Potential Therapeutic Effects of New Ruthenium (^III) Complex with Quercetin: Characterization, Structure, Gene Regulation, and Antitumor and Anti-Inflammatory Studies (Ru^III/Q Novel Complex Is a Potent Immunoprotective Agent)

The aim of this study was to evaluate the antioxidant and anti-inflammatory effects of the new [Ru(Q)(Cl)₂(H₂O)₂] complex (Ru^III/Q). A new vital complex containing quercetin flavonoid compound (Q) with ruthenium (^III) ions was synthesized. The molar conductivity of the Ru^III/Q complex was measured in dimethylsulfoxide (DMSO) with value 12 (Ω⁻¹ mol⁻¹ cm⁻¹, indicating their non-electrolytic nature. Infrared (FTIR) spectroscopic investigation of the Ru^III/Q complex indicated that Q is coordinated as a bidentate with Ru metal ions through the oxygen of carbonyl C(4)=O group and oxygen of phenolic C(3)−O group based on the wavenumber shifts at 1654 and 1335 cm⁻¹ respectively. The electronic (UV−Vis) spectra and the magnetic susceptibility value (1.85 B.M.) revealed that the Ru(^III) complex has an octahedral geometry. The average diameter of the Ru^III/Q nanoparticles was approximately 7–15 nm according to the transmission electron microscopy. The thermogravimetric study (TG/DTG) indicates that the Ru^III/Q compound is quite stable until 300 °C. To assess biological activity, 60 male rats were allocated to six groups, namely control, DG (D-galactose), Q, Ru^III/Q, DG plus Q, and DG plus Ru^III/Q. Antioxidant enzymes (SOD, CAT, GPx, and GRx), markers of lipid peroxidation (such as MDA), expression of genes (namely Nrf2, Cu-ZnSOD, CAT, GPx, cyto c, P53, Bax, BCl2, caspase-3, and caspase-9 in testicular tissue), glutamate, 4-hydroxynonenal (HNE), GSH, HCY, amyloid beta, and GABA levels were evaluated in brain tissues. Cytokines, such as IL-6 and TNF-α, histological and ultrastructural studies were estimated in both the brain and testicular tissues, while the comet assay was performed in the brain tissue. Ru^III/Q administration either alone or combined with DG reduced oxidative injury to normal levels and decreased apoptotic activities. Thus, Ru^III/Q inhibited injury in both the testis and brain and reduced oxidative stress in male rats. The (Ru^III/Q) complex has a potent ameliorative effect against aging neurotoxicity, reproductive toxicity, and antihepatic cancer activity induced by D-galactose (DG).