[The medicinal serum of yi-shen ruan-jian san antagonized the effect of aristolochic acid on human proximal tubular epithelial cells in vitro]

OBJECTIVE: To evaluate whether the medicinal serum of Yi-shen Ruan-jian san can antagonize the fibrogenic effect of human proximal tubular epithelial cell line (HKC) activated by aristolochic acid (AA) in vitro.

METHOD: The HKC was incubated in the media containing 40 mg x L(-1) aristolochic acid sodium salt (AA-Na) with or without 10% concentration of Yi-shen Ruan-jian san medicinal serum. Then the cell proliferation and cytotoxicity of HKC were determined by MTF and lactate dehydrogenase (LDH) release assay respectively, the antigen expression of cytokeratin and alpha-smooth muscle actin on HKC was detected by immunocytochemistry, the mRNA expression of transforming growth factor-beta1 (TGF-beta1), connective tissue growth factor (CTGF), plasminogen activator inhibitor-1 (PAI-1), tissue inhibitor of metalloproteinase-1 (TIMP-1) and type I Collagen (Col I) of HKC was measured by RT-PCR, and their protein expression was measured by ELISA or Western blot.

RESULT: No cytotoxic effect was found in HKC after stimulation of AA-Na with or without the medicinal serum of Yi-shen Ruan-jian san (P > 0.05). No epithelial-myofibroblast transdifferentiation was found in HKC after AA-Na stimulation. The mRNA and protein expression of TGF-beta1, CTGF, PAI-1 and TIMP-1 of HKC was significantly upregulated by AA-Na (P < 0.05). The above-mentioned enhanced mRNA and protein expression, except for PAI-1, was significantly downregulated by the medicinal serum of Yi-shen Ruan-jian san, compared with the control (normal rat serum in the same concentration) (P < 0.05).

CONCLUSION: The fibrogenic effects of HKC activated by AA are antagonized by Yi-shen Ruan-jian san, through downregulating the expression of promoting excellular matrix (ECM) synthesis factors (TGF-beta1, CTGF) and inhibiting ECM degradation factor (TIMP-1).