Name: PRISCILA MURUCCI COELHO
Publication date: 22/06/2018
Advisor:
Name |
Role |
|---|---|
| ANA PAULA LIMA LEOPOLDO | Advisor * |
Examining board:
| Name |
Role |
|---|---|
| ANA PAULA LIMA LEOPOLDO | Advisor * |
| FABIANO KENJI HARAGUCHI | Internal Examiner * |
Summary: Introduction: Overweight and obesity are important risk factors for the development of type 2
diabetes. Excess weight associated to type 2 diabetes mellitus promotes high risk for the
development of cardiovascular diseases. Although the literature suggests that oxidative stress
is related to diabetic cardiomyopathy, the mechanism of generation of reactive oxygen species
is still not well understood. Thus, foods with a high level of antioxidant compounds may be
beneficial in preventing and/or reversing OE in obese diabetic. Studies have shown that both
the extract and flour of lychee peel and seed are rich in phenolic antioxidant compounds.
Objective: To evaluate the flour consumption of seed and peel lychee on oxidative stress,
metabolic and cardiomyocyte contractile function in diabetic obese rats. Methodology: Male
Wistar rats were submitted to obesity condition by high-fat diet, and and subsequently induced
to type 2 Diabetes Mellitus. Then, the animals were randomized into groups: Obese (Ob,
n=10), Diabetic obese (ObD, n=8), Diabetic obese treated with lychee peel flour (ObDPF,
n=10) and Diabetic obese treated with lychee seed flour (ObDSF, n=10). Nutritional and
glycemic profiles, water contente of lung and liver, pancreas weight, and serum oxidative
stress parameters were performed. Furthermore, the total weight of the heart and its relation
to tibia length were analyzed. Cardiomyocytes contractile function was assayed. Data were
expressed as mean ± standard deviation or median ± interquartile range. The comparisons
were performed by students t test or one-way ANOVA and complemented by Bonferroni and
Dunns post hoc tests. The level of significance was 5%. Results: ObD presented lower body
weight, fat pads and pancreas weight in relation to Ob, on the other hand, there was enhanced
of protein carbonylation andsuperoxide dismutase levels. Regarding the cardiomyocyte
contractile function, ObD presented higher systolic Ca2+ with percentual elevation of
shortening, in contrast, there was greater time to peak 50% of shortening. On the other hand,
although ObD rats presented higher maximal velocity of relaxation, there was elevation of
diastolic Ca2+ levels and greater time to peak 50% of recapture. The treatments with flour of
seed and peel lychee did not able to change body and morfologic parameters, and biomarkers
of oxidative stress in ObD. The ObDPF triggered elevation time to peak 50% of shortening
compared to ObD rats, without modifications in relaxation contractile parameters. However,
the ObDSF presented reduction of percentual and maximal velocity of shortening with
consequently increased in time to peak 50% of shortening in relation to ObD.Although diastolic
Ca2+ levels were lower in ObDFS rats, there was no significant difference (p = 0.056). .Between
the ObDSF and ObDPF treatments, results showed that ObDSF presented lower maximal
velocity of relaxation, concomitant to higher time to peak 50% of recapture. Conclusion: The
flour of seed and peel lychee did not revert the oxidative damage and the contractile injury in
cardiomyocytes of obese rats induced to diabetes. In addition, the flour of seed lychee
accentuated the contractile dysfunction without changes in intracellular Ca2+ handling.
