Acta Pharmacologica Sinica 2008 May; 29 (5): 620-627; doi: 10.1111/j.1745-7254.2008.00776.x

Aim: To investigate the reversal effect of Ganoderma lucidum polysaccharides (Gl-PS) on multidrug resistance (MDR) in the adriamycin (ADM)-resistant leukemic cell line K562/ADM.

Methods: Cytotoxicity was assayed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method; the ADM concentration in cells was determined by flow cytometry and confocal laser scanning microscopy techniques; the expression of P-glycoprotein was assayed by flow cytometry; and the mRNA expression levels of MDR-1 and MDR-associated protein (MRP)1 were determined by RT-PCR.

Results: Gl-PS reversed MDR in K562/ADM cells. Gl-PS obviously reversed the resistance of K562/ADM to doxorubicin. The reversing factors of Gl-PS at 10 and 20 mg/L were 6.46 and 6.80, respectively. MDR-1 and MRP1 transcription were downregulated by 10 and 50 mg/L Gl-PS.
Conclusion: Gl-PS can reverse the MDR by downregulating the expression of MDR-1 and MRP1 in K562/ADM cells.

Keywords: multidrug resistance; Ganoderma lucidum polysaccharides; K562/adriamycin; P-glycoprotein; multidrug resistance-1; multidrug resistance-associated protein-1