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1.
Bull World Health Organ ; 101(6): 412-417, 2023 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-37265675

RESUMO

Modern health-care facilities rely on medical devices and equipment. However, keeping up with the development of new technology is unfeasible for many health facilities, especially in low-resource settings. Thus, the demand for refurbished medical devices is increasing worldwide, especially in low- and middle-income countries. Refurbished medical devices are restored devices that are rebuilt to meet safety and performance requirements comparable to their condition when new, without changing the intended use of the original device. While new medical devices are controlled by well-established and stringent safety and quality regulations, a great variation in the regulations of refurbished medical devices exists across countries. Here we discuss the different regulations and practices specific to refurbished medical devices in countries of major markets. We also explore the opportunities and challenges for expanding the refurbished medical device market. Finally, we suggest that regulatory guidelines pertaining to the import, sale, labelling and use of a refurbished medical product are needed, and authorities should implement these guidelines to ensure a high quality and safety standard of refurbished devices.


Les établissements de soins de santé modernes dépendent d'équipements et dispositifs médicaux. Pour nombre de ces établissements, il est toutefois impossible de suivre l'évolution des nouvelles technologies, surtout dans les lieux manquant de ressources. La demande en dispositifs médicaux remis à neuf est donc en hausse partout dans le monde, en particulier dans les pays à revenu faible et intermédiaire. Il s'agit de dispositifs restaurés, remaniés pour répondre aux mêmes exigences de sécurité et de performances que lorsqu'ils sont neufs, sans que l'usage prévu du dispositif d'origine ne soit modifié. Alors que les dispositifs médicaux neufs sont soumis à des normes de qualité et de sécurité strictes et bien établies, leurs équivalents restaurés font l'objet de règles nettement plus variables d'un pays à l'autre. Dans le présent document, nous évoquons les différentes réglementations et pratiques spécifiques aux dispositifs médicaux remis à neuf dans les pays qui abritent les principaux marchés. Nous nous intéressons en outre aux opportunités et aux défis liés à un développement du marché des dispositifs médicaux remis à neuf. Enfin, nous suggérons l'adoption de lignes directrices réglementaires concernant l'importation, la vente, l'étiquetage et l'utilisation de tels dispositifs; ces lignes directrices sont à faire appliquer par les autorités afin de garantir les normes les plus élevées en matière de qualité et de sécurité.


Los centros sanitarios modernos dependen de dispositivos y equipos médicos. Sin embargo, mantenerse al día en el desarrollo de las nuevas tecnologías no es viable para muchos centros sanitarios, sobre todo en los de escasos recursos. Por este motivo, la demanda de dispositivos médicos renovados está aumentando en todo el mundo, especialmente en los países de ingresos bajos y medios. Los dispositivos médicos renovados son dispositivos restaurados que se reconstruyen para que cumplan unos requisitos de seguridad y rendimiento comparables a los que tenían cuando eran nuevos, sin cambiar el uso previsto del dispositivo original. Mientras que los dispositivos médicos nuevos están sujetos a reglamentos estrictos y bien establecidos en materia de seguridad y calidad, los reglamentos de los dispositivos médicos renovados varían mucho de un país a otro. En este artículo, se analizan los diferentes reglamentos y prácticas específicos de los dispositivos médicos renovados en los países de los principales mercados. También se exploran las oportunidades y los desafíos que plantea la expansión del mercado de dispositivos médicos renovados. Por último, se propone que se establezcan directrices reglamentarias relativas a la importación, venta, etiquetado y uso de los dispositivos médicos renovados y que las autoridades las apliquen para asegurar su calidad y seguridad.


