[Effect on zebrafish neurodevelopment and neuroprotection of a polyphenolic extract olive seeds]

To determine the effect of a polyphenolic extract from olive pit on the development of the nervous system as well as its effect on pain induced by the neurotoxin kainic acid, taking the zebrafish as the animal model.

We analyse the effect of the extract at the maximum tolerated dose (100 mg/ml of polyphenols) on the cholinergic activity in zebrafish larvae (72 hours post-fertilization). Only fecundated eggs with no abnormalities are used. 6 eggs/bowl are incubated in a 24 bowls microplate in 2 ml of water with DMSO (0.1%) at 26 ± 1º C: a) neurodevelopment: water (control) and 100 mg/ml of extract, as an essay; b) neuroprotection: water and kainic acid (100 μM) (control) and 100 mg/ml of extract (essay). All incubations are in triplicate. After 72 h, incubations are examined and checked for any abnormalities. Larvae are homogenized and acetyl cholinesterase activity and protein concentration in supernatants is quantified.

The quantity of protein and the morphologic appreciation is similar in all the essays, showing a standard development. Acetyl cholinesterase in fish larvae, with the polyphenolic extract is 162.2% (SD 44.2) compared to controls (100% of activity) (p < 0.01). Fish larvae treated with kainic acid and polyphenolic acid show 140.1% (SD 22.0) of activity, compared to those only incubated with the neurotoxin (100%) (p < 0.05).

Polyphenols extracted from olive pit produce an increase in the cholinergic activity during the larvae neurodevelopment in the zebrafish as well as protection against the neurotoxin kainic acid.