Valproic acid, A Potential Inducer of Osteogenesis in Mouse Mesenchymal Stem Cells

Background: Recent reports have unveiled the potential of flavonoids to enhance bone formation and assuage bone resorption due to their involvement in cell signaling pathways. They also act as an effective alternative to circumvent the disadvantages associated with existing treatment methods, which has increased their scope in orthopedic research. Valproic acid (VA, 2-propylpentanoic acid) is one such flavonoid, obtained from an herbaceous plant, used in the treatment of epilepsy and various types of seizures.

Objective: In this study, the role of VA in osteogenesis and the molecular mechanisms underpinning its action in mouse mesenchymal stem cells (mMSCs) were determined.

Methods & results: Cytotoxic studies validated VA's amiable nature in mMSCs. Alizarin red and von Kossa staining results showed an increased deposition of calcium phosphate in VA-treated mMSCs, which confirmed the occurrence of osteoblast differentiation and mineralization at a cellular level. At the molecular level, there were increased levels of expression of Runx2, a vital bone transcription factor, and other major osteoblast differentiation marker genes in the VAtreated mMSCs. Further, VA-treatment in mMSCs upregulated mir-21 and activated the mitogen-activated protein kinase/extracellular signal-regulated kinase signaling pathway, which might be essential for the expression/activity of Runx2.

Conclusion: Thus, the current study confirmed the osteoinductive nature of VA at the cellular and molecular levels, opening the possibility for its application in bone therapeutics with mir-21.

Keywords: Osteogenesis; Phytocompound; Runx2; Valproic acid; mMSC; mir-21.