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

Figure 4

Quercetin protects primary human osteoblasts from CSM-induced damage via upregulation of anti-oxidative enzymes HO-1 and SOD-1. (a) Representative picture of a Western blot for pNrf2, HO-1, SOD-1, pERK1/2, and pSAPK in primary human osteoblasts treated with or without 100 μM Quercetin. Quercetin induces the expression of HO-1 and SOD-1 and phosphorylation of pNrf2 and ERK1/2. GAPDH was used as loading control. (b) The HO-1 inhibitor ZnPP9 (10 μM) reduces the protective effect of Quercetin (100 μM/pre- and co-incubation) on primary human osteoblasts (𝑁=3, 𝑛=4) treated with CSM (OD₃₂₀ = 0.8) for 4 h. ^∗∗∗𝑃<0.001 compared to untreated cells; ^∘∘∘𝑃<0.001 compared to CSM-treated cells.

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