Effect of baicalein on high glucose-induced expression of extracellular matrix and transforming growth factor β1 in proximal tubular epithelial cells

Objective To investigate the effect of baicalain on high expression of ECM and TGF-β1 in proximal tubular epithelial cells cultured in high glucose concentration. Methods LLC-PK1 cells were divided into six groups: (1)normal glucose group(NG, 5. 5 mmol/L D-glucose), (2)high glucose group(HG, 25 mmol/L D-glucose), (3) HG + PKC inhibitor(10μmol/L chelerythrine chloride), (4)HG + baicalein(50 μmol/L), (5) HG + baicalein(100 μmol/L), (6) HG + baicalein (200 μmol/L) . PKC activity was detected. Expression of ColⅣ, FN and TGF-β1 was examined by in situ hybridization and immunocytochemistry(ABC) techniques. Results At concentrations of 100 μmol/L and 200 μmol/L, baicalein decreased membranous PKC activity in LLC-PK1 cells by 42% and 68% , respectively ( P 0.01) . Administration of 200 μmol/L baicalein to high glucose medium, ColⅣ, FN and TGF-β1 mRNA levels were reduced by 55%, 51%, 46%, respectively, while TGF-β1 protein expression decreased by 51%. Conclusion Baicalein may inhibit the expression of ColⅣ, FN and TGF-β1 in proximal tubular epithelial cells in response to high glucose via its inhibitory effect on PKC activity.