Eucommia ulmoides Oliver enhances the antioxidant capacity and protects Micropterus salmoides from liver damage and immune function impairment caused by a high starch diet

[Display omitted] •This is the demonstration of the therapeutic effect of Eucommia ulmoides Oliver (EuO) on the liver disease of Micropterus salmoides caused by a high starch diet.•The repair of M. salmoides liver disease by EuO is achieved by enhancing antioxidant capacity, inhibiting apoptosis, and repairing damaged tissues.•EuO improves the non-specific immunity of M. salmoides. Eucommia ulmoides Oliver (EuO) is a traditional Chinese herb with effects on repairing disorders of liver lipid metabolism and enhancing immunity in mice. In this study, the effects of EuO on immune enhancement and liver protection of M. salmoides were tested by adding 3% EuO to a high-starch diet and were evaluated by histopathology, enzymology, flow cytometry, and molecular biology. The results showed that the high starch diet promoted hepatocytes apoptosis, damaged the liver, and led to impaired immune function. However, the integrality of liver was recoverd, innate response was enhanced, hepatocyte apoptosis was inhibited, and antioxidant capacity was improved after treatment with EuO. These findings reveal that EuO could improve the immune function while also repairing the M. salmoides liver injury induced by a high starch diet. This study provides a theoretical basis for EuO to solve the liver disease of M. salmoides caused by a high starch diet.