Effects of dietary soy isoflavones on growth, antioxidant status, immune response and resistance of juvenile grass carp ( Ctenopharyngodon idella ) to Aeromonas hydrophila challenge

Abstract

In recent decades, due to the continuous increasing demand for aquatic products, the global fishery industry has been expanding rapidly, and aquaculture output has been increasing at an unprecedented speed (Cole et al., 2009). High-density aquaculture is the current mainstream aquaculture modes worldwide. While the environmental stress induced by high rearing density results in poor resistance to disease and vulnerability to infection by pathogenic microorganisms in fish (Costas, Aragão, Mancera, Dinis, & Conceicão, 2008). For a long time, many antibiotics and chemotherapeutic agents have been used to improve non-specific immunity and to treat some bacterial infections in aquatic animals, but these agents also lead to undesirable effects, such as antibiotic resistance, pharmaceutical bioaccumulation and environmental pollution (Bilen, Bulut, & Bilen, 2011;Harikrishnan, Balasundaram, & Heo, 2011). In recent years, many harmless therapeutic techniques and

Effects of dietary soy isoflavone and soy saponin on growth performance, intestinal structure, intestinal immunity and gut microbiota community on rice field eel (Monopterus albus)

“…In present study, compared with SPC, serum AKP was remarkably increased in SI, serum GOT in dietary soy iso avone and saponin group were signi cantly increased, but serum SOD were showed the decreasing trend in dietary soy iso avone and soy saponin groups. On the one hand, dietary soy iso avone and soy saponin have antioxidant capacity for M. albus, this phenomenon was similar to juvenile grass carp (Ctenopharyngodon idella) [11] . On the other hand, these anti-nutrition factors also damaged the liver of M. albus.…”

“…A paper also reported that dietary soy saponin made higher expression of intestinal IL-1β and IL-8 on juvenile turbot (Scophthalmus maximus), and damaged the intestinal barrier and induced enteritis [6] . While dietary soy iso avone improved immune performance (such as the responses of immune cytokines) of juvenile grass carps [11] . We think that herbivorous sh may have higher adaptability to plant anti-nutritional factors than carnivorous sh.…”

“…While dietary soy iso avone has the negatively affect growth performance on Atlantic salmon (Salmo salar L.) [12] , dietary soy iso avone not signi cantly in uence growth performance on rainbow trout (Oncorhynchus mykiss) [8] . However, dietary higher soy iso avone showed better growth than without supplemented soy iso avone on juvenile golden pompano (Trachinotus ovatus) [31] and juvenile grass carp (Ctenopharyngodon idella) [11] . We speculated that different aquatic animals have different tolerance to different level of soy iso avone and soy saponin.…”

“…We hold that soy saponin decreased the intestinal immunity, and soy iso avone and soy saponin had the stacking effect on M. albus. While there have dietary soy iso avone improved the immune response on juvenile golden pompano (Trachinotus ovatus) [31] and juvenile grass carp (Ctenopharyngodon idella) [11] . May be different types of sh have varying degrees of tolerance by soy iso avone and soy saponin.…”

“…Soy iso avone are heat-stable glycosides present in soybean meal, also widely known to exert oestrogen like biological effects on animals because of the similarity of their structure to the natural oestrogen structure [8] . There has many physiological function about soy iso avone, especially for immune system regulation [9] , include effects of antioxidant, anti-in ammatory on white shrimp (Litopenaeus vannamei) [10] , and improve the immune response and against Aeromonas hydrophila challenge on juvenile grass carp (Ctenopharyngodon idella) [11] . However, soy iso avone affected growth performance and altered the physiological processes of on Atlantic salmon (Salmo salar L.) [12] .…”