Naringin protects against steroid-induced avascular necrosis of the femoral head through upregulation of PPARγ and activation of the Notch signaling pathway

Naringin, a flavonoid, is the effective pharmaceutical ingredient of drynaria, with the effects of healing fractures, strengthening bones and promoting kidney function. The aim of the present study was to investigate the potential effect of naringin on steroid-induced avascular necrosis of the femoral head (SANFH). Treatment with naringin markedly protected against the steroid-induced decrease in serum osteocalcin levels, and the rate of osteonecrosis in a model of SANFH. In addition, naringin decreased the total cholesterol and low density lipoprotein/high density lipoprotein ratio in the SANFH rabbit. It was observed that naringin markedly inhibited caspase-3 activity, increased runt-related transcription factor gamma 2 and transcription factor sp7 mRNA expression, promoted alkaline phosphatase activity and upregulated collagen I, peroxisome proliferator-activated receptor (PPAR) gamma 2, neurogenic locus notch homolog protein (Notch), beta-catenin and phosphorylated-Rac-alpha serine/threonine protein kinase protein expression in the SANFH rabbit. The results of the present study demonstrated that naringin protects against SANFH through upregulation of PPAR gamma 2 and activation of the Notch signaling pathway, and may be a useful addition to the treatment options for diseases of the femoral head.