Assuntos
Equipamentos Médicos Duráveis , Reutilização de Equipamento , Regulamentação Governamental , Equipamentos Médicos Duráveis/normas , Reutilização de Equipamento/legislação & jurisprudência , Reutilização de Equipamento/normas
3.
Front Public Health ; 10: 930696, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36062131

RESUMO

Adverse drug reactions (ADRs) are major concerns to the public health. To monitor ADRs and ensure patients' safety, the Pharmacovigilance Programme of India (PvPI) has been established by the Government of India in 2010. The programme is intact with the Public-Private Partnership (3Ps) in pharmacovigilance for quality services, better management of human resources and risk minimization. The present work is aimed at assessing the 3Ps engagement, performance and tangible outcomes in PvPI and also mapping of resources. The study was carried out for the period of 2011 to 2021 by assessing the various benchmarking tools such as 3Ps categorization, utilization of ADRs reporting tools, trainings, and the Individual Case Safety Reports' (ICSRs) quantity, quality and transmission for regulatory intervention (RI). Under PvPI, Central or State Government medical institutions/hospitals and public health programmes constitute public partners while private medical institutions/hospitals, pharmaceutical companies, corporate hospitals and professional bodies account for private partners. We observed that public partners extensively used ADR reporting form and toll-free helpline number while private partners used mobile based app and emails/post as preferred tools for reporting ADRs. Contribution of public sector in training programmes organized, stakeholders trained and sharing of resource materials was way higher than the private sector. The study revealed that 55.1 and 44.9% ICSRs were received from public and private partners, respectively during the study period. The quality completeness of data received from public partners was found to be 0.92/1 as compared to 0.46/1 from the private partners. The ICSRs data transmitted for RI process from the public and private partners (till 2018) was found to be 79 and 21%, respectively. In terms of sharing of resources for training and capacity building, the public sector played a major role. The 3Ps in India are enabled to establish a robust system for medicines' safety surveillance; however a more focused approach is required in mapping the resources.


Assuntos
Sistemas de Notificação de Reações Adversas a Medicamentos , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Humanos , Farmacovigilância , Saúde Pública , Parcerias Público-Privadas
4.
Graefes Arch Clin Exp Ophthalmol ; 260(7): 2103-2110, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35122500

RESUMO

BACKGROUND: Acute retinal toxicity has been demonstrated to be associated with the intraoperative use of perfluorocarbon liquids (PFCLs), especially perfluorooctane (PFO). Recently, several cases of PFO-associated blindness have been reported in Spain, Holland, France, Italy, the Middle East, and South America. METHODS: As a result, a new ISO guideline (ISO 16672:2020) was drafted, discussed, approved, and released in 2019. This recent ISO16672:2020 guideline recommends performing direct cytotoxicity tests as an option along with chemical analysis to measure PFCL quality (purity and safety). RESULTS: In this review paper, it has been emphasized why an appropriate biological test, specifically direct exposure of PFCL to live cells, for measuring cytotoxicity must be performed with each PFCL batch along with chemical analysis. CONCLUSIONS: The paper intends to compile all available information to discuss possible approaches for avoiding adverse clinical cases in future.


Assuntos
Fluorocarbonos , Descolamento Retiniano , Fluorocarbonos/toxicidade , França , Humanos , Itália , Oriente Médio , Descolamento Retiniano/induzido quimicamente , Descolamento Retiniano/cirurgia , Espanha
5.
Plants (Basel) ; 10(9)2021 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-34579444

RESUMO

Morusflavone, a flavonoid from Morus alba L., was evaluated for its interactive ability and stability with CYP17A1, in comparison with abiraterone, which is a Food and Drug Administration (FDA)-approved CYP17A1 inhibitor. CYP17A1 inhibition is an important therapeutic target for prostate cancer. The CHAMM36 force field was used to perform molecular dynamics (MD) simulations in this study. The results show that Morusflavone has significant interactive ability and stability for CYP17A1, in comparison with abiraterone. The final interaction energies for the Morusflavone-CYP17A1 and abiraterone-CYP17A1 complexes were -246.252 KJ/mol and -207.86 KJ/mol, respectively. Since there are only limited therapeutic agents available, such as abiraterone, galeterone, and seviteronel, which are being developed for prostate cancer, information on any potent natural anticancer compounds, such as vinca alkaloids, for prostate cancer treatment is limited. The results of this study show that CYP17A1 inhibition by Morusflavone could be an important therapeutic target for prostate cancer. Further preclinical and clinical evaluations of the lead compound Morusflavone are required to evaluate whether it can serve as a potential inhibitor of CYP17A1, which will be a new hope for prostate cancer treatment.

