OBJECTIVE: To investigate the effects of rhein on regulating aquaporin4 (AQP4) to LoVo cells cultured with RPMI-1640 medium containing rhein. METHODS: LoVo cells were cultured with RPMI-1640 medium containing different concentration rhein for 24 hours and were cultured with RPMI-1640 containing rhein (20 mg/L) for different time. Four groups were assigned as LoVo cells were cultured respectively with RPMI-1640 medium containing different concentration rhein (40, 20, 10 mg/L and control group), while six groups were assigned as LoVo cells were cultured with RPMI-1640 medium containing rhein (20 mg/L) for different time (3, 6, 12, 24, 48 h and control group). The location of AQP4 protein in LoVo cells was definited by immuocytochemistry dying. Western blotting and semiquantitative RT-PCR were adopted to detect the relative expression of AQP4 protein and mRNA. RESULTS: AQP4 was located mainly in plasma membrane of LoVo cells while partly in cytoplasm. The relative expression of AQP4 protein and mRNA decreased with the increasing of rhein concentration; there was no significant difference of the relative expression of AQP4 in 10 mg/L group compared with that in control group, but it decreased significantly in 40 and 20 mg/L groups. The relative expression of AQP4 in 3 and 6 h groups was lower than that in control group but there was no statistical significance, however that in 12, 24, 48 h groups was lower significantly compared with that in control group. CONCLUSION: Rhein can inhibit the genetic transcription and the translation of AQP4 gene in LoVo cells, which demonstrates that the change of AQP4 expression regulated by rhein may be related to the cathartic effect of rhubarb.
OBJECTIVE: To investigate the effects of rhein on regulating aquaporin4 (AQP4) to LoVo cells cultured with RPMI-1640 medium containing rhein. METHODS: LoVo cells were cultured with RPMI-1640 medium containing different concentration rhein for 24 hours and were cultured with RPMI-1640 containing rhein (20 mg/L) for different time. Four groups were assigned as LoVo cells were cultured respectively with RPMI-1640 medium containing different concentration rhein (40, 20, 10 mg/L and control group), while six groups were assigned as LoVo cells were cultured with RPMI-1640 medium containing rhein (20 mg/L) for different time (3, 6, 12, 24, 48 h and control group). The location of AQP4 protein in LoVo cells was definited by immuocytochemistry dying. Western blotting and semiquantitative RT-PCR were adopted to detect the relative expression of AQP4 protein and mRNA. RESULTS:AQP4 was located mainly in plasma membrane of LoVo cells while partly in cytoplasm. The relative expression of AQP4 protein and mRNA decreased with the increasing of rhein concentration; there was no significant difference of the relative expression of AQP4 in 10 mg/L group compared with that in control group, but it decreased significantly in 40 and 20 mg/L groups. The relative expression of AQP4 in 3 and 6 h groups was lower than that in control group but there was no statistical significance, however that in 12, 24, 48 h groups was lower significantly compared with that in control group. CONCLUSION:Rhein can inhibit the genetic transcription and the translation of AQP4 gene in LoVo cells, which demonstrates that the change of AQP4 expression regulated by rhein may be related to the cathartic effect of rhubarb.