Evaluation of Murraya koenigii Leaf Extract for Enhanced Fish Health and Growth Performance

Abstract

This study evaluated the aqueous leaf extract of Murraya koenigii (ALM) as a phytogenic feed additive for Etroplus suratensis, focusing on phytochemical composition, antibacterial activity, growth, haematological and serum biochemical responses, antioxidant status, and tissue morphology. Qualitative phytochemical screening indicated flavonoids, phenolic compounds, alkaloids, tannins, and saponins, while LC-HRMS profiling of the aqueous extract identified 44 compounds. ALM inhibited Aeromonas hydrophila in vitro at a minimum inhibitory concentration of 0.312 ± 0.00 mg/ml. Fish were fed diets containing 0, 0.5, 1, 1.5, or 2% ALM for 60 days. Growth performance improved across supplemented groups, with the 2% group recording the highest final weight (9.31 ± 0.017 g), weight gain (5.11 ± 0.011 g), and specific growth rate (1.32 ± 0.001%) and the lowest feed conversion ratio (1.47 ± 0.002). Dietary ALM was associated with changes in haematological indices and serum total protein, albumin, albumin-globulin ratio, glucose, and alkaline phosphatase, whereas alanine and aspartate transaminase activities did not differ significantly. Hepatic superoxide dismutase and catalase activities increased with supplementation. Histological observations indicated larger intestinal villi and altered hepatocyte morphology in treated fish. No mortality or visible distress occurred in the acute oral limit test at 2000 mg/kg body weight. These findings support further evaluation of ALM as a potential phytogenic feed additive for E. suratensis.