LAUSR

ETHNOPHARMACOLOGICAL RELEVANCE As a famous Chinese tonic herb for the bones and joints, the clinical efficacy of Morinda officinalis has shown its advantages in the treatment of bone disease. However, the anti-osteoporosis potential and responsible ingredients of M. officinalis polysaccharides (MOPs) worth further investigation. AIM OF THE STUDY This study aimed to investigate the antiosteoporosis effects of different MOP fractions in ovariectomized (OVX) rats, and identify the responsible osteoprotective ingredients by bioassay-guided isolation. MATERIALS AND METHODS MOPs were prepared by hot water and alkali extraction, separated into three fractions (MO50, MO70, and MOB) and evaluated in the classic OVX rat model and MC3T3-E1 cells for anti-osteoporosis activity. RESULTS Administration of MOPs (400 mg/kg/day) could significantly prevented ovariectomy-induced bone loss, biomechanical reduction, deterioration of trabecular microarchitecture and high levels of bone turnover markers in rats. Bioactivity-guided fractionations led to the isolation of two inulin-type fructans MOW50-1 and MOP50-2 with potential anti-osteoprotic activities from MO50, consisting of (2→1)-linked β-D-fructosyl residues (DP = 7 and 13, respectively). Besides, MOW50-1 promoted the osteogenic differentiation of MC3T3-E1 cells by increasing alkaline phosphatase activity. CONCLUSIONS These data suggest very strongly that MOPs, especially MO50 and MOW50-1, may play an important role in osteoporosis prevention and treatment.