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1.
J Biomol Struct Dyn ; 41(5): 1904-1918, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-35014594

RESUMO

Leishmania donavani is the causative agent of leishmaniasis, responsible for social and economic disruption, especially in developing countries. Lack of effective drugs with few side effects have necessitated the discovery of newer therapeutic solutions for leishmaniasis. Glycophosphatidylinositol (GPI) synthesis plays a vital role in protozoan cell membranes structural formation and antigenic modification. Hence, any disruption in its biosynthesis can prove fatal to the parasitic protozoans. N-acetylglucosamine-phosphatidylinositol de-N-acetylase (NAGP-deacetylase) is an enzyme from the GPI biosynthetic pathway that catalyzes the deacetylation of N-acetylglucosaminylphosphatidylinositol to glucosaminylphosphatidylinositol, a step essential for the proper functioning of the enzyme. In the quest for novel scaffolds as anti-leishmaniasis agents, we have executed in silico virtual screening, density function theory, molecular dynamics and MM-GBSA based energy calculations with a natural product library and a diverse library set from Chembridge database. Two compounds, 14671 and 4610, were identified at the enzyme's active site and interacted with catalytic residues, Asp43, Asp44, His41, His147, His 150, Arg80 and Arg231. Both molecules exhibited stable conformation in their protein-ligand complexes with binding free energies for compound-14671 and compound-4610 of -54 ± 4 and -50 ± 4 kcal/mol, respectively. These scaffolds can be incorporated in future synthetic determinations, focusing on developing druggable inhibitor support, increasing potency, and introducing species selectivity.Communicated by Ramaswamy H. Sarma.


Assuntos
Leishmania donovani , Acetilesterase/metabolismo , Acetilesterase/farmacologia , Fosfatidilinositóis/metabolismo , Fosfatidilinositóis/farmacologia , Acetilglucosamina/metabolismo , Acetilglucosamina/farmacologia , Simulação de Dinâmica Molecular , Simulação de Acoplamento Molecular
2.
Sci Rep ; 12(1): 8477, 2022 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-35590022

RESUMO

Carbapenemase-producing clinical isolates are becoming more common over the world, posing a severe public health danger, particularly in developing nations like India. Carbapenem-resistant Gram-negative bacterial (CR-GNB) infection has become a fast-expanding global threat with limited antibiotic choice and significant mortality. This study aimed to highlight the carbapenem-resistance among clinical isolates of hospital admitted patients in Bihar, India. A cross-sectional study was conducted with 101 clinical isolates of Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii, and Pseudomonas aeruginosa. All GNB isolates were tested for their antimicrobial susceptibility using Kirby-Bauer disc diffusion method. Double disc synergy test / modified Hodge test (DDST/MHT) were used to detect carbapenemase production by these isolates. Subsequently, these isolates were evaluated for carbapenem-resistance genes using whole-genome sequencing method. The overall percentage of carbapenem-resistance among GNB was (17/101) 16.8%. The genomic analysis of antimicrobial-resistance (AMR) demonstrates a significantly high prevalence of blaCTX-M followed by blaSHV, blaTEM, blaOXA, and blaNDM ß-lactam or carbapenem resistance genes among clinical isolates of GNB. Co-occurrence of blaNDM with other beta-lactamase-encoding genes was found in 70.6% of carbapenemase-producing isolates. Our study highlights the mechanism of carbapenem-resistance to curb the overwhelming threat posed by the emergence of drug-resistance in India.


Assuntos
Infecções Bacterianas , Infecções por Bactérias Gram-Negativas , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Carbapenêmicos/farmacologia , Estudos Transversais , Escherichia coli , Infecções por Bactérias Gram-Negativas/epidemiologia , Infecções por Bactérias Gram-Negativas/microbiologia , Humanos , Índia/epidemiologia , Klebsiella pneumoniae/genética , Testes de Sensibilidade Microbiana , beta-Lactamases/genética
3.
J Biomol Struct Dyn ; 40(24): 13965-13975, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34766876

RESUMO

Pathogenic RNA viruses are emerging as one of the major threats and posing challenges to human community. RNA viruses have an exceptionally shorter generation time and easy to adapt in host cells. The recent emergence of SARS-CoV-2, a long RNA virus, has shown us how difficult it is to overcome this kind of pandemic without understanding the viral infection and replication mechanisms. It is essential to comprehend replications of the viral genome, including RNA polymerization and the final capping process. The mRNAs of SARS-CoV-2 coronaviruses are protected at their 5'-ends by cap structure. The cap-like system plays a significant role in viral translational process, viral RNA stability, and scatting in detecting innate immune recognition in host cells. Two coronavirus enzymes, Nsp14 and Nsp16, critically help in the formation of capping and are considered as potential drug targets for antiviral therapy. Natural and herbal medicines have a past record of treating various acute respiratory diseases. In this work, we have exploited 56000 natural compounds to screen potential inhibitors against NSP16. In silico virtual screening, docking and Molecular Dynamics (MD) simulation studies were performed to understand how these potential inhibitors are bound to NSP16. We observed that the most highly screened compound binds to protein molecules with a high dock score, primarily through hydrophobic interactions and hydrogen bonding, as previously reported for NSP16. Compound-13 (2-hydroxy-N-({1-[2-hydroxy-1-(hydroxymethyl)ethyl]piperidin-3-yl}methyl)-5-methylbenzamide) and compound-51 (N-(2-isobutoxybenzyl)-N,2-dimethyl-2,8-diazaspiro[4.5]decane-3-carboxamide) occupied in active site along with good pharmokinetices properties. In conclusion, the selected compounds could be used as a novel therapeutic against SARS-CoV-2.Communicated by Ramaswamy H. Sarma.


