Effects of gamma-irradiation on the color and biological activity of ethanol extracts of the brown seaweed Ecklonia cava

Abstract

This study examined the effect of gamma-irradiation on the biological and physical characteristics of brown seaweed, Ecklonia cave ethanol extracts, with the goal of improving their industrial applications. Samples were irradiated with Co-60 gamma rays at doses of 1-30 kGy, after which their color was evaluated. In addition, their antioxidant properties, DPPH radical scavenging activity, inhibition of NO synthesis, and anti-Propionibacterium acnes activity were investigated. The results showed that the Hunter color L. value increased with irradiation in a dose-dependent manner, resulting in extracts that were lighter than the non-irradiated samples, while the Hunter color a and b values decreased with irradiation. Irradiation treatment did not alter the antimicrobial activity, rather it decreased the antioxidant properties and DPPH radical scavenging activity and inhibited NO synthesis. In the safety test of irradiated E. cava extracts, acute toxicity test using mice and a cytotoxicity assay on the murine macrophage cell line RAW264.7 suggested that irradiated E. cava extracts can be safely used by humans at moderate doses. In conclusion, gamma-irradiation lightened the color of E. cava ethanol extracts, lessening its limitations for use as a raw material in the cosmetic and pharmaceutical industries, without adversely affecting its biological activity.