Effects of dietary extra-virgin olive oil on behaviour and brain biochemical parameters in ageing rats.
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.
Pitozzi
Vanessa
V
Department of Preclinical and Clinical Pharmacology, University of Florence, Viale G. Pieraccini 6, 50139 Florence, Italy.
Jacomelli
Michela
M
Zaid
Mohamed
M
Luceri
Cristina
C
Bigagli
Elisabetta
E
Lodovici
Maura
M
Ghelardini
Carla
C
Vivoli
Elisa
E
Norcini
Monica
M
Gianfriddo
Marco
M
Esposto
Sonia
S
Servili
Maurizio
M
Morozzi
Guido
G
Baldi
Elisabetta
E
Bucherelli
Corrado
C
Dolara
Piero
P
Giovannelli
Lisa
L
D000375:Aging / Q000187:drug effects / Q000502:physiology*; D000818:Animals; D000975:Antioxidants / Q000008:administration & dosage / Q000032:analysis; D001007:Anxiety / Q000517:prevention & control; D001522:Behavior, Animal / Q000187:drug effects*; D001921:Brain / Q000187:drug effects / Q000201:enzymology / Q000502:physiology*; D003071:Cognition / Q000187:drug effects; D004042:Dietary Fats, Unsaturated / Q000008:administration & dosage*; D005980:Glutathione Reductase / Q000235:genetics / Q000378:metabolism; D008297:Male; D009043:Motor Activity / Q000187:drug effects; D000069463:Olive Oil; D018384:Oxidative Stress / Q000187:drug effects; D010636:Phenols / Q000008:administration & dosage; D010938:Plant Oils / Q000008:administration & dosage* / Q000737:chemistry; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017208:Rats, Wistar; D015430:Weight Gain
D000975:Antioxidants; D004042:Dietary Fats, Unsaturated; D000069463:Olive Oil; D010636:Phenols; D010938:Plant Oils; D012333:RNA, Messenger; D005980:Glutathione Reductase