Ginsenoside Rh1 Induces Mouse Osteoblast Growth and Differentiation Through the Bone Morphogenetic Protein 2/runt-related Gene 2 Signalling Pathway

Objectives: This study aimed to investigate the stimulative and pharmacological effects of ginsenoside Rh1 (hereinafter referred to as: Rh1) on differentiation and mineralization of osteoblast and its possible mechanism of action on the expression of bone morphogenetic protein 2 (BMP-2)/Runt-related gene 2 (Runx2) signalling pathways using mouse preosteoblastic MC3T3-E1 cell line as in-vitro model.

Methods: An in-vitro stimulative activity of Rh1 was assessed by analyzing alkaline phosphatase activity (ALP), type-I collagen (Coll-I) synthesis, mineralization and glutathione content. Its antioxidant activity was measured by evaluating the reactive oxygen species (ROS) production in the presence of antimycin A (AMA), one of the mitochondrial dysfunction factors. The level of BMP-2/Runx2 signal-regulated osteoblast-specific proteins such as osteocalcin (OCN), Coll-I and ALP were detected using Western blot analysis.

Key Findings: Rh1 was capable to stimulate cell growth, ALP activity, Coll-I synthesis, mineralization and glutathione content in the MC3T3-E1 cells. BMP-2 and Runx2 expression were also increased by Rh1 concentration dependently. Additionally, Rh1 also showed inhibitory action on the level of ROS production enhanced by AMA in MC3T3-E1 cells. Rh1 could increase the expression level of BMP-2/Runx2 signal-regulated osteogenic markers such as ALP, Coll-I and OCN.

Conclusions: Rh1, a protopanaxatriol type's active ingredients of Panax ginseng Meyer, possesses osteoblast differentiation, osteogenic stimulatory and anti-oxidative activity.