Inhibitory effect of ethanolic extract of Ramulus mori on adipogenic differentiation of 3T3-L1 cells and their antioxidant activity

Ramulus mori is known as a medical herb for improving health. The antioxidant and anti-obesity effects of an ethanolic extract of R. mori containing oxyresveratrol (ERM) were investigated. The antioxidant activity of ERM was determined by in vitro chemical- and cell-based methods. ERM showed high antioxidant activities. In particular, ERM showed a high scavenging activity for peroxyl radicals in both chemical- and cell-based assays. To investigate the inhibitory effect of ERM on adipogenic differentiation, 3T3-L1 cells were treated with ERM (20, 30, and 40 μg/mL) for 8 days during induction of differentiation. ERM significantly suppressed lipid accumulation in 3T3-L1 adipocytes and decreased expression levels of adipogenic genes peroxisome proliferator-activated receptor gamma (PPARγ), CCAAT/enhancer-binding proteins alpha (C/EBPα), and sterol regulatory element-binding protein 1 (SREBP1). ERM also induced G₀/G₁ phase arrest in 3T3-L1 adipocytes during mitotic clonal expansion (MCE). The results suggest that ERM possesses anti-adipogenic activity and antioxidant property. Practical applications: Ramulus mori, a branch of Morus alba L., has been used as a traditional herb tea in Asia and is approved as a food source in South Korea, indicating it is safe. An ethanolic extract of R. mori containing oxyresveratrol (ERM) significantly suppresses lipid accumulation in 3T3-L1 adipocytes and inhibits adipogenesis. ERM shows a strong antioxidative activity. Adipogenesis is the process of adipocyte differentiation, which leads to lipid accumulation in obesity. Obesity is one of metabolic disorders and a major risk factor for various chronic diseases. Additionally, antioxidants can protect cells from damage caused by free radicals. Therefore, ERM could be developed as a health functional food to prevent obesity and many diseases caused by oxidative damage.