Chemical composition, radical scavenging and anti-oxidant capacity of <i>Ocimum Basilicum</i> essential oil

<p><i>Ocimum basilicum</i> has several functional characteristics including carminative, stimulant, diuretic, antiseptic, anesthetic, anti-spasmodic, analgesic and anti-tussive properties. <i>O. basilicum</i> essential oil (basil oil) was tested for chemical composition and in vitro and ex vivo anti-oxidant activities. The in vitro anti-oxidant capacity of basil oil was examined using 1, 1-diphenyl-2-picryl-hudrazyl radical (DPPH^•), 2, 2-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) radical (ABTS^•), hydrogen peroxide (H₂O₂), hydroxyl radical (HO^•), nitric oxide (NO) and nitrite (NO₂) scavenging effects. The <i>ex vivo</i> anti-oxidant activity of basil oil was determined through measuring NADH oxidase (NOX) and inducible nitric oxide synthase (iNOS) mRNA expression in lipopolysaccharide-stimulated murine macrophages using real-time polymerase chain reaction (RT-PCR). GC-MS analysis indicated that the main components in the basil oil were methylchavicol (47%), geranial (19%) and neral (15%). Basil oil had effective DPPH^•, ABTS^•, H₂O₂, HO^•, NO and NO₂ scavenging effects. Basil oil significantly reduced NOX and iNOS mRNA expression in lipopolysaccharide-stimulated murine macrophages at concentrations of 1-10 μg/mL. Basil oil had radical scavenging and anti-oxidant activities and could potentially be used as a safe and effective source of natural anti-oxidants in therapy against oxidative damage and stress associated with some inflammatory conditions.</p

Stabilization of DOPA Zwitterions on Laser-Generated Gold Nanoparticles: ONIOM Computational Study of the Charge-Dependent Structural and Electronic Changes of DOPA Adsorbed on the Gold Nanosurface

A stable colloidal solution of gold nanoparticle–3,4-dihydroxyphenylalanine (DOPA) zwitterion conjugates (Au NP–z-DOPA) was prepared using nanosecond-laser ablation of a gold target in an aqueous solution of zwitterionic DOPA (z-DOPA). Spectroscopic data revealed that Au NPs strongly interact with z-DOPA, which lead to a significant change in the electronic structure of z-DOPA. The adsorbed z-DOPA is highly stable against oxidation in aqueous solution, indicating a significant stabilizing effect of the Au NPs surface on this zwitterion. The electronic structures and geometries of z-DOPA and the other forms of DOPA (including uncharged, cationic, and anionic forms) adsorbed on the Au(111) nanosurface were determined by ONIOM calculations. The geometry and electronic structure of each DOPA form are significantly affected by the surface upon adsorption. The analysis of the frontier orbitals confirmed the significant stabilizing effect of the Au NPs on z-DOPA. The calculations are consistent with the variations observed in the recorded absorption spectra of z-DOPA due to its interaction with Au NPs. The Au nanosurface does not necessarily have a stabilizing effect on all DOPA forms. The cytotoxicities of z-DOPA and Au NP–z-DOPA against the Jurkat T-cells were evaluated