BENS, a novel regulator of bone/cartilage healing

Abstract

Enhancing osteoblast proliferation, survival, and extracellular matrix protein secretion are potential therapeutic approaches to treat bone fractures and diseases such as osteoporosis. BENS is a traditional medicine used in many countries such as India for thousands of years to treat many diseases including bone diseases. In this study, molecular, cell-based and in vivo approaches were utilized to investigate the effects of BENS on bone and cartilage regeneration. An osteosarcoma cell line (MG63) was incubated in serum free media with and without 0.8 mg/ml of BENS. BENS significantly increased cell survival up to 30 days and these cells retained their ability to proliferate in fresh media with serum. After adding BENS, there were statistically significant decreases in the expression of both anti-apoptotic and pro-apoptotic proteins. An in vivo non-critical size segmental bone defect Xenopus system was used to evaluate the ability of BENS to enhance cartilage formation. After a small segment of the anterior hemisection of the tarsus bone was excised, the frogs were divided into three groups and given subcutaneous injections of either phosphate-buffered saline or BENS once daily for 30 days and then bone/cartilage formation evaluated. The total cartilage area/total section area was significantly increased (2.6 fold) in the BENS treated samples. In an osteoporotic rat model, the anabolic properties of BENS on bone mass were assessed by histomorphometric analyses. Ovariectomized (OVX) rats received daily intraperitoneal injections for 4 weeks. Bone formation rates (BFRs) for the cortical periosteal bone surface of the midshaft tibia were 383.2, 223.9, 308.8, 304.9, and 370.9 µm3/µm2/year, and for the trabecular surface were 82.2, 113, 212.1, 157, and 165 µm3/µm2/year for the sham, OVX, PTH, 3 mg/kg BENS, and 30 mg/kg BENS groups, respectively. BENS increased both trabecular and cortical BFRs. It generated better results on cortical periosteal bone surface than did PTH. Taken together, these findings suggest that BENS promotes osteoblast survival due to its effects on altering the balance between pro-apoptotic and anti-apoptotic proteins. In addition, in vivo studies revealed that BENS enhanced cartilage formation in Xenopus and BFRs in rats. Therefore, BENS may possess anabolic bone/cartilage properties.