Phytochemical properties of Cyrtocarpa edulis peel exert antimicrobial activity and enhance immunobiological parameters in Almaco jack Seriola rivoliana cells.

Fish aquaculture has increased but also disease problems related to it, along with antimicrobial resistance. The use of medicinal plants containing phytochemicals with antimicrobial, antioxidant, and immunomodulatory activities has been proposed. In this study, C. edulis "peel" was investigated for its phytochemical composition, antioxidant capacity, antimicrobial activities, and immunostimulant properties in leukocytes from Almaco Jack, S. rivoliana. The proximal composition of peel indicated 4.10 % protein 5.37 % ash and 6.93 % crude fiber, whereas total phenolic and flavonoid contents were 180 mg and 50 mg per gram of dry sample, respectively. Superoxide radical scavenging, total antioxidant, and iron chelation activities were also detected. In vitro, Almaco Jack S. rivoliana leukocytes treated with peel extract showed no cytotoxicity, whereas respiratory burst, myeloperoxidase, and SOD activities, as well as nitric oxide production, were enhanced. Most bacterial strains were inhibited 70 % at a concentration of 1 mg/mL C. edulis peel extract, except for Salmonella Enteritidis (40 %) and Vibrio parahaemolyticus (25 %). In conclusion, peel has phytochemicals with antioxidant capacity, immunostimulatory effects for Almaco Jack, Seriola rivoliana, and antimicrobial activity against Gram-positive and Gram-negative pathogens. Future experiments in fish must be conducted using C. edulis peel in diets to confirm their immunostimulant, antioxidant, and antimicrobial properties.