Both central and peripheral leptin administrations reduce body weight, food intake, and adiposity in ob/ob mice. In this study we compared effects of intracerebroventricular (ICV) and subcutaneous (SC) administration of leptin on bone metabolism in the appendicular and axial skeleton and adipose tissue gene expression and determined the effects of ICV leptin on bone marrow gene expression in ob/ob mice. In experiment 1, leptin (1.5 or 0.38 µg/d) or control was continuously injected ICV for 12 days. Gene expression analysis of femoral bone marrow stromal cells showed that expression of genes associated with osteogenesis was increased after ICV injection, whereas those associated with osteoclastogenesis, adipogenesis, and adipocyte lipid storage were decreased. In experiment 2, leptin was injected continuously ICV (0.0 or 1.5 µg/d) or SC (0.0 or 10 µg/d) for 12 days. In both experiments, regardless of mode of administration, leptin decreased body weight, food intake, and body fat and increased muscle mass, bone mineral density, bone mineral content, bone area, marrow adipocyte number, and mineral apposition rate. Serum insulin was decreased, whereas serum osteocalcin, insulin-like growth factor 1, osteoprotegerin, pyridinoline, and receptor activator of nuclear factor κB ligand concentrations were increased. In experiment 2, expression of genes in adipose tissue associated with apoptosis, lipid mobilization, insulin sensitivity, and thermogenesis was increased, whereas expression of genes associated with cell differentiation and maturation was decreased regardless of mode of administration. Thus ICV injection of leptin promotes expression of pro-osteogenic factors in bone marrow, leading to enhanced bone formation in ob/ob mice. © 2011 American Society for Bone and Mineral Research

The natural compounds genistein (G), quercetin (Q), and resveratrol (R) have been reported to each exhibit anti-adipogenic activities in adipocytes and antiproliferative and pro-apoptotic activities in several cell types. We studied the combined effects of G, Q, and R on adipogenesis and apoptosis in primary human adipocytes (HAs) and 3T3-L1 murine adipocyte (MAs). Combined treatment with 6.25 μM G, 12.5 μM Q, and 12.5 μM R during the 14-day differentiation period caused an enhanced inhibition of lipid accumulation in maturing HAs that was greater than the responses to individual compounds and to the calculated additive response. Glycerol 3-phosphate dehydrogenase activity, a marker of late adipocyte differentiation, was decreased markedly in HAs treated with the combination of G+Q+R. In addition, combined treatment with 50 μM G, 100 μM Q, and 100 μM R for 3 days decreased cell viability and induced apoptosis in early- and mid- phase maturing and lipid-filled mature HAs. In contrast, no compound alone induced apoptosis. Oil Red O stain and Hoechst 33342 stain were performed to confirm the effects on lipid accumulation and apoptosis, respectively. We also determined whether MAs responded to the combination treatment similarly to HAs. As in HAs, G+Q+R treatment decreased lipid accumulation in maturing MAs and increased apoptosis in pre- and lipid-filled mature MAs more than the responses to G, Q, and R when used separately. These results show that lower concentrations of combined treatments with several natural compounds may be useful for treatments for obesity through the suppression of adipogenesis and enhanced adipocyte apoptosis.