• Antioxidant effects of Haematococcus pluvialis on arsenic-induced oxidative stress in rainbow trout (Oncorhynchus mykiss) fillet
  • Fatemeh sheykhkanlu Milan,1 Mir-Hassan Moosavy,2,* Shalaleh Mousavi,3 Seyed Amin Khatibi,4
    1. Department of Food Hygiene and Aquatic, Faculty of Veterinary Medicine, University of Tabriz, Tabriz, Iran.
    2. Department of Food Hygiene and Aquatic, Faculty of Veterinary Medicine, University of Tabriz, Tabriz, Iran.
    3. Department of Food Hygiene and Aquatic, Faculty of Veterinary Medicine, University of Tabriz, Tabriz, Iran.
    4. Department of Food Hygiene and Aquatic, Faculty of Veterinary Medicine, University of Tabriz, Tabriz, Iran.


  • Introduction: Generally, fish meat is one of the most important sources of animal proteins, and the farming of rainbow trout (Oncorhynchus mykiss) is a common way for it’s providing in Iran. However, fish is highly susceptible to being spoiled by the oxidation process which is one of the main reasons for the limited shelf life of fish. Arsenic (As) is a water-soluble metal that is found in aquatic environments that long-term exposure of humans and animals to it could be harmful to their health. Continuous exposure of freshwater organisms like fish to the low concentrations of As results in the bioaccumulation particularly in the meat and liver. It also weakens the immune system and antioxidant activity of the fish that even may lead to its death. Haematococcus pluvialis (H. pluvialis), as a green alga, is usually used in food and pharmaceutical industry due to its nutritional and antioxidant properties. Because of the presence of astaxanthin, it has a considerable antioxidant activity. Astaxanthin is a keto-carotenoid which its antioxidant properties and beneficial impacts on the growth have been demonstrated. In the present study, the protective effect of H. pluvialis was evaluated on arsenic-induced oxidative stress in the fillet of rainbow trout.
  • Methods: Juvenile Rainbow trout (100±10 g) (N=80) were purchased from a local farm near Tabriz city, Iran. They were randomly divided into 8 tanks (each tank containing 10 fish) including three treatment groups and one control group (with two replicates). The temperature of water in the tanks was 12±1°C, dissolved oxygen was 8.3 mg/L, NH3 was below 0.01 mg/L, NO2 was under 0.1 mg/L, pH was 7.8 and water hardness was 275 mg/L. After ten days of adaptation, H. pluvialis was added to the diet of treatment groups at 0.28, 0.5 and 1.12 g in 100 g of diet, respectively. After sixty days of breeding, each group was divided into two subgroups (N=5). One of the subgroups in each group was treated with As (9.1mg/L) for 96h. After this period, the fillets of each fish were collected separately under hygienic conditions and then packed and frozen. In order to evaluate their pH and peroxide value, they were sent to the laboratory. After the homogenization of samples, the pH level was analysed using a digital pH meter. The peroxide value was evaluated according to the IDF international standard.
  • Results: The average pH level in fillet samples varied between 6.07 and 6.38. The highest pH belongs to the control group which exposed to As. The peroxide value in control group exposed with As was higher than other groups. In the treatment groups which were fed by different quantities of H. pluvialis, the level of peroxide value was significantly lower than the control group exposed to As (p<0.05).
  • Conclusion: Our results show that H. pluvialis significantly affected the peroxide and pH value in the fillets. Since these factors are the quality indicators of fish fillet, supplementation of H. pluvialis in the diet is effective against the As induced-oxidative stress in rainbow trout in a dose-dependent manner.
  • Keywords: Arsenic, Haematococcus pluvialis, Oxidative stress, Rainbow trout