Effects of low-dose radiation on human blood components after in vitro exposure to gamma radiation from 137Cs radioactivity.

This current study was designed to determine the effects of in vitro exposure to radioactive cesium-137 on human blood components. Whole blood samples were given a radiation dose of 0.02, 0.05, 0.1, 0.2, and 0.3 mGy of gamma radiation using a 137Cs radioactive standard source. The whole blood samples that were exposed to 0 mGy served as sham-controls. The spectrofluoroscopic technique was used to determine the autofluorescence spectrum of protein in plasma or red blood cells by using excitation wavelength and range of emission wavelengths at 280 nm and 300-550 nm, respectively. The hemolysis of red blood cells was evaluated by determination of the release of hemoglobin from the red blood cells to the supernatant. Complete blood counts were also determined in whole blood. The results showed that there was no change in the ratio of fluorescence emission intensity at 340 nm of wavelength of protein extract from irradiated whole blood or red blood cells compared to the corresponding non-irradiated control. The hemolysis value did not change in irradiated whole blood when compared to the corresponding non-irradiated group. In addition, complete blood count values in irradiated groups did not differ from non-irradiated group. These current results suggested that there were no harmful effects of the low-dose gamma radiation from radioactive 137Cs on blood components when human whole blood was exposed to gamma radiation in an in vitro condition.

Effect of pre-low-dose irradiation on anticancer activities of gallic acid in leukemic K562 and K562/Dox cells: cell viability and cellular energetic state studies.

The aim of this study was to determine the effects of pre-low-dose irradiation followed by gallic acid (GA) on cell viability and cellular energetic state of leukemic K562 and K562/Dox cells. The cells were irradiated with 0.02, 0.05, and 0.1 Gy of X-rays. For determining cell viability, pre-low-dose irradiation was followed by 10 or 100 µM GA at 24 h post-irradiation, and the cell viability was then determined at 48 h post-irradiation. For cellular energetic state, pre-low-dose irradiation was followed by 10 or 100 µM GA at 1.5 h post-irradiation and the mitochondrial activity, mitochondrial membrane potential (ΔΨm), and ATP level were determined at 3 h post-irradiation. The % cell viability was significantly decreased in both cells that were irradiated with X-rays followed by treatment with 10 or 100 µM GA at 24 h post-irradiation, when compared with control group. However, this did not happen when compared with GA alone without any pre-low-dose irradiation. The mitochondrial activity had significantly decreased in 10 µM GA-treated K562 cells and the mitochondrial activity, ΔΨm, and ATP levels had significantly decreased in 10 µM GA-treated K562/Dox cells after irradiation to X-rays when compared with GA alone group. In addition, the ΔΨm and ATP levels was significantly decreased in only 100 µM GA-treated K562/Dox cells, but was not decreased in 100 µM GA-treated K562 cells after exposure to X-rays. These findings suggest that pre-low-dose irradiation followed by GA could not kill K562 and K562/Dox cells, but could improve cellular energetic damage of GA effects possibly through mitochondrial impairment.

Effect of iodinated radiographic contrast media on radioimmunoassay for measuring thyroid hormones.

Radioimmunoassay (RIA) is one of the most routine laboratory tests for diagnosing thyroid disease. Patients might receive iodine in the form of intravenous iodinated radiographic contrast media (IRCM) before testing of serum thyroxin (T4) or triiodothyronine (T3) concentration by RIA. The objective was to determine the effect of IRCM on T4 and T3 hormone tests in normal, hypothyroid, and hyperthyroid hormone conditions by RIA. IRCMs (0, 2.5, 5 and 10 mgI/mL) used in this study were iopromide and iodixanol. RIA was determined by commercial T4 RIA kit and T3 RIA kits. The method suggested by the manufacturer was followed. Normal, hypothyroid, and hyperthyroid hormones condition were 1.2 ng/mL, 0.2 ng/mL and 2.2 ng/mL for T3 hormone concentration and 70 ng/mL, 30 ng/mL and 140 ng/mL for T4 hormone concentration, respectively. %Bound values were compared between IRCM-incubated groups and non-incubated group. The data showed that iopromide-incubated groups did not statistically significant change %bound values of T3 and T4 hormone tests in normal, hypothyroid, and hyperthyroid conditions, compared to the non-incubated group. In the same way, %bound values of T3 and T4 hormone tests in iodixanol-incubated groups did not change at all conditions when compared to the non-incubated group. This finding suggested that iodinated radiographic contrast media was unlikely to result in significant problems with radioimmunoassay for measuring T3 and T4 thyroid hormones.

Gallic acid enhances pirarubicin­induced anticancer in living K562 and K562/Dox leukemia cancer cells through cellular energetic state impairment and P­glycoprotein inhibition.

