Original Communication
European Journal of Clinical Nutrition (2005) 59, 1282–1290. doi:10.1038/sj.ejcn.1602241; published online 27 July 2005
Effects of vitamin E on the toxicity of oxidized LDL on endothelial cells in vitro in smokers vs nonsmokers on diets rich in fish
Guarantor: H Vapaatalo.
Contributors: LS was responsible for the manuscript, subjects recruiting, and calculations for living habits and nutrient intake. TL was responsible for the cell cultures. HV, MJT, HV, and RK were responsible for the study plan. All the authors contributed to the preparation of the manuscript.
L Seppo1,2, T Lähteenmäki1, M J Tikkanen3, H Vanhanen3, R Korpela1,2,4 and H Vapaatalo1
- 1Institute of Biomedicine, Pharmacology, University of Helsinki, Finland
- 2Foundation for Nutrition Research, Helsinki, Finland
- 3Department of Medicine, Helsinki University Central Hospital, Helsinki, Finland
- 4Valio Ltd, Helsinki, Finland
Correspondence: H Vapaatalo, Institute of Biomedicine, Pharmacology, University of Helsinki, PO Box 63, Helsinki 00014, Finland. E-mail: heikki.vapaatalo@helsinki.fi
Received 5 August 2004; Revised 26 April 2005; Accepted 15 June 2005; Published online 27 July 2005.
Abstract
Objective:
To clarify whether supplementation of vitamin E can alter the low density lipoprotein (LDL) oxidation properties and thereby affect endothelial cell function and prostacyclin production in smokers compared to nonsmokers on diets rich in fish in a pilot study.
Design:
The LDL of six smokers and six nonsmokers on habitual high fish diet was isolated before and after an 8-week supplementation of vitamin E (800 IU/day). LDL was oxidized by incubation with CuSO4. Cytotoxicity of LDL oxidized to different degrees on endothelial cells was investigated in vitro in these two groups.
Setting:
Helsinki University Central Hospital; Institute of Biomedicine, Pharmacology, University of Helsinki.
Results:
At baseline, the rate of oxidation was higher in nonsmokers than in smokers. The lag phase increased significantly after the supplementation of vitamin E both in smokers and nonsmokers. Native LDL dose dependently tended to reduce the viability of endothelial cells in vitro more markedly when isolated from smokers than from nonsmokers. Vitamin E supplementation had no beneficial effect on the cytotoxicity of oxidized LDLs in endothelial cell culture. On the other hand, simultaneous administration of Trolox®, the water-soluble analogue of vitamin E, attenuated the LDL cytotoxicity on endothelial cells. The vitamin E supplementation to LDL donors attenuated the increase in prostacyclin production both in smokers and nonsmokers.
Conclusion:
Supplementation of LDL donors (healthy male volunteers on habitual fish diet) with vitamin E increased the lag phase of LDL oxidation, but, on the other hand, did not influence in vitro cytotoxicity of LDL, or prostacyclin production.
Sponsorship:
Helsinki University Central Hospital and Biomed 2.
Keywords:
fish oils, diet habits, vitamin E, LDL oxidation, endothelial cells
