Ginsenoside Re promotes osteogenic differentiation via BMP2/p38 pathway in vivo and in vitro

Abstract

Background

Ginsenosides have been used in traditional Chinese medicine to treat fractures. Ginsenoside Re, a key component of P. ginseng, however, the molecular mechanisms underlying these effects remain inadequately understood. This study aims to investigate the effects of Ginsenoside Re on bone formation in fractures and to explore the underlying molecular mechanisms involved.

Methods

Cell proliferation and osteogenic differentiation were evaluated using the Cell Counting Kit-8 (CCK-8) assay and alkaline phosphatase (ALP) staining, respectively. Quantitative PCR (qPCR) and western blotting were employed to quantify mRNA and protein expression levels. To assess bone formation in vivo, a zebrafish caudal fin regeneration model was utilized, with calcein staining applied to visualize mineralized tissue. Additionally, a bone morphogenetic protein 2a (bmp2a) knockout zebrafish model was generated using the CRISPR-Cas9 system to further investigate the molecular mechanisms underlying ginsenoside Re-mediated bone formation.

Results

Ginsenoside Re promotes normal development and survival in zebrafish. In a zebrafish model, ginsenoside Re enhances bone regeneration, accompanied by upregulated expression of osteogenic markers. Following a 10-day treatment with 20 μM ginsenoside Re, mRNA sequencing (mRNA-Seq) analysis identified bmp2a as a critical regulator of bone formation. In vitro, ginsenoside Re stimulates osteogenic differentiation in MC3T3-E1 cells, elevating both mRNA and protein levels of bone morphogenetic protein 2 (BMP2). Co-treatment with noggin or SB203580 reverses ginsenoside Re-induced osteogenesis: noggin suppresses BMP2 expression and p38 phosphorylation, whereas SB203580 specifically inhibits p38 activity. In a bmp2a knockout zebrafish model, the pro-osteogenic effects of ginsenoside Re are completely abolished. Similarly, in wild-type zebrafish, both noggin and SB203580 attenuate the bone-promoting effects of ginsenoside Re. Noggin reduces the expression of bmp2a and p38a, while SB203580 specifically targets p38a.

Conclusions

In conclusion, our findings demonstrate, for the first time, that ginsenoside Re at an optimal concentration of 20 μM enhances bone formation by modulating the osteogenic system. Mechanistically, we reveal that this pro-osteogenic effect is mediated through the BMP2/p38 signaling pathway.