Antiosteoporotic effect of Polycan, β-glucan from Aureobasidium, in ovariectomized osteoporotic mice

Objective We investigated the anti-osteoporotic effects of Polycan, a β-glucan from Aureobasidium pullulans, in ovariectomized mice at doses of 31.25, 62.5, and 125 mg/kg. Methods Polycan was administered orally once a day for 28 d to bilateral ovariectomized mice, beginning 4 wk after surgery. Changes in body weight, bone weight, bone mineral content, bone mineral density, failure load, histologic profiles, and histomorphometric analyses were determined, in addition to serum osteocalcin, calcium, and phosphorus levels. Alendronate was used as a reference drug. Results Polycan significantly and dose-dependently suppressed decreases in bone weight, bone mineral content, failure load, bone mineral density, and serum calcium and phosphorus levels and the increase in serum osteocalcin levels. In addition, Polycan significantly suppressed decreases in histomorphometric parameters such as volume, length, and thickness of trabecular bone and thickness of cortical bone and the increase in osteoclast cells in the femur and tibia. Conclusion Although the effects of Polycan were generally modest and smaller than those of alendronate, the effects on cortical bone thickness were more favorable for Polycan than for alendronate. In addition, Polycan exhibited favorable effects on ovariectomy-induced osteoporosis. However, more long-term studies are needed to confirm the effects of Polycan on osteoporosis.