Neonicotinoid-Induced Neurotoxicity in Developing Brain: A Systematic Review

Developmental neurotoxicity in humans and other animals due to environmental contaminants is one of the serious health risks. Neonicotinoids, a class of insecticides found in nearly all environmental settings, have been linked to certain developmental abnormalities and are an area of growing interest among health scientists. Neonicotinoids impart toxicity by targeting nicotinic acetyl-choline receptors (nAChRs) and have been reported to be insect-specific and less specific to non-target and mammalian nAChRs. Regardless, studies assessing toxic effects also suggested that neonicotinoids can damage the mammalian nervous system. Hence, this systematic review aimed to provide a comprehensive overview of developmental neurotoxicity resulting from exposure to neonicotinoids. Many studies have been performed on animal models, but very few clinical studies have been reported. An intensive search was performed across databases to identify relevant studies in this domain, and they were analysed based on their results. Thereby, a thorough online literature search was conducted through PubMed, ScienceDirect and Semantic Scholar databases using selected keywords. After applying the PRISMA guideline for exclusion and inclusion criteria, we finally selected 35 studies to include in the present review, comprising clinical and experimental studies. After analysing the results and observations from these studies, it was ascertained that neonicotinoid exposure produced different neurotoxic alterations and behavioural abnormalities. Hence, an investigation needs to be done in this direction as neonicotinoid exposure can be a cause of neuropathological changes, neurological disorders, biochemical alterations and genetic alterations.