecção por Zika virus/virologia
8.
J Minim Access Surg ; 14(4): 349-353, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29737317

RESUMO

Solid pseudopapillary tumour (SPT) is one of the uncommon benign cystic neoplasms of pancreas occurring predominantly in young females. Being benign in nature, surgical resection is the treatment of choice with excellent 5-year survival. A 14-year-old girl presented with pain abdomen for 1 week. On evaluation, she was found to have a large SPT involving head and uncinate process of Pancreas She underwent robotic pylorus preserving pancreaticoduodenectomy (R-PPPD) with da Vinci® Si Robotic System (Intuitive Surgical, Sunnyvale, CA, USA). The total operating time was 480 min. Her postoperative recovery was uneventful and she was discharged on postoperative day 6. In the era of minimally invasive surgery, robotic pancreatic resection and reconstruction are becoming more acceptable. Although the operating domain is small in younger age group, the precise movement of robotic arm and high quality magnified three-dimensional view allows the surgeons to perform PPPD on younger patients also. Young female patients suffering from SPTs can electively undergo R-PPPD with minimal morbidity and mortality. R-PPPD can become the treatment of choice for SPTs involving pancreatic head region even in paediatric and adolescent age group.

9.
J Minim Access Surg ; 13(4): 312-314, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28695881

RESUMO

Parastomal hernia is one of the most common but challenging complication after stoma formation. Modified Sugarbaker technique is the recommended procedure for repair parastomal hernia, however, keyhole repair technique had also been used in certain instances. In cases of parastomal hernia following ileal conduit procedure, the Sugarbaker technique is been described, although with associated theoretical risk of conduit failure. We are reporting a case of post-radical cystectomy with ileal conduit presented with symptomatic large parastomal hernia. Laparoscopic modified keyhole plus repair has been done successfully in this patient with no recurrence in 2 years of follow-up. The purpose of our case report is to describe our novel modification of the laparoscopic keyhole technique which can be a feasible and acceptable alternative surgical method in these types of patients.

10.
Comput Biol Chem ; 68: 143-152, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28342423

RESUMO

The Zika virus infections have reached epidemic proportions in the Latin American countries causing severe birth defects and neurological disorders. While several organizations have begun research into design of prophylactic vaccines and therapeutic drugs, computer assisted methods with adequate data resources can be expected to assist in these measures to reduce lead times through bioinformatics approaches. Using 60 sequences of the Zika virus envelope protein available in the GenBank database, our analysis with numerical characterization techniques and several web based bioinformatics servers identified four peptide stretches on the Zika virus envelope protein that are well conserved and surface exposed and are predicted to have reasonable epitope binding efficiency. These peptides can be expected to form the basis for a nascent peptide vaccine which, enhanced by incorporation of suitable adjuvants, can elicit immune response against the Zika virus infections.


Assuntos
Biologia Computacional , Desenho de Fármacos , Peptídeos/imunologia , Vacinas Virais/imunologia , Infecção por Zika virus/imunologia , Zika virus/imunologia , Adjuvantes Imunológicos , Epitopos/química , Epitopos/imunologia , Peptídeos/síntese química , Peptídeos/química , Proteínas do Envelope Viral/química , Proteínas do Envelope Viral/genética , Proteínas do Envelope Viral/imunologia , Vacinas Virais/síntese química , Vacinas Virais/química , Zika virus/química , Zika virus/genética , Infecção por Zika virus/prevenção & controle , Infecção por Zika virus/virologia
11.
Cancer Inform ; 15(Suppl 1): 1-16, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27279731

RESUMO

Human papillomavirus (HPV) occurs in many types, some of which cause cervical, genital, and other cancers. While vaccination is available against the major cancer-causing HPV types, many others are not covered by these preventive measures. Herein, we present a bioinformatics study for the designing of multivalent peptide vaccines against multiple HPV types as an alternative strategy to the virus-like particle vaccines being used now. Our technique of rational design of peptide vaccines is expected to ensure stability of the vaccine against many cycles of mutational changes, elicit immune response, and negate autoimmune possibilities. Using the L1 capsid protein sequences, we identified several peptides for potential vaccine design for HPV 16, 18, 33, 35, 45, and 11 types. Although there are concerns about the epitope-binding affinities for the peptides identified in this process, the technique indicates possibilities of multivalent, adjuvanted, peptide vaccines against a wider range of HPV types, and tailor-made different combinations of the peptides to address frequency variations of types over different population groups as required for prophylaxis and at lower cost than are in use at the present time.