6.
Seizure ; 91: 332-338, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34274893

RESUMO

PURPOSE: Diverse ethnic genetic populations display variability in the risk regarding anti-seizure medicine (ASM)-induced severe cutaneous adverse reactions (SCARs). However, clinical and epidemiological data on ASM-induced SCARs in Asians is limited. METHODS: We conducted a retrospective, post-market study until April 30, 2020 using VigiBase® for demographic characteristics, causative ASMs, complications and mortality. The study included adverse events as classified by Standardized Medical Dictionary for Regulatory Activities (MedDRA) queries of SCARs, mainly Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), drug rash with eosinophilia and systemic symptoms (DRESS), and SJS/TEN overlap reported for ASMs. RESULTS: A total of 694,811 adverse events were reported across the world while using ASMs. Of this, skin and subcutaneous tissue adverse events were 122,885 (17.6%). Among ASM-induced skin and subcutaneous tissue adverse events, SJS, TEN, DRESS and SJS/TEN overlap represented 11,181 (9.1%), 3,645 (3.0%), 5,106 (4.1%) and 6 (0.004%) cases, respectively. Female SJS/TEN/DRESS patients were 54.1%, and 75% of them were adults (>18Y). Nearly 64% of the ASM-induced SCARs were serious and culminated in death (3.5%), life-threatening conditions (11.5%), and hospitalization/prolonged hospitalization (43.5%) of patients on ASM therapy. Carbamazepine (31.6%), phenytoin (29.6%), lamotrigine (24.3%), valproic acid (6.4%) and phenobarbital (5.7%) are the most commonly used ASMs linked with SCARs. ASMs associated with significantly higher risk of SCARs in Asians were carbamazepine [n = 3265, ROR 3.55 (95% CI 3.38-3.72, P < 0.0001)], lamotrigine [n = 1253, ROR 3.90 (95% CI 3.63-4.18, P < 0.0001)], gabapentin [n = 85, ROR 3.58 (95% CI 2.79-4.60, P < 0.0001)], pregabalin [n = 68, ROR 3.16 (95% CI 2.40-4.16, P < 0.0001)], clonazepam [n = 53, ROR 3.19 (95% CI 2.31-4.41, P < 0.0001)], lorazepam [n = 31, ROR 3.07 (95% CI 2.06-4.59, P < 0.0001)] and acetazolamide [n = 28, ROR 3.90 (95% CI 2.45-6.21, P < 0.0001)]. CONCLUSION: Based on our study, carbamazepine, lamotrigine, gabapentin, pregabalin, clonazepam, lorazepam, and acetazolamide are the most common causative ASMs for SCARs in the Asian population.


Assuntos
Síndrome de Stevens-Johnson , Adulto , Anticonvulsivantes/efeitos adversos , Povo Asiático , Feminino , Humanos , Fenitoína/efeitos adversos , Estudos Retrospectivos , Síndrome de Stevens-Johnson/epidemiologia , Síndrome de Stevens-Johnson/etiologia
8.
Toxicol Appl Pharmacol ; 395: 114976, 2020 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-32222375

