Abstract

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.