The antioxidant activity of five brown seaweeds, sourced from the west coast of Ireland, assessed in the Caco-2 cell line

Abstract

Seaweeds are a relatively unexploited source of antioxidants and there is potential for seaweeds to be utilised as health promoting ingredients in the pharmaceutical and functional food industries. Previous data from our laboratory demonstrated considerable antioxidant effects in certain seaweeds(1). The objective of the present study was to determine the effect of methanolic extracts of the seaweeds, Ascophyllum nodosum, Laminaria hyperborea, Pelvetia canaliculata, Fucus vesiculosus and Fucus serratus on the antioxidant status and DNA integrity of Caco-2 cells. Caco-2 cells were supplemented with increasing concentrations of the seaweed extracts for 24 h and cell viability was determined by the MTT assay. A concentration of 100mg/ml was selected for all subsequent experiments. The effect of the extracts on the antioxidant status of the cells was assessed by measuring reduced glutathione (GSH) content following a 24 h exposure to the seaweed extracts(2). The activity of the antioxidant enzyme superoxide dismutase (SOD) was assessed following a 30 min exposure to 200mM hydrogen peroxide (H2O2) which was preceded by a 24 h exposure to the seaweed extracts. DNA damage was also assessed using the comet assay(3) in Caco-2 cells, which were pre-treated with each seaweed extract for 24 h followed by exposure to 50mM H2O2 for 30 min.