Geniposide regulates the miR-101/MKP-1/p38 pathway and alleviates atherosclerosis inflammatory injury in ApoE-/- mice

•Geniposide ameliorates hepatocyte fatty degeneration and increases plaque stability.•Geniposide regulates the expression of certain miRNAs in inflammation.•Geniposide increases the protein expression of MKP-1, a target of miR-101, in ApoE−/− mice and Raw264.7 cells induced by LPS.•Geniposide downregulates the transcriptional level of miR-101 and suppresses the levels of inflammatory factors in the presence of the miR-101 mimic. Atherosclerosis (AS) is the common pathological basis of chronic cardiovascular diseases and is associated with inflammation and lipid metabolism dysfunction. Geniposide, the main active ingredient of Gardenia jasminoides Ellis fruit, exhibits a variety of anti-inflammatory and anti-oxidative functions; however, its role in AS remains unclear. The aim of this study was to investigate the mechanisms of geniposide in alleviating inflammation and thereby attenuating the development of AS. ApoE−/− mice were fed a high fat diet to induce AS and were treated with geniposide (50 mg/kg) for 12 weeks. Blood glucose and lipid levels were measured by biochemical analysis. H&E, Masson and Oil red O staining were performed to observe morphological changes and lipid deposition in the aorta and liver. Serum inflammatory cytokines were detected by ELISA. Dual-luciferase reporter gene assay was used to verify the target relationship between microRNA-101 (miR-101) and mitogen-activated protein kinase phosphatase-1 (MKP-1). The levels of miR-101, p-p38, and MKP-1 in the aorta were detected by qPCR and western blotting. The anti-inflammatory effect of geniposide in vitro was investigated in the RAW264.7 macrophage cell line. A miR-101 mimic and an inhibitor were used to study the effect of miR-101 on regulating the expression of the target MKP-1 and the downstream inflammatory cytokines. Geniposide treatment reduced lipid levels and plaque size in the mouse model of AS. Geniposide downregulated miR-101 to upregulate MKP-1 and suppress the production of inflammatory factors in vitro and in vivo. Geniposide suppressed the levels of inflammatory factors in the presence of the miR-101 mimic, whereas no obvious effect was observed in the miR-101 inhibitor group. We concluded that geniposide reduced the plaque size and alleviated inflammatory injury in ApoE−/− mice and RAW264.7 cells. The specific anti-inflammatory mechanism was related to the miR-101/ MKP-1/p38 signaling pathway.