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

BACKGROUND: 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. Phaseolus vulgaris (bean) is a vegetable highly consumed worldwide. One of its effects, the most reported, is weight reduction in overweight individuals. OBJECTIVE: 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 ex vivo model. DESIGN: 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 ex vivo model. RESULTS: In an ex vivo assay with adipose tissue, methanolic and aqueous green bean extracts increased glycerol release to the medium compared to control (p < 0.05 and p < 0.001 respectively). Treatment of 3T3-L1 adipocytes with green bean extracts (800 and 1000 µg/mL) increased glycerol release significantly (p < 0.0001). Extracts at concentrations between 500 and 1000 µg/mL reduced intracellular triglyceride accumulation by 34.4% and 47.1% compared to control (p < 0.0001). DISCUSSION: Our results propose that bioactive compounds of green beans exert a direct mechanism on adipocytes through lipolysis. CONCLUSION: We have identified a novel capacity of bean extracts related to lipolytic activity both in vitro and ex vivo, 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.