12.
J Biol Chem ; 287(32): 26630-46, 2012 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-22696214

RESUMO

We have investigated the impact of persistent intravascular hemolysis on liver dysfunction using the mouse malaria model. Intravascular hemolysis showed a positive correlation with liver damage along with the increased accumulation of free heme and reactive oxidants in liver. Hepatocytes overinduced heme oxygenase-1 (HO-1) to catabolize free heme in building up defense against this pro-oxidant milieu. However, in a condition of persistent free heme overload in malaria, the overactivity of HO-1 resulted in continuous transient generation of free iron to favor production of reactive oxidants as evident from 2',7'-dichlorofluorescein fluorescence studies. Electrophoretic mobility shift assay documented the activation of NF-κB, which in turn up-regulated intercellular adhesion molecule 1 as evident from chromatin immunoprecipitation studies. NF-κB activation also induced vascular cell adhesion molecule 1, keratinocyte chemoattractant, and macrophage inflammatory protein 2, which favored neutrophil extravasation and adhesion in liver. The infiltration of neutrophils correlated positively with the severity of hemolysis, and neutrophil depletion significantly prevented liver damage. The data further documented the elevation of serum TNFα in infected mice, and the treatment of anti-TNFα antibodies also significantly prevented neutrophil infiltration and liver injury. Deferoxamine, which chelates iron, interacts with free heme and bears antioxidant properties that prevented oxidative stress, NF-κB activation, neutrophil infiltration, hepatocyte apoptosis, and liver damage. Furthermore, the administration of N-acetylcysteine also prevented NF-κB activation, neutrophil infiltration, hepatocyte apoptosis, and liver damage. Thus, hepatic free heme accumulation, TNFα release, oxidative stress, and NF-κB activation established a link to favor neutrophil infiltration in inducing liver damage during hemolytic conditions in malaria.


Assuntos
Heme/metabolismo , Hemólise , Fígado/fisiopatologia , Malária/fisiopatologia , NF-kappa B/metabolismo , Infiltração de Neutrófilos , Animais , Sequência de Bases , Western Blotting , Primers do DNA , Modelos Animais de Doenças , Ensaio de Desvio de Mobilidade Eletroforética , Heme Oxigenase (Desciclizante)/metabolismo , Marcação In Situ das Extremidades Cortadas , Fígado/metabolismo , Malária/parasitologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Estresse Oxidativo , Plasmodium yoelii/isolamento & purificação , Fator de Necrose Tumoral alfa/sangue , Fator de Necrose Tumoral alfa/metabolismo
13.
J Biol Chem ; 287(29): 24844-61, 2012 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-22645149

RESUMO

Macrophage migration inhibitory factor (MIF) is responsible for proinflammatory reactions in various infectious and non-infectious diseases. We have investigated the mechanism of anti-inflammatory activity of epoxyazadiradione, a limonoid purified from neem (Azadirachta indica) fruits, against MIF. Epoxyazadiradione inhibited the tautomerase activity of MIF of both human (huMIF) and malaria parasites (Plasmodium falciparum (PfMIF) and Plasmodium yoelii (PyMIF)) non-competitively in a reversible fashion (K(i), 2.11-5.23 µm). Epoxyazadiradione also significantly inhibited MIF (huMIF, PyMIF, and PfMIF)-mediated proinflammatory activities in RAW 264.7 cells. It prevented MIF-induced macrophage chemotactic migration, NF-κB translocation to the nucleus, up-regulation of inducible nitric-oxide synthase, and nitric oxide production in RAW 264.7 cells. Epoxyazadiradione not only exhibited anti-inflammatory activity in vitro but also in vivo. We tested the anti-inflammatory activity of epoxyazadiradione in vivo after co-administering LPS and MIF in mice to mimic the disease state of sepsis or bacterial infection. Epoxyazadiradione prevented the release of proinflammatory cytokines such as IL-1α, IL-1ß, IL-6, and TNF-α when LPS and PyMIF were co-administered to BALB/c mice. The molecular basis of interaction of epoxyazadiradione with MIFs was explored with the help of computational chemistry tools and a biological knowledgebase. Docking simulation indicated that the binding was highly specific and allosteric in nature. The well known MIF inhibitor (S,R)-3-(4-hydroxyphenyl)-4,5-dihydro-5-isoxazole acetic acid methyl ester (ISO-1) inhibited huMIF but not MIF of parasitic origin. In contrast, epoxyazadiradione inhibited both huMIF and plasmodial MIF, thus bearing an immense therapeutic potential against proinflammatory reactions induced by MIF of both malaria parasites and human.