Assuntos
COVID-19 , Metiltransferases , Humanos , Metiltransferases/química , SARS-CoV-2/genética , RNA Viral/genética , Proteínas não Estruturais Virais/química , Simulação de Acoplamento Molecular
4.
Microbiol Spectr ; 9(2): e0079221, 2021 10 31.
Artigo em Inglês | MEDLINE | ID: mdl-34612693

RESUMO

A wastewater surveillance program targeting a university residence hall was implemented during the spring semester 2021 as a proactive measure to avoid an outbreak of COVID-19 on campus. Over a period of 7 weeks from early February through late March 2021, wastewater originating from the residence hall was collected as grab samples 3 times per week. During this time, there was no detection of SARS-CoV-2 by reverse transcriptase quantitative PCR (RT-qPCR) in the residence hall wastewater stream. Aiming to obtain a sample more representative of the residence hall community, a decision was made to use passive samplers beginning in late March onwards. Adopting a Moore swab approach, SARS-CoV-2 was detected in wastewater samples just 2 days after passive samplers were deployed. These samples also tested positive for the B.1.1.7 (Alpha) variant of concern (VOC) using RT-qPCR. The positive result triggered a public health case-finding response, including a mobile testing unit deployed to the residence hall the following day, with testing of nearly 200 students and staff, which identified two laboratory-confirmed cases of Alpha variant COVID-19. These individuals were relocated to a separate quarantine facility, averting an outbreak on campus. Aggregating wastewater and clinical data, the campus wastewater surveillance program has yielded the first estimates of fecal shedding rates of the Alpha VOC of SARS-CoV-2 in individuals from a nonclinical setting. IMPORTANCE Among early adopters of wastewater monitoring for SARS-CoV-2 have been colleges and universities throughout North America, many of whom are using this approach to monitor congregate living facilities for early evidence of COVID-19 infection as an integral component of campus screening programs. Yet, while there have been numerous examples where wastewater monitoring on a university campus has detected evidence for infection among community members, there are few examples where this monitoring triggered a public health response that may have averted an actual outbreak. This report details a wastewater-testing program targeting a residence hall on a university campus during spring 2021, when there was mounting concern globally over the emergence of SARS-CoV-2 variants of concern, reported to be more transmissible than the wild-type Wuhan strain. In this communication, we present a clear example of how wastewater monitoring resulted in actionable responses by university administration and public health, which averted an outbreak of COVID-19 on a university campus.


Assuntos
COVID-19/epidemiologia , Surtos de Doenças , SARS-CoV-2/isolamento & purificação , Universidades , Vigilância Epidemiológica Baseada em Águas Residuárias , Águas Residuárias/virologia , COVID-19/transmissão , COVID-19/virologia , Humanos , Programas de Rastreamento , Ontário , Saúde Pública , SARS-CoV-2/classificação , SARS-CoV-2/genética
5.
Environ Sci Pollut Res Int ; 28(28): 37570-37579, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33715130

RESUMO

Widespread occurrence of various heterocyclic aromatic compounds is reported in concentrations from 1 to 20 µg/L in surface and groundwater as well as influents and effluents of wastewater treatment plants around the world. These so-called emerging contaminants and their metabolites can cause adverse effects on the environment and humans, even at very low concentration, hence raised environmental concerns. In this study, feasibility of soybean peroxidase-catalyzed removal of three selected heterocyclic aromatics from water was investigated, including sensitivity to the most important operational conditions, pH (range 3.6-9.0), H2O2 concentration (range 0.10-1.50 mM), and enzyme activity (range 0.001-5.0 U/mL). 3-Hydroxycoumarin and 2-aminobenzoxaozle were found to be substrates for the enzyme, having ≥95% and 45% removal efficiency with most effective pHs of 7.0 and 6.0, respectively. Time course study was also conducted to determine the initial first-order rate constants and half-lives; half-lives normalized for enzyme activity (0.0257 and 452 min for the respective substrates) are compared with those of 21 other compounds reactive with soybean peroxidase. High-resolution mass spectrometry was employed to characterize the plausible oligomerization products of enzymatic treatment, which revealed formation of dimers and trimers of the two substrates.


