Naringin exerts antibacterial and anti-inflammatory effects on mice with Staphylococcus aureus-induced osteomyelitis.

Osteomyelitis is an invasive bone infection that can lead to severe pain and even disability, posing a challenge for orthopedic surgery. Naringin can reduce bone-related inflammatory conditions. This study aimed to elucidate the function and mechanism of naringin in a Staphylococcus aureus-induced mouse model of osteomyelitis. Femurs of S. aureus-infected mice were collected after naringin administration and subjected to microcomputed tomography to analyze cortical bone destruction and bone loss. Bacterial growth in femurs was also assessed. Proinflammatory cytokine levels in mouse femurs were measured using enzyme-linked immunosorbent assays. Pathological changes and bone resorption were analyzed using hematoxylin and eosin staining and tartrate-resistant acid phosphatase staining, respectively. Quantitative reverse transcription polymerase chain reaction and western blot analysis were used to quantify the messenger RNA and protein expression of osteogenic differentiation-associated genes in the femurs. The viability of human bone marrow-derived stem cells (hBMSCs) was determined using cell counting kit-8. Alizarin Red S staining and alkaline phosphatase staining were performed to assess the formation of mineralization nodules and bone formation in vitro. Notch signaling-related protein levels in femur tissues and hBMSCs were assessed using western blot analysis. Experimental results revealed that naringin alleviated S. aureus-induced cortical bone destruction and bone loss in mice by increasing the bone volume/total volume ratio. Naringin suppressed S. aureus-induced bacterial growth and inflammation in femurs. Moreover, it alleviated histopathological changes, inhibited bone resorption, and increased the expression of osteogenic markers in osteomyelitic mice. It increased the viability of hBMSCs and promoted their differentiation and bone mineralization in vitro. Furthermore, naringin activated Notch signaling by upregulating the protein levels of Notch1, Jagged1, and Hes1 in the femurs of model mice and S. aureus-stimulated hBMSCs. In conclusion, naringin reduces bacterial growth, inflammation, and bone resorption while upregulating the expression of osteogenic markers in S. aureus-infected mice and hBMSCs by activating Notch signaling.