A fructooligosaccharide from Achyranthes bidentata inhibits osteoporosis by stimulating bone formation.

Achyranthes bidentata is used as a medicinal herb prescribed for the treatment of osteoporosis in China. The anti-osteoporosis activity of the crude polysaccharide from A. bidentata, AB50, was evaluated by ovariectomized rats. The results indicated that AB50 has prominent osteoprotective effects, which was comparable to positive control. To further explore which ingredients are responsible for these effects, a novel fructan, ABW50-1 (1260 Da), was purified for the first time and characterized by chemical methods and nuclear magnetic resonance. The results revealed that ABW50-1 was composed of →2)-β-D-Fruf-(1→, →2)-β-D-Fruf-(1, 6→ and →2)-β-D-Fruf-(6→, terminated with Glu and Fru residues. Morphological analyses indicated that ABW50-1 was fragmented and contained a branched structure. Furthermore, ABW50-1 significantly increased the relative fluorescence intensity of bone mass, without side effects, in a zebrafish model of glucocorticoid-induced osteoporosis (GIOP). Thus, ABW50-1 shows potential for developing new anti-osteoporosis agents for osteoporosis therapy.