The influence of metformin on the expression of mRNA of alkaline phosphatase (ALP, A), osteocalcin (OCL, B), leptin (LEP, C), bone morphogenetic protein-2 (BMP-2, D), and Runx-2 (E) in rASCs osteogenic cultures. Results of RT-qPCR are presented as relative values, obtained through normalization of transcript levels with the endogenous reference control (GAPDH) and in relation to the expression of target genes in non-OG conditions. Calculations of gene transcripts levels were performed using the 2−ΔΔCt algorithm. Data presented as the mean fold change of relative expression and were compared to control cultures (without metformin); error bars represent standard deviation from the mean calculated for normalized values obtained in three separate reactions; asterisks represent statistically significant differences; * p < 0.05; ** p < 0.01, and *** p < 0.001.