Abstract
Obesity-associated chronic inflammation contributes to metabolic dysfunction and propagates atherosclerosis. Recent evidence suggests that increased dietary cholesterol exacerbates inflammation in adipose tissue and liver, contributing to the proatherogenic milieu. The ability of the citrus flavonoid naringenin to prevent these cholesterol-induced perturbations is unknown. To assess the ability of naringenin to prevent the amplified inflammatory response and atherosclerosis induced by dietary cholesterol, male Ldlr⁻/⁻ mice were fed either a cholesterol-enriched high-fat or low-fat diet supplemented with 3% naringenin for 12 weeks. Naringenin, through induction of hepatic fatty acid (FA) oxidation and attenuation of FA synthesis, prevented hepatic steatosis, hepatic VLDL overproduction, and hyperlipidemia induced by both cholesterol-rich diets. Naringenin attenuated hepatic macrophage infiltration and inflammation stimulated by dietary cholesterol. Insulin resistance, adipose tissue expansion, and inflammation were alleviated by naringenin. Naringenin attenuated the cholesterol-induced formation of both foam cells and expression of inflammatory markers in peritoneal macrophages. Naringenin significantly decreased atherosclerosis and inhibited the formation of complex lesions, which was associated with normalized aortic lipids and a reversal of aortic inflammation. We demonstrate that in mice fed cholesterol-enriched diets, naringenin attenuates peripheral and systemic inflammation, leading to protection from atherosclerosis. These studies offer a therapeutically relevant alternative for the prevention of cholesterol-induced metabolic dysregulation.