The present study aimed to investigate the protective effects of Polycan, a β-glucan from Aureobasidium pullulans SM-2001, in a rat model of ovariectomy-induced osteoporosis. Ovariectomized (OVX) rats were orally administered 31.25, 62.5 or 125 mg/kg/day Polycan for 126 days, and alterations in body weight, bone mineral content, bone mineral density, failure load, histological profiles and histomorphometric indices were analyzed. In particular, serum levels of osteocalcin, bone-specific alkaline phosphatase (bALP), calcium and phosphorus, and the urine deoxypyridinoline/creatinine ratio, were measured. Furthermore, the femur, tibia and lumbar vertebrae were harvested from all rats, and histomorphometrical analyses were conducted in order to assess the mass and structure of the bones, and the rates of bone resorption and formation. One group of rats was treated with alendronate, which served as the reference drug. The results of the present study suggested that Polycan treatment was able to inhibit ovariectomy-induced alterations in bone resorption and turnover in a dose-dependent manner. In addition, the serum expression levels of bALP and all histomorphometrical indices for bone formation were markedly increased in the Polycan-treated groups. These results indicated that Polycan was able to preserve bone mass and strength, and increase the rate of bone formation in OVX rats; thus suggesting that Polycan may be considered a potential effective anti-osteoporosis agent.

The aim of the present study was to investigate the optimum composition of Polycan (β-glucan complex) and calcium lactate-gluconate (CaLG) that exhibited the most beneficial effects in ovariectomy (OVX)-induced osteoporotic rats. Polycan and CaLG single formulas (100 mg/kg each), and three doses (50, 100 and 200 mg/kg) of three mixed formulas [polycan:CaLG (PCLG)=1:99, 5:95 and 10:90] were orally administered once a day for 84 days. The effects of the test materials were compared with those of a risedronate sodium-treated group. OVX resulted in an increase in body weight, decreased bone formation, elevated serum osteocalcin levels and urine deoxypyridinoline/creatinine ratio, as well as decreased serum bone-specific alkaline phosphatase levels, femur indices, bone mineral content, bone mineral density and failure load. However, these OVX-induced osteoporotic changes markedly decreased following the administration of the test materials. Continuous oral treatment of Polycan or CaLG single formulas and the PCLG mixed formulas preserved bone mass and strength. The PCLG 10:90 mixed formula exhibited the most favorable synergistic antiosteoporotic effects in the OVX-induced osteoporotic rats as compared with equal doses of the Polycan or CaLG single formulas.