Six week old homozygous Ren-2 rats received DiOHF (1 mg/kg/day) by oral gavage for six weeks. Cardiac function was assessed via echocardiography and left ventricular cardiac catheterization before the animals were sacrificed and hearts removed for histological and molecular analyses. Treatment with DiOHF prevented the development of diastolic dysfunction and was associated with reduced oxidative stress and interstitial fibrosis.

HL-60 human myelocytic cells were cultured in RPMI 1640 containing 10% FCS. Neutrophil differentiation of HL-60 cells was induced by incubation with 1.5% DMSO for 3 to 4 days. Differentiated HL-60 cells were resuspended in Hanks' balanced salt solution containing 200 μM cytochrome c and loaded into a 96-well assay plate (∼2 × 106 cells in 100-μl volume per well). PMA 100 ng/ml was used to induce NADPH oxidase activation in HL-60 cells resulting in a burst of superoxide release as determined by SOD-inhibitable cytochrome c reduction over a period of up to 1 h. Cotreatment with DiOHF (0, 10, 30, or 100 micro-M) inhibited the PMA-induced superoxide accumulation in a concentration-dependent manner.