Research & Development, Research Special Skincare, Beiersdorf AG, Unnastrasse 48, Bf, 520, 20245 Hamburg, Germany.
Nutr Metab (Lond). 2010 Aug 5;7:66. doi: 10.1186/1743-7075-7-66.
The cellular and molecular mechanisms of adipose tissue biology have been studied extensively over the last two decades. Adipose tissue growth involves both an increase in fat cell size and the formation of mature adipocytes from precursor cells. To investigate how natural substances influence these two processes, we examined the effects of lotus leaf extract (Nelumbo nucifera-extract solution obtained from Silab, France) and L-carnitine on human preadipocytes and adipocytes.
For our in vitro studies, we used a lotus leaf extract solution alone or in combination with L-carnitine. Utilizing cultured human preadipocytes, we investigated lotus leaf extract solution-induced inhibition of triglyceride incorporation during adipogenesis and possible effects on cell viability. Studies on human adipocytes were performed aiming to elucidate the efficacy of lotus leaf extract solution to stimulate lipolytic activity. To further characterize lotus leaf extract solution-mediated effects, we determined the expression of the transcription factor adipocyte determination and differentiation factor 1 (ADD1/SREBP-1c) on the RNA- and protein level utilizing qRT-PCR and immunofluorescence analysis. Additionally, the effect of L-carnitine on beta-oxidation was analyzed using human preadipocytes and mature adipocytes. Finally, we investigated additive effects of a combination of lotus leaf extract solution and L-carnitine on triglyceride accumulation during preadipocyte/adipocyte differentiation.
Our data showed that incubation of preadipocytes with lotus leaf extract solution significantly decreased triglyceride accumulation during adipogenesis without affecting cell viability. Compared to controls, adipocytes incubated with lotus leaf extract solution exhibited a significant increase in lipolysis-activity. Moreover, cell populations cultivated in the presence of lotus leaf extract solution showed a decrease in adipocyte differentiation capacity as indicated by a decrease in the ADD1/SREBP-1c signal. Importantly, our results demonstrated that a combination of lotus leaf extract solution and L-carnitine reduced triglyceride accumulation to a greater extent compared to incubation with either substance alone.
Overall, our data demonstrate that a combination of lotus leaf extract and L-carnitine reduced triglyceride accumulation in human (pre)adipocytes by affecting different processes during the adipocyte life cycle. For this reason, this combination might represent a treatment option for obesity-related diseases.
过去二十年，人们对脂肪组织生物学的细胞和分子机制进行了广泛的研究。脂肪组织的生长涉及脂肪细胞大小的增加和前体细胞向成熟脂肪细胞的形成。为了研究天然物质如何影响这两个过程，我们研究了荷叶提取物（法国 Silab 公司获得的莲属植物提取物溶液）和左旋肉碱对人前体脂肪细胞和脂肪细胞的影响。
在我们的体外研究中，我们单独使用或联合使用荷叶提取物溶液和左旋肉碱。利用培养的人前体脂肪细胞，我们研究了荷叶提取物溶液在脂肪生成过程中对甘油三酯摄取的抑制作用以及对细胞活力的可能影响。对人脂肪细胞的研究旨在阐明荷叶提取物溶液刺激脂肪分解活性的功效。为了进一步描述荷叶提取物溶液介导的作用，我们利用 qRT-PCR 和免疫荧光分析，在 RNA 和蛋白质水平上测定了转录因子脂肪细胞决定和分化因子 1（ADD1/SREBP-1c）的表达。此外，利用人前体脂肪细胞和成熟脂肪细胞分析了左旋肉碱对β氧化的影响。最后，我们研究了在人前体脂肪细胞/脂肪细胞分化过程中，荷叶提取物溶液和左旋肉碱联合使用对甘油三酯积累的附加作用。
我们的数据表明，在脂肪生成过程中，前体脂肪细胞与荷叶提取物溶液孵育可显著减少甘油三酯的积累，而不影响细胞活力。与对照组相比，用荷叶提取物溶液孵育的脂肪细胞的脂肪分解活性显著增加。此外，与对照组相比，在荷叶提取物溶液存在的情况下培养的细胞群体显示出脂肪细胞分化能力降低，表现为 ADD1/SREBP-1c 信号降低。重要的是，我们的结果表明，与单独孵育相比，荷叶提取物溶液和左旋肉碱的联合使用可更显著地减少甘油三酯的积累。
总的来说，我们的数据表明，荷叶提取物和左旋肉碱的联合使用通过影响脂肪细胞生命周期中的不同过程，减少了人（前）脂肪细胞中的甘油三酯积累。因此，这种联合治疗可能是肥胖相关疾病的一种治疗选择。
