Herbal medicine applications in aquaculture stress management: a comprehensive review integrating environmental, nutritional, and health perspectives

Global production of animal protein from aquaculture systems is increasing in importance; however, increasing intensification of aquaculture farming systems has exposed farmed fish and shellfish to multiple stressors, including environmental variability, nutritional imbalance, and pathogens, which can disrupt the normal physiological homeostasis of animals, suppress their immune response, and lead to reduced productivity. Therefore, the industry is increasingly interested in developing sustainable alternatives to conventional chemotherapy drugs. Therapeutic plant-based products, which can include medicinal herbs, phytogenic feed additives, and botanical extracts, represent a promising ecological alternative to conventional chemotherapy agents. This review provides a comprehensive analysis of the literature regarding the use of herbs for managing stress in aquaculture with an emphasis on their immunomodulatory, antioxidant, growth-promoting, and disease-mitigating properties. In particular, the roles of these botanicals in regulating the physiological processes associated with environment, nutrition, and health of aquatic animals are emphasized. Specific bioactive phytochemicals including flavonoids, alkaloids, terpenoids, and phenolic compounds are examined for their ability to modulate redox-mediated stress pathways, cytokine networks, and metabolic efficiency under conditions of high-intensity aquaculture production. A number of representative botanicals ( Curcuma longa, Zingiber officinale, Allium sativum , and Camellia sinensis ) have demonstrated significant potential in improving the immune response of fish, their feed conversion efficiency, and their resistance to pathogens. Overall, this review demonstrates that phyto-therapeutics offer biodegradable and low-residue options for reducing dependence on antibiotics, while at the same time promoting sustainable food production. We also discuss some of the challenges that need to be addressed before phytotherapy can be translated into practical application in climate-resilient aquaculture systems.