Abstract
Background. Obesity involves the excessive expansion of white adipose tissue, typically associated with adipocyte hypertrophy and inflammation, especially in visceral depots, a process influenced by sex. Natural compounds like Copaiba’s oil (CO) exhibit anti-inflammatory and anti-adiposity effects, though their impact on white adipose tissue histology is unknown.
Aims. This study evaluated the effect of oral CO supplementation on the histology and content of visceral WAT depots in hypothalamic obese male and female Wistar rats.
Methods. The litter size was adjusted to 6-8 pups per dam (3-4 males and females) at birth. Hypothalamic obesity was induced in the neonatal period via subcutaneous injection of Monosodium L-glutamate (4g.Kg-1). Non-obese group received equimolar saline (1.25 kg-1). Half of the animals from each group received oral CO-supplementation (0.5mL.kg-1; three times/week) from pos natal days 30 to 90, while non-supplemented groups received saline (0.9%) during the same period, via and frequency. At 92 pos natal days, following 12h of fasting, the animals were euthanized, blood samples were collected, and plasma was used to dosage glucose and triglycerides from which the TyG index was calculated to evaluate insulin resistance. Visceral Perigonadal and Perirenal depots were excised, weighed, and analyzed histologically.
Results. CO-supplementation showed nonsignificant effects in non-obese groups (males or females). Obese male and female animals show higher triglycerides, increased insulin resistance, heavier visceral adipose tissue depots, lower adipocyte numbers, and increased hypertrophy than males and females non-obese. Moreover, obese males displayed hyperglycemia compared to non-obese males. CO supplementation's effects were sex-dependent in obese males, CO worsened triglyceride levels without affecting visceral adipose tissue content or histology. Conversely, in obese females, CO supplementation improved triglyceride levels, decreased perigonadal weight, and increased adipocyte numbers in perigonadal and perirenal depots.
Conclusion. Chronic oral CO supplementation does not prevent adipose tissue expansion or metabolic dysfunction in male hypothalamic obese rats. In contrast, obese female CO-supplemented showed a slight reduction in adiposity with increased adipocyte proliferation and improved fasting triglycerides levels, indicating greater responsiveness in females to the beneficial effects of CO on obesity.