Plant Phytochemicals and Inhibitory Roles Against Fish Diseases

Abstract

The phytochemical potentials of different plant parts have been reported, necessitating further assessment of their inhibitory roles against fish diseases. This research investigated the phytochemicals present in Lemon grass (Cymbopogon citratus), Neem plant (Azadirachta indica), Pawpaw plant (Carica papaya), Scent plant (Ocimum gratissimum), Mango plant (Mangifera indica), Bitter plant (Vernonia amygdalina), and Moringa plant (Moringa oleifera), with barks of these plants being the parts used for the study. Using qualitative and quantitative methods of phytochemical determination, zones of inhibition were assessed against Gram-positive and Gram-negative bacteria through in-vivo and in-vitro experiments with plant part extracts. Neem, mango, and Moringa bark, scent leaf, bitter leaf, pawpaw, neem, and moringa leaves, and whole lemon grass extracts showed the best results in terms of qualitative and quantitative presence and exerted antibacterial properties on tested fish pathogens such as Aeromonas veronii (0.70 and 0.40mm diameter), Bacillus subtilis (0.60 and 0.45mm diameter), Staphylococcus aureus (0.90 and 0.36mm diameter), and Pseudomonas aeruginosa (0.75 and 0.20mm diameter). The study concluded that these plant extracts contain botanicals capable of inhibiting fish diseases, offering a potential alternative to synthetic antibiotics in aquaculture.