British Journal of Nutrition

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British Journal of Nutrition (2010), 103:1674-1683 Cambridge University Press
Copyright © The Authors 2010
doi:10.1017/S0007114509993655

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Behaviour, Appetite and Obesity

Effects of dietary extra-virgin olive oil on behaviour and brain biochemical parameters in ageing rats


Vanessa Pitozzia1, Michela Jacomellia1, Mohamed Zaida1, Cristina Luceria1, Elisabetta Bigaglia1, Maura Lodovicia1, Carla Ghelardinia1, Elisa Vivolia1, Monica Norcinia1, Marco Gianfriddoa2, Sonia Espostoa3, Maurizio Servilia3, Guido Morozzia4, Elisabetta Baldia5, Corrado Bucherellia5, Piero Dolaraa1 and Lisa Giovannellia1 c1

a1 Department of Preclinical and Clinical Pharmacology, University of Florence, Viale G. Pieraccini 6, 50139 Florence, Italy
a2 Siena Biotech Spa, Via Fiorentina 1, 53100 Siena, Italy
a3 Department of Food Sciences, University of Perugia, Via S. Costanzo, 06126 Perugia, Italy
a4 Department of Public Health, University of Perugia, Via del Giochetto, 06126 Perugia, Italy
a5 Department of Physiology, University of Florence, Viale Morgagni 63, 50139 Florence, Italy
Article author query
pitozzi v [PubMed]  [Google Scholar]
jacomelli m [PubMed]  [Google Scholar]
zaid m [PubMed]  [Google Scholar]
luceri c [PubMed]  [Google Scholar]
bigagli e [PubMed]  [Google Scholar]
lodovici m [PubMed]  [Google Scholar]
ghelardini c [PubMed]  [Google Scholar]
vivoli e [PubMed]  [Google Scholar]
norcini m [PubMed]  [Google Scholar]
gianfriddo m [PubMed]  [Google Scholar]
esposto s [PubMed]  [Google Scholar]
servili m [PubMed]  [Google Scholar]
morozzi g [PubMed]  [Google Scholar]
baldi e [PubMed]  [Google Scholar]
bucherelli c [PubMed]  [Google Scholar]
dolara p [PubMed]  [Google Scholar]
giovannelli l [PubMed]  [Google Scholar]

Abstract

The aim of the present study was to verify whether extra-virgin olive oil, a dietary component naturally containing phenolic antioxidants, has the potential to protect the brain from the deleterious effects of ageing. To accomplish this goal, we used male rats fed a high-energy diet containing either maize oil, or extra-virgin olive oil with high or low phenol content (720 or 10 mg total phenols/kg oil, corresponding to a daily dose of 4 or 0·05 mg total phenols/kg body weight, respectively) from age 12 months to senescence. The measured endpoints were biochemical parameters related to oxidative stress and functional tests to evaluate motor, cognitive and emotional behaviour. Olive oil phenols did not exert major protective actions on motor and cognitive function, as we observed only a tendency to improved motor coordination on the rotarod in the old animals treated with the oil rich in phenols (40 % average increase in the time to first fall; P = 0·18). However, an interesting finding of the present study was a reduced step-through latency in the light–dark box test, found in the older animals upon treatment with the oil rich in antioxidant phenols, possibly indicating an anxiety-lowering effect. This effect was associated with decreased glutathione reductase activity and expression in the brain, a phenomenon previously associated with decreased anxiety in rodents. These results indicate a previously undetected effect of a diet containing an olive oil rich in phenols. Further studies are warranted to verify whether specific food antioxidants might also have an effect on emotional behaviour.

(Received July 30 2009)

(Revised October 06 2009)

(Accepted December 03 2009)

(Online publication January 14 2010)

Key Words:Olive oil phenols; Oxidative damage; Anxiety; Glutathione reductase

Correspondence:

c1 Corresponding author: Dr L. Giovannelli, fax +39 055 4271 280, email lisa.giovannelli@unifi.it

Footnotes

Abbreviations: 3,4-DHPEA, hydroxytyrosol; FPG, formamidopyrimidine glycosylase; GPx, glutathione peroxidase; GR, glutathione reductase; GSH, reduced glutathione; GSSG, oxidised glutathione; H-EVOO, extra-virgin olive oil rich in natural antioxidants; L-EVOO, extra-virgin olive oil poor in natural antioxidants; MO, maize oil; SOD, superoxide dismutase; XO, xanthine oxidase


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