Research Progress on the Efficacy of Tuna Peptides

Tuna belongs to the classes Osteichthyes, Perciformes, and Scombridae, encompassing several genera of the genus Thunnus. Characterized by low fat and high protein content, tuna is regarded as one of the three nutritionally valuable fish species recommended by global nutrition authorities and is also known as “marine gold” [1].

Research findings indicate that the human body can rapidly absorb various bioactive peptides, with absorption efficiency far exceeding that of intact proteins and free amino acids [2].

Bioactive peptides derived from the hydrolysis or enzymatic digestion of marine fish proteins exhibit a broad spectrum of biological functions, including antioxidant activity and immunoregulatory effects [3].

Antioxidant Activity

Tuna peptides possess both antibacterial and antioxidant properties. Wang et al. [4] found that pancreatic hydrolyzed peptides from tuna could enhance the cell viability of oxidatively damaged INS1 cells, thereby promoting cell proliferation, inhibiting apoptosis, and improving insulin secretion in oxidatively injured INS1 cells. This study confirmed the antioxidant activity of tuna peptides.

Uric Acid-Lowering Activity

Uric acid is the final metabolic product of purines and is excreted via the kidneys. Xanthine oxidase (XOD) is the terminal and key enzyme in purine metabolism. Effective inhibition of XOD activity can reduce serum uric acid levels in humans; thus, XOD activity can be used to a certain extent as an indicator of uric acid concentration in the human body.

Accordingly, Li et al. used tuna as the research material to optimize the enzymatic preparation process of anti-gout active peptides from tuna. Using complex enzymatic hydrolysis, they obtained anti-gout tuna peptides with high protein recovery rate and favorable XOD inhibitory activity. The experimental results showed a protein recovery rate of 83.46% and an XOD inhibition rate of 43.51%. After enzymatic hydrolysis, the peptides in the hydrolysate were predominantly small molecular peptides, and the content of large molecular peptides decreased by 90.7% compared with the untreated sample, demonstrating that small molecular peptides possess relatively high anti-gout activity [5].

Anti-Fatigue Activity

Excessive depletion of nutrients in the body leads to inefficient functioning of various physiological systems, resulting in physical fatigue. Administration of bioactive peptides can rapidly replenish deficient nutrients, improve systemic function, restore homeostatic balance, and thereby alleviate fatigue.

Li et al. experimentally demonstrated that the enzymatic hydrolysate of tuna dark muscle contains high levels of amino acids closely associated with anti-fatigue effects [6].

Su et al. found that the enzymatic hydrolysate of tuna dark meat prolonged the weight-loaded swimming time of mice, increased hepatic glycogen storage, and reduced blood urea nitrogen content in mice, indicating that the hydrolysate exhibits significant anti-fatigue activity [7].

Anti-Osteoporosis Activity (Indirect)

Loss of collagen peptides and bone calcium directly contributes to osteoporosis, which is characterized by reduced bone mass and destruction of the bone tissue microstructure. For effective prevention and treatment, adequate supplementation of collagen peptides and calcium is generally recommended.

Hu et al. experimentally verified that tuna bone collagen peptidechelated calcium exerts inhibitory effects on osteoporosis [8]. Subsequently, Yang et al., during the optimization of TCPCa preparation technology, observed its promoting effect on alkaline phosphatase secretion in human osteocytes [9]. Zhou further optimized the enzymatic hydrolysis and chelation conditions of TCPCa during food processing. The prepared tuna bone collagenchelated peptide granules were uniformly distributed with a particle size ranging approximately from 0.5 to 0.7 μm, exhibiting favorable food processing characteristics [10].

Conclusion

Tuna peptides have attracted extensive attention due to their easy absorbability, high bioactivity, and beneficial effects including antioxidant, uric acid-lowering, and anti-osteoporosis activities.

With continuous improvement in tuna peptide preparation technologies, additional novel biological activities are being gradually explored. The diversification and low cost of raw materials provide tuna peptides with substantial advantages for largescale production. As more functional properties are identified, tuna peptides show promising application prospects in cosmetics, pharmaceuticals, healthcare products, and related industries.

References

[1] Miao Z Q, Huang X C. Analysis of the current status of the world tuna fishery[J]. Journal of Zhejiang Ocean University (Natural Science Edition), 2002, 21(4): 307313.

[2] Singh B P, Vij S, Hati S. Functional significance of bioactive peptides derived from soybean[J]. Peptides, 2014, 54: 171179.

[3] Dekkers E, Raghavan S, Kristinsson H G, et al. Oxidative stability of mahi mahi red muscle dipped in tilapia protein hydrolysates[J]. Food Chemistry, 2011, 124(2): 640645.

[4] Wang X F, Shen H T, Sun X L, et al. Protective effect of tuna (Thunnus sp.) pancreatic hydrolysate on H₂O₂induced oxidative damage in insulinoma cells (INS1)[J]. Oceanologia et Limnologia Sinica, 2019, 50(5): 11461153.

[5] Li G F, He D F, Zheng L B, et al. Optimization of preparation process of antigout active peptides from tuna protein by response surface methodology[J]. Journal of Zhejiang Ocean University (Natural Science Edition), 2020, 39(1): 4150.

[6] Li S F, Li X, Han J J, et al. Antifatigue and gut microbiota regulatory effects of tuna dark muscle hydrolysate in mice[J]. Science and Technology of Food Industry, 2019, 40(17): 314320, 326.

[7] Su Y. Analysis of nutritional components of three tuna species from the South China Sea and antifatigue activity of muscle protein hydrolysates[D]. Zhanjiang: Guangdong Ocean University, 2015.

[8] Hu S W, Zhou X M, Li C, et al. Effect of tuna bone collagen peptidechelated calcium on osteoporosis in ovariectomized rats[J]. Food and Nutrition Sciences, 2019, 8(1): 6167.

[9] Yang H C, Hu S W, Zhou X M, et al. Preparation technology of tuna bone collagen peptidechelated calcium and its effect on alkaline phosphatase secretion in MG63 cells[J]. Chinese Journal of Marine Drugs, 2020, 39(1): 918.

[10] Zhou X M, Zheng W Y, Li C. Preparation of tuna bone collagen polypeptidechelated calcium[J]. The Food Industry, 2020, 41(7): 2226.