Assuntos
Poluentes Químicos da Água , Monitoramento Ambiental , Humanos , Peróxido de Hidrogênio , Peroxidase , Peroxidases , Glycine max , Águas Residuárias/análise , Água , Poluentes Químicos da Água/análise
6.
J Health Pollut ; 10(25): 200307, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32175178

RESUMO

BACKGROUND: Some industrial manufacturing processes generate and release dyes as water pollutants, many of which are toxic and hazardous materials. There is a need for milder, greener methods for dye treatment. OBJECTIVES: The objective of the present study was to investigate and optimize azo dye decoloration by a crude soybean peroxidase (SBP), based on two dyes that have widespread industrial use, but that differ greatly in structural complexity, Acid Black 2 and Acid Orange 7, and to investigate the effects of specific parameters on the removal process. METHODS: Batch reactors were used to remove 95% of the dyes' color and to produce substantial precipitates. RESULTS: The optimum pH for enzymatic decoloration of Acid Black 2 was in the acidic region, pH 4.4, and that of Acid Orange 7 occurred under neutral conditions, pH 6.9. The minimum enzyme activity needed for sufficient removal was 1.2 U/mL for both dyes at 0.5 mM. The minimum molar hydrogen peroxide/substrate ratio was 3 for Acid Orange 7 and 2.5 for Acid Black 2 to achieve approximately 95% removal. First-order fitting of progress curve data collected under the respective optimum conditions gave half-lives of 23.9 and 28.9 minutes for Acid Orange 7 and Acid Black 2, respectively. CONCLUSIONS: The feasibility of SBP-catalyzed treatment of industrial dyes Acid Black 2 and/or Acid Orange 7, or dyes that resemble them, as they might occur in industrial effluents, was successfully demonstrated. COMPETING INTERESTS: The authors declare no competing financial interests.

7.
Artigo em Inglês | MEDLINE | ID: mdl-31494629

RESUMO

Background Subtenon anticancer drugs are given as an adjunct to systemic chemotherapy for conditions like retinoblatoma. This study evaluated the ocular kinetics of nano-emulsion formulation of etoposide (NanoEt) and compared it with an equal dose of commercially available alcohol-based etoposide formulation in healthy rabbits. Methods A nanoemulsion formulation of NanoEt was developed and then evaluated for its ocular kinetics by subtenon administration in healthy rabbits. After the sterile subtenon administration of the drug, the eyes were enucleated after CO2 euthanasia at time intervals of 2 h, 6 h, 12 h, and 24 h, and ocular tissues, blood, and plasma were separated. The concentration of etoposide in the ocular tissues and blood was quantified using liquid chromatography tandem mass spectrometry (LC MS/MS). Results This study found that subtenon injection of NanoEt showed 24 times higher concentration in rabbit retina compared to an equal dose of conventional marketed formulation. Based on the ocular tissue bioavailability calculations (AUC0-24), the present study revealed that the formulation enhanced 90% ocular bioavailability of etoposide, when it was injected in the form of nano-emulsion in most of the tissues. Conclusions NanoEt has better bioavailability compared to the commercial alcohol-based formulation for subtenon injection. Low systemic exposure showed further advantage for its projected use in retinoblastoma (Rb) as an adjunct therapy. Further studies in Rb animal models are required to evaluate its safety and efficacy, for its clinical utility.


Assuntos
Etoposídeo/administração & dosagem , Etoposídeo/farmacocinética , Olho/metabolismo , Animais , Disponibilidade Biológica , Composição de Medicamentos , Emulsões/administração & dosagem , Emulsões/farmacocinética , Feminino , Injeções Intraoculares , Masculino , Nanotecnologia , Coelhos
8.
Chemosphere ; 236: 124246, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31310973

RESUMO

The single-stage biological sulfate reduction process for treatment of heavy metal laden wastewater is a promising treatment method, but the formation of metal precipitates has been suggested to be inhibitory to the activity of sulfate reducers. The present study examined the impact of copper (Cu) precipitates on anaerobic biological sulfate reduction in semi continuous stirred tank reactors (SCSTRs) at 35 ±â€¯2 °C. The results show that Cu precipitates significantly affected the sulfate reduction process. At an HRT of 50 days, steady-state sulfate reduction was approximately 55% at influent Cu concentrations of 0 (control) and 200 mg/L, which reduced to approximately 39% at influent Cu concentration of 400 mg/L. Microbial population (measured as volatile suspended solids) and rate of sulfate reduction were also affected, with reductions observed even at influent Cu of 200 mg/L. Copper precipitates also affected the microbial community diversity distribution.


