OBJECTIVE: To examine changes in the morphology and physiological functions of human proximal tubular epithelial cells(HK-2 cells) caused by total Dahuang(Radix Et Rhizoma Rhei Palmati) anthraquinones(TDA) and emodin.METHODS: HK-2 cells were cultured on polycarbonate(PCF) membranes to form a complete monolayer of cells.A fluorescein isothiocyanatedextran(FITC) permeability assay was conducted and secretion of γ-glutamyltranspeptidase(GGT),lactate dehydrogenase(LDH), N-acetyl-β-D-glucosaminidase(NAG) and kidney injury molecule 1(KIM-1) was examined.The reabsorption of glucose and the excretion of para-aminohippuric acid(PAH)by HK-2 cells were also examined.The morphology of HK-2 cells was observed using optical microscopy and scanning electron microscopy.The cytoskeleton of HK-2 cells was observed under a fluorescence microscope.RESULTS: Compared with the results for the dimethyl sulfoxide group, treatment of cells with TDA and emodin showed statistically significant differences in the FITC leakage rate, the apical/basolateral ratio of LDH and GGT, and the secretion of GGT,LDH, NAG and KIM-1.At 64 μg/mL, TDA markedly inhibited blood glucose reabsorption and remarkably suppressed PAH excretion by HK-2 cells.Both TDA and emodin caused various degrees of damage to the morphology and cytoskeleton of HK-2 cells with the degree of damage correlating positively with the dosage of the tested substances.CONCLUSION: Both TDA and emodin caused damage to human renal proximal tubular epithelial cells at certain dosages.At the same dosage, TDA caused more severe damage than emodin to the HK-2 cells.