Assuntos
Anti-Inflamatórios/farmacologia , Limoninas/farmacologia , Fatores Inibidores da Migração de Macrófagos/farmacologia , Macrófagos/efeitos dos fármacos , Animais , Azadirachta/química , Linhagem Celular , Ensaio de Desvio de Mobilidade Eletroforética , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , NF-kappa B/metabolismo , Óxido Nítrico/metabolismo , Plasmodium falciparum/metabolismo , Plasmodium yoelii/metabolismo
14.
Free Radic Biol Med ; 53(1): 129-42, 2012 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-22588006

RESUMO

We have synthesized a new series of aryl aryl methyl thio arenes (AAMTAs) and evaluated antimalarial activity in vitro and in vivo against drug-resistant malaria. These compounds interact with free heme, inhibit hemozoin formation, and prevent Plasmodium falciparum growth in vitro in a concentration-dependent manner. These compounds concentration dependently promote oxidative stress in Plasmodium falciparum as evident from the generation of intraparasitic oxidants, protein carbonyls, and lipid peroxidation products. Furthermore, AAMTAs deplete intraparasite GSH levels, which is essential for antioxidant defense and survival during intraerythrocytic stages. These compounds displayed potent antimalarial activity not only in vitro but also in vivo against multidrug-resistant Plasmodium yoelii dose dependently in a mouse model. The mixtures of enantiomers of AAMTAs containing 3-pyridyl rings were found to be more efficient in providing antimalarial activity. Efforts have been made to synthesize achiral AAMTAs 17-23 and among them, compound 18 showed significant antimalarial activity in vivo.


Assuntos
Antimaláricos/uso terapêutico , Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Hidrocarbonetos Aromáticos/química , Malária/prevenção & controle , Estresse Oxidativo/efeitos dos fármacos , Plasmodium falciparum/efeitos dos fármacos , Animais , Glutationa/metabolismo , Heme/metabolismo , Malária/parasitologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C
15.
Nucleic Acids Res ; 40(3): 1174-90, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22006844

RESUMO

We have investigated the DNA-binding nature as well as the function of a putative Alba (Acetylation lowers binding affinity) family protein (PfAlba3) from Plasmodium falciparum. PfAlba3 possesses DNA-binding property like Alba family proteins. PfAlba3 binds to DNA sequence non-specifically at the minor groove and acetylation lowers its DNA-binding affinity. The protein is ubiquitously expressed in all the erythrocytic stages of P. falciparum and it exists predominantly in the acetylated form. PfAlba3 inhibits transcription in vitro by binding to DNA. Plasmodium falciparum Sir2 (PfSir2A), a nuclear localized deacetylase interacts with PfAlba3 and deacetylates the lysine residue of N-terminal peptide of PfAlba3 specific for DNA binding. PfAlba3 is localized with PfSir2A in the periphery of the nucleus. Fluorescence in situ hybridization studies revealed the presence of PfAlba3 in the telomeric and subtelomeric regions. ChIP and ChIP ReChIP analyses further confirmed that PfAlba3 binds to the telomeric and subtelomeric regions as well as to var gene promoter.


