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

Abstract

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 [3H]-oleic acid (OA) to [3H]-H2O. 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.

Anti-Inflammatory Potential of Cultured Ginseng Roots Extract in Lipopolysaccharide-Stimulated Mouse Macrophages and Adipocytes

“…Dried GR was kindly provided by Joybio (Jeju, South Korea). GR was extracted using the pressurized hot water extraction method (modified from [ 16 ]), as we described previously. Briefly, a 10 g sample (dry weight) of GR was mixed with 100 mL of Milli-Q water.…”

“…The total polyphenol content (TPC) of the GRE extract was analyzed using the modified Folin–Ciocalteu method [ 16 ]. The diluted sample and Folin–Ciocalteu’s phenol reagent (FMD Millipore Corporation, Darmstadt, Germany) were added into 96-well assay plates and incubated at room temperature for 5 min.…”

“…The analysis of the total flavonoid content (TFC) of the GRE was modified from a previously described TFC method [ 16 ]. The diluted sample and 5% sodium nitrate (Daejung Chemicals & Metals Co. Ltd., Gyeonggi-do, Korea) were added into 96-well assay plates and incubated for 6 min at room temperature.…”

“…The 3T3-L1 cells (American Type Culture Collection (ATCC), VA, USA) were grown as described previously [ 16 ]. Briefly, to make confluence in a basal medium, DMEM with penicillin/streptomycin and 2 mM L-glutamine (Sigma) was supplemented with 10% newborn calf serum (Linus, Madrid, Spain).…”

“…Mitochondrial respiration activities detected by the O 2 consumption were measured using an XF24 extracellular flux analyzer (Agilent Technologies, Santa Clara, California, USA), as described previously [ 16 ], in the RAW264.7 cells. Briefly, the RAW264.7 cells were seeded in a Seahorse microplate (24-well) and preincubated with GRE (100 μg/mL) or DMSO for 48 h, and LPS (1 μg/mL) was loaded for 2–4 h. The cells were then treated with oligomycin (oligo, 2 μM) to measure the ATP turnover.…”