Effects of Morinda officinalis Polysaccharides on the Proliferation and Viability of Osteoblasts in Rats with Osteoporosis

Abstract

Qiao et al.: Effects of Morinda officinalis Polysaccharides in RatsWe aimed to evaluate the effects of Morinda officinalis polysaccharides on the proliferation and viability of osteoblasts in rats with osteoporosis. 24 non-parous Sprague-Dawley rats were assigned into normal, model, low-dose and high-dose Morinda officinalis polysaccharide groups. The model of osteoporosis was established by ovariectomy. After successful modeling, 50 mg/kg and 75 mg/kg Morinda officinalis polysaccharides were subcutaneously injected in low-dose and high-dose Morinda officinalis polysaccharide groups, respectively. After 3 w of intervention, osteoblasts were prepared using the skull and their proliferation index and alkaline phosphatase activity were measured. The histopathological changes in femoral tissues were observed. The bone mineral density and levels of serum osteocalcin, calcium and phosphorus, as well as the protein levels of receptor activator of nuclear factor kappa-B, receptor activator of nuclear factor kappa-B ligand and osteoprotegerin were determined. The proliferation index and alkaline phosphatase activity were highest in high-dose Morinda officinalis polysaccharide group (p<0.05). Bone tissues had decreased cell spaces and gradually reduced spaces between the medullary cavities inMorinda officinalis polysaccharide groups. Model group had the highest bone mineral density and levels of serum osteocalcin, calcium and phosphorus (p<0.05). The protein expression levels of receptor activator of nuclear factor kappa-B ligand and receptor activator of nuclear factor kappa-B showed a decreasing trend, while that of osteoprotegerin displayed a rising trend sequentially in model, low-dose, high-dose Morinda officinalis polysaccharide and normal groups (p<0.05). Morinda officinalis polysaccharides promotes the proliferation of osteoblasts, enhances their viability and maintains the balance between bone resorption and formation in rats with osteoporosis probably by modulating the protein expression of the receptor activator of nuclear factor kappa-B ligand/receptor activator of nuclear factor kappa-B/osteoprotegerin pathway.