Effects of Phaseolus vulgaris Extract on Lipolytic Activity and Differentiation of 3T3-L1 Preadipocytes into Mature Adipocytes: A Strategy to Prevent Obesity

<jats:p><jats:italic>Background</jats:italic>. Overweight and obesity are defined as abnormal or excessive fat accumulation that may be harmful for health. A global trend in this area is the search for natural compounds that have a proven beneficial effect and no clinical complications. <jats:italic>Phaseolus vulgaris</jats:italic> (bean) is a vegetable highly consumed worldwide. One of its effects, the most reported, is weight reduction in overweight individuals. <jats:italic>Objective</jats:italic>. The objective of this study was to investigate the antiobesity activity of this legume in mature 3T3-L1 adipocytes and in rat white adipose tissue in an <jats:italic>ex vivo</jats:italic> model. <jats:italic>Design</jats:italic>. Mature adipocytes 3T3-L1 and rat adipose tissue were treated with bean extracts. We quantified lipolysis in mature 3T3-L1 adipocytes and in rat white adipose tissue in an <jats:italic>ex vivo</jats:italic> model. <jats:italic>Results</jats:italic>. In an <jats:italic>ex vivo</jats:italic> assay with adipose tissue, methanolic and aqueous green bean extracts increased glycerol release to the medium compared to control (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M1"><mml:mrow><mml:mi>p</mml:mi><mml:mo>&lt;</mml:mo><mml:mn>0.05</mml:mn></mml:mrow></mml:math> and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M2"><mml:mrow><mml:mi>p</mml:mi><mml:mo>&lt;</mml:mo><mml:mn>0.001</mml:mn></mml:mrow></mml:math> respectively). Treatment of 3T3-L1 adipocytes with green bean extracts (800 and 1000 <jats:italic>µ</jats:italic>g/mL) increased glycerol release significantly (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M3"><mml:mrow><mml:mi>p</mml:mi><mml:mo>&lt;</mml:mo><mml:mn>0.0001</mml:mn></mml:mrow></mml:math>). Extracts at concentrations between 500 and 1000 <jats:italic>µ</jats:italic>g/mL reduced intracellular triglyceride accumulation by 34.4% and 47.1% compared to control (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M4"><mml:mrow><mml:mi>p</mml:mi><mml:mo>&lt;</mml:mo><mml:mn>0.0001</mml:mn></mml:mrow></mml:math>). <jats:italic>Discussion</jats:italic>. Our results propose that bioactive compounds of green beans exert a direct mechanism on adipocytes through lipolysis. <jats:italic>Conclusion</jats:italic>. We have identified a novel capacity of bean extracts related to lipolytic activity both <jats:italic>in vitro</jats:italic> and <jats:italic>ex vivo</jats:italic>, resulting in a powerful lipolytic effect. Moreover, we also found that bean extracts has an antiadipogenic effect during the differentiation of 3T3-L1 preadipocytes. These results suggest that bean is a good candidate for the development of functional ingredients that can help reduce the high rates of death from cardiovascular diseases associated with obesity.</jats:p>