Mechanism of action of gypenosides on type 2 diabetes and non-alcoholic fatty liver disease in rats

Figure 1 General structure of dammarane-type gypenosides consisting of both the hydrophobic sapogenin part and the hydrophilic sugar part in the molecule (where R1 and R2 = glucose, rhamnose; R3 = glucose, xylose).

Figure 2 Effects of gypenosides on body weight (A) and liver index (B). ^bP < 0.01 vs group I; ^cP < 0.05, ^dP < 0.01 vs group II.

Figure 3 Effects of gypenosides on blood lipid and glucose levels. A: Oral glucose tolerance: the blood glucose levels were measured before the glucose challenge; B: The area under the curve (AUC _{0-120 min}) after 30, 60, 90 or 120 min challenge was calculated and analyzed. (I) normal control, (II) model, (III) gypenosides (GPs) (200 mg/kg) + HFSD, (IV) GPs (400 mg/kg) + HFSD, (V) GPs (800 mg/kg) + HFSD. The values are expressed as mean ± SD in each group. ^aP < 0.05 vs normal control, ^cP < 0.05 vs model; n = 12.

Figure 4 Appearance of the liver (A) and histopathological examination using hematoxylin and eosin staining (B) (HE, × 200 magnification). (I) normal control, (II) model, (III) gypenosides (GPs) (200 mg/kg) + HFSD, (IV) GPs (400 mg/kg) + HFSD, (V) GPs (800 mg/kg) + HFSD. HFSD: High fat and sugar diet.

Figure 5 Representative photographs of immunohistochemical examination (× 400 magnification). A: TNF-α; B: NF-κB. (I) normal control, (II) model, (III) gypenosides (GPs) (200 mg/kg) + HFSD, (IV) GPs (400 mg/kg) + HFSD, (V) GPs (800 mg/kg) + HFSD, (VI) Quantification of TNF-α and NF-κB stained cells. Data are expressed as mean ± SD of 12 rats. ^bP < 0.01 vs normal control; ^cP < 0.05, ^dP < 0.01 vs model.

Figure 6 Effects of gypenosides on the gene expression in the liver tissue of high fat and sugar feed treated rats. A: Rabbit anti-proliferator activated receptory (PPARγ); B: Rabbit anti-cytochrome P₄₅₀1A1 (CYP1A1). (I) normal control, (II) model, (III) gypenosides (GPs) (200 mg/kg) + HFSD, (IV) GPs (400 mg/kg) + HFSD, (V) GPs (800 mg/kg) + HFSD. The values are expressed as mean ± SD in each group. ^bP < 0.01 vs normal control; ^cP < 0.05, ^dP < 0.01 vs model, n = 12.