Anti-proliferative effect and underlying mechanism of ethoxy-substituted phylloquinone (vitamin K1 derivative) from Spinacia oleracea leaf and enhancement of its extractability using radiation technology

In our previous studies, a novel antimutagenic compound, 2-ethoxy-3-(3,7,11,15-tetramethylhexadec-2-ethyl) naphthaquinone-1,4-dione (ethoxy-substituted phylloquinone; ESP) from spinach was characterized and mechanism contributing to its antimutagenicity was deduced. In the current study, anti-proliferative activity of ESP was assessed in lung cancer (A549) cells using MTT [3-(4,5-dimethylthiazole-2yl)-2,5-diphenyl tetrazolium bromide], clonogenic assays and cell cycle analysis. ESP treatment showed selective cytotoxicity against lung cancer cells and no cytotoxicity in normal lung (WI38) cells. Cell cycle analysis revealed that ESP treatment arrests A549 cell population in G2-M phase. In-silico analysis indicated positive drug-likeness features of ESP. Molecular docking showed H-bonding and hydrophobic interactions between ESP and B-DNA dodecamer residues at minor groove. SWATH-MS (Sequential Window Acquisition of All Theoretical Mass Spectra) based proteomic analysis indicated down-regulation of proteins involved in EGFR signaling, NEDDylation and other metabolic pathways and up-regulation of tumor suppressor (STAT1 and NDRG1) proteins. Treatment of spinach powder with gamma radiation (5-20 kGy) from cobalt (Co-60) enhanced the extractability of ESP up to 4.4-fold at the highest dose of 20 kGy. Scanning electron microscopy of spinach powder displayed decrease in smoothness and compactness with increase in radiation dose attributing to its enhanced extractability. Increase in the extractability of ESP with increasing radiation doses as measured by fluorescence intensity and dry weight basis was strongly correlated. Nonetheless, radiation treatment did not affect the functionality of ESP in terms of anti-proliferative and antimutagenic activities. Current findings thus highlight broad spectrum bioactivity of ESP from spinach, its underlying mechanism and applicability of radiation technology in enhancing extractability.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-022-03264-6.

An electrochemical technique for fabrication of Mn-54 sources towards characterization of gamma counting nuclear instruments

Long lived sealed radioactive sources are used for the energy calibration and efficiency determination of counting systems used in the nuclear sector. Using a sulphate bath, a facile electrochemical method was developed by electrodeposition of ⁵⁴Mn on 5 mm (φ) stainless steel substrates for the preparation of ⁵⁴Mn sources for such uses. Inactive sources prepared under suitable experimental parameters characterized by XRD revealed that manganese is deposited in oxide form. SEM and EDS analyses of electrodeposited surfaces confirmed uniform distribution of elements and the absence of fractures, flaws, and spatial variations. Cyclic voltammetry (CV) scans provided information about the electrochemical processes involved in the deposition process. Uniform distribution of radioactivity on surface of source was ascertained by autoradiography. Swipe tests of the encapsulated sources confirmed negligible removable surface contamination. The ⁵⁴Mn sources containing up to 185KBq of ⁵⁴Mn on stainless steel discs were prepared. These sources along with other longer lived sources were supplied to various users as a package of radiation sources for characterization of gamma counting systems over a wide energy range.

Studies on the development of ¹⁶⁹Yb-brachytherapy seeds: New generation brachytherapy sources for the management of cancer

This paper describes development of (169)Yb-seeds by encapsulating 0.6-0.65 mm (ϕ) sized (169)Yb2O3 microspheres in titanium capsules. Microspheres synthesized by a sol-gel route were characterized by XRD, SEM/EDS and ICP-AES. Optimization of neutron irradiation was accomplished and (169)Yb-seeds up to 74 MBq of (169)Yb could be produced from natural Yb2O3 microspheres, which have the potential for use in prostate brachytherapy. A protocol to prepare (169)Yb-brachytherapy sources (2.96-3.7 TBq of (169)Yb) with the use of enriched targets was also formulated.

An electrochemical route to prepare planar 204Tl sources for the calibration of beta surface contamination monitors

This paper describes the utility of the electrochemical technique for the preparation of a circular planar 204Tl source required for the calibration of beta surface contamination monitors. The electrolytic cell, the experimental set up used and the process of deposition are described. The factors that influence the electrodeposition of 204Tl onto the circular copper substrate were investigated and a careful control has been exercised to ensure an optimum deposition of the 204Tl activity onto the substrate. The morphology of the deposited layer was examined by SEM, AFM and EDS analyses. Sources containing ∼3.7 MBq (∼0.1 mCi) 204Tl on a copper sheet of 20 mm diameter working area were prepared and housed in a holder. Quality control tests on the leachability, distribution of activity and stability of the source were performed to ensure compliance with regulatory safety requirements.

On the application of electrochemical techniques for the preparation of 57Co source core, encapsulation and quality evaluation for radiometric assay of nuclear fuel rods

This paper describes an electrochemical method for the preparation of 57Co source to be used in quality evaluation of nuclear fuel rods. The electrolytic cell, the experimental set up used and the process of deposition are described. The effect of various parameters such as pH of the electrolyte, bath temperature, current density, content of cobalt in the bath, electrolyte volume in the cell and deposition time were investigated and optimized for maximum deposition. The texture and morphology of the electrodeposited samples were examined by X-ray diffraction (XRD), SEM and EDS analyses. Sources containing ∼370 MBq (10 mCi) 57Co on a circular copper foil of 4 mm diameter could be prepared and encapsulated in an aluminum capsule. Quality assurance tests performed to ensure non-leachability, uniform distribution of activity and stability of the sources gave satisfactory results.

Development of a (147)Pm source for beta-backscatter thickness gauge applications

This paper describes a method for the preparation of (147)Pm sources, utilized in the determination of graphite coating thickness on the inner surface of the zircaloy cladding tube of nuclear fuels. (147)Pm was adsorbed on a limited surface area [1.5mm (ϕ)×2mm (l)] of a cylindrical aluminum rod [1.5mm (ϕ)×10mm (l)]. In brief, the selected tip area [1.5mm (ϕ)×2mm (l)] was anodized at a current density of 15mA/cm(2) at 15°C in 3M·H(2)SO(4) for 2h followed by immersion of this area in 10μL of (147)Pm solution containing 37MBq (1mCi) of activity at pH 6.0 for 24h. The radioactive area was subsequently covered with a thin layer of Polymethyl Methacrylate (PMMA) to prevent leaching of (147)Pm from the source. The quantity of incorporated (147)Pm activity was assayed in a calibrated ion chamber. Quality control tests were carried out to ensure nonleachability, uniform distribution of activity and stability of the sources.