Lack of Beneficial Effects of Epicatechin in Obese Male and Female Mice

Recent reports highlight the potential antiobesity effects of epicatechin (EC) in metabolism regulation. Most studies use rodent models housed at standard temperatures (ST) of 22 °C ± 2 °C, which may induce chronic cold exposure, affecting metabolism. Housing mice at thermoneutrality (TN) of 28 °C ± 2 °C may better reflect human conditions. Many studies also focus only on males, overlooking sex differences in metabolic dysregulation. We studied male and female C57Bl/6 mice, lean and obese, receiving 12 or 20 mg/kg EC by gavage for 12 weeks at ST or TN. Contrary to prior findings, EC had no antiobesity effects. Mice showed similar weight gain, adiposity, biochemical profiles, and liver fat as untreated controls. Obese males given 20 mg of EC at TN exhibited increased subcutaneous fat and worsened glucose tolerance. Thus, EC gavage did not improve obesity, steatosis, or insulin resistance, suggesting that the administration route and dosage may critically modulate its effects.