RESUMO

Filgrastim, a biopharmaceutical listed on WHO model list of essential medicines, was approved in USA in 1991 for patients with non-myeloid malignancies associated with severe neutropenia and fever. Several filgrastim biosimilars have now been approved in USA, Europe and elsewhere since 2008, based on the reference product which has lost patent exclusivity; however their immunogenicity and safety is controversial. We conducted a retrospective, post market study between 1991 and May 2018 using VigiBase®. The study included all adverse events with case reports ≥150. Overall, 11,183 adverse drugs reaction reports were identified during observation period; of which 5764; 51.5% reports concerned to Neupogen®, the originator, and rest consists of Leucostim® (N = 680), Zarzio® (N = 622), Grasin® (N = 545), Nivestim® (N = 359) and Tevagrastim® (N = 152) biosimilars. When compared with the originator, Grasin® was associated with higher reporting of pyrexia (11.5% vs 7.9%, ROR 1.52, IC025 1.12), myalgia (37% vs 2.2%, ROR 25.94, IC025 2.11) and back pain (11.3% vs 4%, ROR 3.09, IC025 2.32). Zarzio® was associated with increased reporting of arthralgia (4.5% vs 2.9%, ROR 1.59, IC025 1.25) and neutropenia (11.4% vs 4%, ROR 2.59, IC025 3.07). Bone pain was reported more often with Nivestim® (14.4% vs 8.3%, ROR 1.87, IC025 5.30). Drug ineffectiveness was reported in cases with Zarzio® (35.9%), Nivestim® (19.4%) and Tevagrastim® (42.2%). Authors observed significant differences among originator and biosimilars in particular to efficacy, adverse events reported and time to onset of occurrences. Large epidemiologic studies are needed to further confirm these finding and provide additional insights.


Assuntos
Antineoplásicos/efeitos adversos , Medicamentos Biossimilares/efeitos adversos , Neutropenia Febril/tratamento farmacológico , Filgrastim/efeitos adversos , Fator Estimulador de Colônias de Granulócitos , Adolescente , Adulto , Criança , Pré-Escolar , Aprovação de Drogas , Neutropenia Febril/induzido quimicamente , Feminino , Filgrastim/uso terapêutico , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Farmacovigilância , Estudos Retrospectivos , Adulto Jovem
9.
Bull World Health Organ ; 98(3): 206-211, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-32132755

RESUMO

PROBLEM: Rapid growth in the use of medical devices has drawn attention to gaps in the systematic monitoring of medical device-associated adverse events in India. APPROACH: Implementation of national regulations on medical devices started in January 2018. Supported by a nationwide network of monitoring centres, the Indian Pharmacopoeia Commission coordinates adverse event reports from manufacturers, legal representatives and patients or users. The commission follows-up and reviews reports with subject expert groups and sends recommendations on necessary action to the national regulatory authority. LOCAL SETTING: Before 2015, no systematic structure was in place to collate adverse events associated with medical devices. Several reports of deaths and hospitalization due to faulty hip implants, cardiac stents and poor-quality devices prompted the health ministry to launch the materiovigilance programme. RELEVANT CHANGES: From July 2015 to October 2019, the commission received 1931 adverse event reports, mostly from marketing authorization holders; 1277 were serious events. Reporting increased markedly after 2017. Cardiac stents were the most reported device (926 events; 47.95%). To encourage a culture of reporting, the commission has raised awareness about the programme among stakeholders, developed user-friendly reporting tools and guidelines, and conducted training for hospital personnel on medical device adverse event reporting. LESSONS LEARNT: Regular training to stakeholders develops a sense of responsibility towards reporting medical device adverse events and ensures quality data reporting. Reporters must be assured that reporting adverse events does not have any legal implications for them and given acknowledgement of their role in high-quality device associated adverse event reporting.


