Skin mucus of saltwater fish: a new source of antioxidant activity and cytotoxicity

Fish mucus layers are the main surface of exchange between fish and the environment, and they possess important biological and ecological functions. In the present study, the antioxidant activity (reducing power, total antioxidant capacity, and free radical scavenging of DPPH) and cytotoxicity (test of saltwater shrimp larvae) of four species of Solea elongate, Euryglossa orientalis, Netuma bilineata, Muraenesox cinereus were investigated. The results showed that E. orientalis fish mucus had the highest reducing power (1.6 ± 0.2), N. bilineata fish mucus had the highest total antioxidant capacity (0.93 ± 0.3) and the highest percentage of free radical scavenging DPPH (89 ± 0.2). In the cytotoxicity test, the highest mortality rate under the influence of S. elongate mucus was about 97.5 ± 2.5. The results of the present study showed that fish mucus can be introduced as a potential source of natural biological compounds with high antioxidant activity and cytotoxicity.