Lycopene influences osteoblast functional activity and prevents femur bone loss in female rats submitted to an experimental model of osteoporosis.

Antioxidant properties of several nutrients may influence bone metabolism, affording protection against damaging effects caused by oxidative stress. Thus, we hypothesized that lycopene may benefit bone tissue metabolism and functional activity of osteoblastic cells from bone marrow of osteoporotic female rats. Wistar rats were ovariectomized and paired with sham animals. In vitro evaluations were performed after 60 days of surgery, when cells were cultured in osteogenic medium and divided in control (C), ovariectomized (OVX) and ovariectomized + 1 µmol/L lycopene (OVXL) groups. Besides, in vivo studies were carried out to evaluate femur bone remodeling by histological and histomorphometric analyses after daily intake of 10 mg/kg of lycopene for 30 and 60 days after ovariectomy. Cell proliferation was significantly higher in OVX and OVXL groups after 10 days of culture. Alkaline phosphatase activity (ALP) was higher in OVXL group in later periods of cell culture, whereas its in situ detection was higher for this group in all experimental periods; nevertheless, mineralization did not show significant differences among the groups. There was a significant upregulation of genes Sp7, Runx2 and Bsp after 3 days and genes Runx2 and Bglap after 10 days from OVXL when compared to OVX. In vivo results demonstrated that daily intake of 10 mg/kg of lycopene for 60 days decreased bone loss in femur epiphysis in ovariectomized rats by maintaining trabecular bone similar to controls. Data obtained suggest that lycopene might benefit the functional activity of osteoblastic cells from ovariectomized rats, as well as avoid further bone resorption.

Influence of collagen membrane on bone quality in titanium mesh reconstructions-Study in rats.

BACKGROUND: New bone formation and tissue remodeling are the major challenges in implantology today. Titanium meshes have demonstrated reconstructive potential for vertical bone gain. However, the soft tissue healing is technically sensitive to the surgical procedure. The combined usage of collagen membrane and specification of the meshes may ensure greater predictability. Therefore, this study aims to evaluate the influence of collagen membrane on the quality of the new bone formation in guided bone regeneration (GBR) procedures with different titanium meshes. METHODS: Twenty-eight Wistar rats were randomly allocated into four main experimental groups, according to mesh pore size in µm: Group P300 (titanium meshes, with 0.3-mm thickness and 3-mm pore size; n = 7); Group P175 (titanium meshes, with 0.3-mm thickness and 1.75-mm pore size; n = 7); Group P85: (titanium meshes, with 0.04-mm thickness and 0.85-mm pore size; n = 7); Group P15: (titanium meshes. with 0.04-mm thickness and 0.15-mm pore size; n = 7). The femurs of each animal were subdivided into test and control groups: Test: bovine bone graft associated with porcine collagen and collagen membrane was used; control: bovine bone graft associated with porcine collagen was used without association with collagen membrane. Bone quality evaluation by in vivo microtomography and histologic analysis were performed. RESULTS: Bone volume formation was similar between groups (P >0.05). However, the titanium meshes with pore size >1 mm demonstrated higher mineral bone density in comparison with meshes with pore size <1 mm (P <0.05), regardless of the combined usage of collagen membrane. All groups showed a spongy bone formation after 30 days. CONCLUSIONS: Combined usage of collagen membrane in GBR procedures with titanium mesh did not show improvements in new bone quality in rat femur model. However, titanium mesh pore size specifications may influence bone quality.