Ginsenoside Rb Enhances Plaque Stability and Inhibits Adventitial Vasa Vasorum via the Modulation of miR-33 and PEDF.

Atherosclerosis is closely associated with proliferation of the adventitial vasa vasorum, leading to the atherosclerotic plaque progression and vulnerability. In this report, we investigated the role of Ginsenoside Rb (Rb) on atherosclerotic plaque stabilization and adventitial vasa vasorum (VV) along with the mechanisms involved. Apolipoprotein E-deficient (ApoE) mice were fed with a high-fat diet for 20 weeks, and then Ginsenoside Rb (50 mg/kg/d, intraperitoneal) was given for 4 weeks. Rb treatment significantly inhibited adventitial VV proliferation, alleviated inflammation, decreased plaque burden, and stabilized atherosclerotic plaques in apoE mice. However, the beneficial effects of Rb on atherosclerotic lesion was attenuated by overexpression of miR-33. The analysis from atherosclerotic plaque revealed that Rb treatment could result in an induction of Pigment epithelium-derived factor (PEDF) expression and reduction of the miR-33 generation. Overexpression of miR-33 significantly reverted the Rb-mediated elevation of PEDF and anti-angiogenic effect. Ginsenoside Rb attenuates plaque growth and enhances plaque stability partially through inhibiting adventitial vasa vasorum proliferation and inflammation in apoE mice. The anti-angiogenic and anti-inflammation effects of Rb are exerted via the modulation of miR-33 and its target gene PEDF.