Natural products as an alternative therapeutic towards increasing fish survival: a review

Natural products, which are secondary metabolites produced by plants, have long been used in the treatment of human diseases, with their applications well-documented throughout history. These compounds exhibit a wide range of bioactivities, including anti-inflammatory, anti-parasitic, and anti-bacterial properties. Natural products have been used as alternatives to antibiotics for disease control and treatment aiming to minimize the emergence of bacterial strains with antimicrobial resistance (AMR) which could compromise the effectiveness of future treatments. Furthermore, the usage of antibiotics might expose consumers to health problems, due to their residues in fish products. Besides that, the routine use of chemicals as disinfectants poses long-term health hazards to aquaculture operators, as some of these chemicals are harmful and potentially carcinogenic. Natural products have been shown to effectively treat bacterial and parasitic diseases in aquaculture. Furthermore, the use of natural products in fish feed have also increased their survival against pathogens and improved fish growth. However, since plants typically produce their active components in minute quantities, there is a growing need to produce analogues with similar bioactivities. Chemical synthesis of these active component analogues will enable mass production of these analogues for extensive use in aquaculture industries as commercial products. The future of these naturally derived antimicrobial compounds looks promising, reducing the dependency of antibiotics in aquaculture and ensuring fish products are safe for human consumption.