Copper oxide nanoparticles (CuO‐NPs) are extensively utilized in several industries and in pharmaceutical production. This excess exposure elevates the concern about its expected poisonous impacts on humans and animals. Pomegranate juice (PJ) is a natural source of polyphenols and exhibits potent antioxidant activities. Our experiment intended to explore the neurobehavioral and toxicopathological impacts of CuO-NPs and to explain the mechanistic role of PJ to reduce their toxicity. Thirty Wistar albino rats received the subsequent materials through oral gavage, every day for 28d: (1) normal saline, (2) 3 mL/kg bwt PJ, (3) 6 mL/kg bwt PJ, (4) 300 mg/kg bwt CuO-NPs, (5) CuO-NPs + 3 mL/kg bwt PJ, (6) CuO-NPs + 6 mL/kg bwt PJ. Continuous exposure to CuO-NPs caused a significant elevation of MDA levels and reduction of total antioxidant capacity associated with remarkable pathological alterations in all brain regions including cerebrum, hippocampus and cerebellum. Progressive decline of memory along with cognitive and psychiatric disturbances were observed in rats exposed to CuO-NPs not in PJ co-treated rats. Continuous exposure to CuO-NPs caused over expression of the immunohistochemical markers of caspase-3, iNOS and GFAP altogether with DAN fragmentation and down-regulation of HO-1 and Nrf2 gene in the whole brain tissues. Conversely, rats co-treated with PJ showed dose dependent improvements in the entire toxicological, behavioral, and pathological parameters. We showed that PJ had the ability to reduce the oxidative stress damage via up-regulation of HO-1 and Nrf2 genes in the brain. So that PJ had the ability to protect the brain and DNA from further damage.
