Chemical characterization and therapeutic properties of Achillea biebersteinii leaf aqueous extract synthesized copper nanoparticles against methamphetamine-induced cell death in PC12: A study in the nanotechnology and neurology fields

Recently, scientist have used metallic nanoparticles for synthesizing many new drugs in the field of neurology. One of the metals used in the metallic nanoparticles is copper. The role of Achillea biebersteinii in increasing the physiological activities of central nervous system in Iranian traditional medicine is well known. In this study fresh leaves of A. biebersteinii were used for the biosynthesis of copper nanoparticles. We also assessed the effect of copper nanoparticles on methamphetamine-induced cell death in the PC12 cell line. The nanoparticles were analyzed by Fourier-transform infrared spectroscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy, field emission scanning electron microscopy, and ultraviolet–visible spectroscopy. A 2,2-Diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging experiment was carried out to assess the antioxidant properties of Cu(NO₃)₂, A. biebersteinii, and CuNPs. The DPPH test revealed similar antioxidant activities for A. biebersteinii, CuNPs, and butylated hydroxytoluene. In the cellular and molecular part of the present study, the Trypan blue test was performed to assess cell viability. The terminal deoxynucleotidyl transferase 2′-Deoxyuridine, 5′-Triphosphate (dUTP) nick end labeling test clarified the DNA fragmentation and apoptosis occurrence. The Griess reaction was used to measure nitric oxide production and caspase-3 activity was evaluated by spectrophotometry. The obtained results were fed into SPSS-22 software and analyzed by one-way ANOVA, followed by Tukey's post hoc test (p ≤ 0.01). The results indicate that both doses of CuNPs had cell death-suppressing effects on nerve cells. In particular, both doses of CuNPs significantly (p ≤ 0.01) increased cell viability and NO production, and decreased cell cytotoxicity, cell death index, and caspase-3 activity near the normal. According to these results, it seems that CuNPs could be administrated as a neuroprotective supplement or drug for the treatment of central nervous system disorders in clinical trials.