Papers by Tayanne Malafaia
Frontiers in Nutrition, Jan 10, 2024
Introduction and aims: Obesity is a multifactorial condition with high health risk, associated wi... more Introduction and aims: Obesity is a multifactorial condition with high health risk, associated with important chronic disorders such as diabetes, dyslipidemia, and cardiovascular dysfunction. Citrus aurantium L. (C. aurantium) is a medicinal plant, and its active component, synephrine, a β-3 adrenergic agonist, can be used for weight loss. We investigated the effects of C. aurantium and synephrine in obese adolescent mice programmed by early postnatal overfeeding. Methods: Three days after birth, male Swiss mice were divided into a small litter (SL) group (3 pups) and a normal litter (NL) group (9 pups). At 30 days old, SL and NL mice were treated with C. aurantium standardized to 6% synephrine, C. aurantium with 30% synephrine, isolated synephrine, or vehicle for 19 days. Results: The SL group had a higher body weight than the NL group. Heart rate and blood pressure were not elevated. The SL group had hyperleptinemia and central obesity that were normalized by C. aurantium and synephrine. In brown adipose tissue, the SL group showed a higher lipid droplet sectional area, less nuclei, a reduction in thermogenesis markers related to thermogenesis (UCP-1, PRDM16, PGC-1α and PPARg), and mitochondrial disfunction. C. aurantium and synephrine treatment normalized these parameters. Our data indicates that the treatment with C. aurantium and synephrine could be a promising alternative for the control of some obesity dysfunction, such as improvement of brown adipose tissue dysfunction and leptinemia.
Journal of Nutritional Biochemistry, 2014
Nutritional transition has contributed to growing obesity, mainly by changing eating habits of th... more Nutritional transition has contributed to growing obesity, mainly by changing eating habits of the population. The mechanisms by which diet-induced obesity leads to cardiac injury are not completely understood, but it is known that obesity is associated to impaired cardiac function and energy metabolism, increasing morbidity and mortality. Therefore, our study aimed to investigate the mechanisms underlying cardiac metabolism impairment related to Western diet-induced obesity. After weaning, male Swiss mice were fed a Western diet for 16 weeks in order to induce obesity. After this period, the content of proteins involved in heart energy metabolism GLUT1, cytosolic lysate and plasma membrane GLUT4, AMPK, pAMPK, IRβ, IRS-1, PGC-1α, CPT1 and UCP2 was evaluated. Also, the oxidative phosphorylation of myocardial fibers was measured by high-resolution respirometry. Mice in the Western diet group (WG) presented altered biometric parameters compared to those in control group, including higher body weight, increased myocardial lipid deposition and glucose intolerance, which demonstrate the obesogenic role of Western diet. WG presented increased CPT1 and UCP2 contents and decreased IRS-1, plasma membrane GLUT4 and PGC-1α contents. In addition, WG presented cardiac mitochondrial dysfunction and reduced biogenesis, demonstrating a lower capacity of carbohydrates and fatty acid oxidation and also decreased coupling between oxidative phosphorylation and adenosine triphosphate synthesis. Cardiac metabolism impairment related to Western diet-induced obesity is probably due to damaged myocardial oxidative capacity, reduced mitochondrial biogenesis and mitochondria uncoupling, which compromise the bioenergetic metabolism of heart.
Insulin sensitivity as a predictor of longitudinal changes on body mass index in Brazilian adolescents
American Journal of Human Biology, 2022
OBJECTIVES We aimed to investigate the effect of insulin sensitivity and insulin resistance statu... more OBJECTIVES We aimed to investigate the effect of insulin sensitivity and insulin resistance status at baseline on longitudinal body mass index, and the possible effect modification by sex. METHODS This is a secondary analysis of a randomized intervention community trial, in which a subgroup of 84 adolescents, aged between 10 and 12 years, were analyzed. Body weight, height, and body mass index (BMI) were determined before and after 8 months of follow-up. Glucose and serum insulin were examined at baseline and IR was defined based on the homeostasis model assessment-insulin resistance (HOMA-IR), with a cutoff >2.5 for both genders. Linear mixed-effects models were performed to evaluate the influence of HOMA-IR at baseline on BMI changes over time. Models were adjusted for age, pubertal stage, and stratified by sex. RESULTS The sample comprised 65.4% of girls and the prevalence of overweight/obesity was 54.7% among girls and 50.0% among boys. The overall prevalence of IR was 75.3%, of which 60.7% for boys and 83.0% for girls. We found an interaction effect by sex (p = .004) for HOMA-IR as a continuous variable, with a decreased BMI rate of change among boys (β = -0.13; p = .03) but not for girls (β = +0.03; p = .36). Longitudinal BMI changes considering IR status at baseline (IR vs. non-IR) did not demonstrate any statistically significant difference for both boys (-0.1 vs. +0.4; p = .28) and girls (+0.7 vs. +1.0; p = .44). CONCLUSION Increased HOMA-IR values at baseline were associated with greater BMI reduction over time among boys but not girls, with no influence of IR status.
Western diet induces nonalcoholic fatty liver disease and impairs liver mitochondrial metabolism in adult mice
The FASEB Journal, 2015
The Journal of Nutritional Biochemistry, 2014
Nutritional transition has contributed to growing obesity, mainly by changing eating habits of th... more Nutritional transition has contributed to growing obesity, mainly by changing eating habits of the population. The mechanisms by which diet-induced obesity leads to cardiac injury are not completely understood, but it is known that obesity is associated to impaired cardiac function and energy metabolism, increasing morbidity and mortality. Therefore, our study aimed to investigate the mechanisms underlying cardiac metabolism impairment related to Western diet-induced obesity. After weaning, male Swiss mice were fed a Western diet for 16 weeks in order to induce obesity. After this period, the content of proteins involved in heart energy metabolism GLUT1, cytosolic lysate and plasma membrane GLUT4, AMPK, pAMPK, IRβ, IRS-1, PGC-1α, CPT1 and UCP2 was evaluated. Also, the oxidative phosphorylation of myocardial fibers was measured by high-resolution respirometry. Mice in the Western diet group (WG) presented altered biometric parameters compared to those in control group, including higher body weight, increased myocardial lipid deposition and glucose intolerance, which demonstrate the obesogenic role of Western diet. WG presented increased CPT1 and UCP2 contents and decreased IRS-1, plasma membrane GLUT4 and PGC-1α contents. In addition, WG presented cardiac mitochondrial dysfunction and reduced biogenesis, demonstrating a lower capacity of carbohydrates and fatty acid oxidation and also decreased coupling between oxidative phosphorylation and adenosine triphosphate synthesis. Cardiac metabolism impairment related to Western diet-induced obesity is probably due to damaged myocardial oxidative capacity, reduced mitochondrial biogenesis and mitochondria uncoupling, which compromise the bioenergetic metabolism of heart.
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Papers by Tayanne Malafaia