The role of Eleutherine palmifolia (Dayak Onion) as a natural immunostimulant for enhancing fish disease resistance in aquaculture systems

The global food crisis, driven by population growth, climate change, and natural resource degradation, has intensified the need for efficient, affordable, and environmentally sustainable sources of animal protein. In aquaculture, this demand has accelerated the exploration of alternative feed ingredients and natural additives that enhance immune responses, suppress pathogens, and promote fish growth. Eleutherine palmifolia (Dayak onion), an endemic plant from Kalimantan, has emerged as a promising candidate due to its strong antibacterial activity and safety profile without chemical residues. Using a PRISMA-guided systematic review, this study synthesises current evidence on the phytochemical composition, immunological mechanisms, antibacterial activity, and application potential of E. palmifolia in sustainable aquaculture. The extract exhibits anti-inflammatory effects by modulating pro-inflammatory cytokines, enhancing TNF-α expression while reducing IL-β levels, thereby supporting a balanced immune response without excessive oxidative stress. Both ethanol and aqueous extracts effectively inhibit Escherichia coli, Salmonella typhi, and Vibrio cholerae. The plant’s secondary metabolites, including flavonoids, naphthoquinones, polyphenols, tannins, and saponins, demonstrate broad biological activities that improve fish health, growth, and disease resistance. Overall, E. palmifolia holds strong potential as an immunostimulant, antioxidant, and phytobiotic agent for environmentally friendly aquaculture practices.