Toxicological effects of azadirachtin on aquatic species: A review of its role in biopesticides

Azadirachtin (AZA) is a bioactive compound extracted from the neem tree Azadirachta indica. It is commonly used in biopesticide formulations due to its antifeedant, growth-inhibiting, and reproductive-disrupting properties. While AZA is considered an environmentally friendly alternative to synthetic pesticides because it degrades rapidly in soil and is compatible with organic farming and aquaculture, there are growing concerns about its ecotoxicological effects on aquatic ecosystems. Therefore, this review critically examines the acute and chronic toxicity to non-target aquatic organisms. The review presents studies on the biomolecular, behavioural, and physiological toxicity effects of AZA on aquatic species, providing a comprehensive overview of its impact. Studies on acute and chronic exposure reveal significant lethal and sublethal effects on various species, including fish and invertebrates. Additionally, uncertainties regarding the behaviour of AZA metabolites and AZA formulations raise further concerns about potential long-term environmental impacts. This is particularly important in aquatic environments where AZA may persist and affect non-target species. Despite its biodegradability, AZA ability to disrupt aquatic ecosystems highlights the need for further research on its environmental fate, the effects of its degradation by-products, and the long-term risks associated with its widespread use. Addressing these knowledge gaps is essential for ensuring AZA-based pesticides are safe and sustainable for application in integrated pest management (IPM) programs.