Magnolol causes alterations in the cell cycle in androgen insensitive human prostate cancer cells in vitro by affecting expression of key cell cycle regulatory proteins

Nutr Cancer. 2014;66(7):1154-64. doi: 10.1080/01635581.2014.951736. Epub 2014 Sep 29.


Prostate cancer, one of the most common cancers in the Western world, affects many men worldwide. This study investigated the effects of magnolol, a compound found in the roots and bark of the magnolia tree Magnolia officinalis, on the behavior of 2 androgen insensitive human prostate cancer cell lines, DU145 and PC3, in vitro. Magnolol, in a 24-h exposure at 40 and 80 μM, was found to be cytotoxic to cells. Magnolol also affected cell cycle progression of DU145 and PC3 cells, resulting in alterations to the cell cycle and subsequently decreasing the proportion of cells entering the G2/M-phase of the cell cycle. Magnolol inhibited the expression of cell cycle regulatory proteins including cyclins A, B1, D1, and E, as well as CDK2 and CDK4. Protein expression levels of pRBp107 decreased and pRBp130 protein expression levels increased in response to magnolol exposure, whereas p16(INK4a), p21, and p27 protein expression levels were apparently unchanged post 24-h exposure. Magnolol exposure at 6 h did increase p27 protein expression levels. This study has demonstrated that magnolol can alter the behavior of androgen insensitive human prostate cancer cells in vitro and suggests that magnolol may have potential as a novel anti-prostate cancer agent.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antineoplastic Agents, Phytogenic / pharmacology
  • Biphenyl Compounds / pharmacology*
  • Cell Cycle / drug effects*
  • Cell Cycle Proteins / genetics
  • Cell Cycle Proteins / metabolism*
  • Cell Line, Tumor
  • Cyclin A / genetics
  • Cyclin A / metabolism
  • Cyclin B1 / genetics
  • Cyclin B1 / metabolism
  • Cyclin D1 / genetics
  • Cyclin D1 / metabolism
  • Cyclin E / genetics
  • Cyclin E / metabolism
  • Cyclin-Dependent Kinase 2 / genetics
  • Cyclin-Dependent Kinase 2 / metabolism
  • Cyclin-Dependent Kinase 4 / genetics
  • Cyclin-Dependent Kinase 4 / metabolism
  • Cyclin-Dependent Kinase Inhibitor p27 / genetics
  • Cyclin-Dependent Kinase Inhibitor p27 / metabolism
  • Humans
  • Lignans / pharmacology*
  • Magnolia / chemistry
  • Male
  • Plant Extracts / pharmacology
  • Prostatic Neoplasms / drug therapy
  • Prostatic Neoplasms / pathology*


  • Antineoplastic Agents, Phytogenic
  • Biphenyl Compounds
  • CCNB1 protein, human
  • CCND1 protein, human
  • Cell Cycle Proteins
  • Cyclin A
  • Cyclin B1
  • Cyclin E
  • Lignans
  • Plant Extracts
  • magnolol
  • Cyclin D1
  • Cyclin-Dependent Kinase Inhibitor p27
  • CDK2 protein, human
  • CDK4 protein, human
  • Cyclin-Dependent Kinase 2
  • Cyclin-Dependent Kinase 4