Harnessing medicinal plants to control Pseudomonas aeruginosa induced infection in Red Tilapia

Aquaculture plays a crucial role in global food production, yet disease outbreaks pose a significant challenge to the sustainability of fish farming. The overuse of antibiotics and synthetic chemicals raises concerns regarding environmental impact, resistance development, and food safety. Consequently, there is growing interest in natural products as alternative antimicrobial agents and immunostimulants to enhance fish immunity, promote disease resistance, and reduce reliance on synthetic treatments. This study investigated the antibacterial and immunomodulatory effects of Rosmarinus tournefortii and Juniperus oxycedrus against Pseudomonas aeruginosa infection in red tilapia (Oreochromis spp.). Antibacterial assays revealed that ethanolic extracts were more potent than aqueous extracts, with the ethanolic extract of R. tournefortii exhibiting the lowest minimum inhibitory concentration (7 mg/mL). In vivo experiments highlighted contrasting effects; while R. tournefortii triggered an unbalanced immune response and high mortality, J. oxycedrus enhanced key hematological parameters, including elevated white blood cell, neutrophil, and lymphocyte counts, reducing infection severity. These results underscore the therapeutic potential of J. oxycedrus as an immunomodulatory agent in aquaculture, while cautioning against the uncalibrated use of R. tournefortii. Future research should focus on dose optimization and long-term impacts to maximize the benefits of plant-based treatments.