Chenopodium ambrosioides L. (Amaranthaceae), popularly known as "mastruz" or "erva-de-santa-maria", is a perennial plant found in Brazil and used in folk medicine for the treatment of contusions and fractures. The objective of this study was to evaluate the topical effect of a cataplasm prepared from fresh C. ambrosioides leaves on the treatment of fractures experimentally induced in rabbits. Thirty rabbits were divided into three groups (n = 10). After anesthesia, a radius fracture was created and the animals received topical applications of C. ambrosioides cataplasm (MZG), diclofenac sodium (DG) and isotonic solution 0.9% NaCl (Control). At 30 days, we evaluated the animal bone regeneration through both qualitative macroscopic analysis of the fracture focus as by determination of serum alkaline phosphatase (ALP). The evolution of bone repair has been verified at 30 and 45 days through the histological analysis. No significant difference in ALP levels was observed between groups. In addition, no allergic reactions or impairment of tissue adjacent to the fracture focus were seen in any of the groups. In contrast, although all groups exhibited similar tissue architecture, the histological analysis revealed greater formation of mature bone tissue in MZG at 30 days, when compared to DG and control group. In addition, higher collagen fiber density was observed in MZG at 45 days. These results indicate Chenopodium ambrosioides as a promising therapeutic agent for bone regeneration. The plant may be useful as a raw material for the production of biomaterials for fracture healing, contributing to its validation in ethnomedicine.

BackgroundBone 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.MethodsForty-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.ResultsThe 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.ConclusionsThe 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.