Naringenin attenuates carotid restenosis in rats after balloon injury through its anti-inflammation and anti-oxidative effects via the RIP1-RIP3-MLKL signaling pathway

Vascular restenosis has been proved as the major drawback of percutaneous coronary interventions, which is characterized by neointimal hyperplasia. Naringenin is a kind of natural dihydroflavonoid with a variety of beneficial effects, including anti-oxidative, anti-microbial, anti-cancer and anti-inflammatory properties. However, the effects of naringenin on vascular restenosis remain unclear. This study aimed at investigating the effect and the mechanisms of naringenin on balloon injury (BI)-induced neointimal hyperplasia in the common carotid artery (CCA). BI model of CCA was induced by a 2F Forgarty catheter balloon, and the pathological process of neointimal hyperplasia was noted at 1, 3, 7 and 14 days. Neointimal hyperplasia in CCA increased significantly, especially on day 14 after BI. Subsequently, naringenin (25, 50, 100 mg/kg/d)or volume-matched vehicle were administered to the rats by gavage daily for 14 days. Ultrasound detection and histopathological examination showed that naringenin dose-dependently inhibited BI-induced intimal hyperplasia, as evidenced by reducing imima-media thickness (IMT), neointimal area (NIA), neointimal area/media area (NIA/MA)and neointimal area/internal elastic area (NIA/IELA). Immunohistochemistry revealed that naringenin decreased the expression of proliferating cell nuclear antigen (PCNA)and the cluster of differentiation 163 (CD163). ELISA indicated naringenin significantly reduced the overproduction of IL-1β and TNF-α. By detecting the activity of superoxide dismutase and the level of malondialdehyde and glutathione, we found that naringenin attenuated BI-induced oxidative stress. Additionally, RT-qPCR demonstrated that receptor-interacting protein 1 (RIP1), RIP3 and mixed lineage kinase domain-like (MLKL)mRNA expression were further down-regulated by naringenin treatment. These results suggested that naringenin can suppress BI-induced vascular neointimal hyperplasia through anti-inflammation and anti-oxidative stress, which may be related to the regulation of RIP1-RIP3-MLKL signaling pathway.