Dietary oleuropein supplementation affects lipolysis in broilers

Oleuropein, a phenolic compound derived from olives, was investigated for its effects on the adipose tissue physiology of broiler chickens during the initial 10 days post-hatch. We hypothesized that oleuropein could modulate the adipose tissue of the chicken due to its known bioactive properties. Sixty-eight day-of-hatch Cobb-Hubbard broilers were randomly divided into treatment groups receiving different amounts of oleuropein (0, 125, 250, or 500 mg/kg of commercial starter diet). Diets were fed ad-lib and on day 10 post-hatch, blood and adipose tissue samples (abdominal and subcutaneous) were collected from 12 broilers in each group. Plasma was collected to measure non-esterified fatty acids (NEFA) concentrations. The mRNA levels of key regulators of adipogenesis and lipolysis were assessed by real-time PCR. At day 10, body weights were lower in the 125 and 250-dose groups. In both adipose tissue depots, lipolytic enzyme adipose triglyceride lipase (ATGL) mRNA was higher in the 125-dose group compared to other groups. Diacylglycerol O-acyltransferase 2 (DGAT2) and peroxisome proliferator-activated receptor γ (PPARγ) were lower in the 125-dose group relative to other groups. Plasma NEFAs were greater in the 125-dose group than in the other groups. This suggests that oleuropein has pro-lipolytic and anti-adipogenic properties and may provide a means to reduce excessive adipose tissue accumulation in broilers.