Assuntos
Anaerobiose/genética , Cobre/química , Metais Pesados/química , Sulfatos/química
9.
Chemosphere ; 235: 365-372, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31265982

RESUMO

The search for an effective and sustainable treatment method to remove the recalcitrant atom-bridged bis-anilino compounds, 4,4'-methylenedianiline (MDA) and 4,4'-thiodianiline (TDA) from water is a major challenge and focus of this study. The escalating discharge of these two toxic and carcinogenic pollutants from industrial sources may pose a serious threat to the environment. Crude soybean peroxidase (SBP), isolated from soybean seed hulls (coats), catalyzes the oxidative polymerization of these aqueous pollutants in the presence of hydrogen peroxide. The effects of several process parameters, i.e., pH, hydrogen peroxide-to-substrate concentration ratio and SBP concentration, were investigated to optimize the performance of enzymatic treatment. The minimum effective SBP concentration required for removal of MDA was 0.70 U/mL, which was higher than that of TDA (0.15 U/mL). The reaction time course to achieve ≥95% removal of these compounds from water was determined under those optimum conditions. Identification of the transformed products was performed by means of high-resolution electrospray ionization mass spectrometry. The products generally observed were protonated oxidized oxidative dimers and higher oligomers (most commonly azo-coupled products). Michaelis constant, KM, and maximum reaction velocity, Vmax, obtained from the Michaelis-Menten (M-M) model revealed that TDA had a 65-fold lower KM than MDA (indicating TDA's higher affinity for SBP), and almost 5-fold higher Vmax than MDA. A pro-forma cost analysis is presented to assess the possibility of commercialization of enzymatic treatment as an alternative to conventional/traditional treatment methods.


Assuntos
Glycine max/enzimologia , Peroxidases/metabolismo , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água/métodos , Compostos de Anilina/isolamento & purificação , Catálise , Peróxido de Hidrogênio , Cinética , Oxirredução , Peroxidases/química , Glycine max/metabolismo , Água , Poluentes Químicos da Água/química
10.
Environ Manage ; 63(3): 408-415, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30607547

RESUMO

Personal care products and pharmaceuticals have been reported in various concentrations in the effluent of municipal sewage treatment plants (STP). Although they are generally found in the nanogram to microgram per liter range, many of them might have adverse health effects on humans at these concentrations. Conventional treatments applied at the STP are unable to effectively remove most of these recalcitrant compounds, thus there is a necessity for development of alternative treatment techniques. In this article, the efficiency of enzymatic treatment using soybean peroxidase in treating some commonly found micropollutants is discussed. The target compounds were, two phenolic surfactant breakdown products, nonylphenol and octylphenol, two antimicrobial agents, Triclosan and sulfamethoxazole and three phenolic steroids. The effects of the most important parameters pH, enzyme concentration and peroxide concentration have been evaluated for each compound. The treatment of synthetic wastewater was shown to be effective (≥95% removal), except for sulfamethoxazole, in concentration ranges of 10 s of µM at neutral pH with 2-5 mU/L of catalytic activity and 2-3 molar equivalents of hydrogen peroxide. The effectiveness of the treatment has also been determined for lower concentrations (6-9 nM) which approximate those in real wastewater. A matrix effect was found in the treatment of Triclosan in spiked real wastewater indicating that re-optimization of important parameters for STP treatment would be required to achieve high removal efficiency. A reverse-phase, solid-phase extraction technique was used to concentrate target analytes in real wastewater, enabling chromatographic detection by UV absorbance.


Assuntos
Águas Residuárias , Poluentes Químicos da Água , Humanos , Peroxidase , Peroxidases , Glycine max , Eliminação de Resíduos Líquidos
11.
Leuk Lymphoma ; 60(2): 418-425, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30124353

RESUMO

Therapeutic drug monitoring of imatinib in patients with chronic myeloid leukemia (CML) is an ongoing debate. We studied the influence of imatinib trough levels on therapeutic response in 206 newly diagnosed patients with CML. We also compared the drug levels in patients taking branded and generic imatinib. Imatinib levels were measured using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Marked inter-individual variability was seen in imatinib levels (coefficient of variation = 69%). Trough levels were significantly higher in patients who attained complete cytogenetic response than those who did not (2213.9 ± 1101 vs. 1648.6 ± 1403.4ng/mL; p < .001). Patients with major molecular response (MMR) had higher trough levels than those without MMR (2333.4 ± 1112 vs. 1643.4 ± 1383.9ng/mL; p = .001). Patients with trough levels ≤1000ng/mL were at high risk for failure of imatinib therapy [RR =1.926; 95%CI (1.562, 2.374); p < .001]. Trough levels emerged as an independent predictor of imatinib response in multivariate analysis. To conclude, imatinib trough levels significantly influence cytogenetic and molecular response and might emerge as a potential biomarker for therapeutic response in CML.


Assuntos
Antineoplásicos/uso terapêutico , Mesilato de Imatinib/uso terapêutico , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Adulto , Antineoplásicos/farmacologia , Biomarcadores Tumorais , Aberrações Cromossômicas , Feminino , Humanos , Mesilato de Imatinib/farmacologia , Leucemia Mielogênica Crônica BCR-ABL Positiva/diagnóstico , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento , Adulto Jovem
12.
Water Environ Res ; 90(8): 675-684, 2018 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-29776461

RESUMO

Representative azo dyes (Acid Blue 113 [AB113] and Direct Black 38 [DB38]) were treated in a single step with soybean peroxidase (SBP) and hydrogen peroxide (H2O2), or in two steps, zero-valent iron (Fe°) pretreatment followed SBP/H2O2. The purpose of this research was to compare both treatment processes and to determine which one was the optimal for degradation of each azo dye. For AB113, the preferred process was the single-step process, 1.0 mM AB113 required 2.5 mM H2O2, 1.5 U/mL SBP at pH 4.0 for ≥ 95% color and dye removal and 30% total organic carbon (TOC) removal. For DB38, due to the products formed after Fe° reduction, which are enzyme substrates (aniline and benzidine; two of four products) a two-step process was preferred, which allowed reduction in the required SBP and H2O2 concentrations by 5- and 2-fold, respectively, compared to a single-step treatment for ≥ 95% color, dye, and aniline/benzidine removal and 88% TOC removal.