Leukemia is a common malignancy affecting humans worldwide. Pirarubicin (Pira) is one of the anticancer agents used for the treatment of leukemia. Although Pira is effective, drug resistance may develop in cancer cells exposed to this drug, whereas the combination of natural products with Pira may help to overcome this problem. The aim of the present study was to focus on the effect of gallic acid (GA) on the anticancer activity of Pira in K562 leukemia cells and K562/doxorubicin (Dox)­resistant leukemia cells in order to investigate the possible underlying mechanisms. The cell viability, mitochondrial activity, mitochondrial membrane potential (ΔΨm) and ATP levels were assessed in living K562 and K562/Dox cancer cells following treatment with GA/Pira combination, GA alone or Pira alone. P­glycoprotein­mediated efflux of Pira was determined in GA­treated K562/Dox cancer cells. The results demonstrated that GA/Pira combination decreased cell viability, mitochondrial activity, ΔΨm and ATP levels in K562 and K562/Dox cancer cells in a GA concentration­dependent manner compared with non­treated or Pira­treated cells. GA inhibited P­glycoprotein­mediated efflux of Pira in GA­treated K562/Dox cancer cells. Therefore, GA enhanced the anticancer effect of Pira on K562 and K562/Dox cancer cells through cellular energy status impairment, and was able to reverse drug resistance in living K562/Dox cancer cells by inhibiting the function of P­glycoprotein.

Protein binding of 4-hydroxybenzoic acid and 4-hydroxy-3-methoxybenzoic acid to human serum albumin and their anti-proliferation on doxorubicin-sensitive and doxorubicin-resistant leukemia cells.

4-Hydroxybenzoic acids (4-HBA) and 4-hydroxy-3-methoxybenzoic acid (Vanillic acid, VA) have exhibited several pharmacological activities. Generally, the biological activities of compounds are highly involved in the interaction between protein and compounds in blood plasma. The objective was to investigate the interaction of 4-HBA or VA with human serum albumin (HSA) and their anti-proliferation properties on doxorubicin-sensitive K562 and doxorubicin-resistant K562/Dox leukemia cells. The protein binding of 4-HBA or VA to HSA was investigated using fluorescence quenching at temperatures of 298 and 310 Kelvin (K) under the pH of 6.0, 7.4, and 8.0 conditions. The effect of 4-HBA and VA on anti-proliferation was also studied on doxorubicin-sensitive K562 and doxorubicin-resistant K562/Dox leukemia cells using resazurin assay. The results showed that 4-HBA and VA could interact with HSA. The fluorescence quenching process in HSA-4-HBA system might be attributed to static quenching mechanism. In contrast, a dynamic quenching mechanism might be mainly involved in the fluorescence quenching process in the HSA-VA system. Thermodynamic data suggested that the spontaneous interaction between HSA and 4-HBA or VA had occurred in the system and it also indicated that hydrogen bonds and Van der Waals forces contributed to the binding of HSA to 4-HBA or VA. In addition, 4-HBA and VA decreased K562 and K562/Dox cells viability in a dose- and time-dependence manner. In conclusions, the 4-HBA and VA could interact with HSA. In addition, the 4-HBA and VA decreased in cell viability for both doxorubicin-sensitive K562 and doxorubicin-resistant K562/Dox leukemia cells in a dose- and time-dependence manner. Therefore, these current studies could provide useful information about the nature of 4-HBA or VA binding to protein HSA and their anticancer activities in both of these types of leukemia cells. The cell death mechanisms should be investigated through future study.

Different responses of normal cells (red blood cells) and cancer cells (K562 and K562/Dox cells) to low-dose 137Cs gamma-rays.

High-dose radiation is deleterious to cells or tissues. However, the health risks of exposure to low-dose radiation remain unclear. The present study aimed to investigate the biological responses of low-dose gamma-ray in vitro exposure to normal red blood cells (RBCs) and erythroleukemia (K562 and K562/Dox) cancer cells. Cells were given a low dose of 0.03, 0.05 and 0.1 mGy of 137Cs gamma-rays (at a dose rate of 0.001 Gy/min) under in vitro conditions. Cells exposed to 0 Gy served as controls. Hemolysis and reactive oxygen species (ROS) were measured in exposed RBCs following exposure to low-dose gamma-rays. In addition, complete blood count (CBC) parameters were determined in irradiated whole blood. For irradiated K562 and K562/Dox cancer cells, ROS and mitochondrial activity were measured at 0, 30, 60 and 120 post-irradiation times. The results showed no change in the percentage of ROS and hemolysis in irradiated RBCs. The data indicated no perturbation in the CBC parameters in irradiated whole blood. By contrast, statistically significant dose-dependent increases in the percentage of ROS and decreases in the mitochondrial activity in the K562 and K562/Dox cancer cells were observed from 0 min up to 120 min post-irradiation. These findings concluded that there were differences in biological responses in normal cells (RBCs) and cancer cells (K562 and K562/Dox) to low-dose gamma-rays when cells were irradiated under in vitro conditions.

Differences in Spectroscopic Properties of Saliva Taken From Normal Subjects and Oral Cancer Patients: Comparison Studies.

