Evaluating The Prophylactic and Therapeutic Potential of Ceratophyllum Demersum Ethanol Extract Against Aeromonas Sobria Infection in Botia Rostrata (Günther, 1868): A Bioassay-Guided Fractionation Approach

Present study aims to point out the antibacterial phytocomponents in Ceratophyllum demersum against Aeromonas sobria infection in Botia rostrata. In disc diffusion assay, C. demersum ethanol extract (CE) showed the highest antibacterial activity (17.66±0.33 mm). In subsequent in vivo study, healthy, juvenile B. rostrata males (Weight: 2.7±0.5 g; Length: 4.9±0.8 cm) were fed basal and CE-fortified (0.4 g/kg feed) diets for 30 days either before being intraperitoneally injected with A. sobria (96h LD50 single dose: 1*107.261cfu/ml; 25 μl) and basal diet feeding for 7 days (prophylactic) or after bacterial inoculation and basal diet feeding for 7 days (therapeutic). Fish fed CE fortified-diet showed significantly (P<0.05) lower mortality, serum cortisol, cytokines, gill and liver reactive oxygen species (ROS) levels, while significantly (P<0.05) higher innate immune parameters than the basal diet-fed fish. CE seemed equally effective as a prophylactic agent to stimulate innate immunity and provide resistance against A. sobria, and a therapeutic agent to reduce A. sobria induced physiological alterations. Chromatography and GC-MS analysis disseminated the presence of 1-tetradecene, 1-heptacosanol, ethane 1,1 diethoxy and cyclotrisiloxane hexamethyl in CE, which were described to manifest antibacterial, antioxidative and immunostimulatory potential.