Sanguinarine Alleviates the Adverse Effects of Excessive Dietary Histamine on Growth and Intestinal and Hepatic Health in Juvenile American Eels (Anguilla rostrata)

Histamine is a significant risk factor in brown fishmeal and negatively affects histamine-sensitive fish species. The present study aimed to explore the potential protective effects of dietary sanguinarine supplementation against the adverse impacts of excessive dietary histamine on growth and intestinal and hepatic health in American eels. Four experimental diets were formulated: the basal diet (control diet), the basal diet supplemented with 500 mg kg−1 of histamine (HH diet), and the HH diet supplemented with 100 mg kg−1 and 200 mg kg−1 of sanguinarine (HH+SAN100 and HH+SAN200 diets, respectively). After a 10-week feeding trial, both sanguinarine supplementation diets alleviated HH-diet-induced growth retardation, reduced feed utilization, serum dyslipidemia, and hepatic and intestinal structural damage; decreased hepatic and intestinal antioxidant capacity; increased intestinal and hepatic malondialdehyde levels; inhibited intestinal lipase activities; elevated intestinal pro-inflammatory-related gene abundance; and lowered intestinal anti-inflammatory-related gene expression. Furthermore, the HH+SAN100 diet partially ameliorated HH-diet-induced gut microbiota dysbiosis and intestinal metabolic disturbances. Collectively, these findings identify sanguinarine as a functional dietary additive that mitigates histamine-associated growth suppression and intestinal and hepatic injury in American eels, promoting the sustainable utilization of brown fishmeal in American eel culture.