Oral cancer disease is among the most common cancers in the world and are associated with mortality and morbidity. The characterization of saliva samples may help to distinguish patients with oral cancer disease from normal subjects. To characterize spectra of saliva samples from normal subjects and oral cancer patients by use of fluorescence, absorption, and 1H-NMR spectroscopy. Whole unstimulated saliva samples were collected from patients with oral cancer disease and normal subjects. The saliva samples were analyzed by absorption, fluorescence and 1H-NMR spectroscopic techniques. The characteristic spectra of saliva samples from patients with oral cancer disease and normal subjects were compared. For fluorescence spectroscopic studies, six fluorophores were found in saliva samples. Autofluorescence emission spectra and synchronous spectra of saliva were different between normal subjects and oral cancer patients. For absorption spectroscopic studies, the typical absorption spectra of saliva samples from normal subjects and oral cancer patients were also different in absorption intensity, 1st and 2nd derivative of absorption spectra values. For 1H-NMR studies, nine metabolites and four metabolites were found in saliva samples taken from normal subjects and oral cancer patients, respectively. The metabolic profiles of saliva samples from normal subjects and oral cancer patients were not similar. The characteristic spectra of saliva samples from normal subjects and oral cancer patients were found. These results showed differences in the spectra of saliva samples between both that groups. The spectra from each spectroscopic techniques could determine a candidate saliva biomarkers for distinguishing patients with oral cancer disease from normal subjects.

Effects of gadolinium-based magnetic resonance imaging contrast media on red blood cells and K562 cancer cells.

BACKGROUND: Gadolinium-based contrast media (GBCM) are commonly used in diagnostic magnetic resonance imaging (MRI) in clinical applications. The objective of this study is to evaluate the antioxidant properties and effects on red blood cells (RBCs) and K562 cancer cells of three GBCMs (i.e.; gadoterate meglumine, gadopentetate dimeglumine, and gadobenate dimeglumine) inin vitro levels. METHODS: For determiningin vitro antioxidant properties, the di (phenyl)-(2,4,6-trinitrophenyl) iminoazanium (DPPH) and ferric reducing ability of plasma (FRAP) assay were used. For determining effect on red blood cells, hemolysis, morphology and reactive oxygen species (ROS) were used. For determining effect on K562 cancer cells, cytotoxicity and ROS were used. The GBCM -exposed cells were compared to corresponding non-exposed control groups at various harvest times. RESULTS: The results show no changes occurring in the DPPH data. However, there were significant increases based on FRAP data in three GBCMs compared to the corresponding control at all concentrations. The ROS, morphology, and percentage of hemolysis in red blood cells indicated that no change had occurred in three GBCMs-exposed red blood cells compared to the corresponding non-exposed control groups at all harvest times. The percentage of cell viability in K562 cancer cells showed decreases in gadoterate meglumine- and gadobenate dimeglumine- in a concentration dependent manner, but did not show same in gadopentetate dimeglumine-exposed K562 cancer cells. The percentage of ROS in K562 cancer cells indicated that no change in three GBCMs-exposed cells had occurred when compared to the corresponding non-exposed control groups at all harvest times. CONCLUSION: These findings suggests thatin vitro antioxidant properties exhibited by those three GBCMs depends on their concentration and species of radical in testing assay. There were no toxic effects from those GBCMs when red blood cells were exposed in an in vitro condition. In addition, some of those GBCMs could induce cell death in cancer cells.

The Effects of Iodinated Radiographic Contrast Media on Multidrug-resistant K562/Dox Cells: Mitochondria Impairment and P-glycoprotein Inhibition.

Iodinated radiographic contrast media is used in cancer radiography for cancer diagnosis. The aim of this present study was to examine five iodinated radiographic contrast media (IRCM) (i.e., iohexol, iopamidol, iobitridol, ioxaglate, and iodixanol) in terms of their cytotoxicity, mitochondria membrane potential (ΔΨm), and P-glycoprotein function in multidrug resistant K562/Dox cancer cells and corresponding sensitive cancer cells. The cytotoxicity was determined by colorimetric resazurin reduction assay. The ΔΨm and P-glycoprotein function was measured using a noninvasive functional spectrofluorometry. Rhodamine B, fluorescence probe, was used to estimate ΔΨm. The kinetic of P-glycoprotein-mediated efflux pirarubicin was used to monitor P-glycoprotein function in multidrug resistant (MDR) cancer cells. The results showed that ioxaglate and iodixanol show similar efficacy in MDR cancer cells and for their corresponding sensitive cancer cells. Iopamidol, iohexol, and iobitridol showed higher efficacy in MDR cancer cells than for the corresponding sensitive cancer cells by approximately 2 fold. The results also showed no significant change in the |ΔΨm| values in treated K562 and K562/Dox cancer cells when compared to the non-treated K562 and K562/Dox cancer cells. However, there were notable changes detected for iobitridol and iodixanol at 50 mgI/mL. Similarly, the results showed significant differences in P-glycoprotein function of K562/Dox cancer cells after treatment with IRCM when compared to the non-treated K562/Dox cancer cells, with iohexol and iodixanol being the notable exceptions once again. In this present study, IRCM exhibited cytotoxicity on MDR cancer cells and their corresponding sensitive cancer cells. IRCM also showed potential as an anticancer agent in the future.