Figure 1.

Nicotine and cotinine do not affect osteogenic differentiation of SCP-1. SCP-1 cells were osteogenically differentiated with nicotine (50 and 320 ng/ml) or its primary metabolite cotinine (100 and 300 ng/ml). Cell viability by Resazurin conversion (a) and AP activity (b) was measured on day 14. (c) Matrix mineralization was evaluated by Alizarin red after 21 days. (d) Primary cilium length was measured on day 21. (e) DCFH-DA assay was used to detect ROS in SCP-1 cells exposed to nicotine and cotinine. 0.01% V/V H₂O₂ was used as a positive control. Each experiment was conducted at least four times independently with triplicate. The statistical significance was determined by the Kruskal-Wallis H test followed by Dunn's posttest. Data are represented as the mean ± SEM, and the significance was represented as ^∗∗∗ p < 0.001 vs the control group.