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Interação entre exercício físico e o tratamento com resveratrol nas alterações hepáticas induzidas pelo diabetes mellitus em um modelo de pós-menopausa experimental

Tue, 16 Dec 2025 00:00:00 GMT

Título: Interação entre exercício físico e o tratamento com resveratrol nas alterações hepáticas induzidas pelo diabetes mellitus em um modelo de pós-menopausa experimental Autor(es): Amado, Larissa Cruz Primeiro Orientador: Soares, Telma de Jesus Abstract: Type 1 diabetes mellitus (T1DM) is characterized by hypoinsulinemia resulting from autoimmune destruction of pancreatic beta cells. Hyperglycemia can induce alterations in liver function and structure associated with increased oxidative stress and inflammation. However, liver alterations in T1DM have been less documented, especially in postmenopausal women with T1DM. The search for new strategies is necessary to improve or delay the progression of liver lesions induced by T1DM in the postmenopausal period. In this context, we evaluated the isolated and combined effects of physical exercise and resveratrol (RES) on liver enzyme levels, morphology, redox balance, and inflammation in hepatocytes of ovariectomized (OVX) rats with T1DM. Twenty-four rats were OVX, and diabetes was induced by injection of streptozotocin (STZ/40 mg/kg). Next, the rats were divided into 4 groups (n=6/each): OSD, sedentary diabetic OVX rats; OTD, trained diabetic OVX rats; OSD+RES, sedentary diabetic OVX rats + RES; OTD+RES, trained diabetic OVX rats + RES. The OTD and OTD+RES groups underwent 8 weeks of exercise. Treatment with RES was performed by intraperitoneal injection, at a dose of 5 mg/kg/day, 5 days/week, for 8 weeks in the OSD+RES and OTD+RES groups. The rats were euthanized and the liver was removed for histological, morphometric, immunohistochemical, and oxidative stress studies. The results demonstrate that the interaction of RES with physical training preserved the structure of the liver tissue and reduced total nitrite levels, hepatic expression of NF-κB, nitrotyrosine, and TGF-β. However, in isolation, RES and physical training increased glycogen content, GPx enzyme activity, and reduced laminin immunostaining in the liver tissue of rats in the SDO+RES and OTD groups. RES alone decreased TBARS levels and increased SOD enzyme activity in the liver of OSD+RES rats. In conclusion, our results show that exercise and RES, separately, have hepatoprotective effects, but the interaction of these therapeutic strategies induced additional beneficial effects in the liver of OVX rats with T1DM. Editora / Evento / Instituição: Universidade Federal da Bahia Tipo: Dissertação

Espectrometria de Massas e Molecular Networking como ferramentas para o estudo da diversidade química de espécies nativas de Passiflora L. (Passifloraceae).

Mon, 11 Jul 0007 00:00:00 GMT

Título: Espectrometria de Massas e Molecular Networking como ferramentas para o estudo da diversidade química de espécies nativas de Passiflora L. (Passifloraceae). Autor(es): Garcia, Laryana Borges Primeiro Orientador: Amaral, Juliano Geraldo Abstract: The Passifloraceae family, with more than 630 species, is predominant in tropical and subtropical regions, with Passiflora being the most extensive and diverse genus. This study aims to deepen the knowledge about the Passifloraceae family and the metabolic profiles of Passiflora subspecies, known for their rich phytochemical composition, including glycosylated flavonoids, carotenoids, cyanogenic glycosides, alkaloids, steroids, lignans, fatty acids, amino acids, chlorogenic acid derivatives and proanthocyanidins. Initially, we performed a comprehensive review covering studies from 1983 to 2023, offering a detailed overview of the scientific discoveries on the chemical compounds present in the genus Passiflora. Then, we combined mass spectrometry and molecular networking to explore the chemical diversity of native species of the genus Passiflora from Brazil. We developed a comprehensive database using liquid chromatography coupled to mass spectrometry (HPLC-MS/MS) to analyze the metabolic profile of several subspecies. The generated data were submitted to the GNPS platform, which generated a Molecular Networking, in which the same substances were grouped in a single node and the similar ones in clusters. The data generated by the network were dereplicated and also analyzed by multivariate statistical methods, and thus this work revealed metabolic similarities between species, such as P. incarnata, suggesting shared pharmacological potential. We documented 25 species not previously studied, expanding the knowledge about their medicinal properties and opening paths for the development of new products. Editora / Evento / Instituição: Universidade Federal da Bahia Tipo: Dissertação

