Antioxidant and anticancer activities of enzymatic hydrolysates of solitary tunicate (<Emphasis Type="Italic">Styela clava</Emphasis>)

The antioxidant and anticancer activities of solitary tunicate (Styela clava) hydrolysate manufactured with different proteases (Alcalase 2.4 L FG, Thermoase PC10F, and pepsin) and optimized by response surface methodology (RSM) were investigated. The hydrolysate produced by Alcalase generally had greater antioxidant and anticancer activities. Two major fractions, F₁ and F₂, were produced by applying Alcalase hydrolysates to Sephacryl S-100 HR gel filtration chromatography. Fraction F₂ with a lower molecular weight (3.6±0.1 kDa) had higher ABTS and DPPH radical scavenging activities than F₁ (5.0±1.0 kDa), with IC₅₀ values of 11.4 and 227.5 μg/mL, respectively. Moreover, fraction F₂ had higher anticancer activitiy, with IC₅₀ values of 577.1, 1,163.3, and 887.2 μg/mL against AGS, DLD-1, and HeLa cells, respectively. Fraction F₂ was also rich in tyrosine, lysine, arginine, phenylalanine, and histidine. These results suggest that solitary tunicate hydrolysates have significant health-promoting effects with excellent antioxidant and anticancer activities.