Cancer Chemotherapy and Pharmacology

, Volume 62, Issue 6, pp 1015–1026

Reversal of P-glycoprotein-mediated multidrug resistance of cancer cells by five schizandrins isolated from the Chinese herb Fructus Schizandrae

Authors

  • Min Huang
    • Division of Oncology, Department of Internal MedicineStanford University
  • Jing Jin
    • Welsh School of PharmacyCardiff University
  • Hua Sun
    • Department of Pharmacology, Institute of Materia MedicaPeking Union Medical College and Chinese Academy of Medical Sciences
    • Department of Pharmacology, Institute of Materia MedicaPeking Union Medical College and Chinese Academy of Medical Sciences
Original Article

DOI: 10.1007/s00280-008-0691-0

Cite this article as:
Huang, M., Jin, J., Sun, H. et al. Cancer Chemother Pharmacol (2008) 62: 1015. doi:10.1007/s00280-008-0691-0

Abstract

Purpose

Fructus Schizandrae (FS) is commonly used as a tonic in traditional Chinese medicine. Recently, FS was found to significantly improve liver dysfunction in chronic hepatitis patients. The present study was to assess the reversal effect of five schizandrins and crude extract from FS (named LCC) on multidrug resistance (MDR) of cancer cells, both in vitro and in vivo. Chemically, the five schizandins are derivatives of dibenzo-(a, c)-cyclooctene lignan with distinct structures differing from any known MDR reversal agents.

Methods

A panel of sensitive and resistant cancer cell lines were treated with various concentrations of LCC and schizandrins. Drug sensitivity, accumulation of Doxorubicin (Dox), expression of P-glycoprotein and protein kinase C (PKC), and apoptosis were determined in vitro. The in vivo effect was tested in nude mice grafted with sensitive and resistant human epidermal cancer cell line to vincristine (VCR) (KB, KBv200).

Results

The tested five compounds at 25 μM showed various levels of MDR reversal activity, of which, schizandrin A (Sin A) was the most potent one. Sin A reversed VCR resistance in KBv200 cells, MCF-7/Dox cells and Bel7402 cells by 309-, 38-, and 84-folds, respectively. Also, Sin A reversed the resistance of Dox in the above cancer cell lines. LCC at 25 μg/ml reversed VCR resistance by 619-folds in KBv200, 181-folds in MCF-7/Dox cell line, and 1,563-folds in innate resistance of human hepatic cellular carcinoma Bel7402 cells to VCR. Furthermore, LCC and its active component Sin A potently reversed the cross-resistance to paclitaxel in those cell lines. Both Sin A and LCC markedly increased intracellular Dox accumulation and enhanced apoptosis, down-regulated Pgp protein and mRNA and total PKC expression in MDR cells. Coadministration of LCC (p.o.) significantly potentiated the inhibitory effect of VCR (i.p.) on tumor growth in nude mice bearing KBv200 xenograft.

Conclusions

The LCC and its active component Sin A have remarkable reversal effect on MDR in cancer cells by inhibition of both the function and expression of Pgp and total PKC.

Keywords

Multidrug resistancePgpFructus SchizandraeSchizandrins

Abbreviations

FS

Fructus Schizandrae

Sin A

Schizandrin A

Sin B

Schizandrin B

Sin C

Schizandrin C

Sol A

Schizandrol A

Sol B

Schizandrol B

VPL

Verapamil

Dox

Doxorubicin

MDR

Multidrug-resistance

Pgp

P-glycoprotein

LCC

Crude extract of Fructus Schizandrae

PKC

Protein kinase C

VCR

Vincristine

MTT

3-(4,5-Dimethylthiazole-2-yle)-2,5-diphenyltetrazolium bromide

Rho 123

Rhodamine 123

PI

Propidium iodide

FITC

Fluorescence isothiocyanate

LPS

Lipopolysaccharides

CAM

Camptothecin

ETO

Etoposide

NBT

Nitroblue tetrazolium chloride

BCIP

5-Bromo-4-chloro-3-inDoxyl-phosphate

Copyright information

© Springer-Verlag 2008