Effect of Estrogenic Compounds on Superoxide and Nitric Oxide Production by Activated Macrophages Assessed by Sensitive Microplate Assays

The effect of estrogenic compounds (bisphenol A, genistein, and 17β-estradiol) on the ability of macrophages to produce superoxide and nitric oxide in response to stimulants was investigated. The assays were performed using 96-well microplates to measure multiple samples. Superoxide and nitric oxide were measured by chemiluminescence and fluorescence methods, respectively. Thioglycollate-induced mouse peritoneal macrophages incubated for 24 hr with the estrogenic compounds were stimulated with phorbol 12-myristate 13-acetate and lipopolysaccharide (LPS). The ability of the macrophages to produce superoxide was increased when treated with bisphenol A or genistein, but 17β-estradiol had little effect. Conversely, the ability of the macrophages to produce nitric oxide in response to LPS was strongly suppressed by high concentrations of bispenol A and genistein. 17β-estradiol was ineffective. These results suggest that bisphenol A and genistein similarly affect superoxide and nitric oxide production by a mechanism other than that involving estrogenic activity.