Assuntos
Compostos Azo/metabolismo , Glycine max/enzimologia , Ferro , Peroxidases/metabolismo , Compostos Azo/química , Catálise , Poluentes Químicos da Água/química , Poluentes Químicos da Água/metabolismo , Purificação da Água
13.
Pharmacol Res ; 120: 138-145, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28330783

RESUMO

Polymorphisms in genes coding for imatinib transporters and metabolizing enzymes may affect imatinib pharmacokinetics and clinical response. Aim of this study was to assess the influence of polymorphisms in MDR1 and CYP3A5 genes on imatinib trough levels, cytogenetic and molecular response in patients with CML. Newly diagnosed patients with chronic-phase CML started on imatinib therapy were enrolled and followed up prospectively for 24 months. The following single nucleotide polymorphisms were genotyped; C1236T, C3435T, G2677T/A in MDR1 gene and A6986G in CYP3A5 gene. Genotyping was done using PCR-RFLP method and validated by direct gene sequencing. Trough levels of imatinib were measured using LC-MS/MS. Cytogenetic response was assessed by conventional bone-marrow cytogenetics. Molecular response was assessed by qRTPCR using international scale. A total of 173 patients were included, out of which 71 patients were imatinib responders, while 102 were non-responders. Marked inter-individual variability in trough levels of imatinib was seen. Patients with GG genotype for CYP3A5-A6986G (P=0.016) and TT genotype for MDR1-C3435T (P=0.013) polymorphisms had significantly higher trough levels of imatinib. Patients with AA genotype for CYP3A5-A6986G [RR=1.448, 95% CI (1.126, 1.860), P=0.029] and CC genotype for MDR1-C1236T [RR=1.397, 95% CI (1.066, 1.831), P=0.06] &MDR1-C3435T [RR=1.508, 95% CI (1.186, 1.917), P=0.018] polymorphisms were at high risk for failure of imatinib therapy. Patients with CGC haplotype for MDR1 polymorphisms had significantly lower imatinib trough levels and were at a higher risk of imatinib failure [RR=1.547, 95% CI (1.324, 1.808), P<0.001]. GG vs. non-GG genotype for CYP3A5-A6986G [adjusted OR: 0.246; 95% CI (0.116, 0.519); P<0.001] and TT vs. non-TT genotype for MDR1-C1236T [adjusted OR: 0.270; 95% CI (0.110, 0.659); P=0.004] &MDR1-C3435T [adjusted OR: 0.289; 95% CI (0.135, 0.615); P=0.001] polymorphisms were independent factors predicting imatinib response in multivariate analysis. To conclude, MDR1 and CYP3A5 genetic polymorphisms significantly influence plasma trough levels and therapeutic response of imatinib in patients with CML. Genotyping of these polymorphisms could be of value to individualize the therapy and optimize the clinical outcomes.


Assuntos
Antineoplásicos/uso terapêutico , Citocromo P-450 CYP3A/genética , Mesilato de Imatinib/uso terapêutico , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Polimorfismo de Nucleotídeo Único , Subfamília B de Transportador de Cassetes de Ligação de ATP/genética , Adolescente , Adulto , Antineoplásicos/sangue , Feminino , Genótipo , Humanos , Mesilato de Imatinib/sangue , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Adulto Jovem
14.
Drug Des Devel Ther ; 10: 811-23, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26955263

RESUMO

OBJECTIVE: Corneal permeability of drugs is an important factor used to assess the efficacy of topical preparations. Transcorneal penetration of drugs from aqueous formulation is governed by various physiological, physiochemical, and formulation factors. In the present study, we investigated the effect of formulation factors like concentration, pH, and volume of instillation across the cornea using cassette dosing technique for ophthalmic fluoroquinolones (FQs). MATERIALS AND METHODS: Sterile cocktail formulations were prepared using four congeneric ophthalmic FQs (ofloxacin, sparfloxacin, pefloxacin mesylate, and gatifloxacin) at concentrations of 0.025%, 0.5%, and 0.1%. Each formulation was adjusted to different pH ranges (4.5, 7.0, and 8.0) and assessed for transcorneal penetration in vivo in rabbit's cornea (n=4 eyes) at three different volumes (12.5, 25, and 50 µL). Aqueous humor was aspirated through paracentesis after applying local anesthesia at 0, 5, 15, 30, 60, 120, and 240 minutes postdosing. The biosamples collected from a total of 27 groups were analyzed using liquid chromatography-tandem mass spectroscopy to determine transcorneal permeability of all four FQs individually. RESULTS: Increase in concentration showed an increase in penetration up to 0.05%; thereafter, the effect of concentration was found to be dependent on volume of instillation as we observed a decrease in transcorneal penetration. The highest transcorneal penetration of all FQs was observed at pH 7.0 at concentration 0.05% followed by 0.025% at pH 4.5. Lastly, increasing the volume of instillation from 12.5 to 50 µL showed a significant fall in transcorneal penetration. CONCLUSION: The study concludes that formulation factors showed discernible effect on transcorneal permeation; therefore, due emphasis should be given on drug development and design of ophthalmic formulation.


