Mohamed Hammami of the University of Monastir in Tunisia and King Saud University in Riyadh, Saudi Arabia, separated 80 rats into a control group, an olive oil group and six groups exposed to the herbicide 2,4-Dichlorophenoxyacetic acid with or without either whole olive oil, or two olive oil extracts -- hydrophilic fraction or the lipophilic fraction.
All rats exposed to the herbicide showed signs of significant liver damage. However, the rats that ate the extra virgin olive oil and hydrophilic fraction had a significant increase in antioxidant enzyme activity and a decrease in markers of liver damage.
"The hydrophilic fraction of olive oil seems to be the effective one in reducing toxin-induced oxidative stress, indicating that hydrophilic extract may exert a direct antioxidant effect on hepatic cells," Hammami says in a statement.
"However, more detailed studies about the effect of antioxidant compounds separately and/or their interactions are necessary to substantiate these observations."
The findings were published in the journal Nutrition and Metabolism.