Banca de QUALIFICAÇÃO: ERICA KAMILA TRINDADE BARROS

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : ERICA KAMILA TRINDADE BARROS
DATE: 15/12/2025
TIME: 14:30
LOCAL: Auditório PPGBIOEF
TITLE:

Obesity, energy metabolism, and neuroinflammation: Anorexigenic and anti-inflammatory effects of Opuntia cochenillifera extract

KEY WORDS:

Obesity; Energy metabolism; Neuroinflammation; White adipose tissue; Nopalea cochenillifera.

PAGES: 79
BIG AREA: Ciências Biológicas
AREA: Morfologia
SUBÁREA: Histologia
SUMMARY:

Obesity is a current and relevant public health problem that reduces life expectancy and consumes significant financial resources. It is also associated with several comorbidities, including cardiovascular disease, hepatic disease, dyslipidemia, and insulin resistance, collectively referred to as metabolic syndrome (MS). The clinical manifestations of obesity primarily affect white adipose tissue (WAT) and the central regulators of energy metabolism, particularly the hypothalamus. There is an increased production of inflammatory cytokines by WAT, mainly leptin, interleukins, and TNF-α, which leads to systemic and hypothalamic inflammation. This inflammatory state exerts negative effects on the regulation of POMC/CART and AgRP/NPY neurons, which are responsible for anorexigenic and orexigenic activity, respectively. In parallel, leptin resistance contributes to hippocampal inflammation. In this context, therapeutic strategies that counteract obesity and its metabolic consequences are needed. Opuntia cochenillifera is a cactus rich in phenolic compounds and traditionally used in the Brazilian semi-arid region for the treatment of various comorbidities. Therefore, this study aims to evaluate the effects of the hydroethanolic extract of O. cochenillifera (EOC) on energy metabolism and neuroinflammation in diet-induced obese mice. Forty C57BL/6 mice were allocated into four experimental groups (n = 10): Control (C), Control + EOC (CP), High-Fat (HF), and High-Fat + EOC (HFP). Obesity was induced for 12 weeks, followed by EOC treatment (200 mg/kg body mass) for an additional 8 weeks. Body mass, food and energy intake, adiposity, glycemic and lipid profiles, WAT and hippocampal histological and stereological parameters were analyzed. Compared to the HF group, the HFP group showed a 24% reduction in body mass (p<0.0001) and a 321% and 242% reduction in epididymal and subcutaneous fat accumulation, respectively (p<0.0001). Regarding carbohydrate and lipid metabolism, the HFP group exhibited a 35% reduction in fasting blood glucose (p<0.0001), a considerable improvement in glucose tolerance, and decreased plasma levels of total cholesterol (−46%, p<0.0001) and triacylglycerol (−40%, p<0.01). Histological analyses revealed inflammatory infiltrate and hypertrophy of white adipocytes in the WAT of the HF group; EOC reversed these alterations. The mean cross-sectional area (ASM) of adipocytes showed a significant increase in the HF group compared to the C group (+172%, p<0.0001), whereas EOC treatment significantly reduced ASM relative to the HF group (−67%, p<0.0001). Analysis of the CA1 region of the hippocampus demonstrated that, compared to the C group, the HF group exhibited dysmorphic, hyperchromatic (dark) neurons with pyknotic nuclei, alterations indicative of apoptosis. EOC treatment reversed these structural neuronal damages. Stereological analyses supported these findings, showing that the HF group presented a 40% reduction in the density of viable neuronal volumes (p<0.001), while the HFP group recovered neuronal viability (+34%, p<0.001). These preliminary results indicate that EOC exerts anti-obesogenic, anorexigenic, anti-adipogenic, anti-inflammatory, and neuroprotective effects in this obesity model. Ongoing analyses of gene expression related to the leptin signaling pathway, anorexigenic/orexigenic pathways, and inflammatory pathways will help complement these findings and elucidate the mechanisms of action of EOC in energy metabolism and neuroinflammation.

COMMITTEE MEMBERS:
Presidente - 3357609 - FABIANE FERREIRA MARTINS
Interna - 4507066 - CHRISTINA DA SILVA CAMILLO
Interna - 1733434 - RENATA FIGUEIREDO ANOMAL
Externo ao Programa - 2318723 - SERGIO ADRIANE BEZERRA DE MOURA - UFRN