DEFAR - Departamento de Farmácia

URI permanente desta comunidadehttp://www.hml.repositorio.ufop.br/handle/123456789/530

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Resultados da Pesquisa

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    Spironolactone and eplerenone are cardioprotective during early phase of ischemia in rats submitted to acute coronary occlusion.
    (2022) Amancio, Gabriela de Cássia Sousa; Hermidorff, Milla Marques; Alvarenga, Ana Cláudia; Lima, Wanderson Geraldo de; Guimarães, Homero Nogueira; Rodrigues, Henrique Resende; Silva, Emília Calil; Assis, Leonardo Vinícius Monteiro de; Guimarães, Andrea Grabe; Isoldi, Mauro César
    Introduction: Mineralocorticoid receptor antagonists (MRAs) are effective in reducing left ventricle remodeling and sudden death after acute myocardial infarction (AMI). Objectives: MRAs in vitro display cardioprotective effects, independent of MR; however, it is unknown whether the rapid effects of MRAs are cardioprotective in vivo. This study evaluated the acute effects of spironolactone and eplerenone in the first minutes of AMI. Methods: Wistar Rats, submitted or not to bilateral adrenalectomy, were treated orally with spironolactone (20 mg/kg) or eplerenone (10 mg/kg), and submitted to the left coronary ligation, under anesthesia. Electrocardiogram (ECG) recordings were obtained to evaluate ST-T segment, QT, and QTc intervals. Arterial pressure was also measured before (baseline) and after coronary ligation. Results: Spironolactone or eplerenone given, one hour before coronary ligation, prevented ST- T segment elevation in adrenalectomized and non-adrenalectomized. QT interval analysis showed that MRAs prevented its prolongation after coronary ligation. QT and QTc intervals remained similar to baseline and were smaller than the values displayed by the non-treated group. Animals treated with spironolactone, regardless of adrenalectomy, showed a 3-fold reduced mortality rates compared to the control group. Conclusion: MRAs display acute cardioprotective effects in early phase of AMI, which are independent of aldosterone.
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    Reduced cardiotoxicity and increased oral efficacy of artemether polymeric nanocapsules in Plasmodium berghei-infected mice.
    (2018) Souza, Ana Carolina Moreira; Mosqueira, Vanessa Carla Furtado; Silveira, Ana Paula Amariz; Antunes, Lidiane Rodrigues; Richard, Sylvain; Guimarães, Homero Nogueira; Guimarães, Andrea Grabe
    Artemether (ATM) cardiotoxicity, its short half-life and low oral bioavailability are the major limiting factors for its use to treat malaria. The purposes of this work were to study free-ATM and ATM-loaded poly-ε-caprolactone nanocapules (ATM-NC) cardiotoxicity and oral efficacy on Plasmodium berghei-infected mice. ATM-NC was obtained by interfacial polymer deposition and ATM was associated with polymeric NC oily core. For cardiotoxicity evaluation, male black C57BL6 uninfected or P. berghei-infected mice received, by oral route twice daily/4 days, vehicle (sorbitol/carboxymethylcellulose), blank-NC, free-ATM or ATMNC at doses 40, 80 or 120 mg kg−1 . Electrocardiogram (ECG) lead II signal was obtained before and after treatment. For ATM efficacy evaluation, female P. berghei-infected mice were treated the same way. ATM-NC improved antimalarial in vivo efficacy and reduced mice mortality. Free-ATM induced significantly QT and QTc intervals prolongation. ATMNC (120 mg kg−1 ) given to uninfected mice reduced QT and QTc intervals prolongation 34 and 30%, respectively, compared with free-ATM. ATM-NC given to infected mice also reduced QT and QTc intervals prolongation, 28 and 27%, respectively. For the first time, the study showed a nanocarrier reducing cardiotoxicity of ATM given by oral route and it was more effective against P. berghei than free-ATM as monotherapy.
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    Prolonged cardioprotective effect of pyridostigmine encapsulated in liposomes.
    (2010) Vidal, Alessandra Teixeira; Guimarães, Homero Nogueira; Paula, Danielle Cristiane Correa de; Frezard, Frederic Jean Georges; Barcellos, Neila Marcia Silva; Guimarães, Andrea Grabe
    Aims: The purpose of the present work was to investigate the ability of pyridostigmine encapsulated in longcirculating liposomes, to protect against ECG(electrocardiogram) alterations induced by sympathetic stimulation in rats. Main methods: The encapsulation of pyridostigmine was carried out by freeze–thaw and extrusion. Blood pressure and ECG (limb lead II) were monitored in anaesthetized male Wistar rats. The formulation containing pyridostigmine was intravenously administrated in 0.1, 0.3 and 1.0 mg/kg doses, and sympathetic stimulation was conducted by administration of 1 or 3 μg of noradrenaline (NA) after 1, 2, 4 or 6 h. The obtained cardiovascular parameters were compared to animals that received intravenous injection of pyridostigmine in free form or saline. Key findings: After saline, NA induced a significant increase in QT interval (22.3% after 3.0 μg). Previous administration of free pyridostigmine significantly prevented the increase of QT interval after sympathetic stimulation and the most prominent effect was observed after 1h for the dose of 0.3 mg/kg (6.8% after 3.0 μg of NA) and was no longer observed after 2 h of the treatment. On the other hand, the maximum effect of pyridostigmine in liposomal formulation preventing QT interval increasewas observed 2 h after treatment (9.7% after 3.0 μg of NA) and was still present until 6 h when 1 mg/kg was previous administrated. Significance: The results of the present study, beyond to confirm the cardioprotective action of pyridostigmine, suggest that liposomal pyridostigmine may be a potential therapeutic alternative to prevent cardiovascular disturbances resulting from sympathetic hyperactivity.