RESUMEN
This study aims primarily to investigate the usage of differences in microwave (MW) saturation behaviour of food samples for identification of radiation treatment. Twenty different samples (dry plant, herbal, spice etc.) which do not have radiation specific satellite ESR signal were especially selected. It is not possible to detect radiation treatment on these samples by European standard (EN 1787, 2000). MW saturation studies were performed on all samples in the range of 0.01-160mW. Our experimental results demonstrate that radiation identification can be possible for ten samples and cannot be possible for the other ten samples by performing the MW saturation studies.
Asunto(s)
Irradiación de Alimentos , Microondas , Plantas Comestibles/efectos de la radiación , Especias/efectos de la radiación , Espectroscopía de Resonancia por Spin del Electrón , Plantas Comestibles/clasificación , Especias/clasificaciónRESUMEN
PURPOSE: An ex vivo method for detection of free radicals and their neutralization by aqueous tea in human normal lymphocytes and MEC-1 leukemia cells under ultraviolet (UV) irradiation was investigated. MATERIALS AND METHODS: This method is based on the electron paramagnetic resonance (EPR) spectroscopy spin-trapping technique. 5-tert-butoxycarbonyl 5-methyl-1-pyrroline N-oxide (BMPO) was used as the spin trap. Normal human lymphocytes and leukemia cells were exposed to UVB radiation (290-315 nm) at 47.7 and 159 mJ/cm(2) and to UVA radiation (315-400 nm) at 53.7 J/cm(2). RESULTS: No significant radical production at 47.7 mJ/cm(2) UVB dose in both cell lines was observed. In normal cells, free radical production was observed at 159 mJ/cm(2) UVB and 53.7 J/cm(2) UVA doses. However, both UV sources did not significantly produce free radicals in leukemia cells. A radical scavenging property of tea extracts (black, green, sage, rosehip) was observed in normal lymphocytes after both UVB and UVA exposure. In leukemia cells, the intensities of EPR signals produced in BMPO with tea extracts were found to be increased substantially after UVA exposure. CONCLUSION: These results showed that UV radiation induced free radical formation in normal human lymphocytes and indicated that tea extracts may be useful as photoprotective agents for them. On the other hand, tea extracts facilitated free radical production in leukemia cells.
Asunto(s)
Leucemia/metabolismo , Linfocitos/metabolismo , Extractos Vegetales/administración & dosificación , Especies Reactivas de Oxígeno/metabolismo , Té/química , Rayos Ultravioleta , Adulto , Células Cultivadas , Relación Dosis-Respuesta a Droga , Relación Dosis-Respuesta en la Radiación , Espectroscopía de Resonancia por Spin del Electrón/métodos , Femenino , Humanos , Linfocitos/efectos de los fármacos , Linfocitos/efectos de la radiación , Dosis de Radiación , Tolerancia a Radiación/efectos de los fármacos , Protectores contra Radiación/administración & dosificación , Marcadores de Spin , Adulto JovenRESUMEN
The purpose of the present research is to examine whether human hair root cells can be used for dose assessment after in vitro exposure to ionizing radiation. Hair root samples plucked from random head regions were collected from 5 healthy human subjects. Some of these hair samples were used as control and some were irradiated with 0.5-5Gy of gamma ray using a Cs-137 gamma irradiator at a dose rate of 0.14Gy/s. DNA damage (single-strand breaks) was determined in hair root cells of these samples using the comet assay technique. The comet assay parameters, tail length (TL) and tail moment (TM), showed a significant increase (p<.05) in single-strand DNA breaks in hair roots cells of the exposed samples compared to control. A linear dose-effect relationship was observed when tail moment or tail length was plotted against the log of the radiation dose. This research suggests a possible use of human hair root cell DNA damage as a biomarker especially for low dose radiation.