Yang Jeong-Yeh, Della-Fera Mary Anne, Hartzell Diane L, Nelson-Dooley Cass, Hausman Dorothy B, Baile Clifton A
Department of Animal and Dairy Science, University of Georgia, Athens, GA 30602-2771, USA.
Obesity (Silver Spring). 2006 Oct;14(10):1691-9. doi: 10.1038/oby.2006.194.
To determine the effects of esculetin, a plant phenolic compound with apoptotic activity in cancer cells, on 3T3-L1 adipocyte apoptosis and adipogenesis.
3T3-L1 pre-confluent preadipocytes and lipid-filled adipocytes were incubated with esculetin (0 to 800 microM) for up to 48 hours. Viability was determined using the Cell Titer 96 Aqueous One Solution cell proliferation assay; apoptosis was quantified by measurement of single-stranded DNA. Post-confluent preadipocytes were incubated with esculetin for up to 6 days during maturation. Adipogenesis was quantified by measuring lipid content using Nile Red dye; cells were also stained with Oil Red O for visual confirmation of effects on lipid accumulation.
In mature adipocytes, esculetin caused a time- and dose-related increase in adipocyte apoptosis and a decrease in viability. Apoptosis was increased after only 6 hours by 400 and 800 microM esculetin (p < 0.05), and after 48 hours, as little as 50 microM esculetin increased apoptosis (p < 0.05). In preadipocytes, apoptosis was detectable only after 48 hours (p < 0.05) with 200 microM esculetin and higher concentrations. However, results of the cell viability assay indicated a reduction in preadipocyte number in a time- and dose-related manner, beginning as early as 6 hours with 400 and 800 microM esculetin (p < 0.05). Esculetin also inhibited adipogenesis of 3T3-L1 preadipocytes. Esculetin-mediated inhibition of adipocyte differentiation occurred during the early, intermediate, and late stages of the differentiation process. In addition, esculetin induced apoptosis during the late stage of differentiation.
These findings suggest that esculetin can alter fat cell number by direct effects on cell viability, adipogenesis, and apoptosis in 3T3-L1 cells.
确定七叶亭（一种对癌细胞具有凋亡活性的植物酚类化合物）对3T3-L1脂肪细胞凋亡和脂肪生成的影响。
将3T3-L1汇合前的前脂肪细胞和充满脂质的脂肪细胞与七叶亭（0至800微摩尔）孵育长达48小时。使用Cell Titer 96 Aqueous One Solution细胞增殖测定法测定细胞活力；通过测量单链DNA对凋亡进行定量。汇合后的前脂肪细胞在成熟过程中与七叶亭孵育长达6天。通过使用尼罗红染料测量脂质含量对脂肪生成进行定量；还用油红O对细胞进行染色，以直观确认对脂质积累的影响。
在成熟脂肪细胞中，七叶亭导致脂肪细胞凋亡呈时间和剂量依赖性增加，细胞活力降低。400和800微摩尔七叶亭仅在6小时后凋亡增加（p<0.05），48小时后，低至50微摩尔的七叶亭即可增加凋亡（p<0.05）。在前脂肪细胞中，仅在48小时后，200微摩尔及更高浓度的七叶亭可检测到凋亡（p<0.05）。然而，细胞活力测定结果表明，前脂肪细胞数量呈时间和剂量依赖性减少，早在400和800微摩尔七叶亭处理6小时后就开始减少（p<0.05）。七叶亭还抑制3T3-L1前脂肪细胞的脂肪生成。七叶亭介导的脂肪细胞分化抑制发生在分化过程的早期、中期和晚期。此外，七叶亭在分化后期诱导凋亡。
这些发现表明，七叶亭可通过直接影响3T3-L1细胞的细胞活力、脂肪生成和凋亡来改变脂肪细胞数量。