Assuntos
Equipamentos e Provisões/efeitos adversos , Equipamentos e Provisões/estatística & dados numéricos , Gestão da Segurança/estatística & dados numéricos , Segurança de Equipamentos , Humanos , Índia , Notificação de Abuso , Vigilância de Produtos Comercializados , Sistema de Registros , Gestão da Segurança/legislação & jurisprudência
11.
Drug Discov Today ; 24(1): 148-162, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30296551

RESUMO

Exquisite selectivity, remarkable efficacy, and minimal toxicity are key attributes inherently assigned to peptides, resulting in increased research interest from the pharmaceutical industry in peptide-based therapeutics (PbTs). Pharmacopoeias develop authoritative standards for PbT by providing standard specifications and test methods. Nevertheless, a lack of harmonization in test procedures adopted for PbT in the latest editions of Pharmacopoeias has been observed. Adoption of a harmonized monograph could increase further the interest of the global pharmaceutical industry in PbTs. Here, we provide an overview of pharmacopoeial methodologies and specifications commonly observed in PbT monographs and highlight the main differences among the pharmacopoeias in terms of the active pharmaceutical ingredients that they focus on. We also address the prospects for PbTs to mature as a new therapeutic niche.


Assuntos
Nanoestruturas/uso terapêutico , Peptídeos/uso terapêutico , Animais , Humanos , Legislação de Medicamentos , Farmacopeias como Assunto
12.
Toxicol Appl Pharmacol ; 347: 92-103, 2018 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-29626488

RESUMO

Pleckstrin homology domain leucine-rich repeat protein phosphatase 2 (PHLPP2) has been known to exert tumor suppressive activity for long without much knowledge about its regulation and implications. Protein kinase B (Akt), Protein kinase C (PKC) and Ribosomal protein S6 Kinase (S6K) are known downtargets of PHLPP2, regulating a plethora of life processes viz. cell growth, survival and evasion from apoptosis. Present study decoded the crucial role of PHLPP2 in inducing apoptosis by its interaction with the newly found binding partner Mammalian sterile 20-like kinase 1 (Mst1) in berberine (BBR)-treated human hepatoma cells. HepG2 cells were exposed to (50 µM, 100 µM) berberine for different time intervals (18 h, 24 h). The results showed enhanced expression of PHLPP2 at transcriptional (2.13 fold, P < 0.01) and translational level (4 fold, P < 0.001), but not of PHLPP1, in berberine-treated HepG2 cells. Elevated expression of PHLPP2 was reported to inactivate Akt by dephosphorylating it on Ser473 (P < 0.001). As Akt is known to inhibit apoptotic effect of Mst1, we found that PHLPP2 mediated inactivation of Akt releases its repression from Mst1 leading to heightened phosphorylation of Mst1 on its activating site Thr183 (1.5 fold, P < 0.001). Consequently, coordination between PHLPP2, Akt and Mst1 stimulated downstream targets c-jun N-terminal kinase (JNK), Bim and Bak which are direct activators of pro-apoptotic proteins leading to cell death. Further, PHLPP2/Mst1 knock-down efficiently curtailed anti-proliferative effect of berberine by restoring the basal level of downstream anti-apoptotic proteins. In addition, pre-treatment of NAC (5 mM) showed that ROS generation was a primitive event to initiate activation of stress kinases. Thus, our findings suggest that PHLPP2, Akt and Mst1 constitute an autoinhibitory triangle which may be partly responsible for antiproliferative effect of berberine.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Apoptose/efeitos dos fármacos , Berberina/farmacologia , Carcinoma Hepatocelular/tratamento farmacológico , Neoplasias Hepáticas/tratamento farmacológico , Mitocôndrias/efeitos dos fármacos , Fosfoproteínas Fosfatases/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteína 11 Semelhante a Bcl-2/genética , Proteína 11 Semelhante a Bcl-2/metabolismo , Carcinoma Hepatocelular/enzimologia , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Células Hep G2 , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Neoplasias Hepáticas/enzimologia , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Mitocôndrias/enzimologia , Mitocôndrias/patologia , Fosfoproteínas Fosfatases/genética , Fosforilação , Proteínas Serina-Treonina Quinases/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos dos fármacos , Fatores de Tempo , Proteína Killer-Antagonista Homóloga a bcl-2/genética , Proteína Killer-Antagonista Homóloga a bcl-2/metabolismo
13.
Eur J Cell Biol ; 96(8): 728-738, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29100606