Assuntos
Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/metabolismo , Plasmodium falciparum , Proteínas de Protozoários/química , Proteínas de Protozoários/metabolismo , Sequência de Aminoácidos , Imunoprecipitação da Cromatina , DNA/química , DNA/metabolismo , Proteínas de Ligação a DNA/análise , Lisina/metabolismo , Modelos Moleculares , Dados de Sequência Molecular , Peptídeos/metabolismo , Ligação Proteica , Proteínas de Protozoários/análise , Proteínas de Ligação a RNA/química , Sirtuína 2/metabolismo , Transcrição Gênica
16.
Bioorg Med Chem ; 19(24): 7365-73, 2011 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-22088307

RESUMO

Macrophage migration inhibitory factor (MIF), a pro-inflammatory cytokine, is involved in the development of an array of inflammatory disorders including rheumatoid arthritis, inflammatory bowel disease, psoriasis, multiple sclerosis and sepsis. The synthesis of MIF-inhibitor is a rationale approach to develop novel anti-inflammatory agent to treat multitude of inflammatory diseases. In this work, we have synthesized and evaluated MIF-inhibitory activity of a series of small molecules containing isoxazoline skeleton. Mode of binding of this inhibitor to human MIF (huMIF) was determined by docking studies. The synthesized molecules inhibit tautomerase activity of huMIF. The anti-inflammatory activity of the most active inhibitor, 4-((3-(4-hydroxy-3-methoxyphenyl)-4, 5-dihydroisoxazol-5-yl) methoxy) benzaldehyde (4b) was evaluated against huMIF-induced inflammation in a cellular model (RAW 264.7 cell). Compound 4b significantly inhibits huMIF-mediated NF-κB translocation to the nucleus, up-regulation of inducible nitric oxide synthase and nitric oxide production in RAW 264.7 cell which are the markers for inflammation. The compound 4b is not cytotoxic as evident from cell viability assay. Hence, the compound 4b has potential to be a novel anti-inflammatory agent.


Assuntos
Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Isoxazóis/química , Isoxazóis/farmacologia , Fatores Inibidores da Migração de Macrófagos/antagonistas & inibidores , Transporte Ativo do Núcleo Celular/efeitos dos fármacos , Animais , Anti-Inflamatórios/síntese química , Sítios de Ligação , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Humanos , Isoxazóis/síntese química , Fatores Inibidores da Migração de Macrófagos/química , Fatores Inibidores da Migração de Macrófagos/imunologia , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Macrófagos/metabolismo , Camundongos , Modelos Moleculares , NF-kappa B/metabolismo , Óxido Nítrico/imunologia , Óxido Nítrico Sintase Tipo II/genética , Óxido Nítrico Sintase Tipo II/imunologia , Regulação para Cima
17.
Free Radic Biol Med ; 50(11): 1659-68, 2011 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-21406224

RESUMO

Plasmodium falciparum macrophage migration inhibitory factor (PfMIF) exhibits thioredoxin (Trx)-like oxidoreductase activity but the active site for this activity and its function have not been evaluated. A bioinformatics search revealed that the conserved CXXC motif, which is responsible for Trx-like oxidoreductase activity, is absent from PfMIF. In contrast, the adjacent N-terminal Cys-3 and Cys-4 are conserved in MIF across species of malarial parasites. Mutation of either vicinal Cys-3 or Cys-4 of PfMIF abolished the Trx-like activity, whereas the mutation of the remaining Cys-59 or Cys-103 did not affect it. PfMIF has an antioxidant function. It prevents reactive oxygen species-mediated lipid peroxidation and oxidative damage of DNA as evident from DNA nicking assay. Interestingly, chemical modification of the vicinal cysteines by phenylarsine oxide (PAO), a specific vicinal thiol modifier, significantly prevented this antioxidant activity. Modification of Cys-3 and Cys-4 was confirmed by MALDI-TOF mass spectroscopy of peptide fragments obtained after cyanogen bromide digestion of PAO-modified PfMIF. Furthermore, mutation of either Cys-3 or Cys-4 of PfMIF resulted in the loss of both Trx-like oxidoreductase and antioxidant activities of PfMIF. Altogether, our results suggest that the vicinal Cys-3 and Cys-4 play a critical role in the Trx-like oxidoreductase activity and antioxidant property of PfMIF.


