Chenopodium ambrosioides as a bone graft substitute in rabbits radius fracture

Background: Bone defects caused by trauma, infection or tumor resection are common in orthopedic clinic and depending on the extent of the fracture; the vast majority require treatment with bone substitutes. Among the bone grafts employees, the autograft is defined as the gold standard, but with some limitations, principally related to morbidity at the site of its removal, with the need to search for other biomaterials as adjuvant in bone regeneration. Therefore, the objective of the present study was to evaluate the use of Chenopodium ambrosioides as a bone graft substitute for the osseointegration of fractures in rabbits, compared to other bone grafts already employed in the surgical routine as Ricinus communis (castor oil) polyurethane and autogenous bone marrow. Methods: Forty-eight rabbits were divided into four groups. After anesthesia, a radius fracture was created and the animals were treated with the following grafts: C. ambrosioides graft, autogenous bone marrow, castor oil and saline (control). After 30, 60 and 90 days, the animals were submitted to radiographical and histological analyses and bone alkaline phosphatase, osteocalcin, biomechanical tension, and collagen were measured. We also realized a phytochemical screening and in vitro antioxidant activity including 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radical. Results: The data showed that the growth of the bone callus was more expressive and biomechanical assessment showed better tensile strength in C. ambrosioides graft. The experimental results also revealed that there was significantly greater activity of the bone alkaline phosphatase and osteocalcin during early fracture healing, similarly to the group receiving autogenous bone marrow. Histologically, immature bone was observed in C. ambrosioides graft at 30 days, whereas the formation of cartilaginous tissue predominated in the other groups. A higher amount of type I collagen was observed in C. ambrosioides graft throughout treatment. It was detected strong presence of flavonoids and appreciable antioxidant activity. Conclusions: The results indicate that C. ambrosioides graft and autogenous bone marrow have similar ability to enhance bone regeneration, higher than the castor oil graft, suggesting that the medicinal plant can provide therapeutic benefits for bone tissue.