Oral administration of baicalin and geniposide induces regression of atherosclerosis via inhibiting dendritic cells in ApoE-knockout mice

Atherosclerosis is a systemic inflammatory disease characterized by the accumulation of dendritic cells (DCs) and other types of immune cells in atherosclerotic plaque. In this study, baicalin and geniposide were isolated from Scutellaria baicalensis Georgi and Gardenia jasminoids Ellis, which are the plants used in traditional Chinese medicine to treat a variety of inflammatory diseases. We then investigated whether baicalin and geniposide could induce regression of atherosclerotic lesions in ApoE −/− mice fed a high cholesterol diet and used as a model of atherosclerosis. Following model induction, these mice were treated with baicalin (100 mg/kg), geniposide (100 mg/kg), and then a mixture containing baicalin (100 mg/kg) and geniposide (100 mg/kg) administered daily by gavage for a period of 12 weeks. The combined administration of baicalin and geniposide significantly reduced atherosclerotic lesions, and modulated the phenotype of dendritic cells in bone marrow and atherosclerotic plaque. Geniposide lowered both plasma lipid levels and DC numbers, while baicalin administered either alone or in combination with geniposide did not decrease plasma lipids. Our results suggest that baicalin and geniposide may have immune-regulatory effects and prevent the formation of atherosclerotic lesions by decreasing the DC numbers, and inhibit DC maturation in bone marrow and infiltration into lesions.