Biological efficacy of novel metal complexes of Nitazoxanide: Synthesis, characterization, anti-COVID-19, antioxidant, antibacterial and anticancer activity studies

Pharmaceutical manifestation of Knoevenagel condensed metal (II) complexes through virtual, in vitro and in vivo assessments

Sulphur containing compounds possess a great deal of interest due to wide range of beneficial activities towards biotic species. This work also deals with the study of biological examination of newly synthesized sulphur containing Cu(II) and Zn(II) complexes derived from (E)-4-(phenylimino)-3-((E)-1-(phenylimino)ethyl)pent-2-ene-1-thiol Schiff bases. Moreover, the DNA nuclease efficiency of the synthesized metal complexes is studied by UV absorption studies, Fluorescence studies, Viscosity and CV titrations which confirm the intercalative mode of binding. Pharmacokinetic studies and drug like activity of these compounds are screened with the help of SWISS ADME online freeware. Their morphological nature is corroborated by various spectral techniques. Optimized geometry and biologically accessible nature of the synthesized compounds are investigated by Gaussian 09 W software. Interestingly, molecular docking studies are carried out against cancer DNA and 6J10 cancer cell. Anti-inflammatory and in vitro antioxidant activities have been studied to validate the theoretical prediction. Based on these preliminary pharmacological activities, the in vitro cytotoxicity and in vivo antitumor activities are examined using MCF-7, HeLa, Hep-2, HepG-2 and Ehrlich ascites carcinoma (EAC) cell lines. All the above examinations reveal that the nitro substituted transition metal complexes possess higher biological bustle.Communicated by Ramaswamy H. Sarma.

Investigating the Biological Potency of Nitazoxanide-Based Cu(II), Ni(II) and Zn(II) Complexes Synthesis, Characterization and Anti-COVID-19, Antioxidant, Antibacterial and Anticancer Activities

In this work, the biological potency of nitazoxanide (NTZ) was enhanced through coordination with transition metal ions Cu(II), Ni(II), and Zn(II). Initially, complexes with a ligand-metal stoichiometry of 2:1 were successfully synthesized and characterized by spectroscopic techniques and thermogravimetric methods. Measurement of the infrared spectrum revealed the bidentate nature of the ligand and excluded the possibility of the metal ion-amide group interaction. Nuclear magnetic resonance spectra showed a reduction in the NH- intensity signal and integration, indicating the possibility of enolization and the formation of keto-enol tautomers. To interpret these results, density functional theory was utilized under B3LYP/6-311G** for the free ligand and B3LYP/LANL2DZ for the metal complexes. We used UV-Vis and fluorescence spectroscopy to understand the biological properties of the complexes. This showed stronger interactions of NTZ-Cu(II) and NTZ-Ni(II) with DNA molecules than the NTZ-Zn(II) compound, with a binding constant (Kb) for the copper complex of 7.00 × 105 M-1. Both Cu(II)- and Ni(II)-NTZ had functional binding to the SARS-CoV-2 (6LU7) protease. Moreover, all metal complexes showed better antioxidation properties than the free ligand, with NTZ-Ni(II) having the best IC50 value of 53.45 μg/mL. NTZ-Ni(II) was an effective antibacterial, with a mean inhibitory concentration of 6 μM, which is close to that of ampicillin (a reference drug). The metal complexes had moderated anticancer potencies, with NTZ-Cu(II) having IC50 values of 24.5 and 21.5 against human breast cancer cells (MCF-7) and cancerous cervical tumor cells (HeLa), respectively. All obtained complexes exhibited high selectivity. Finally, the metal ions showed a practical role in improving the biological effectiveness of NTZ molecules.

Antileishmanial effects and drugability characteristics of a heterocyclic copper complex: An in silico, in vitro and molecular study

Leishmaniasis caused by the protozoan Leishmania presents a severe illness, principally in tropical and subtropical areas. Antileishmanial metal complexes, like Glucantime®️ with proven activity, are routinely studied to probe their potency. We investigated the effects of a Cu (II) homoleptic complex coordinated by two dimethyl-bipyridine ligands against Leishmania major stages in silico and in vitro. The affinity of this heterocyclic Cu (II) complex (CuDMBP) towards a parasitic metacaspase was studied by molecular docking. Key pharmacokinetic and pharmacodynamic properties of the complex were predicted using three web-based tools. CuDMBP was tested for in vitro antileishmanial activities using MTT assay, model murine macrophages, flow cytometry, and quantitative real-time polymerase chain reaction (qPCR). Molecular docking confirmed the tendency between the target macromolecule and the complex. ADMET evaluations highlighted CuDMBP's key pharmacological features, including P-glycoprotein-associated GI absorption and lack of trans-BBB permeability. MTT showed significant inhibitory effects against promastigotes. CuDMBP significantly increased the level of cellular IL-12 expression (p < 0.05), while the upregulation observed in the expression of iNOS was considered not significant (p > 0.05). It decreased the expression of IL-10 significantly (p < 0.05). Findings demonstrated that CuDMBP deserves to be introduced as a leishmanicidal candidate provided further studies are carried out.