Assuntos
Córnea/metabolismo , Fluoroquinolonas/farmacologia , Soluções Oftálmicas/farmacologia , Animais , Química Farmacêutica , Córnea/efeitos dos fármacos , Relação Dose-Resposta a Droga , Fluoroquinolonas/administração & dosagem , Concentração de Íons de Hidrogênio , Soluções Oftálmicas/administração & dosagem , Permeabilidade/efeitos dos fármacos , Coelhos
15.
Indian J Physiol Pharmacol ; 60(2): 182-192, 2016 04.
Artigo em Inglês | MEDLINE | ID: mdl-29809376

RESUMO

An appropriate model to predict the effect of xenobiotics on the vision perception in neuropsychoharmacological studies is of great importance in drug development and toxicity studies. The present study valuated the effect of CNS stimulant, depressant and therapeutic agents known to have ocular toxicity on ptomotor response (OMR) using goldfish in a newly developed device. A digital light processing aided gyrating poly-chromatic dotted pattern-OMR (Gyro-dot-OMR) analyzer was developed and standardized for this study in our laboratory. Goldfishes were exposed to varying concentrations of caffeine and pentobarbitone sodium to evaluate the effect of CNS stimulation and depression on OMR in white light. Ethambutol induced ocular toxicity was evaluated by intravitreal injection into both eyes of goldfishes. They were subjected for polychromatic Gyro-dot-OMR in both clock and anticlockwise directions. At the low concentration (5, 10 and 20 ng/mL) caffeine exposed animals showed significant (p<0.05) stimulant effect and the EC(50) of caffeine in goldfish was found to be 4.806 ng/mL. In contrast, pentbbarbitone sodium treated fishes showed significant (p<0.05) depressant effect with increasing the concentration. Ethambutol toxicity was reflected by the color iscrimination in the Gyro-dot-OMR pattern. For the first time, this model proved the possibility of running Irwin profile test on goldfish using Gyro-dot-OMR. This model successfully predicted ethambutol induced toxicity with poor discrimination of red-green color. This model can be used for predicting toxicity of drugs affecting vision perception.


Assuntos
Avaliação Pré-Clínica de Medicamentos/instrumentação , Etambutol/toxicidade , Olho/efeitos dos fármacos , Carpa Dourada , Testes de Toxicidade/instrumentação , Percepção Visual/efeitos dos fármacos , Animais , Cafeína/farmacologia , Percepção de Cores/efeitos dos fármacos , Avaliação Pré-Clínica de Medicamentos/métodos , Desenho de Equipamento , Feminino , Processamento de Imagem Assistida por Computador , Locomoção , Masculino , Fenobarbital/farmacologia , Estimulação Luminosa , Reprodutibilidade dos Testes , Testes de Toxicidade/métodos
16.
Indian J Physiol Pharmacol ; 60(3): 268-81, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-29957983

RESUMO

To study the protective effect of NMDA and non-NMDA receptor antagonists against ethambutol (EMB) induced retinal toxicity in Wistar rats using flash electroretinogram (ERG). Rats were randomized into four groups: Group-1 received vehicle. Group-2 received oral EMB (200 mg/kg/day). Group-3 and 4 were fed with oral EMB along with memantine (MEM) (1 mg/kg, ip) and trimetazidine (TMZ) (3mg/kg, ip) respectively. All treatments were continued up to 28 days. ERG was recorded at 0 and 21st day using green and white lights. Ethambutol and 2, 2' ethylene diimino dibutyric acid (EDBA) levels were quantified in rat body fluids and tissues using LC-MS/MS. A higher rate of rat mortality was observed between 21st and 28th day, 21st day considered for ERG recording among groups. Ethambutol did not cause any significant change in 'a'-wave amplitude of rat ERG but caused a predictable decrease in 'b'-wave amplitude of the rat ERG on the 21st day. Memantine treatment showed a significant (P=0.029) protection against the fall of 'b'-wave amplitude on 21st day. Interestingly, we found that plasma levels of EMB in memantine treated rats were significantly reduced when compared to the positive control group. Memantine reversed the effects of EMB on 'b'-wave of rat ERG suggests its protective role. We suggest MEM may be considered as a possible preventive treatment modality for EMB induced vision toxicity warranting further clinical investigations.


