Antidepressant effects of curcumin-coated iron oxide nanoparticles in a rat model of depression

The antidepressant effect of curcumin-coated iron oxide nanoparticles (Cur-IONPs) was investigated in the current study using depression rat model induced by reserpine. IONPs were synthesized by curcumin as a reducing agent producing Cur-IONPs. Rats were divided into control, depression rat model, and depressed rats treated with Cur-IONPs. After treatment rat behavior was evaluated using forced swimming test (FST). Serotonin (5-HT), norepinephrine (NE), dopamine (DA), monoamine oxidase (MAO), acetylcholinesterase (AchE), Na⁺, K⁺, ATPase, lipid peroxidation (MDA), reduced glutathione (GSH), glutathione-s-transferase (GST) and nitric oxide (NO) were measured in the cortex and hippocampus. In depressed rats, FST showed increased immobilization time and reduced swimming time. This was associated with a significant decrease in 5-HT, NE, DA and GSH and a significant increase in MDA and NO levels and GST, MAO, AchE and Na⁺, K⁺, ATPase activities in the cortex and hippocampus. Treatment with Cur-NONPs for two weeks increased the swimming time reduced the immobility time, and elevated 5-HT, NE and DA levels. Cur-IONPs attenuated the oxidative stress induced by reserpine and restored the MAO, AchE and Na⁺, K⁺, ATPase. The present green method used curcumin in the IONPs synthesis and has several merits; obtaining nanoform of iron oxide, increasing the bioavailability of curcumin and reducing the oxidative stress induced by iron. The present antidepressant effect of Cur-IONPs could be attributed to the ability of Cur-IONPs to restore monoamine neurotransmitter levels by increasing their synthesis and reducing their metabolism. In addition, the antioxidant activity of curcumin prevented oxidative stress in the depressed rats.