Evaluation of the Osteogenic Potential of Apigenin via Inducing Autophagy: An In Vitro Study

The present study aimed to evaluate the effect of apigenin (Api) on the osteogenic differentiation of adipose tissue-derived mesenchymal stem cells (ASCs) by stimulating autophagy. ASCs were isolated from fresh adipose tissues using mechanical and enzymatic digestion and characterized using flow cytometry. ASCs were treated with Api (0, 5, 10, 25, and 50 µM) for 48 and 72 h. After determining the optimal doses of Api (5 and 10 µM), ASCs were differentiated into the osteogenic lineage for 7 and 21 days. The expression of osteogenic and autophagy genes and proteins, as well as alkaline phosphatase (ALP) activity and calcium deposition, were assessed. About 94% of ASCs expressed CD73, CD90, and CD105, while 99% didn't express CD34 and CD45. Api treatment increased the expression of ALP, RUNX2, COL I, osteocalcin (OCN), ATG5, ATG7, and LC3A genes, and RUNX2, OCN, LC3-1, and LC3-II proteins dose-dependently. ALP activity and calcium deposition were significantly higher in Api-treated groups than in the control. Api increased the osteogenic differentiation of ASCs via inducing autophagy, an effect advantageous for enhancing SC differentiation efficiency.