Novel green synthesis and antioxidant, cytotoxicity, antimicrobial, antidiabetic, anticholinergics, and wound healing properties of cobalt nanoparticles containing Ziziphora clinopodioides Lam leaves extract

The aim of the experiment was a green synthesis of cobalt nanoparticles from the aqueous extract of Ziziphora clinopodioides Lam (CoNPs) and assessment of their cytotoxicity, antioxidant, antifungal, antibacterial, and cutaneous wound healing properties. The synthesized CoNPs were characterized using different techniques including UV-Vis., FT-IR spectroscopy, X-ray diffraction (XRD), energy dispersive X-ray spectrometry (EDS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). According to the XRD analysis, 28.19 nm was measured for the crystal size of NPs. TEM and SEM images exhibited a uniform spherical morphology and average diameters of 29.08 nm for the biosynthesized nanoparticles. Agar diffusion tests were done to determine the antibacterial and antifungal characteristics. Minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and minimum fungicidal concentration (MFC) were specified by macro-broth dilution assay. CoNPs indicated higher antibacterial and antifungal effects than many standard antibiotics (p ≤ 0.01). Also, CoNPs prevented the growth of all bacteria at 2-4 mg/mL concentrations and removed them at 2-8 mg/mL concentrations (p ≤ 0.01). In the case of antifungal effects of CoNPs, they inhibited the growth of all fungi at 1-4 mg/mL concentrations and destroyed them at 2-16 mg/mL concentrations (p ≤ 0.01). The synthesized CoNPs had great cell viability dose-dependently and indicated this method was nontoxic. DPPH free radical scavenging test was done to assess the antioxidant potentials, which revealed similar antioxidant potentials for CoNPs and butylated hydroxytoluene. In vivo experiment, after creating the cutaneous wound, the rats were randomly divided into six groups: untreated control, treatment with Eucerin basal ointment, treatment with 3% tetracycline ointment, treatment with 0.2% Co(NO₃)₂ ointment, treatment with 0.2% Z. clinopodioides ointment, and treatment with 0.2% CoNPs ointment. These groups were treated for 10 days. For histopathological and biochemical analysis of the healing trend, a 3 × 3 cm section was prepared from all dermal thicknesses at day 10. Use of CoNPs ointment in the treatment groups substantially raised (p ≤ 0.01) the wound contracture, hydroxyl proline, hexosamine, hexuronic acid, fibrocyte, and fibrocytes/fibroblast rate and remarkably decreased (p ≤ 0.01) the wound area, total cells, neutrophil, and lymphocyte compared to other groups. In conclusion, CoNPs can be used as a medical supplement owing to their non-cytotoxic, antioxidant, antibacterial, antifungal, and cutaneous wound healing effects. Additionally, the novel nanoparticles (Co(NO₃)₂ and CoNPs) were good inhibitors of the α-glycosidase, and cholinesterase enzymes.