Evaluation of the Immunomodulatory Effects of Silymarin Extract (<I>Silybum Marianum</I>) on Some Immune Parameters of Rainbow Trout, <I>Oncorhynchus Mykiss</I> (Actinopterygii: Salmoniformes: Salmonidae)

Abstract

Ataeimehr B. 2012. Evaluation of the immunomodulatory effects of silymarin extract (Silybum marianum) on some immune parameters of rainbow trout, Oncorhynchus mykiss (Actinopterygii: Salmoniformes: Salmonidae). Acta Ichthyol. Piscat. 42 (2): 113-120.Background. Herbal medicines are increasingly used for their effects on the immune system. Silymarin, a mixture of flavonolignans from the seed of milk thistle (Silybum marianum), is used in treatment of liver disease, food and drug poising, and foetal diseases such as viral hepatitis, diabetes, and ischemia. Although, immunostimulant effects of the dietary silymarin were studied on different experimental animals, no information is available about the effects of silymarin on immune parameters of fish. The presently reported study was conducted to investigate the immunomodulatory effects of silymarin on some immunological and haematological parameters of rainbow trout. Materials and methods. Juvenile rainbow trout, Oncorhynchus mykiss (Walbaum, 1792), were maintained in 1000 L fiberglass tanks at 15 ± 2ºC supplied with systems of water recirculation and aeration. Silymarin extract incorporated into diets (0.0, 0.1, 0.4, and 0.8 g of per 1 kg of feed) of fish. The trout were fed silymarin-supplemented diet for 30 days. Haematological parameters, such as red blood cell count (RBC), white blood cell count (WBC), haematocrit (Hct), haemoglobin (Hb), differential leukocyte-and immunological parameters such as peroxidase, lysozyme, and complement activities, total protein, albumin and globulin levels were measured on day 7, 15, and 30 days of silymarin treatment. Results. The results indicated that oral administration of silymarin in fish, after 15 and 30 days of experimental periods, might enhance haematological and immunological parameters including lysozyme and complement activities, total protein and globulin levels, compared to the controls. Conclusion. The results suggest that oral administration of silymarin may be useful to strengthen the immune system in rainbow trout.

Effects of Vitamin E, Selenium and Vitamin C on Various Biomarkers Following Oxidative Stress Caused by Diazinon Exposure in Rainbow Trout

“…A similar study using an antioxidant compound called silymarin reported reduced CAT levels in rainbow trout exposed to diazinon. The authors explained their finding by the secretion of diazinon metabolites in presence of silymarin [56]. We found comparable results in the group supplemented with vitamin E and selenium.…”

Effects of Aflatoxin-Contaminated Feed on Immunological Parameters of Common Carp (Cyprinus Carpio)

“…In all these three routes, complement C3 and C4 are the main proteins [30]. Therefore, any changes in the activity level of total complement (ACH50) can affect the immunity of fish in removing pathogens [32]. In experimental animals, effects of aflatoxin B1 in disturbing thymus function, a reduction in the number and disturbance in the function of T lymphocytes, reduced activity of phagocytosis and a decrease in the complement activity are reported [29].…”

Fish Nutrition Additives in SHK-1 Cells: Protective Effects of Silymarin

“…But this is not its only exclusive mechanism [13] [14]. Apart from antioxidant properties, it has anti-lipid peroxidative, anti-fibrotic, anti-inflammatory, membrane stabilizing, immunomodulation, as well as anti-tumoral properties, and shows anti-arteriosclerotic and anti-diabetic activity [15] [16]. In fish, the use of silymarin as an antioxidant is not widely studied [17], and it is used in diets as an additive that boosts development and growth [18].…”

“…Its use in diets is diverse; it can be used in the farming of freshwater fish [19], or in the fattening of saltwater fish [18]. It has been used as an immunomodulator [15] or a protectant against agents such as curcumin [17], and can regulate function in fish glial cells [20]. Its action mechanism in fish is unknown, and is identified as an additive that is absorbed as a flavonoid through the intestinal wall.…”

“…Once in the bloodstream, it plays a role in improving cellular nutritional conditions. This could be because of undescribed antioxidant properties, or due to being a metal-chelating agent, improving cell function and development in fishes [15] [17].…”