Lycopene prevents bone loss in ovariectomized rats and increases the number of osteocytes and osteoblasts

Osteoporosis is a prevalent disease with a high incidence in women at the onset of menopause mainly because of hormonal changes, genetics, and lifestyle, leading to decreased bone mass and risk of fractures. Maintaining bone mass is a challenge for postmenopausal women, with calcium-rich food intake being essential for bone health. Nevertheless, other nutrients such as carotenoids may influence bone metabolism because of their high antioxidant properties. This study aimed to evaluate the effect of the carotenoid lycopene on bone cells and in the microarchitecture of ovariectomized rats employing in vitro and in vivo assays. After 8 weeks of ovariectomy, femurs were removed to isolate bone marrow mesenchymal cells to be cultured in osteogenic medium (sham and ovariectomized/OVX) or with 1 μmol/L lycopene (OVX/Lyc). There were performed assays for alkaline phosphatase activity and its in situ detection, mineralization nodules, and quantitative expression of genes associated with osteogenesis. Daily ingestion of 10 mg/kg of lycopene by oral gavage for 8 weeks after ovariectomy was conducted for stereological evaluation of the number and volume of osteoblasts, osteoclasts, and osteocytes of femur distal epiphysis and for microtomographic evaluation of the bone microarchitecture of the femoral proximal epiphysis. Data were normalized and analyzed by comparison among the groups using one-way ANOVA followed by post hoc tests with the significance level set out at 5%. Results showed that lycopene promoted an increase in ALP in situ detection as well as a significant increase in mineralized nodules deposition and expression of genes Runx2 and Bglap when compared with the OVX group. The administration by oral gavage of lycopene increased the total number of osteoblasts and osteocytes when compared to sham and ovariectomized groups. Additionally, it decreased the volume and number of osteoclasts and also reduced the volume of osteocytes compared to the sham group. These results suggest that lycopene improves bone cell metabolism and bone remodeling with the onset of osteoporosis. Future studies with different concentrations and periods of administration should be carried out to shed further light on it.