Studies of Jatrogossone A as a Reactive Oxygen Species Inducer in Cancer Cellular Models

J Nat Prod. 2019 May 24;82(5):1301-1311. doi: 10.1021/acs.jnatprod.8b01087. Epub 2019 May 14.

Abstract

Natural products continue to provide a platform to study biological systems. A bioguided study of cancer cell models led us to a new member of the jatrophane natural products from Jatropha gossypiifolia, which was independently identified and characterized as jatrogossone A (1). Purification and structure elucidation was performed by column chromatography and high-performance liquid chromatography-mass spectrometry and NMR techniques, and the structure was confirmed via X-ray crystallography. The unique molecular scaffold of jatrogossone A prompted an evaluation of its mode of action. Cytotoxicity assays demonstrated that jatrogossone A displays selective antiproliferative activity against cancer cell models in the low micromolar range with a therapeutic window. Jatrogossone A (1) affects mitochondrial membrane potential (ΔΨm) in a time- and dose-dependent manner. This natural product induces radical oxygen species (ROS) selectively in cancer cellular models, with minimal ROS induction in noncancerous cells. Compound 1 induces ROS in the mitochondria, as determined by colocalization studies, and it induces mitophagy. It promotes also in vitro cell death by causing cell arrest at the G2/M stage, caspase (3/7) activation, and PARP-1 cleavage. The combined findings provide a potential mechanism by which 1 relies on upregulation of mitochondrial ROS to potentiate cytotoxic effects through intracellular signaling.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetylcysteine / pharmacology
  • Antineoplastic Agents, Phytogenic / chemistry
  • Antineoplastic Agents, Phytogenic / pharmacology*
  • Antioxidants / pharmacology
  • Cell Cycle Checkpoints / drug effects
  • Cell Line, Tumor
  • Cell Proliferation / drug effects
  • Cell Survival / drug effects
  • Dose-Response Relationship, Drug
  • Humans
  • Jatropha / chemistry
  • Membrane Potential, Mitochondrial / drug effects
  • Mitophagy / drug effects
  • Neoplasms / metabolism*
  • Poly (ADP-Ribose) Polymerase-1 / drug effects
  • Poly (ADP-Ribose) Polymerase-1 / metabolism
  • Reactive Oxygen Species / metabolism*

Substances

  • Antineoplastic Agents, Phytogenic
  • Antioxidants
  • Reactive Oxygen Species
  • PARP1 protein, human
  • Poly (ADP-Ribose) Polymerase-1
  • Acetylcysteine