Hydroxylated Rotenoids Selectively Inhibit the Proliferation of Prostate Cancer Cells

J Nat Prod. 2020 Jun 26;83(6):1829-1845. doi: 10.1021/acs.jnatprod.9b01224. Epub 2020 May 27.

Abstract

Prostate cancer is one of the leading causes of cancer-related death in men. The identification of new therapeutics to selectively target prostate cancer cells is therefore vital. Recently, the rotenoids rotenone (1) and deguelin (2) were reported to selectively kill prostate cancer cells, and the inhibition of mitochondrial complex I was established as essential to their mechanism of action. However, these hydrophobic rotenoids readily cross the blood-brain barrier and induce symptoms characteristic of Parkinson's disease in animals. Since hydroxylated derivatives of 1 and 2 are more hydrophilic and less likely to readily cross the blood-brain barrier, 29 natural and unnatural hydroxylated derivatives of 1 and 2 were synthesized for evaluation. The inhibitory potency (IC50) of each derivative against complex I was measured, and its hydrophobicity (Slog10P) predicted. Amorphigenin (3), dalpanol (4), dihydroamorphigenin (5), and amorphigenol (6) were selected and evaluated in cell-based assays using C4-2 and C4-2B prostate cancer cells alongside control PNT2 prostate cells. These rotenoids inhibit complex I in cells, decrease oxygen consumption, and selectively inhibit the proliferation of prostate cancer cells, leaving control cells unaffected. The greatest selectivity and antiproliferative effects were observed with 3 and 5. The data highlight these molecules as promising therapeutic candidates for further evaluation in prostate cancer models.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antineoplastic Agents / chemistry*
  • Antineoplastic Agents / pharmacology*
  • Blood-Brain Barrier
  • Cattle
  • Cell Division / drug effects
  • Cell Line, Tumor
  • Cell Proliferation / drug effects
  • Cell Survival / drug effects
  • Drug Screening Assays, Antitumor
  • Electron Transport Complex I / drug effects
  • Humans
  • Male
  • Mitochondrial Membranes / drug effects
  • Molecular Structure
  • Prostatic Neoplasms / drug therapy*
  • Rotenone / analogs & derivatives*
  • Rotenone / chemistry
  • Rotenone / pharmacology*
  • Uncoupling Agents / chemistry
  • Uncoupling Agents / pharmacology*

Substances

  • Antineoplastic Agents
  • Uncoupling Agents
  • Rotenone
  • Electron Transport Complex I