(+)-Z-Bisdehydrodoisynolic acid ameliorates obesity and the metabolic syndrome in female ZDF rats

Objective: The putative selective estrogen receptor modulator (+)-Z-bisdehydrodoisynolic acid (Z-BDDA) has been found to improve cardiovascular risk in rodents. The objective of this study was to investigate the effectiveness of (+)-Z-BDDA compared with the antidiabetic drug, rosiglitazone, in treating obesity and risk factors associated with the metabolic syndrome. Research Methods and Procedures: Female Zucker Diabetic Fatty rats were randomly assigned to three treatment groups for 29 weeks: control (C), 1.8 mg (+)-Z-BDDA/kg diet [control diet + (+)-Z-BDDA (CB)], or 100 mg rosiglitazone/kg diet [control diet + rosiglitazone (CR)]. At sacrifice, physiological, biochemical, and molecular parameters were examined. Results: CB animals gained less weight and exhibited a decrease in total body lipids (p < 0.05) as compared with C or CR rats. Body weight and total body lipids were the highest in CR rats (p < 0.05). Liver weights in CB and CR rats were lower (p < 0.05) than in C rats, whereas kidney weights were lower in CB (p < 0.05) than in C and CR animals. Fasting plasma glucose was lower (p < 0.05) in the CB and CR animals when compared with C animals. C rats exhibited the highest concentration of total plasma cholesterol, and CR-treated rats exhibited the lowest concentration. Plasma triglycerides followed the same pattern as plasma cholesterol. Histomorphometry of heart vasculature revealed that CB and CR treatments produced a significant shift from small to large venules and arterioles compared with C (p < 0.05). Liver expression profiles of peroxisome proliferator-activated receptor (PPAR) α, PPARγ, and PPAR-regulated genes revealed encouraging CB-induced effects. Discussion: These results suggest that (+)-Z-BDDA may have applications in treating obesity and complications associated with the metabolic syndrome.