Fig. 4
Effects of 1,25(OH)2D3 on levels of lipopolysaccharide (LPS)-induced reactive oxygen species (ROS) production, nitrite accumulation, and inducible nitric oxide synthase (iNOS) expression. Cultured cells were untreated (PBS) or treated with 1,25(OH)2D3 (100 nM), LPS (100 ng/ml), or various concentration of 1,25(OH)2D3 (1, 10, or 100 nM) plus LPS for 24 h. a ROS production by cells was detected by DCF fluorescence. The y-axis of the graph is expressed in DCF fluorescent arbitrary units (AU). b The culture medium was collected to analyze levels of nitrite accumulation. c After treatment, cells were harvested to analyze levels of iNOS protein expression using Western blotting. Levels of iNOS were normalized to β-actin and then quantified. iNOS expression induced by LPS was set to 100 % expression. Data are expressed as the mean ± SEM (n = 5 in each group). *p < 0.05, **p < 0.01, ***p < 0.001 vs. the control (Cont.); +++ p < 0.001 vs. LPS