Compounds PL, 47, 49, and 48 abrogated the upregulation of OXR1 in WI-38 senescent cells induced by irradiation: (A) representative western blot analysis of OXR1 and β‐actin in WI‐38 normal or nonsenescent cells (NCs) and ionizing radiation-induced WI-38 senescent cells (IR‐SCs) 24 h after incubation with vehicle (Veh) or 5 µM of compound PL, 47, 49, or 48; (B) quantitative analysis of OXR1 levels in WI‐38 NCs and IR‐SCs 24 h after incubation with Veh or 5 µM of compound PL, 47, 49, or 48. Data in bar graphs are presented as mean ± SEM, n = 3, *p < 0.05 indicates significant difference comparing with IR-SCs with vehicle treatment.