Antiobesity Effects of Ginsenoside Rg1 on 3T3-L1 Preadipocytes and High Fat Diet-Induced Obese Mice Mediated by AMPK

Figure 1. Effect of Rg1 treatment on body weight and adipose mass. (A) Body weight; (B) Body weight gain in 4–8 weeks; (C) Fat mass of epididymal, mesenteric, and perirenal tissues; (D) Epididymal adipose tissues stained by H&E; (E) Adipocyte size; (F) Liver tissue stained by H&E. High and low doses (20 and 10 mg/kg, respectively) of Rg1 were administered from the fourth to the eighth week, and 10 mL/kg 0.5% carboxymethyl cellulose sodium(CMC-Na) solution was used as a vehicle, administered by gavage to STD and HFD groups. Body weight was recorded weekly. STD: standard treatment diet + 0.5% CMC-Na group, HFD: high-fat diet + 0.5% CMC-Na group, L-Rg1: high-fat diet + 10 mg/kg Rg1, H-Rg1: high-fat diet + 20 mg/kg Rg1. Data are represented as means ± standard deviation (SD, n = 9). * p < 0.05 versus HFD group; ** p < 0.01 versus the HFD group. HFD: high-fat diet; H&E: hematoxylin and eosin.

Figure 2. Effect of Rg1 on the expression of adipogenesis-related genes in epididymal white adipose tissue (WAT). Total RNA was extracted from epididymal WAT, and relative mRNA expression levels of adipogenic transcription factors (A), and ACC (B), FABP4 (C), FAS (D), HSL (E), and PLIN (F) were measured using RT-PCR. Data are represented as means ± SD (n = 3), * p < 0.05 versus HFD group; ** p < 0.01 versus HFD group. PPARγ: peroxisome proliferator-activated receptor γ, C/EBP: CCAA/enhancer-binding protein family members, SREBP-1c: sterol regulatory element binding protein 1c, FAS: fatty acid synthase, FABP4: fatty acid binding protein 4, HSL: hormone-sensitive lipase, and PLIN: perilipin 1.

Figure 3. Effect of Rg1 on cell viability and accumulation of lipid droplets in 3T3-L1 cells. (A) Cells were treated with different concentration of Rg1 (10, 20, 40 μM) for 72 h and measured by MTT assay. Data are represented as means ± SD (n = 3). The 3T3-L1 cells were supplemented with differentiation medium in the presence of Rg1 for 8 days; 0.1% dimethyl sulfoxide was used as a vehicle. The cells were stained with Oil Red O (C), and lipid content (B) was determined. “None” means cells were cultured in normal medium without Rg1 treatment, and “Control” means cells were cultured in differentiation medium without Rg1 treatment. Data are represented as means ± SD (n = 6), ** p < 0.01 versus control.

Figure 4. Effect of Rg1 on the expression of adipogenesis-related genes in 3T3-L1 cells. Total RNA was extracted from 3T3-L1 cells, and relative mRNA expression levels of adipogenic transcription factors (A), and ACC (B), FABP4 (C), FAS (D), HSL (E), and PLIN (F) were measured using RT-PCR. Data are represented as means ± SD (n = 9), * p < 0.05 versus control group; ** p < 0.01 versus control group.

Figure 5. Effect of Rg1 on the activation of AMPK pathway in epididymal WAT and 3T3-L1 cells. The protein expression of AMPK, p-AMPK, ACC, p-ACC, PPARγ (A,C) and relative protein levels (B,D) were measured by western blot analysis (The concentrations refer to ginsenoside Rg1). Data was means ± SD (n = 6), * p < 0.05 versus HFD or control; ** p < 0.01 versus HFD or control. “None” means cells were cultured in normal medium without Rg1 treatment, and “Control” means cells were cultured in differentiation medium without Rg1 treatment.