Assuntos
Cisteína/metabolismo , Eritrócitos/metabolismo , Fatores Inibidores da Migração de Macrófagos/metabolismo , Malária/metabolismo , Plasmodium falciparum/enzimologia , Proteínas de Protozoários/metabolismo , Animais , Arsenicais/farmacologia , Biologia Computacional , Cisteína/química , Cisteína/genética , Dano ao DNA/efeitos dos fármacos , Ativação Enzimática/efeitos dos fármacos , Eritrócitos/parasitologia , Eritrócitos/patologia , Fatores Inibidores da Migração de Macrófagos/química , Malária/genética , Malária/parasitologia , Mutagênese Sítio-Dirigida , Mutação/genética , Estresse Oxidativo/efeitos dos fármacos , Oxirredutases/metabolismo , Plasmodium falciparum/patogenicidade , Proteínas de Protozoários/química , Coelhos , Estereoisomerismo , Tiorredoxinas/química , Tiorredoxinas/metabolismo
18.
Free Radic Biol Med ; 49(2): 258-67, 2010 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-20406680

RESUMO

Nonsteroidal anti-inflammatory drug (NSAID)-induced oxidative stress plays a critical role in gastric mucosal cell apoptosis and gastropathy. NSAIDs induce the generation of hydroxyl radical ((*)OH) through the release of free iron, which plays an important role in developing gastropathy. Thus, molecules having both iron-chelating and antiapoptotic properties will be beneficial in preventing NSAID-induced gastropathy. Gallic acid (GA), a polyphenolic natural product, has the capacity to chelate free iron. Here, we report that GA significantly prevents, as well as heals, NSAID-induced gastropathy. In vivo, GA blocks NSAID-mediated mitochondrial oxidative stress by preventing mitochondrial protein carbonyl formation, lipid peroxidation, and thiol depletion. In vitro, GA scavenges free radicals and blocks (*)OH-mediated oxidative damage. GA also attenuates gastric mucosal cell apoptosis in vivo as well as in vitro in cultured gastric mucosal cells as evident from the TUNEL assay. GA prevents NSAID-induced activation of caspase-9, a marker for the mitochondrial pathway of apoptosis, and restores NSAID-mediated collapse of the mitochondrial transmembrane potential and dehydrogenase activity. Thus, the inhibition of mitochondrial oxidative stress by GA is associated with the inhibition of NSAID-induced mitochondrial dysfunction and activation of apoptosis in gastric mucosal cells, which are responsible for gastric injury or gastropathy.


Assuntos
Anti-Inflamatórios não Esteroides/administração & dosagem , Apoptose , Ácido Gálico/farmacologia , Quelantes de Ferro/farmacologia , Mitocôndrias/efeitos dos fármacos , Gastropatias/tratamento farmacológico , Animais , Anti-Inflamatórios não Esteroides/efeitos adversos , Apoptose/efeitos dos fármacos , Caspase 9/genética , Caspase 9/metabolismo , Células Cultivadas , Ativação Enzimática/efeitos dos fármacos , Ácido Gálico/administração & dosagem , Mucosa Gástrica/efeitos dos fármacos , Mucosa Gástrica/metabolismo , Mucosa Gástrica/patologia , Quelantes de Ferro/administração & dosagem , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias/metabolismo , Carbonilação Proteica/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Gastropatias/induzido quimicamente , Gastropatias/patologia , Gastropatias/fisiopatologia
19.
J Pineal Res ; 46(3): 314-23, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19220725

