OBJECTIVETo observe the antagonist effect of Curcuma Aromatica (CA) on renal tubular epithelial-myofibroblast transdifferentiation (EMT) induced by transforming growth factor-beta1 (TGF-beta1).

METHODSNormal renal tubular epithelial NRK-52E cells in vitro cultured were randomly divided into 6 groups, i.e., the normal control group (Group C), the TGF-beta1 induced model group (Group T), the low dose CA treated group (Group E1), the moderate dose CA treated group (Group E2), the high dose CA group (Group E3), and the Benazepril Hydrochloride Tablet treated group (Group Y). Except Group C, corresponding medication (with an action of 48 h) was administered to cells in the rest groups after they were induced by TGF-beta1 for 24 h. The morphological changes were observed by inverted phase contrast microscope. The distribution of beta-actin protein was detected by immunohistochemical assay. The mRNA expressions of alpha-smooth muscle actin (alpha-SMA) and E-cadherin (E-cad) were detected by real-time PCR. The concentration of fibronectin (FN) was detected by ELISA.

RESULTSAfter induced by TGF-beta1 for three days, hypertrophy and elongated cells in fusiform-shape occurred,with increased expressions of beta-actin protein in the cytoskeletal structure (P < 0.05), bundle fibrous structure occurred inside cytoplasm with significantly up-regulated intracellular alpha-SMA mRNA expressions (P < 0.05), E-cad mRNA expression decreased (P < 0.05), the FN content in the supernate increased (P < 0.05) in Group T. Compared with Group T, partial cells in Group E1, E2, and E3 showed fibrous changes, accompanied with decreased expression of beta-actin protein and FN concentration (P < 0.05). The expression of alpha-SMA mRNA increased and the expression E-cad mRNA decreased in Group E2 and E3 (both P < 0.05). But there was no statistical difference in the expression levels of E-cad and alpha-SMA mRNA (P > 0.05). Compared with Group E1, the expression of beta-actin protein and FN concentration decreased in Group E2 and E3 (P < 0.05). The expressions of alpha-SMA mRNA decreased and E-cad mRNA increased in Group E3 (P < 0.05). Compared with Group Y, the expression of beta-actin mRNA and FN concentration increased in Group E1 (P < 0.05); the expression of beta-actin mRNA increased in Group E3 (P < 0.05); the expression of E-cad mRNA decreased in Group E3 (P < 0.05). There was no statistical difference in the expression of alpha-SMA mRNA among Group E1, E2, and E3 (P > 0.05).

CONCLUSIONCA could inhibit the occurrence of TGF-beta1 induced EMT, which could be used as an effective drug for treating chronic renal insufficiency.