Effect of whole walnuts and walnut-skin extracts on oxidant status in mice
Received 4 February 2009; accepted 2 September 2009. published online 29 January 2010. Corrected Proof
Abstract
Objective
To evaluate the effect of the intake of whole walnuts and walnut fractions on the oxidant status in mice.
Methods
Thirty-six C57BL/6J male mice were randomized to be fed one of three diets: 1) a standard diet (control group), 2) a standard diet with 10% of whole walnuts (walnut-diet group), or 3) a standard diet with 2% of walnut skins (walnut-skin-diet group) for 8 wk. The plasma antioxidant capacity was measured by oxygen radical-absorbance capacity and plasma ferric-reducing antioxidant potential. Conjugated diene formation and reduced glutathione levels were also analyzed.
Results
We observed no changes in plasma oxidation capability between the walnut and walnut-skin groups with the exception of conjugated dienes. Plasma total antioxidant capacity and the ratio between reduced and oxidized forms of glutathione were lower in the walnut and walnut-skin groups than in the control group.
Conclusion
The decrease in the antioxidant burden observed in enzymatic and non-enzymatic antioxidant systems after sustained consumption of a whole-walnut or a walnut-skin diet in mice may be related to the plasma oxidation capability being maintained in the groups consuming the walnut diets.
aHuman Nutrition Unit, Department of Biochemistry and Biotechnology, Facultat de Medicinia i Ciències de la Salut, ISPV, Universitat Rovira i Virgili, Reus, Spain
bCIBER Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Santiago de Compostela, Spain
cUnit of Pharmacology, Facultat de Medicinia i Ciències de la Salut, Universitat Rovira i Virgili, Reus, Spain
dNutrition and Dietetics Unit, Internal Medicine Department, Hospital Universitari de Sant Joan, Reus, Spain
Patricia López-Uriarte is the recipient of a predoctoral fellowship from the Catalan government's Department of Universities, Research, and the Information Society.
ABSTRACT