Inhibitory Effect of Dihydroartemisinin, An Active Ingredient of Artemisia annua, on Lipid Accumulation in Differentiating 3T3-L1 Preadipocytes

Abstract

Objectives: Artemisinin and its derivatives extracted from Artemisia annua, a Chinese herbal medicine, have variable biological effects due to structural differences. Up to date, the anti-obesity effect of dihydroartemisinin (DHA), a derivative of artemisinin, is unknown. The purpose of this study was to investigate the anti-adipogenic and lipolytic effects of DHA on 3T3-L1 preadipocytes.

Methods: Oil Red O staining and AdipoRed assay were used to measure lipid accumulation and triglyceride (TG) content in 3T3-L1 cells, respectively. Cell count analysis was used to determine the cytotoxicity of 3T3-L1 cells. Western blot and real-time reverse transcription polymerase chain reaction analyses were used to analyze the expression of protein and mRNA in 3T3-L1 cells, respectively.

Results: DHA at 5 μM markedly inhibited lipid accumulation and reduced TG content in differentiating 3T3-L1 cells with no cytotoxicity. Furthermore, DHA at 5 μM inhibited the expression of CCAAT/enhancer-binding protein-α (C/EBP-α), peroxisome proliferator-activated receptor-γ (PPAR-γ), fatty acid synthase (FAS), and perilipin A as well as the phosphorylation of signal transducer and activator of transcription-3 (STAT-3) in differentiating 3T3-L1 cells. Moreover, while DHA at 5 μM had no effect on the mRNA expression of adiponectin, it strongly suppressed that of leptin in differentiating 3T3-L1 cells. However, DHA at 5 μM had no lipolytic effect on differentiated 3T3-L1 cells, as assessed by no enhancement of glycerol release.

Conclusions: These results demonstrate that DHA at 5 μM has a strong anti-adipogenic effect on differentiating 3T3-L1 cells through the reduced expression and phosphorylation of C/EBP-α, PPAR-γ, FAS, perilipin A, and STAT-3.