Banca de QUALIFICAÇÃO: CAMILA DE CARVALHO GOMES

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : CAMILA DE CARVALHO GOMES
DATE: 19/08/2021
TIME: 08:00
LOCAL: Videoconferência
TITLE:

Evaluation of Vitamin A Nutritional Status in Obesity

KEY WORDS:

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

PAGES: 80
BIG AREA: Ciências Biológicas
AREA: Bioquímica
SUMMARY:

The growing prevalence of obesity and non-communicable chronic diseases associated with it has increased, and with it, the search for new strategies to control them. Vitamin A plays an important role in regulating body weight through metabolites of this nutrient on different aspects in individuals with obesity. This thesis is divided into two chapters. First, to understand this relationship and the physiological effects of vitamin A on obesity, a narrative review was carried out. A search in the databases was carried out, 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. Furthermore, it was shown that encapsulating vitamin A or its precursors improves stability, bioavailability, and functionality and may favor better effects in treating obesity. In the second chapter, a study was carried out to evaluate the effect of crude extract of 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. For this, the crude extract of carotenoids (CE) was obtained by processing, drying, and extracting the bioactive compound from the melon pulp, which was 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 incorporating 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 + CE diet (12.5 mg/kg), and three treated with HGLI + EPG diet (50 mg/kg) administered by gavage (1 mL) for ten days. These animals were evaluated for variation in food consumption 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 TGO/TGP 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 and polydispersion index of 0.47 (0.09), and the presence of new chemical interactions, indicating that CE was encapsulated in porcine gelatin. Furthermore, the incorporation efficiency of carotenoids was equal to 95,20% (0,74). The in vivo experiments showed that animals treated with EPG presented a significant reduction (p < 0.05) in dietary intake. In addition, the same group had significantly higher concentrations (p < 0.05) of hepatic retinol [266 (45) mcg/g] when compared to the untreated group [186 (23.8) mcg/g] and treated with CE [175 (8.08) mcg/g]. The liver damage assessment scores did not show significant differences, but their means were reduced in animals treated with EPG. These findings showed that the nanoencapsulation of carotenoids promoted protection and ensured the absorption of the bioactive compound without causing liver changes. In this way, it allowed an increase in the concentration of vitamin A (retinol) in liver of animals with obesity. EPG presents itself as a candidate for future clinical studies, aiming to evaluate the beneficial effects in the treatment of diseases involving vitamin A deficiencies, such as obesity.

BANKING MEMBERS:
Interno - 2195251 - HUGO ALEXANDRE DE OLIVEIRA ROCHA
Externa ao Programa - 2578592 - KARLA DANIELLY DA SILVA RIBEIRO RODRIGUES
Externa ao Programa - 2275877 - THAIS SOUZA PASSOS