RESUMO

Augmentation of gastric mucosal cell apoptosis due to development of oxidative stress is one of the main pathogenic events in the development of nonsteroidal anti-inflammatory drug (NSAID)-induced gastropathy. Identification of a nontoxic, anti-apoptotic molecule is warranted for therapy against NSAID-induced gastropathy. The objective of the present study was to define the mechanism of the anti-apoptotic effect of melatonin, a nontoxic molecule which scavenges reactive oxygen species. Using an array of experimental approaches, we have shown that melatonin prevents the development of mitochondrial oxidative stress and activation of mitochondrial pathway of apoptosis induced by indomethacin (a NSAID) in the gastric mucosa. Melatonin inhibits the important steps of indomethacin-induced activation of mitochondrial pathway of apoptosis such as upregulation of the expression of Bax and Bak, and the downregulation of Bcl-2 and BclxL. Melatonin also prevents indomethacin-induced mitochondrial translocation of Bax and prevents the collapse of mitochondrial membrane potential. Moreover, melatonin reduces indomethacin-mediated activation of caspase-9 and caspase-3 by blocking the release of cytochrome c and finally rescues gastric mucosal cells from indomethacin-induced apoptosis as measured by the TUNEL assay. Histologic studies of gastric mucosa further document that melatonin almost completely protects against gastric damage induced by indomethacin. Thus, melatonin has significant anti-apoptotic effects to protect gastric mucosa from NSAID-induced apoptosis and gastropathy, which makes its use as potential therapy against gastric damage during NSAID treatment.


Assuntos
Antioxidantes/farmacologia , Apoptose/efeitos dos fármacos , Mucosa Gástrica/efeitos dos fármacos , Indometacina/farmacologia , Melatonina/farmacologia , Mitocôndrias/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Análise de Variância , Animais , Caspase 3/metabolismo , Caspase 9/metabolismo , Inibidores de Ciclo-Oxigenase/farmacologia , Mucosa Gástrica/citologia , Mucosa Gástrica/metabolismo , Marcação In Situ das Extremidades Cortadas , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Ratos , Ratos Sprague-Dawley , Proteína Killer-Antagonista Homóloga a bcl-2/metabolismo , Proteína X Associada a bcl-2/metabolismo , Proteína bcl-X/metabolismo
20.
J Biol Chem ; 283(21): 14391-401, 2008 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-18375387

RESUMO

We have investigated the mechanism of antiapoptotic and cell renewal effects of lansoprazole, a proton pump inhibitor, to protect and heal gastric mucosal injury in vivo induced by indomethacin, a non-steroidal anti-inflammatory drug (NSAID). Lansoprazole prevents indomethacin-induced gastric damage by blocking activation of mitochondrial and Fas pathways of apoptosis. Lansoprazole prevents indomethacin-induced up-regulation of proapoptotic Bax and Bak and down-regulation of antiapoptotic Bcl-2 and Bcl(xL) to maintain the normal proapoptotic/antiapoptotic ratio and thereby arrests indomethacin-induced mitochondrial translocation of Bax and collapse of mitochondrial membrane potential followed by cytochrome c release and caspase-9 activation. Lansoprazole also inhibits indomethacin-induced Fas-mediated mucosal cell death by down-regulating Fas or FasL expression and inhibiting caspase-8 activation. Lansoprazole favors mucosal cell renewal simultaneously by stimulating gene expression of prosurvival proliferating cell nuclear antigen, survivin, epidermal growth factor, and basic fibroblast growth factor. The up-regulation of Flt-1 further indicates that lansoprazole activates vascular epidermal growth factor-mediated controlled angiogenesis to repair gastric mucosa. Lansoprazole also stimulates the healing of already formed ulcers induced by indomethacin. Time course study of healing indicates that it switches off the mitochondrial death pathway completely but not the Fas pathway. However, lansoprazole heals mucosal lesions almost completely after overcoming the persisting Fas pathway, probably by favoring the prosurvival genes expression. This study thus provides the detailed mechanism of antiapoptotic and prosurvival effects of lansoprazole for offering gastroprotection against indomethacin-induced gastropathy.


Assuntos
2-Piridinilmetilsulfinilbenzimidazóis/farmacologia , Anti-Inflamatórios não Esteroides/farmacologia , Citoproteção/efeitos dos fármacos , Mucosa Gástrica/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Gastropatias/patologia , Receptor fas/metabolismo , Animais , Caspases/metabolismo , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Mucosa Gástrica/lesões , Mucosa Gástrica/metabolismo , Mucosa Gástrica/patologia , Indometacina/farmacologia , Lansoprazol , Microscopia Eletrônica de Transmissão , Mitocôndrias/metabolismo , Ratos , Ratos Sprague-Dawley , Transdução de Sinais , Gastropatias/induzido quimicamente , Gastropatias/metabolismo , Cicatrização/efeitos dos fármacos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA