Milk thistle (Silybum marianum) application in aquaculture: a phytogenic powerhouse for health and sustainability – a comprehensive review

The intensification of aquaculture necessitates sustainable alternatives to synthetic growth promoters and antibiotics. Silybum marianum (milk thistle) has emerged as a promising phytogenic additive rich in silymarin, a flavonolignan complex with potent hepatoprotective, antioxidant, and immunomodulatory properties. This review synthesizes recent findings on the use of milk thistle in fish and crustacean diets, highlighting improvements in growth performance, hepatic function, antioxidant enzyme activity, and immune responses. Evidence indicates that silymarin stabilizes hepatocyte membranes, enhances detoxification pathways, and strengthens stress resilience, thereby reducing disease incidence and antibiotic dependence. Advances in nanoencapsulation and synergistic combinations with probiotics and selenium have further enhanced its bioavailability and efficacy. Despite encouraging outcomes, research gaps persist regarding standardized dosing, species-specific responses, long-term safety, and cost-effectiveness under farm conditions. Future studies should integrate molecular and omics approaches to clarify mechanisms and optimize formulations for commercial application. Overall, S. marianum represents a multifunctional, eco-friendly additive that supports sustainable and health-oriented aquaculture production.