In vitro identification and characterisation of iron chelating catechol-containing natural products and derivatives

Biometals. 2021 Aug;34(4):855-866. doi: 10.1007/s10534-021-00312-1. Epub 2021 Apr 28.

Abstract

Iron is an essential component for multiple biological processes. Its regulation within the body is thus tightly controlled. Dysregulation of iron levels within the body can result in several disorders associated with either excess iron accumulation, including haemochromatosis and thalassaemia, or iron deficiency. In cases of excess body iron, therapy involves depleting body iron levels either by venesection, typically for haemochromatosis, or using iron chelators for thalassemia. However, the current chelation options for people with iron overload are limited, with only three iron chelators approved for clinical use. This presents an opportunity for improved therapeutics to be identified and developed. The aim of this study was to examine multiple compounds from within the Davis open access natural product-based library (512 compounds) for their ability to chelate iron. In silico analysis of this library initially identified nine catechol-containing compounds and two closely related compounds. These compounds were subsequently screened using an in vitro DNA breakage assay and their ability to chelate biological iron was also examined in an iron-loaded hepatocyte cellular assay. Toxicity was assessed in hepatocyte and breast cancer cell lines. One compound, RAD362 [N-(3-aminopropyl)-3,4-dihydroxybenzamide] was able to protect against DNA damage, likely through the prevention of free radicals generated via the Fenton reaction; RAD362 treatment resulted in decreased ferritin protein levels in iron-loaded hepatocytes. Lastly, RAD362 resulted in significantly less cell death than the commonly used iron chelator deferoxamine. This is the first study to identify compound RAD362 as an iron chelator and potential therapeutic.

Keywords: Catechol; Fenton reaction; Ferritin; Hydroxyl radical; Iron chelation; Natural product.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antineoplastic Agents / chemistry
  • Antineoplastic Agents / pharmacology*
  • Biological Products / chemistry
  • Biological Products / pharmacology*
  • Catechols / chemistry
  • Catechols / pharmacology*
  • Cell Proliferation / drug effects
  • DNA Breaks
  • Dose-Response Relationship, Drug
  • Drug Screening Assays, Antitumor
  • Humans
  • Iron Chelating Agents / chemistry
  • Iron Chelating Agents / pharmacology*
  • Tumor Cells, Cultured

Substances

  • Antineoplastic Agents
  • Biological Products
  • Catechols
  • Iron Chelating Agents
  • catechol