Cell experiment:

Mouse embryo fibroblasts 3T3-L1 cells are incubated in DMEM, containing 10% FBS and 1% AB, at 37℃ and 5.6% CO2 atmosphere. To induce differentiation, two days after confluence, preadipocytes (designated day 0) are cultured in the differentiation medium (DM), which is consisted of DMEM, 10% FBS, 1% AB, and DMI (0.28 unit/mL insulin, 0.5 mM Isobutylmethylxanthine and 1 μM Dexamethasone) for 2 d in the presence or absence of 50 μM and 100 μM of Ginsenoside Rh1, and switched to DM containing 10% FBS and 10 μg/mL insulin and then changed to DMEM medium with 10% FBS for every 2 d[1].

Animal experiment:

Mice[1]Male C57BL/6J mice are separated into 3 groups, LFD, HFD and HFDRh1. Each group is consisted of ten mice. LFD group fed LFD for 8 weeks. HFD group fed HFD for 8 weeks. HFDRh1 group fed HFD diet for 4 weeks and then simultaneously treated with HFD and 20 mg/kg/d Ginsenoside Rh1, which is orally administrated. Weight and food intake of mice are measured daily. After finishing treatment for 4 weeks, blood and epididymal fats are collected for further analysis.

Ginsenoside Rh1 (Prosapogenin A2; Sanchinoside B2; Sanchinoside Rh1) is isolated from the root of Panax Ginseng. Ginsenoside Rh1 inhibits the expression of PPAR-γ, TNF-α, IL-6, and IL-1β.

The effect of Ginsenoside Rh1 is examined on adipogenesis in 3T3-L1 cells. Ginsenoside Rh1 potently inhibits the adipogenesis, as assessed by Oil-red O staining and lipid contents in 3T3-L1 adipocytes. Ginsenoside Rh1, at concentrations of 50 μM and 100 μM, inhibit the adipogenesis by 50% and 63%, respectively.The expression levels of adipocytespecific genes such as PPAR-γ, C/EBP-α, FAS, aFABP and some genes are examined during early phase of differentiation such as Pref-1, C/EBP-δ and Glucocorticoid receptor (GR). After the treatment with Ginsenoside Rh1 in 3T3-L1 cells, mRNA is extracted on 18 h and 24 h for Pref-1, C/EBP-δ and GR and day 8 for PPAR-γ, C/EBP-α, FAS, aFABP. Then, the expression profiles of adipocyte-specific genes are investigated by RT-PCR. PPAR-γ, C/EBP-α, FAS, and aFABP expressions are significantly increased in DMI-stimulated differentiated adipocyte compared to those of non-stimulated adipocyte cells. However, treatment with DMI in the presence of Ginsenoside Rh1 significantly suppresses the expression levels of PPAR-γ, C/EBP-α, FAS, and aFABP in a dose- dependent manner, whereas the expression levels of Pref-1, C/EBP-δ and GR are not affected[1].

When high-fat diet (HFD) fed mice for 8 weeks, body and epididymal fat weight gains are significantly increased compared to those of low-fat diet (LFD)-fed mice. However, when Ginsenoside Rh1 is treated in HFD-fed mice, body and epididymal fat weight gains are significantly decrease compared with those of the HFD-fed mice. TG, glucose, insulin, total cholesterol, and HDL levels in the blood are significantly increased in HFD-fed mice group compared to LFD-fed mice group. Treatment with Ginsenoside Rh1 in HFD-fed mice significantly lowers TG level alone[1].

References:
[1]. Gu W, et al. Ginsenoside Rh1 ameliorates high fat diet-induced obesity in mice by inhibiting adipocyte differentiation. Biol Pharm Bull. 2013;36(1):102-7.