IN VITRO ANTIBACTERIAL ACTIVITY AND IN VIVO EVALUATION OF TERMINALIA CHEBULA SUPPLEMENTED FUNCTIONAL FEED AGAINST AEROMONAS HYDROPHILA IN CHANNA STRIATA

Abstract

Aquaculture intensification has increased interest in plant-derived feed additives as potential alternatives or complements to conventional approaches for managing bacterial diseases. This study evaluated a functional feed containing 2% methanolic Terminalia chebula fruit extract in juvenile Channa striata exposed to Aeromonas hydrophila. The formulated floating pellets had a mean diameter of 1.37 ± 0.21 mm, floating ability of 100%, water stability of 76.87 ± 0.12%, pellet durability of 99.33 ± 0.01%, and bulk density of 0.4393 ± 0.0003 g cm⁻³. Proximate analysis indicated 33.48% crude protein, 2.57% crude lipid, 6.37% crude fibre, 4.78% ash, and 10.64% moisture. Supporting in vitro assays demonstrated antibacterial activity against A. hydrophila following thermal exposure at 40, 60, and 80°C for 1 h and at 95°C for 1.5 h. Fish received the experimental diets for 20 days before bacterial challenge. The available growth summary descriptively favoured the methanolic-extract feed group; however, original fish-level and replicate-level growth records were unavailable for independent verification, so these indices require confirmation against primary records. Following bacterial challenge, mean mortality was 23.3% in the methanolic-extract feed group and 43.3% in the challenged positive control; mortality was also recorded in the unchallenged control. PCR detected the reported target in the bacterial isolate and yielded amplification bands in post-challenge tissue samples, although the target of the tissue assay requires confirmation from the original laboratory records. Overall, the findings characterise the physical and nutritional properties of the formulated feed and provide preliminary evidence of in vitro antibacterial activity and observed post-challenge responses. Further studies incorporating quantitative pathogen-load assessment and host-response analyses are warranted to establish the protective efficacy of T. chebula -supplemented functional feed.