The
neuroprotective effect of virgin
olive oil (VOO)
polyphenols has been related to their
antioxidant effect. The main objective was to analyze how
tyrosol and
hydroxytyrosol contribute to the
antioxidant and
neuroprotective effects of VOO in a model of
hypoxia-reoxygenation in rat brain slices. Rats were treated per os (po) (10 or 20 mg/kg/day) with
hydroxytyrosol ethyl ether (HTEE),
tyrosol ethyl ether (TEE), or 3,4-di-o-methylidene-hydroxytyrosol
ethyl ether (MHTEE), used as a negative control for
antioxidant effects. Lipid peroxidation was inhibited with HTEE, TEE, and MHTEE (from 5.0 ± 1.5 to 2.6 ± 1.5, 4.5 ± 1.5, and 4.8 ± 1.5 nmol/mg
protein, respectively). However, all three compounds had similar
neuroprotective effects: from 2.8 ± 0.07 to 1.8 ± 0.02 arbitrary units for HTEE, 1.4 ± 0.09 arbitrary units for TEE, and 1.3 ± 0.2 arbitrary units for MHTEE. All three compounds inhibited
3-nitrotyrosine production (from 3.7 ± 0.3 to 1.2 ± 0.03 nmol/0.1 g tissue for HTEE, 1.0 ± 0.2 nmol/0.1 g tissue for TEE, and 1.3 ± 0.1 nmol/0.1 g tissue for MHTEE),
prostaglandin E2 production (from 55.7 ± 2.2 to 46.4 ± 1.9 pg/0.1 g tissue for HTEE, 24.7 ± 1.3 pg/0.1 g tissue for TEE, and 27.6 ± 2.6 pg/0.1 g tissue for MHTEE), whereas only HTEE inhibited IL1β production (from 35.7 ± 1.5 to 21.6 ± 0.8 pg/0.1 g tissue). Pearson correlation coefficients related
neuroprotective effect with an
antioxidant effect for HTEE (R = 0.72, p < 0.001), and inhibition of nitrosative stress (R = 0.78, 0.67, and 0.66 for HTEE, TEE, and MHTEE, respectively, p < 0.001) and inflammatory mediators (R = 0.72, 0.79, and 0.64 for HTEE, TEE, and MHTEE, respectively, p < 0.001) with all three compounds.