Modulation of plasma antioxidant levels, glutathione S-transferase activity and DNA damage in smokers following a single portion of broccoli: a pilot study

J Sci Food Agric. 2014 Feb;94(3):522-8. doi: 10.1002/jsfa.6283. Epub 2013 Jul 22.

Abstract

Background: Broccoli is a rich source of bioactive compounds (i.e. glucosinolates, carotenoids, vitamin C and folate) that may exert an antioxidant effect and reduce oxidative damage. The objective of this pilot study was to investigate the effect of broccoli consumption on carotenoids, vitamin C and folate absorption, glutathione S-transferase (GST) activity, and oxidatively induced DNA damage in male smokers.

Methods: Ten healthy subjects consumed a single portion of steamed broccoli (250 g) with cooked pasta. Blood was drawn at baseline and at 3, 6 and 24 h from consumption.

Results: Broccoli significantly (P ≤ 0.01) increased plasma level of vitamin C and folate (+35% and 70%, respectively) at 3 h, and β-carotene (+8%) at 6 h. A modulation of GST activity occurred in plasma 6 h after broccoli consumption. A significant (P ≤ 0.01) reduction of the levels of H₂O₂-induced DNA damage (-18%) was observed in blood mononuclear cells 24 h after broccoli intake in GSTM1 positive, but not in GSTM1 null subjects.

Conclusion: One portion of broccoli increased plasma antioxidant levels, modulated plasma GST activity and improved cell resistance against H₂O₂-induced DNA damage in healthy smokers. These results support the importance of consuming fruit and vegetable regularly.

Keywords: antioxidants; broccoli; glutathione S-transferase, DNA damage; smokers.

Publication types

  • Clinical Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Antioxidants / metabolism*
  • Ascorbic Acid / blood
  • Brassica / chemistry*
  • DNA Damage / drug effects*
  • Folic Acid / blood
  • Glutathione Transferase / blood*
  • Humans
  • Hydrogen Peroxide
  • Male
  • Oxidative Stress / drug effects*
  • Pilot Projects
  • Plant Preparations / pharmacology
  • Plant Preparations / therapeutic use*
  • Smoking / blood
  • Smoking / drug therapy*
  • Smoking / genetics
  • Young Adult
  • beta Carotene / blood

Substances

  • Antioxidants
  • Plant Preparations
  • beta Carotene
  • Folic Acid
  • Hydrogen Peroxide
  • Glutathione Transferase
  • glutathione S-transferase M1
  • Ascorbic Acid