Objective: The present study was aimed to evaluate the anti-osteoporotic activity of methanolic extract of NR/CAL/06 in ovariectomized (OVX) rats.
Methods: Bilateral ovariectomy was performed in female Sprague-Dawley rats under aseptic conditions and the rats were divided into five groups (n=10). Two different doses of methanolic extract of NR/CAL/06 (200 and 400 mg/kg, per oral (p.o.)) were evaluated for anti-osteoporotic activity and raloxifene (5.4 mg/kg, p.o.) was used as a reference standard. Treatment was given for 90 d. Anti-osteoporotic potential of NR/CAL/06 was evaluated based on various parameters, namely, body weight, organ weight, bone weight, bone mineral content, bone strength, calcium and phosphorus in serum and urine, and serum alkaline phosphatase (ALP). External diameter, length and thickness of the femur bone were measured by using scanning electron microscopy (SEM).
Results: The bilateral ovariectomy in rats resulted in decreased bone strength, bone mineral content and bone weight. The SEM images showed porous, perforated and disintegrated femur bone architecture and decreases in bone length and thickness in OVX rats. These changes were associated with elevated serum levels of calcium, phosphorus and ALP. Increases in body weight and adipose weight and a decrease in uterine weight were also observed and the changes were highly significant when compared with the sham-control group. Treatment with methanolic extract of NR/CAL/06 (200 and 400 mg/kg, p.o.) for 90 d dose-dependently restored the ovariectomy-induced alterations in bone weight, bone mineral content, bone strength, serum calcium, phosphorus and ALP, body weight and adipose weight nearly to normal levels. Furthermore, the SEM images of the femur bones of NR/CAL/06 (200 and 400 mg/kg, p.o.)-treated rats showed reduced pore formation and improved bone compactness compared with the OVX-control group.
Conclusion: These findings suggest that the methanolic extract of NR/CAL/06 possesses significant anti-osteoporotic activity and may be useful in the treatment of osteoporosis.