RESUMO

BH3-only proteins constitute major proportion of pro-apoptotic members of B-cell lymphoma 2 (Bcl-2) family of apoptotic regulatory proteins and participate in embryonic development, tissue homeostasis and immunity. Absence of BH3-only proteins contributes to autoimmune disorders and tumorigenesis. Bim (Bcl-2 Interacting Mediator of cell death), most important member of BH3-only proteins, shares a BH3-only domain (9-16 aa) among 4 domains (BH1-BH4) of Bcl-2 family proteins and highly pro-apoptotic in nature. Bim initiates the intrinsic apoptotic pathway under both physiological and patho-physiological conditions. Reduction in Bim expression was found to be associated with tumor promotion and autoimmunity, while overexpression inhibited tumor growth and drug resistance as cancer cells suppress Bim expression and stability. Apart from its role in normal homeostasis, Bim has emerged as a central player in regulation of tumorigenesis, therefore gaining attention as a plausible target for chemotherapy. Regulation of Bim expression and stability is complicated and regulated at multiple levels viz. transcriptional, post-transcriptional, post-translational (preferably by phosphorylation and ubiquitination), epigenetic (by promoter acetylation or methylation) including miRNAs. Furthermore, control over Bim expression and stability may be exploited to enhance chemotherapeutic efficacy, overcome drug resistance and select anticancer drug regimen as various chemotherapeutic agents exploit Bim as an executioner of cell death. Owing to its potent anti-tumorigenic activity many BH3 mimetics e.g. ABT-737, ABT-263, obatoclax, AT-101and A-1210477 have been developed and entered in clinical trials. It is more likely that in near future strategies commanding Bim expression and stability ultimately lead to Bim based therapeutic regimen for cancer treatment.


Assuntos
Antineoplásicos/farmacologia , Proteína 11 Semelhante a Bcl-2/metabolismo , Fragmentos de Peptídeos/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Animais , Humanos , Terapia de Alvo Molecular , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo
14.
ACS Appl Mater Interfaces ; 9(5): 4519-4533, 2017 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-28051856

RESUMO

Biogenic synthesis of silver nanoparticles for enhanced antimicrobial activity has gained a lot of momentum making it an urgent need to search for a suitable biocandidate which could be utilized for efficient capping and shaping of silver nanoparticles with enhanced bactericidal activity utilizing its secondary metabolites. Current work illustrates the enhancement of antimicrobial efficacy of silver nanoparticles by reducing and modifying their surface with antimicrobial metabolites of cell free filtrate of Trichoderma viride (MTCC 5661) in comparison to citrate stabilized silver nanoparticles. Nanoparticles were characterized by visual observations, UV-visible spectroscopy, zetasizer, and transmission electron microscopy (TEM). Synthesized particles were monodispersed, spherical in shape and 10-20 nm in size. Presence of metabolites on surface of biosynthesized silver nanoparticles was observed by gas chromatography-mass spectroscopy (GC-MS), energy dispersive X-ray analysis (EDAX), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The antimicrobial activity of both silver nanoparticles was tested against Shigella sonnei, Pseudomonas aeruginosa (Gram-negative) and Staphylococcus aureus (Gram-positive) by growth inhibition curve analysis and colony formation unit assay. Further, it was noted that internalization of biosynthesized nanoparticles inside the bacterial cell was much higher as compared to citrate stabilized particles which in turn lead to higher production of reactive oxygen species. Increase in oxidative stress caused severe damage to bacterial membrane enhancing further uptake of particles and revoking other pathways for bacterial disintegration resulting in complete and rapid death of pathogens as evidenced by fluorescein diacetate/propidium iodide dual staining and TEM. Thus, study reveals that biologically synthesized silver nanoarchitecture coated with antimicrobial metabolites of T. viride was more potent than their chemical counterpart in killing of pathogenic bacteria.