Análise in silico de fatores de virulência de Chlamydia psittaci com potencial aplicação no desenvolvimento de vacinas e estudo do MHC de psitacídeos endêmicos do Brasil

Mon, 17 Nov 2025 00:00:00 GMT

Título: Análise in silico de fatores de virulência de Chlamydia psittaci com potencial aplicação no desenvolvimento de vacinas e estudo do MHC de psitacídeos endêmicos do Brasil Autor(es): Teixeira, Sabrina Barbosa Primeiro Orientador: Bastos, Bruno Lopes Abstract: Chlamydia psittaci is an obligate intracellular pathogen of major zoonotic importance, widely associated with avians of the group Psittaciformes, with the potential to cause avian chlamydiosis and psittacosis in humans. The close relationship between these hosts and the infectious agent represents both a sanitary and conservation concern. The study of the Major Histocompatibility Complex (MHC) in psittacine species can serve as an important model for investigating host-pathogen interactions and the adaptive immune response of these avians, contributing to the development of strategies for the conservation of the group. This study aimed to investigate in silico the MHC of psittacine species endemic to Brazil and to perform the prediction of virulence factors and potential vaccine targets against C. psittaci. In the first chapter, 39 MHC class II sequences from Forpus passerinus and Amazona aestiva were identified and analyzed, with phylogenetic analyses indicating functional relationships with mammalian DRB and avian BL loci. Epitope prediction of the MOMP protein revealed regions with high binding affinity to MHC II molecules, including one shared between avians and mammals, suggesting potential for the development of broad-spectrum immunogens. In the second chapter, the complete proteome of a C. psittaci strain was analyzed for the identification of proteins associated with virulence, subcellular localization, and protein-protein interactions (PPI), highlighting molecular targets relevant to understanding pathogenesis and vaccine design. The results reinforce the applicability of in silico approaches in the immunogenetics of non-model species and in the search for new strategies for the prevention and control of avian chlamydiosis. Editora / Evento / Instituição: Universidade Federal da Bahia Tipo: Dissertação

Análise da metilação do DNA em amostras gástricas e associação com infecção por Helicobacter pylori

Fri, 11 Jul 2025 00:00:00 GMT

Título: Análise da metilação do DNA em amostras gástricas e associação com infecção por Helicobacter pylori Autor(es): Sandes, Lidiane Ferraz Primeiro Orientador: Marques, Cintia Rodrigues Abstract: Helicobacter pylori infection is a significant risk factor for the development of inflammatory and neoplasic changes in the stomach, contributing to the pathogenesis of gastric diseases, particularly through epigenetic mechanisms. This experimental study aimed to examine the DNA methylation profile of the IL6, SOCS1, MGMT, and MLH1 genes in gastric mucosal samples, considering the presence of H. pylori infection and the detection of the virulence gene cagA. Samples underwent DNA extraction, followed by sodium bisulfite conversion and analysis using the MS-HRM technique. IL6 methylation was categorized into 0-25% and 25-50%, with stratification by sex, age, and bacterial strain status. Statistical analyses included the Student’s t-test to compare mean methylation levels between H. pylori-positive and -negative groups, and chi-square or Fisher’s exact test, as appropriate, considering p < 0,05 as the significance threshold for associations between categorical variables. The results indicated that infected individual were twice as likely to exhibit moderate methylation of the IL6 gene compared to non-infected individuals (OR = 2.00; 95% CI: 0.56–7.62; p = 0.284), and those infected with cagA-positive strains had a higher risk compared to those with cagA- negative strains (OR = 1.56; 95% CI: 0.41–5.85; p = 0.508), although these differences were not statistically significant. Among men, a significant association was observed (p = 0.035), with 100% of infected individuals showing moderate methylation versus 40% in the non- infected group; no significant difference was found among women (p = 0.765). Methylation of the SOCS1 and MLH1 genes was not detected in any of the samples, regardless of infection status, while MGMT methylation was observed in only three individuals (6.82%), all at low levels, preventing statistical analysis. Although no statistically significant association was observed with cagA status, all men infected with cagA-positive strains exhibited moderate methylation. These findings suggest that H. pylori infection may modulate IL6 gene methylation, particularly in males, and underscore the role of epigenetic mechanisms in the molecular pathways underlying gastric inflammation and disease progression, especially in high- prevalence populations. Editora / Evento / Instituição: Universidade Federal da Bahia Tipo: Dissertação