Antiosteoporotic effect of sequential extracts and freeze-dried juice of Cissus quadrangularis L. in ovariectomized mice

Background: Osteoporosis becomes a major health problem in aging populations, and this disease increases the risk of bone fractures, leading to disability and mortality. Cissus quadrangularis L. (CQ) has been reported to have beneficial effects on bone metabolism; however, there has been no investigation to identify the active compounds responsible for this activity. Objective: Sequential extracts (hexane, dichloromethane, ethanol, and water) and freeze-dried CQ juice were investigated to determine their effects on bone metabolism in an ovariectomized (ovx) mouse model. Methods: Six-week-old ICR mice were divided into eight groups: sham-operated, ovx-control, estradiol (E-2)-treated and five CQ-treated ovx-mouse groups (n = 3). The CQ extracts were orally administered at a dose equivalent to 5g of crude powder/kg/day for 8 weeks. Bone mineral densities (BMD) of the femur and tibia, serum levels of osteocalcin (bone formation marker) and TRAP5b (bone resorption marker), and histomorphological change of lumbar spine were determined at the end of the experiment. Results: The BMD of the femur and tibia in the hexane-treated group were elevated to the same level as those of sham-operated group. This BMDs correlated with restoration of the trabecular bone of the lumbar spine, which was only observed in the hexane-treated group. These results were also supported by the lowest serum levels of osteocalcin and TRAP5b observed in this group, compared to the ovx-control and E-2-treated groups, representing a decrease in the bone turnover rate. Neither signs of abnormality nor pathological changes of internal organs were observed after the experiment. Conclusion: The hexane extract possessed antiosteoporotic activity in ovariectomized mice without any toxicity throughout the experiment. Therefore, the hexane extract is the most interesting for further bioassay-guided purification of pharmacologically active compounds.