Anti-obesity and Anti-inflammatory Effects of Polygonum Cuspidatum Root Extract in Differentiated OP9 Adipocytes

Obesity is associated with adipose tissue expansion and chronic low-grade inflammation, contributing to insulin resistance and metabolic disorders. Polygonum cuspidatum root contains bioactive compounds with reported anti-inflammatory and metabolic regulatory effects, but its impact on adipocyte differentiation remains unclear. This study evaluated the effects of P. cuspidatum root extract (PCE) on adipogenesis and inflammation in OP9 cells. OP9 cells were differentiated into adipocytes and treated with PCE at non-cytotoxic concentrations. Lipid accumulation was assessed by Oil Red O staining. Expression of adipogenic markers (PPARγ, C/EBPα), lipogenic enzyme (ACC), and phosphorylated AMPK was measured by qRT-PCR and Western blot. NF-κB phosphorylation and pro-inflammatory cytokines (TNF-α, IL-6) were also analyzed. PCE significantly reduced lipid accumulation and decreased expression of PPARγ, C/EBPα, and ACC, while increasing AMPK phosphorylation. PCE also inhibited NF-κB activation and reduced TNF-α and IL-6 expression and secretion, indicating concurrent anti-adipogenic and anti-inflammatory effects. PCE may be associated with decreased adipocyte differentiation and lipid accumulation through the PPARγ–C/EBPα–ACC pathway and may reduce inflammation through NF-κB–TNF-α/IL-6–related signaling. These dual actions suggest PCE as a promising functional food ingredient or therapeutic adjuvant for obesity and related metabolic disorders, warranting further in vivo study.