Interaction of free radicals of DOPA-melanin-streptomycin complexes with paramagnetic oxygen O&lt;sub&gt;2&lt;/sub&gt;

Wiernek, Barbara K.; Pilawa, Barbara; Zdybel, Magdalena; Buszman, Ewa; Wrześniok, Dorota

doi:10.1016/j.jab.2013.12.002

Cited by 6 publications

(8 citation statements)

References 38 publications

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“…The comparison of lineshape of the obtained EPR spectra of HEMn-DP cells presented in Figure 5 and the model DOPA-melanin [23][24][25] indicates the presence of eumelanin in the tested melanocytes. EPR spectra of HEMn-DP cells and synthetic DOPA-melanin are broad single lines.…”

Section: Impact Of Kanamycin On Melanization Process In Melanocytesmentioning

confidence: 85%

Kanamycin induces free radicals formation in melanocytes: An important factor for aminoglycosides ototoxicity

Wrześniok

Rok

Beberok

et al. 2018

J of Cellular Biochemistry

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Ototoxicity is well‐documented but not fully understood undesirable side effect of aminoglycoside antibiotic, kanamycin. Kanamycin is capable of binding to melanin biopolymers—natural pigments of the skin, hair, and eyes. Melanin‐producing cells, melanocytes, are also present in the inner ear and are known to be necessary for normal hearing. It was considered that melanin content in the inner ear may influence aminoglycoside‐induced ototoxic effect. The impact of kanamycin on melanocytes homeostasis may thus play role in the antibiotic‐induced ototoxic effect. Previously, we demonstrated that kanamycin disturbs homeostasis in light‐pigmented melanocytes. To investigate if/how melanization contributes to this phenomenon, the study using in vitro model of dark‐pigmented melanocytes is required. Spectrophotometric measurements and electron paramagnetic resonance (EPR) spectroscopy analysis were performed. Kanamycin induced a concentration‐dependent loss in HEMn‐DP melanocytes viability. The value of IC 50 was estimated to be 5.0 mM. Modulation of the activity of analyzed antioxidant enzymes and increased production of free radicals as well as the decrease of the melanin content were observed. Our results confirmed that kanamycin generates oxidative stress in melanocytes. The increased level of free radicals caused by kanamycin may be responsible for the imbalance of antioxidant defense and the reduction of melanin content in melanocytes. The role of melanin in the mechanism of kanamycin‐induced hearing impairment was discussed and the obtained results were compared with the previously demonstrated data concerning light‐pigmented melanocytes.

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Section: Impact Of Kanamycin On Melanization Process In Melanocytesmentioning

confidence: 85%

Kanamycin induces free radicals formation in melanocytes: An important factor for aminoglycosides ototoxicity

Wrześniok

Rok

Beberok

et al. 2018

J of Cellular Biochemistry

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“…VPA and cisplatin increase free radical concentration in melanins isolated from A‐375 cells . The concentration of o ‐semiquinone free radicals is also higher in dihydroxyphenylalanine (DOPA)‐melanin complexes with aminoglycoside antibiotics, gentamicin, kanamycin, netilmicin, than in DOPA‐melanin and changes with increase of the amount of the drug bound to melanin . The effect of the increase in the number of paramagnetic centers in DOPA‐melanin was also observed for its complexes with moxifloxacin .…”

Section: Introductionmentioning

confidence: 90%

Effect of simvastatin in different concentrations on free radicals in A‐2058 human melanoma malignum cells—EPR studies

Zdybel

Chodurek

Pilawa

2018

J of Cellular Biochemistry

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The influence of concentration of simvastatin (SIM) on free radicals in A‐2058 human melanoma malignum cells was studied. The proliferation assay for melanoma A‐2058 cells with SIM in concentration range from 0.1 to 20 µM was performed. SIM in the concentrations of 0.1, 0.3, and 1 μM only slightly changed the growth of A‐2058 cells, but the growth of the cells considerably decreased for higher concentrations of SIM. Free radicals in the cells were examined by an X‐band (9.3 GHz) electron paramagnetic resonance (EPR) spectroscopy. o‐Semiquinone free radicals with g‐factors in the range of 2.0060 to 2.0065 were found in A‐2058 cells. The asymmetric broad EPR spectra with linewidths (ΔBpp) from 0.87 to 1.25 mT were measured. The fast spin‐lattice relaxation processes characterized all the tested cells. The free radical concentrations in the all A‐2058 cells cultured with SIM were lower than in the control cells. The quenching of free radicals in A‐2058 cells depended on concentration of SIM. This effect was the weakest for concentration of SIM of 3 μM. The strongest decrease of free radical concentration caused SIM in concentration of 1 μM.

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“…Melanin by free radicals interacts with drugs [55][56][57]. The efect of the antitumor substances on free radicals in the human tumor melanotic cells was shown by the use of the EPR spectroscopy [58][59][60].…”

Section: Melanin 80mentioning

confidence: 99%

Application of Electron Paramagnetic Resonance Spectroscopy to Examine Free Radicals in Melanin Polymers and the Human Melanoma Malignum Cells

Pilawa¹,

Zdybel²,

Chodurek³

2017

Melanin

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The studies of free radicals in melanin and the human melanoma malignum cells by an X-band (9.3 GHz) electron paramagnetic resonance (EPR) spectroscopy were presented. The original results were compared with those published earlier. The aim of this work was application of the advanced spectral analysis to determine free radical properties in melanin biopolymers obtained from diferent melanotic tumor cells and free radicals existing in the human melanoma cells. Magnetic spin-latice interactions in melanin samples were tested. The evolution of lineshape of tumor cells with increasing of microwave power was determined to conirm their complex free radical system. The useful shape parameters were proposed. The shape of melanotic tumor cells was analyzed. EPR spectra of free radicals in the melanin isolated from diferent tumor cells measured in the wide range of microwave power were analyzed. The melanins were obtained from the control tumor cells and the cells cultured with the several antitumor substances. The usefulness of the electron paramagnetic resonance spectroscopy was conirmed.

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Interaction of free radicals of DOPA-melanin-streptomycin complexes with paramagnetic oxygen O<sub>2</sub>

Cited by 6 publications

References 38 publications

Kanamycin induces free radicals formation in melanocytes: An important factor for aminoglycosides ototoxicity

Kanamycin induces free radicals formation in melanocytes: An important factor for aminoglycosides ototoxicity

Effect of simvastatin in different concentrations on free radicals in A‐2058 human melanoma malignum cells—EPR studies

Application of Electron Paramagnetic Resonance Spectroscopy to Examine Free Radicals in Melanin Polymers and the Human Melanoma Malignum Cells

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