Polygonatum sibiricum polysaccharide inhibits osteoporosis by promoting osteoblast formation and blocking osteoclastogenesis through Wnt/β-catenin signalling pathway.

Li Du,Jin-Min Zhao,Shao-Hui Zong,Gao-Feng Zeng,Meng-Ni Nong,Xiao-Ming Peng

doi:10.1038/srep32261

Abstract

Bone homeostasis is maintained by a balance between bone formation by osteoblasts and bone resorption by osteoclasts. Osteoporosis occurs when osteoclast activity surpasses osteoblast activity. Our previous studies showed the plant-derived natural polysaccharide (Polygonatum sibiricum polysaccharide or PSP) had significant anti-ovariectomy (OVX)-induced osteoporosis effects in vivo, but the mechanisms of PSP’s anti-osteoporosis effect remains unclear. In this study, we assessed PSP’s effect on the generation of osteoblast and osteoclast in vitro. This study showed that PSP promoted the osteogenic differentiation of mouse bone marrow stromal cells (BMSCs) without affecting BMPs signaling pathway. This effect was due to the increased nuclear accumulation of β-catenin, resulting in a higher expression of osteoblast-related genes. Furthermore, the study showed PSP could inhibit the receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclastogenesis and exert prophylatic protection against LPS-induced osteolysis in vivo. This effect was also related to the increased nuclear accumulation of β-catenin, resulting in the decreased expression of osteoclast-related genes. In conclusion, our results showed that PSP effectively promoted the osteogenic differentiation of mouse BMSCs and suppressed osteoclastogenesis; therefore, it could be used to treat osteoporosis.

Highlights

Polygonatum sibiricum, which could have anti-inflammatory characteristics[9] and attenuate amyloid-β-induced neurotoxicity[10]; there is little research on PSP’s effect on osteoporosis
We found that PSP had the ability to promote osteoblast formation and inhibit osteoclast formation probably through Wnt/β-catenin pathway
We primarily explored the effect of PSP on osteoblast formation

Summary

Introduction

Polygonatum sibiricum, which could have anti-inflammatory characteristics[9] and attenuate amyloid-β-induced neurotoxicity[10]; there is little research on PSP’s effect on osteoporosis. The increased nuclear accumulation of β-catenin has a significant role in promoting osteoblast differentiation and bone formation[13]. The increased nuclear accumulation of β-catenin inhibits osteoclast differentiation[14]. We found that bone loss was reversed and osteoporosis was prevented in vivo by administrating PSP to ovariectomized rats[15]; the mechanisms of PSP’s anti-osteoporosis effects remain unclear. We tried to assess the effects of PSP on the generation of osteoblast and osteoclast in vitro, and initially explore whether Wnt/β-catenin pathway was required in the therapeutic action of PSP on osteoporosis

Methods

Results

Conclusion