Assuntos
Eletrorretinografia , Etambutol/toxicidade , Memantina/farmacologia , Receptores de N-Metil-D-Aspartato/antagonistas & inibidores , Doenças Retinianas/induzido quimicamente , Trimetazidina/farmacologia , Animais , Etambutol/sangue , Etambutol/metabolismo , Etilenodiaminas/sangue , Etilenodiaminas/metabolismo , Antagonistas de Aminoácidos Excitatórios/farmacologia , Feminino , Masculino , Ratos , Ratos Wistar , Doenças Retinianas/prevenção & controle , Vasodilatadores/farmacologia
17.
Asian Pac J Trop Biomed ; 4(Suppl 1): S129-38, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-25183067

RESUMO

OBJECTIVE: To evaluate the antiangiogenic potential of twenty two marine invertebrate species of Phylum Mollusca from south east coast of India. METHODS: Live specimens of molluscan species were collected and their methanolic extracts were evaluated for preliminary antiangiogenic activity using the in ovo chick chorio-allantoic membrane assay. The extracts were further evaluated for in vivo antiangiogenic activity using chemical cautery induced corneal neovascularization assay in rats and oxygen induced retinopathy assay in rat pups. RESULTS: In the chick chorio-allantoic membrane assay, four methanolic extracts of marine molluscan species viz. Meretrix meretrix, Meretrix casta, Telescopium telescopium and Bursa crumena methanolic extracts exhibited noticeable antiangiogenic activity at the tested concentration of 200 µg whereby they significantly inhibited the VEGF induced proliferation of new blood vessels. Among these four extracts, the methanolic extract of Meretrix casta exhibited relatively higher degree of antiangiogenic activity with an inhibitiory percentage (64.63%) of the VEGF induced neovascularization followed by the methanolic extracts of Telescopium telescopium (62.02%), Bursa crumena (60.48%) and Meretrix meretrix (47.01%). These four methanolic extracts were further evaluated for in vivo antiangiogenic activity whereby the methanolic extract of Telescopium telescopium exhibited most noticeable inhibition (42.58%) of the corneal neovascularization in rats in comparison to the sham treated group, and also exhibited most noticeable inhibition (31.31%) of the oxygen induced retinal neovascularization in rat pups in comparison to the hyperoxia group that was observed for considerable retinal neovascularization. CONCLUSIONS: The significant antiangiogenic activity evinced by the extract of Telescopium telescopium merits further investigation for ocular neovascular diseases.

18.
Enzyme Microb Technol ; 55: 65-71, 2014 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-24411447

RESUMO

Soybean peroxidase (SBP)-catalyzed removal of phenol from wastewater has been demonstrated as a feasible wastewater treatment strategy and a non-ionic surfactant, Triton X-100, has the potential for increasing the enzyme economy of the process. Systematic studies on the enzyme-surfactant system have been lacking as well as demonstration of its applicability to industrial wastewater. This paper addresses those two gaps, the latter based on real wastewater from alkyd resin manufacture. The minimum effective Triton X-100 concentrations for crude SBP-catalyzed phenol conversion (≥95%) over 1-10 mM showed a linear trend. To illustrate translation of such lab results to real-world samples, this data were used to optimize crude SBP needed for phenol conversion over that concentration range. Triton X-100 increases enzyme economy by 10- to 13-fold. This treatment protocol was directly applied to tote-scale (700-1000 L) treatment of alkyd resin wastewater, with phenol ranging from 7 to 28 mM and total organic carbon content of >40 g/L, using a crude SBP extract derived from dry soybean hulls by simple aqueous elution. This extract can be used to remove phenol from a complex industrial wastewater and the process is markedly more efficient in the presence of Triton X-100. The water is thus rendered amenable to conventional biological treatment whilst the hulls could still be used in feed, thus adding further value to the crop.


Assuntos
Glycine max/enzimologia , Octoxinol/farmacologia , Peroxidase/metabolismo , Fenol/metabolismo , Proteínas de Plantas/metabolismo , Tensoativos/farmacologia , Poluentes Químicos da Água/metabolismo , Ração Animal , Biodegradação Ambiental , Carbono/análise , Indústria Química , Relação Dose-Resposta a Droga , Peroxidase/isolamento & purificação , Proteínas de Plantas/isolamento & purificação , Sementes/enzimologia , Águas Residuárias/análise , Purificação da Água/métodos
19.
Exp Eye Res ; 116: 27-35, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23892056

RESUMO

The present study was conducted to test the hypothesis; OCT may be active from blood-to-vitreous for the uptake of its substrates. Ocular uptake of Tetraethylammonium (TEA) across blood ocular barriers and the tissue distribution was evaluated in vivo in New Zealand albino rabbits after intravenous administration. Quinidine (blocker) pretreatment resulted in a significant (p < 0.05) reduction in the Area Under the Curve (AUC) of TEA in vitreous (4.2 fold) and aqueous humor (1.8 fold) as compared to the control group which supports the role of OCT in uptake transport of its substrate across Blood ocular barrier. The blockade of OCT also affected the elimination of its substrate resulting in increased plasma levels. In most of the tissues, OCT are functionally present from apical to basolateral. The gene expression studies also showed the presence of OCT1, OCTN1 and OCTN2 in various ocular tissues studied. The present findings suggest that OCT are functionally active in blood ocular barriers and involved in the transport of its substrate from blood-to-vitreous humor.


