Journal of traditional Chinese medicine = Chung i tsa chih ying wen pan

Reversal effect of bufalin on multidrug resistance in K562/VCR vincristine-resistant leukemia cell line.

PMID 25618972


To probe insights into the reversal effect of bufalin on vincristine-acquired multidrug resistance (MDR) in human leukemia cell line K562/VCR. Proliferative inhibition rate and the reversal index (RI) of bufalin were determined by Methyl thiazolyl tetrazolium assay. The uptake of Adriamycin (ADM) in K562/VCR cells, cell cycle and apoptosis rate were determined by flow cytometry (FCM). Cell morphologic changes were observed with Wright-Giemsa staining. The expression of P-glycoprotein (P-gp), multidrug-associated protein-1 (MRP1), Bcl-xL and Bax protein were measured by immunocytochemistry. The human leukemia multidrug resistant K562/VCR cells showed no cross-resistance to bufalin. The RIs of bufalin at concentrations of 0.0002, 0.001 and 0.005 μmol/L were 4.85, 6.94 and 14.77, respectively. Preincubation of 0.001 μmol/L bufalin for 2 h could increase intracellular ADM fluorescence intensity to 28.07% (P < 0.05) and down-regulate MRP1 expression simultaneously, but no remarkable effect was found on P-gp protein. Cell cycle analysis indicated increased apoptosis rate and apparent decreased G2/M phase proportion after treatment with bufalin. When exposed to 0.01 μmol/L bufalin, typical morphological changes of apoptosis could be observed. Down-regulation of Bcl-xL and up-regulation of Bax expression in K562/VCR cells could be detected by immunocytochemistry. Bufalin could partly reverse the MDR of K562/VCR cells, with a possible mechanism of down-regulating MRP1 expression and activating apoptosis pathway by altering Bcl-xL/Bax ratio.

Related Materials

Product #



Molecular Formula

Add to Cart

Vincristine sulfate, European Pharmacopoeia (EP) Reference Standard
C46H56N4O10 · H2SO4