Fig 2: CAA improves the insulin sensitivity impaired by Dex in HepG2 cells and 3T3-L1 adipocytes. (A) Glucose consumption in response to insulin in the HepG2 cell line. (B) Glucose consumption in response to insulin in 3T3-L1 adipocytes. (C) Expression and phosphorylation of insulin signaling proteins in HepG2 cells analyzed using western blot analysis. (D) Expression and phosphorylation of insulin signaling proteins in 3T3-L1 adipocytes analyzed using western blot analysis. Prior to CAA treatment, the cells were incubated with 0 (-) or 1 µM (+) Dex for 48 h. For glucose consumption experiments, the cells were treated with CAA (0, 6.25, 12.5 and 25 µM) in 0.5% fetal calf serum and 10 nM insulin for 24 or 48 h. For western blot analysis, the cells were treated with 25 µM CAA for 24 h followed by 100 nM insulin for 30 min. All results are expressed as the mean ± standard error of the mean (n=3-6). *P<0.05, vs. cells without DEX treatment; #P<0.01, vs. cells without CAA treatment. PTP1B, protein-tyrosine phosphatase 1B; IR, insulin receptor; IRS, insulin receptor substrate; GLUT1, glucose transporter 1; GLUT4, glucose transporter 4; PI3K, phosphoinositide 3-kinase; AKT, serine/threonine protein kinase; CAA, cajanonic acid A; p-, phosphorylated; Dex, dexamethasone.

Fig 3: The effect of chronic URB597 treatment on total expressions of glucose transporter 1—GLUT1 (a) and glucose transporter 4—GLUT4 (b) in the left ventricle of the control Wistar Kyoto rats (WKY) and spontaneously hypertensive rats (SHRs). Total expressions of the above proteins were presented as a percentage difference compared to the control group, which was set as 100%. The data are expressed as the mean ± SD, n = 6 in each group.

Fig 4: Glut4 expression in the Pcm and Icm at metestrus (M) and proestrus (P). (A) Representative immunoblot showing Glut4 expression in the Pcm and Icm. Relative expression of Glut4 in the Pcm (B) and Icm (C) is shown as the quotient (arbitrary units [a.u.]) obtained by dividing the density of the Glut4 band by that of the glyceraldehyde phosphate dehydrogenase (GAPDH) band (D, E). Data are means±standard error of the mean (n=7 for each group). Two-tailed unpaired t-tests; *P<0.05. Glut4, glucose transporter 4; Pcm, pubococcygeus muscle; Icm, iliococcygeus muscle.

Fig 5: GLUT4 (A) and CD36 (B) protein content. Panel (C) shows representative images of CD36 and GLUT4. SED, sedentary; EXE, exercised; EXElow, exercised and supplemented with 0.31 mg/kg/d of hydroxytyrosol; EXEmid, exercised and supplemented with 4.61 mg/kg/d. Note that the GLUT4 images shown in panel (C) are from two membranes; in the first one the experimental group does not follow the same order as in the other membranes. * p < 0.05 if compared with Sed.