Assessment of Ionizing Radiation Effects on the Hematological Parameters of Radiation-Exposed Workers

Surniyantoro HNE, Lusiyanti Y, Rahardjo T, Nurhayati S, Tetriana D. 2018. Association between XRCC1 exon 10 (Arg399Gln) gene polymorphism and micronucleus as a predictor of DNA damage among radiation workers. Biodiversitas 19: 1676-1682. This study was aimed to examine the association between XRCC1 exon 10 gene polymorphism and micronucleus frequencies in radiation workers and their relation to the confounding factors. This study involved 37 radiation workers and 37 controls from several hospitals in Indonesia. Genotyping of X-ray cross-complementing group 1 (XRCC1) exon 10 gene polymorphism and micronucleus assay were performed using Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) and Cytokinesis-Block Micronucleus assay (CBMN assay), respectively. The results indicated that MN frequencies were not significantly higher in the exposed workers than in controls (20.46±6.42 versus 16.89 ±9.72; P=0.07). The micronucleus frequencies of radiation workers with mutant genotype showed not significantly higher than controls in the same genotypes (22±6.64 versus 11.75 ± 8.13; P=0.11). The confounding factors, like age, years of employment and equivalent doses were significantly associated with micronucleus frequencies (P<0.05). The equivalent dose has a significantly positive correlation with micronucleus frequencies among radiation workers, increasing the MN frequencies by 16.3 per 1 mSv of equivalent dose (P=0.001). The genetic polymorphism of XRCC1 gene exon 10 demonstrated no association with the extent of DNA damage in the hospital radiation workers. The MN frequencies were strongly associated with age, equivalent dose and years of employment.

Polymorphism of XRCC1 Gene Exon 6 (Arg194Trp) in Relation to Micronucleus Frequencies in Hospital Radiation Workers

The study was aimed to examine the deoxyribonucleic acid (DNA) damage level between medical and non-medical radiation workers using the comet assay method. The radiation-exposed group (29 subjects) and the control group (29 subjects) were chosen from the administration staff. The assessment of single-strand DNA damage hosted by peripheral blood lymphocyte was performed using the alkaline comet assay, the tail length and long-tailed DNA were measured to detect the DNA damage. An independent sample t-test was used to assess the statistical difference between groups. The results showed that comet tail length mean measured in the exposed worker’s group was 25.57±4.4 μm whereas the mean percentage of long-tailed DNA was 6.97±1.53. In the control group, the mean tail length was 23.15±7.57 μm and the long-tailed nucleus percentage was 5.65±1.99. Mean values for the tail length measured were no significantly higher in the exposed group compared to the control group (P=0.15), whereas the percentage of long-tailed nuclei was significantly higher in the exposed group compared to the control group (P=0.007) . The observed single-strand DNA can be measured by using the alkaline comet assay. The DNA damage can be influenced by radiation exposure in medical radiation workers.

Objective: The aim of this study was to assess the effect of radiation exposure, human 8-oxoguanine DNA N-glycosylase-1 (hOGG1) exon 7 genetic polymorphism and confounding factors on DNA damage response. Methods: Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) and alkaline Comet assay method were applied to determine the hOGG1 genetic polymorphisms and DNA damage response. A total of 80 participants were enrolled in this study, consisting of 40 radiation-exposed workers as a case group and 40 non-radiation workers as a control group. Result: The genotypes frequencies for controls were Ser/Ser (35%), Ser/Cys (32.5%), and Cys/Cys (32.5%), with frequencies of alleles being 326Ser (0.52) and 326Cys (0.48), whereas the genotypes frequencies for radiation-exposed workers (cases group) were Ser/Ser (17.5%), Ser/Cys (57.5%), and Cys/Cys (25%), with frequencies of alleles being 326Ser (0.46) and 326Cys (0.54). The results indicated that DNA damage response were not significantly higher in the exposed workers than in controls (22.55 ± 6.02 versus 21.72 ± 7.14; P=0.58). The time of exposure has a significantly negative correlation with comet tail length value among radiation workers. In addition, it was found that the DNA damage response was strongly associated with age and time of exposure with a decrease of 0.6 percent (P-value: 0.008) and 0.58 percent (P-value: 0.009), respectively. Whereas gender, smoking habit, and equivalent dose were not correlated with DNA damage. Conclusion: The single-nucleotide polymorphism of hOGG1 exon 7 (rs1052133) demonstrated no association with the extent of DNA damage in radiation-exposed workers.

Objective: The purpose of this study was to assess the immune response and malondialdehyde levels in irradiated rats supplemented with Curcuma xanthorriza Roxb extract as a candidate for mitigating radiation exposure. Methods: Twenty-four male Wistar rats were grouped into eight treatment groups, then Curcuma xanthorrhiza Roxb extract was administered orally and irradiated at 6 Gy. Measurement of rats IL-6 and INF-γ was performed using a sandwich ELISA Kit, while the MDA concentration was quantified according to the method of Wills (1971). The statistical test is determined by one way ANOVA test. P-value <0.05 was considered statistically significant. Result: The concentration of IL-6 in all groups showed no statistically significant difference (P=0.18). There was an increase in the concentration of IL-6 in the group of rats irradiated with 6 Gy for 7 days and 14 days. Meanwhile, the INF-γ concentration also showed no significant results in all treatment groups (P=0.28). The average of MDA concentration showed a significant difference in the liver and spleen of irradiated rats at 6 Gy for 14 days compared to the control (0.044 nmol/mg vs 0.008 nmol/mg, P=0.03 and 0.032 nmol/mg vs 0.014 nmol/mg, P=0.05, respectively). Conclusion: The administration of Curcuma xanthorriza Xorb extract was able to reduce MDA concentrations in the liver and spleen although not statistically significant. In addition, exposure to ionizing radiation at a dose of 6 Gy significantly increased lipid peroxidation in the liver and spleen by 5.5 times and 2.3 times, respectively.