Naringin Increases Bone Formation

Introduction: Statin, a common anticholesterol drug, a HMG-CoA reductase inhibitor, was shown to turn on the gene for bone formation, however, it occasionally causes serious muscle problems. Naringin is a flavonoid available commonly in citrus fruits which is also a HMG-CoA reductase inhibitor. Objectives: To compare the amount of new bone produced by naringin in collagen (carrier) to that produced by statin in collagen and collagen alone. Methods: Twenty bone defects were created in the parietal bone of 12 New Zealand White rabbits. In the experimental groups, 5 defects were grafted with naringin mixed with collagen, 5 defects were grafted with statin mixed with collagen. In the control groups, 5 defects were grafted with collagen alone (active control) and 5 were left empty (passive control). Animals were killed on day 14 and the defects were dissected and prepared for histological assessment. Serial sections were cut across each defect. Quantitative analysis of new bone formation was made on 150 sections (50 sections for each group) using image analysis. Results: A total of 48% and 490% more new bone was present in defects grafted with naringin in collagen than those grafted with statin in collagen and collagen alone respectively (p<0.0001). No bone was formed in the passive control group. Conclusions: Naringin in collagen have the effect of increasing new bone formation locally, even more than statin, and can be used as a bone graft material. This has tremendous potential as naringin is available commonly in edible fruits. Besides statin, this provided further evidence that blocking the HMG-CoA reductase in the cholesterol production pathway will increase the bone formation. Funded by Research Grant no. 39008.10205789.36170.08003.323.01, University of Hong Kong.