Quercetin Protects Primary Human Osteoblasts Exposed to Cigarette Smoke through Activation of the Antioxidative Enzymes HO-1 and SOD-1

Figure 1

CSM damages primary human osteoblasts in a time- and concentration-dependent manner. (a) Primary human osteoblasts (𝑁=3, 𝑛=6) were treated with concentrated CSM for 0, 1.5, 3, 6, 12, and 24 h. After stimulation viability was determined by resazurin conversion. (b) The optical density of different dilutions (0, 10, 20, 30, 40, 50, 60, 70, 80, 90, and 100%) of CSM was determined at 𝜆 = 320 nm (OD₃₂₀). (c) The same dilutions were tested for their toxic effect after 4 h stimulation (EC₅₀≈0.75 OD₃₂₀). (d) After 15 min CSM induces significantly (𝑃<0.01 from 50% CSM on) the production of ROS in primary human osteoblasts (𝑁=3, 𝑛=4).

(a)

(b)

(c)

(d)