Figure 8. Effects of eucalyptol on TGF-β1 induction by high glucose (A and B), inhibition of TGF-β1-induced expression of Snail1, ILK1 and β-catenin by eucalyptol (C), and effects of TGF-β1 receptor inhibitor on expression of E-cadherin and N-cadherin (D).

Human renal proximal tubular epithelial cells were treated with 1-20 μM eucalyptol for 72 h in the culture media of 33 mM glucose (A and B). Cells were also incubated in 5.5 mM glucose and 27.5 mM mannitol as osmotic controls. In other experiments, cells was cultured with 10 ng/ml TGF-β1 or 20 ng/ml TGF-β1 receptor inhibitor in the absence and presence of 20 μM eucalyptol for 72 h (C and D). TGF-β1 in culture media was measured by using an ELISA kit (A). Cell lysates were subject to 8-12% SDS-PAGE and Western blot analysis with a primary antibody against TGF-β1, Snail1, β-catenin, E-cadherin or N-cadherin (B, C and D). β-Actin protein was used as an internal control. The bar graphs (mean ± SEM, n=3) in the bottom panels represent quantitative desitometric results. Values not sharing a common letter are significantly different at P<0.05.