Assuntos
Nanopartículas Metálicas , Antibacterianos , Testes de Sensibilidade Microbiana , Extratos Vegetais , Pseudomonas aeruginosa , Prata , Espectroscopia de Infravermelho com Transformada de Fourier
15.
Sci Rep ; 6: 27575, 2016 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-27273371

RESUMO

Biosynthesis of nanoparticles has gained great attention in making the process cost-effective and eco-friendly, but there are limited reports which describe the interdependency of physical parameters for tailoring the dimension and geometry of nanoparticles during biological synthesis. In the present study, gold nanoparticles (GNPs) of various shapes and sizes were obtained by modulating different physical parameters using Trichoderma viride filtrate. The particles were characterized on the basis of visual observation, dynamic light scattering, UV-visible spectroscopy, transmission electron microscopy, fourier transform infrared spectroscopy, and X ray diffraction. While the size varied from 2-500 nm, the shapes obtained were nanospheres, nanotriangles, nanopentagons, nanohexagons, and nanosheets. Changing the parameters such as pH, temperature, time, substrate, and culture filtrate concentration influenced the size and geometry of nanoparticles. Catalytic activity of the biosynthesized GNP was evaluated by UV-visible spectroscopy and confirmed by gas chromatography-mass spectrometric analysis for the conversion of 4-nitrophenol into 4-aminophenol which was strongly influenced by their structure and dimension. Common practices for biodegradation are traditional, expensive, require large amount of raw material, and time taking. Controlling shapes and sizes of nanoparticles could revolutionize the process of biodegradation that can remove all the hurdles in current scenario.


Assuntos
Fenômenos Químicos , Ouro/química , Nanopartículas Metálicas/química , Trichoderma/química , Catálise , Química Verde , Nanopartículas Metálicas/ultraestrutura , Microscopia Eletrônica de Transmissão , Tamanho da Partícula , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
16.
Toxicol Appl Pharmacol ; 291: 70-83, 2016 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-26712469

RESUMO

Post-translational modifications i.e. phosphorylation and acetylation are pivotal requirements for proper functioning of eukaryotic proteins. The current study aimed to decode the impact of acetylation/deacetylation of non-histone targets i.e. FoxO1/3a and p53 of sirtuins (NAD(+) dependent enzymes with lysine deacetylase activity) in berberine treated human hepatoma cells. Berberine (100 µM) inhibited sirtuins significantly (P<0.05) at transcriptional level as well as at translational level. Combination of nicotinamide (sirtuin inhibitor) with berberine potentiated sirtuins inhibition and increased the expression of FoxO1/3a and phosphorylation of p53 tumor suppressor protein. As sirtuins deacetylate non-histone targets including FoxO1/3a and p53, berberine increased the acetylation load of FoxO1/3a and p53 proteins. Acetylated FoxO and p53 proteins transcriptionally activate BH3-only proteins Bim and PUMA (3.89 and 3.87 fold respectively, P<0.001), which are known as direct activator of pro-apoptotic Bcl-2 family protein Bax that culminated into mitochondria mediated activation of apoptotic cascade. Bim/PUMA knock-down showed no changes in sirtuins' expression while cytotoxicity induced by berberine and nicotinamide was curtailed up to 28.3% (P<0.001) and it restored pro/anti apoptotic protein ratio in HepG2 cells. Sirtuins inhibition was accompanied by decline in NAD(+)/NADH ratio, ATP generation, enhanced ROS production and decreased mitochondrial membrane potential. TEM analysis confirmed mitochondrial deterioration and cell damage. SRT-1720 (1-10 µM), a SIRT-1 activator, when pre-treated with berberine (25 µM), reversed sirtuins expression comparable to control and significantly restored the cell viability (P<0.05). Thus, our findings suggest that berberine mediated sirtuins inhibition resulting into FoxO1/3a and p53 acetylation followed by BH3-only protein Bim/PUMA activation may in part be responsible for mitochondria-mediated apoptosis.


