The natural polyamine spermine functions directly as a free radical scavenger

The natural polyamine spermine functions directly as a free radical scavenger

^*Department of Oncology, The Johns Hopkins School of Medicine, Baltimore, MD 21231; ^†Department of Environmental Health Sciences, The Johns Hopkins School of Hygiene and Public Health, Baltimore, MD 21205; ^§Department of Medicine, The Johns Hopkins School of Medicine, Baltimore, MD 21224; and ^‡Department of Pharmaceutical Sciences, Wayne State University, Detroit, MI 48207

Communicated by Paul Talalay, The Johns Hopkins University School of Medicine, Baltimore, MD (received for review May 31, 1998)

Abstract

The polyamines are small organic cations that are absolutely required for eukaryotic cell growth. Although their growth requirements are well established, the molecular functions of the polyamines are ill-defined. Oxidative damage to DNA by reactive oxygen species is a continual problem that cells must guard against to survive. The polyamine spermine, which is normally found in millimolar concentrations in the nucleus, is shown here to function directly as a free radical scavenger, and adducts formed as a result of this function are identified. These data suggest that spermine is a major natural intracellular compound capable of protecting DNA from free radical attack.

Footnotes

↵ ¶ To whom reprint requests should be addressed at: The Johns Hopkins Oncology Center Research Laboratories, 424 North Bond Street, Baltimore, MD 21231. e-mail: casero{at}welchlink.welch.jhu.edu.
ABBREVIATIONS:

DMPO,

5,5-dimethyl-1-pyrroline-N-oxide;

ROS,

reactive oxygen species;

CI,

chemical ionization;

TSP,

sodium 3-(trimethylsilyl)propionate