Medicated serum prepared with Chinese herbal medicine Zhizhen Recipe down-regulates activity of nuclear factor-κB and expression of P-glycoprotein in human colorectal cancer multidrug-resistant cell line HCT-8/VCR

To investigate the effects of medicated serum prepared with Chinese herbal medicine Zhizhen Recipe (ZZR) on activity of nuclear factor-κB (NF-κB) and expression and function of P-glycoprotein (P-gp) in human colorectal cancer multidrug-resistant cell line HCT-8/VCR.The multidrug resistance of HCT-8/VCR cells was detected by cell counting kit-8 method, and the experimental concentrations of ZZR-medicated serum were determined by the same way. HCT-8 and HCT-8/VCR cells were treated with ZZR-medicated serum of medium dose for 24 h. The activity of NF-κB was determined by enzyme-linked immunosorbent assay. The intracellular distribution of P-gp was detected by laser scanning confocal microscopy, and the mean fluorescence intensity of rhodamine 123 was detected by flow cytometry.ZZR-medicated sera with volume fraction of 8%, 16% and 32% of medium dose were confirmed as the experimental sera. Compared with the untreated group, NF-κB activities of the ZZR-medicated serum groups (ZZR-medicated serum with volume fraction of 8%, 16% and 32% of medium dose) were obviously down-regulated (P<0.01), which had a negative correlation with the concentrations. After interfering HCT-8/VCR with ZZR-medicated serum of different concentrations for 24 h, P-gp in HCT-8/VCR transmitted gradually from cell membrane to cytoplasm and nuclei. Nuclei became pyknotic and cracking. Compared with the untreated group, the mean fluorescence intensities of ZZR-medicated serum groups declined with concentration gradients (P<0.01). The efflux of intracellular rhodamine 123 decreased, the wave crest shifted to right, and the intracellular fluorescence intensity strengthened (P<0.01).ZZR-medicated sera of experimental concentrations down-regulate activity of NF-κB and expression and function of P-gp in human colorectal cancer multidrug-resistant cell line HCT-8/VCR and the effect is related to the concentrations.