Assuntos
Barreira Hematorretiniana/fisiologia , Proteínas de Transporte de Cátions/metabolismo , Oftalmopatias/tratamento farmacológico , Tetraetilamônio/farmacocinética , Animais , Humor Aquoso/metabolismo , Transporte Biológico , Proteínas de Transporte de Cátions/genética , Cromatografia Líquida , Modelos Animais de Doenças , Oftalmopatias/metabolismo , Regulação da Expressão Gênica , Injeções Intravenosas , Bloqueadores dos Canais de Potássio/administração & dosagem , Bloqueadores dos Canais de Potássio/farmacocinética , RNA/genética , Coelhos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Tetraetilamônio/administração & dosagem , Distribuição Tecidual , Corpo Vítreo/metabolismo
20.
BMC Complement Altern Med ; 13: 1, 2013 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-23280361

RESUMO

BACKGROUND: The polyherbal eye drop (Itone™) is a mixture of aqueous distillates of nineteen traditionally used ingredients that sum up to impart potency to the formulation and make it a useful adjunct in various ocular pathologies. However, as there have been no controlled experimental studies accounting to the above claim, therefore, the present study was designed to evaluate the polyherbal formulation (PHF) for antiangiogenic, anti-inflammatory, anticataract, antioxidant and cytotoxicity in addition to the evaluation of intraocular penetration of PHF in rabbit eyes using LC-MS/MS. MATERIALS AND METHODS: Antiangiogenic activity of the PHF was evaluated using in ovo chick chorio-allantoic membrane (CAM) assay and in vivo cautery induced corneal neovascularization assay in rats. Anticataract potential was evaluated using steroid induced cataract in developing chick embryos, sodium selenite induced cataract in rat pups and galactose induced cataract in rats. The antioxidant activity was evaluated using di-phenyl picryl hydrazyl (DPPH) radical scavenging assay. Anti-inflammatory activity was evaluated in vitro using inhibition of LTB4 formation in human WBCs and in vivo using carrageenan induced paw edema assay in rats. The cytotoxicity was evaluated against HeLa cancer cell lines using (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Furthermore evaluation of the intraocular penetration of the PHF was carried out in rabbit eyes via aqueous humor paracentesis and further analysis using LC-MS/MS. RESULTS: PHF significantly inhibited VEGF induced proliferation of new blood vessels in CAM assay and inhibited the cautery induced corneal neovascularization in rats. Additionally, PHF showed noticeable delay in the progression of cataract in the selenite and galactose induced cataract models whereby the PHF treated lenses were graded for stages II and III respectively. However, the PHF did not show any anticataract activity in the hydrocortisone induced cataract model. Moreover, PHF exhibited anti-inflammatory activity whereby it showed 39.34% inhibition of LTB4 formation and significantly inhibited carrageenan induced paw edema in rats. Eight compounds of PHF viz. camphor, casticin, curcumin-II, quercetin, rosmarinic acid, γ-terpinene, ß-pinene and dipentene exhibited transcorneal penetration in rabbit eyes. CONCLUSION: The significant antiangiogenic and anti-inflammatory activities evinced by the PHF merits further investigation for ocular neovascular and inflammatory diseases in humans.


Assuntos
Inibidores da Angiogênese/uso terapêutico , Anti-Inflamatórios/uso terapêutico , Catarata/prevenção & controle , Olho/efeitos dos fármacos , Soluções Oftálmicas/uso terapêutico , Fitoterapia , Extratos Vegetais/uso terapêutico , Inibidores da Angiogênese/farmacologia , Animais , Anti-Inflamatórios/farmacologia , Humor Aquoso/efeitos dos fármacos , Humor Aquoso/metabolismo , Compostos de Bifenilo/metabolismo , Vasos Sanguíneos/efeitos dos fármacos , Carragenina , Catarata/induzido quimicamente , Embrião de Galinha , Córnea/irrigação sanguínea , Córnea/efeitos dos fármacos , Edema/induzido quimicamente , Edema/tratamento farmacológico , Olho/metabolismo , Olho/patologia , Feminino , Galactose , Células HeLa , Humanos , Hidrocortisona , Inflamação/induzido quimicamente , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Cristalino/efeitos dos fármacos , Cristalino/patologia , Leucócitos/efeitos dos fármacos , Leucócitos/metabolismo , Leucotrieno B4/metabolismo , Masculino , Ayurveda , Modelos Animais , Soluções Oftálmicas/química , Picratos/metabolismo , Extratos Vegetais/farmacologia , Coelhos , Ratos , Ratos Wistar , Selenito de Sódio , Esteroides , Fator A de Crescimento do Endotélio Vascular/metabolismo
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