Banca de DEFESA: RICARDO BASÍLIO DE OLIVEIRA CALAND

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : RICARDO BASÍLIO DE OLIVEIRA CALAND
DATA : 21/06/2019
HORA: 14:00
LOCAL: Sala de Videoconferência do Centro de Convivência da UFRN
TÍTULO:
PALAVRAS-CHAVES:

Natural products, oxidative stress, longevity, Alzheimer's disease and Huntington's disease.

PÁGINAS: 120
GRANDE ÁREA: Ciências Biológicas
ÁREA: Bioquímica
RESUMO:

The orange juice Citrus sinensis L. Osbeck is considered an excellent food source of several bioactive compounds with properties beneficial to human health due to its high content of flavonoids, carotenoids, sugars, minerals and fibers. Some epidemiological and interventional studies have provided evidence to support the inverse correlation between orange juice consumption and the occurrence of cardiovascular disease and cancer. In this study, we used two naturally enriched oranges, originated through spontaneous mutation, called Bahia and Cara Cara. These oranges are high in vitamin C and flavonoids; however, Cara Cara orange is distinguished by being rich in carotenoids (phytoene, phytofluene, lycopene and β-carotene). Considering that oxidative damage and increased neuroinflammation are critically related to pathogenesis and neuronal loss in neurodegenerative diseases, the neuroprotective effect of some components of orange has been of specific interest in the search for effective treatments for these diseases. However, there is still a lack of in vivo studies to show the therapeutic effects of orange juice in its full and complete form, since its compounds have already been shown to have positive antioxidant and neuroprotective effects. In this context, we used the nematode Caenorhabditis elegans which is a widely established model organism for animal behavior, physiology and genetics studies. The objective of this work was to evaluate and compare the antioxidant, neuroprotective and physiological changes related to the aging of the treatment with the pasteurized orange juices Bahia and Cara Cara in the C. elegans model. To perform the experiments, the animals were synchronized in the L1 larval stage and treated at 20 ºC in petri dishes with solid nematode growth medium (NGM), with different concentrations of Bahia orange or Cara Cara, seeded with Escherichia coli OP50 or E. coli HT115. The treatment with orange juice provided positive antioxidant effects in C. elegans, such as reduction in endogenous levels of reactive oxygen species (ROS), increased survival under standard and oxidative stress conditions, and increased expression of antioxidant reporter genes g- glutamyl cysteine synthetase (gcs-1), glutathione-S-transferase (gst-4) and superoxide dismutase (sod-3) and hsp-16.2 chaperonin. Regarding the neuroprotective effects, it was observed that the orange treatment delays the profile of paralysis induced by the superexpression of the Aβ1-42 peptide in the muscle of the C. elegans model for Alzheimer's disease and decreases the polyglutamine aggregation in the C. elegans model for Huntington's disease. To investigate whether stress response signaling pathways would play an important role in juice effects, ERO quantification, oxidative stress resistance, gst-4::GFP expression, paralysis, and longevity in animals with knockdown were performed. the transcription factors SKN-1, DAF-16 and HSF-1 through interference RNA (RNAi). The results showed that the effects provided by the treatment with Bahia and Cara Cara orange juices were mainly dependent on the SKN-1 and DAF-16 transcription factors, especially SKN-1. In relation to physiological changes related to aging, the treatment increased the life span, the body movements and the rate of pharyngeal beats. We concluded that orange juice treatments provided excellent antioxidant and neuroprotective effects and were able to improve physiological parameters related to aging, which are strongly involved in the quality of life of C. elegans with emphasis on Cara Cara orange juice induced significantly better responses, possibly due to the higher carotenoid content.

MEMBROS DA BANCA:
Externa à Instituição - RENATA NASCIMENTO DE FREITAS - UFOP
Externa à Instituição - DAIANA SILVA DE ÁVILA - UFP
Interno - 2195251 - HUGO ALEXANDRE DE OLIVEIRA ROCHA
Presidente - 1251018 - RIVA DE PAULA OLIVEIRA
Interna - 1199127 - SILVIA REGINA BATISTUZZO DE MEDEIROS