Banca de DEFESA: CAMILA DE CARVALHO GOMES

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : CAMILA DE CARVALHO GOMES
DATE: 27/09/2021
TIME: 14:00
LOCAL: Videoconferência
TITLE:

Evaluation of the Nutritional Status of Vitamin A and Precursors in Obesity 

KEY WORDS:

Cucurbitaceae. Beta-carotene. Nanotechnology. Retinol Adipose tissue. Liver.

PAGES: 96
BIG AREA: Ciências Biológicas
AREA: Bioquímica
SUMMARY:

The increasing prevalence of obesity and chronic non-communicable diseases associated with it has increased, and the search for new strategies to control them. In this sense, vitamin A plays an important role in regulating body weight through the action of metabolites of this nutrient on different aspects in individuals with obesity. Based on this, this thesis is divided into two chapters. In the first chapter, a narrative review was performed to understand this relationship and the physiological effects of vitamin A on obesity. A search was carried out in the databases, selecting the studies that involved vitamin A or its active metabolites, encapsulated or not, and the role and relationship with obesity. Studies were found showing that there is an inverse relationship between adiposity and vitamin A concentration. In addition, it was demonstrated that encapsulating vitamin A or its precursors improves stability, bioavailability, and functionality and may favor better effects in the treatment of obesity. In the second chapter, a study was carried out to evaluate the impact of the crude extract rich in carotenoids from Cantaloupe melon (Cucumis melo L. var cantalupensis) nanoencapsulated in porcine gelatin (EPG) on the concentration of vitamin A in the liver of obese Wistar rats. The crude extract rich in carotenoids (CE) was obtained by processing, drying, and extracting bioactive compounds from the melon pulp, being used to synthesize the nanoformulation through the O/W emulsification technique. The nanoparticles were characterized in terms of physical and chemical aspects and evaluated the efficiency of incorporation of carotenoids. In the preclinical study, Wistar rats with obesity induced by a high glycemic index diet and a high glycemic load (HGLI diet) were divided into three groups (n = 5): 1. no treatment (HGLI diet + water), 2. treated with HGLI diet + CE (12.5 mg/kg), and 3. treated with HGLI diet + EPG (50 mg/kg) administered by gavage (1 mL) for ten days. These animals were evaluated for variation in dietary intake, retinol, and weight, hematological parameters, fasting glucose, and lipid profile. In addition, the investigation of hepatic retinol concentration and liver function was performed by determining the AST/ALT ratio and the FIB-4 (Fibrosis-4 Index for Liver Fibrosis) and APRI (AST to Platelet Ratio Index) scores. The results obtained for the characterization of the particles confirmed the presence of spherical particles with smooth surface, mean diameter of 80 (8.59) nm, polydispersion index of 0.47 (0.09), and the presence of new chemical interactions, indicating that CE was encapsulated in porcine gelatin. Furthermore, the CE incorporation efficiency was equal to 95.20% (0.74). For animals treated with EPG, lower dietary and retinol consumption was observed (p < 0.05). In addition, the same group of animals had significantly higher concentrations (p < 0.05) of hepatic retinol [266 (45) µg/g] when compared to the untreated group [186 (23.8) µg/g] and the one treated with CE [175 (8.08) µg/g]. The liver damage assessment scores did not show significant differences (p > 0.05), but the lowest means were observed in the group of animals treated with EPG. These findings suggest that nanoencapsulation promoted protection, guaranteed the absorption of carotenoids in the intestine, and bioconversion to retinol in the liver, without causing liver alterations. Thus, EPG presents itself as a candidate for future clinical studies, aiming to evaluate the beneficial effects of treating diseases that involve vitamin A deficiency, such as obesity.

BANKING MEMBERS:
Presidente - 2578619 - ANA HELONEIDA DE ARAUJO MORAIS
Externa à Instituição - DANIELLE SOARES BEZERRA
Externa ao Programa - 2578592 - KARLA DANIELLY DA SILVA RIBEIRO RODRIGUES
Externo à Instituição - KÁTIA GOMES DE LIMA ARAÚJO - UFF
Externa à Instituição - MAIRA CONCEIÇÃO JERONIMO DE SOUZA LIMA - UnP