Assuntos
Proteínas Reguladoras de Apoptose/metabolismo , Berberina/toxicidade , Fatores de Transcrição Forkhead/metabolismo , Genes p53/fisiologia , Proteínas de Membrana/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Sirtuínas/antagonistas & inibidores , Acetilação/efeitos dos fármacos , Apoptose/efeitos dos fármacos , Apoptose/fisiologia , Proteína 11 Semelhante a Bcl-2 , Relação Dose-Resposta a Droga , Proteína Forkhead Box O1 , Proteína Forkhead Box O3 , Genes p53/efeitos dos fármacos , Células Hep G2 , Humanos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Sirtuínas/metabolismo
17.
Free Radic Biol Med ; 76: 185-99, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25128467

RESUMO

Mammalian forkhead-box family members belonging to the 'O' category (FoxO) manipulate a plethora of genes modulating a wide array of cellular functions including cell cycle regulation, apoptosis, DNA damage repair, and energy metabolism. FoxO overexpression and nuclear accumulation have been reported to show correlation with hindered tumor growth in vitro and size in vivo, while FoxO's downregulation via phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) pathway has been linked with tumor promotion. In this study, we have explored for the first time intervention of berberine, a plant-derived isoquinoline alkaloid, with FoxO family proteins in hepatoma cells. We observed that berberine significantly upregulated the mRNA expression of both FoxO1 and FoxO3a. Their phosphorylation-mediated cytoplasmic sequestration followed by degradation was prevented by berberine-induced downmodulation of the PI3K/Akt/mTOR pathway which promoted FoxO nuclear retention. PTEN, a tumor suppressor gene and negative regulator of the PI3K/Akt axis, was upregulated while phosphorylation of its Ser380 residue (possible mechanism of PTEN degradation) was significantly decreased in treated HepG2 cells. Exposure to berberine induced a significant increase in transcriptional activity of FoxO, as shown by GFP reporter assay. FoxO transcription factors effectively heightened BH3-only protein Bim expression, which in turn, being a direct activator of proapoptotic protein Bax, altered Bax/Bcl-2 ratio, culminating into mitochondrial dysfunction, caspases activation, and DNA fragmentation. The pivotal role of Bim in berberine-mediated cytotoxicity was further corroborated by knockdown experiments where Bim-silencing partially restored HepG2 cell viability during berberine exposure. In addition, a correlation between oxidative overload and FoxO's nuclear accumulation via JNK activation was evident as berberine treatment led to a pronounced increase in JNK phosphorylation together with enhanced ROS generation, lipid peroxidation, decreased activities of superoxide dismutase and catalase, and diminished glutathione levels. Thus, our findings suggest that the antiproliferative effect of berberine may in part be due to mitochondria-mediated apoptosis with Bim acting as a pivotal downstream factor of FoxO-induced transcriptional activation.


Assuntos
Proteínas Reguladoras de Apoptose/metabolismo , Apoptose/efeitos dos fármacos , Berberina/farmacologia , Carcinoma Hepatocelular/patologia , Núcleo Celular/metabolismo , Fatores de Transcrição Forkhead/metabolismo , Proteínas de Membrana/metabolismo , Mitocôndrias/patologia , Proteínas Proto-Oncogênicas/metabolismo , Antioxidantes/metabolismo , Proteínas Reguladoras de Apoptose/genética , Proteína 11 Semelhante a Bcl-2 , Western Blotting , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/metabolismo , Caspases/metabolismo , Ciclo Celular/efeitos dos fármacos , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/genética , Proliferação de Células/efeitos dos fármacos , Proteína Forkhead Box O1 , Proteína Forkhead Box O3 , Fatores de Transcrição Forkhead/genética , Técnicas Imunoenzimáticas , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Proteínas de Membrana/genética , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Fosforilação/efeitos dos fármacos , Proteínas Proto-Oncogênicas/genética , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais/efeitos dos fármacos , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo , Células Tumorais Cultivadas
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