Peanut Sprout Extracts Attenuate Triglyceride Accumulation by Promoting Mitochondrial Fatty Acid Oxidation in Adipocytes

Peanut sprouts (PS), which are germinated peanut seeds, have recently been reported to have anti-oxidant, anti-inflammatory, and anti-obesity effects. However, the underlying mechanisms by which PS modulates lipid metabolism are largely unknown. To address this question, serial doses of PS extract (PSE) were added to 3T3-L1 cells during adipocyte differentiation. PSE (25 µg/mL) significantly attenuated adipogenesis by inhibiting lipid accumulation in addition to reducing the level of adipogenic protein and gene expression with the activation of AMP-activated protein kinase (AMPK). Other adipocyte cell models such as mouse embryonic fibroblasts C3H10T1/2 and primary adipocytes also confirmed the anti-adipogenic properties of PSE. Next, we investigated whether PSE attenuated lipid accumulation in mature adipocytes. We found that PSE significantly suppressed lipogenic gene expression, while fatty acid (FA) oxidation genes were upregulated. Augmentation of FA oxidation by PSE in mature 3T3-L1 adipocytes was confirmed via a radiolabeled-FA oxidation rate experiment by measuring the conversion of [(3)H]-oleic acid (OA) to [(3)H]-H(2)O. Furthermore, PSE enhanced the mitochondrial oxygen consumption rate (OCR), especially maximal respiration, and beige adipocyte formation in adipocytes. In summary, PSE was effective in reducing lipid accumulation in 3T3-L1 adipocytes through mitochondrial fatty acid oxidation involved in AMPK and mitochondrial activation.