Anti-mold effect of fat soluble extract of Angelica sinensis by-product on pellet feed and biochemical indicators of tissues in Cyprinus carpio var. Jian

As feed raw materials, the fat soluble extract of Angelica sinensis's effects on feed and fish are still unclear. Therefore, we explored the effects of fat soluble extract of A. sinensis by-product (FSE) on the growth of fungi in pellet feed and the biochemical indicators in various tissues and organs of carp (Cyprinus carpio var. Jian), in order to provide a theoretical basis for the development of FSE as a functional raw material for fish feed. Firstly, we obtained four polar extracts of A. sinensis by-product by using solvent extraction method, and obtaied FSE by mixing petroleum ether extract (PEE) and ethyl acetate extract (EAE) of A. sinensis by-product. Then, we formulated the experimental diets by adding extracts of A. sinensis by-product to the basal diet, and fed the carps with diets containing different levels of FSE. The results show that FSE inhibited the growth of mold in pellet feed significantly while affecting multiple physiological parameters in fish. It decreased the plasma hemoglobin (Hb) levels, tissue hydrogen peroxide (H₂O₂) levels, intestinal malondialdehyde (MDA) levels, and red blood cell methemoglobin (MetHb) levels, while increased the levels of triglycerides (TG) and glucose (GLU) in plasma, multiple tissue's reduced glutathione (GSH) levels, and key enzyme activities, including lactate dehydrogenase (LDH), lipase (LPS), α-amylase (AMS), Na⁺, K⁺-ATPase, alkaline phosphatase (AKP) and other digestive, absorptive and metabolism related enzymes, as well as antioxidant enzymes such as catalase (CAT), glutathione peroxidase (GPx), and superoxide dismutase (SOD). The study indicates that FSE exhibits antifungal effects in pellet feed and can improve the digestive, absorptive and respiratory function as well as antioxidant capacity in fish.