Nanoparticles (NPs 1–100 nm) play a vital role in medicine, food, and agriculture owing to their unique reactivity and size-dependent optical properties. There are growing concerns about health risks from exposure to engineered NPs. Among these, copper oxide nanoparticles (CuONPs) are an area of research because of their unique electronic, optical, and chemical properties. CuONPs can interact with biological systems, causing oxidative stress, inflammation, neurobehavioral changes, and other pathophysiological effects. This study evaluated the ability of a probiotic (Lactobacillus acidophilus) to prevent CuONP-treated neurotoxicity. In the present study, 24 animals were classified into four groups: control, probiotic (Lactobacillus acidophilus 6.42 mg/kg b.wt.), CuONPs-treated (80 mg/kg b.wt.), and co-administered CuONPs (80 mg/kg b.wt.) + Probiotic (6.42 mg/kg b.wt.). Neurotoxicity was assessed through behavioral tests, including open field, exploratory behavior, pole test, and grip strength tests. Levels of key neurotransmitters viz. acetylcholinesterase, dopamine, and serotonin were measured and histopathological analyses were performed. The CuONP-treated group displayed significant behavioral deficits, decreased neurotransmitter levels, and histopathological abnormalities. In contrast, co-administration of probiotic with CuONPs reduced these effects, as observed by normal behavioral parameters and neurotransmitter levels and improved histopathological architecture. These findings suggested that CuONPs caused neurotoxicity at the tested dose, but co-administration of probiotic effectively mitigated this toxicity. Hence, a probiotic is a promising preventative strategy against CuONP-induced neurotoxic effects.
