Antioxidant and anti-inflammatory activities of ethyl acetate extracts of chub mackerel (Scomber colias): a thorough seasonal evaluation

The seasonal variation of key bioactivities in ethyl acetate extracts of chub mackerel (Scomber colias), an underutilised fish species, was evaluated through a complete monthly sampling. The phenolic content had a seasonal variation, ranging from 39 +/- 5 mg GAE/100 g ww (February) to 340 +/- 6 mg GAE/100 g ww (October). Ferric reducing antioxidant power (FRAP) increased from 1.3 +/- 0.4 mu mol Fe2+ Eq/g ww (January) to 10.3 +/- 0.1 mu mol Fe2+ Eq/g ww (September). ABTS had no antioxidant activity between June and December, being the highest value in February, 64.3 +/- 6.3 mu mol Trolox Eq/100 g ww. For phenolic content and FRAP, there was a strong seasonality, which was similar to that of the lipid content. Therefore, correlations were high, being R-2 0.95 for lipid vs. phenolic contents. Anti-inflammatory activity did not show large changes throughout most part of the year, remaining high in the 70-80% of COX-2 inhibition. This finding and the seasonality of the antioxidant properties warrant further research.