Abstract:

Objective: To evaluate the improvement effect of sialoglycoprotein from crucian carp (Carassius auratus)
spawn on osteoporosis in ovariectomized female rats and to explore the underlying mechanism. Methods: The animal
model of osteoporosis was established by removing bilateral ovaries. The rats were intragastrically administered with the
sialoglycoprotein at a daily dosage of 400 mg/(kg·d) for 90 days. At the end of the experiment, serum and urine indexes
indicating bone absorption and formation, and osteoprotegerin (OPG) level, receptor activator for nuclear factor-κB (RANK)
and receptor activator for nuclear factor-κB ligand (RANKL) in serum were determined. Results: Sialoglycoprotein from
crucian carp spawn showed a suppressive effect on the contents of deoxypyridinoline, calcium and phosphorus in urine and
the activity of tartrate-resistant acid phosphatase and cathepsin-K in serum associated with bone absorption, the activity of
bone alkaline phosphatase and the contents of osteocalcin, propeptide carboxy-terminal procollagen in serum associated with
bone formation. Meanwhile, it also up-regulated the contents of OPG, down-regulated the contents of RANKL and decreased the
ratio of RANKL to OPG. Therefore, the sialoglycoprotein could prevent bone absorption in ovariectomized rats with osteoporosis
and inhibit its high bone turnover rate. Conclusion: Sialoglycoprotein from crucian carp spawn could prevent osteoporosis of
ovariectomized rats, and its functional mechanism is probably related to the decrease of RANKL/OPG ratio.

Key words: Carassius auratus spawn, sialoglycoprotein, ovariectomized rats, bone turnover, osteoprotegerin, receptor activator for nuclear factor-κB ligand