In Vitro Antidiabetic and Antioxidant Potential of the Ethanolic Extract of Skipjack Tuna (Katsuwonus Pelamis) Heart

Skipjack tuna, Katsuwonus pelamis, are distributed throughout the Pacific Ocean in the tropical and subtropical areas, including South Korea, Japan and Indonesia. The antidiabetic and antioxidant potential of 70% ethanol (EtOH) extract of skipjack tuna heart were investigated via protein tyrosine phosphatase 1B (PTP1B), α-glucosidase, human recombinant aldose reductase (HRAR), 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, peroxynitrite (ONOO−), 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical, and total reactive oxygen species (ROS). The 70% EtOH tuna heart extract exhibited potent inhibitory activity against PTP1B, α-glucosidase and HRAR with inhibition percentages of 85.42, 82.70 and 51.1%, respectively, at a concentration range of 1–2 mg/mL. In addition, it was a potent inhibitor against DPPH, ABTS, ONOO−, and ROS with inhibition percentages of 69.45, 58.31, 96.20 and 34.02%, respectively, at a concentration of 1 mg/mL. The total phenolic content present in tuna extract was 15.80 mg/g GAE. The results demonstrate the potential antidiabetic and antioxidant activities of tuna heart extract. Practical Application Tuna has been consumed as a healthy protein source for hundreds of years. As a food, skipjack is a very good source of protein, vitamins, minerals and omega-3 fatty acids and can lower blood pressure and cholesterol. Generally, the meat of skipjack tuna is used as food and other parts such as the heart are used as fertilizer. Recent studies have identified a number of bioactive components from fish muscle protein, collagen, peptides, gelatin, oil, bone and internal organs that remain after processing. These fish components showed antioxidant, antihypertensive, antiproliferative, antimicrobial and antianemic activities. The findings demonstrated antidiabetic and antioxidant potential of tuna heart extract.