Résumé
8-hydroxydeoxyguanosine (8-OHdG) in human urine is a marker reflecting oxidative stress and DNA oxidative damage. People spend 80%-90% of their life indoors; therefore, indoor air quality is directly related to human health. In this paper, the urinary 8-OHdG levels were presented in populations grouped by different demographic characteristics, lifestyle, occupational exposure, and health status, and elucidated indoor pollutants affecting human urinary 8-OHdG level, such as pollutants from outdoor sources, smoking, indoor combustion and cooking fumes, the chemicals in interior decoration materials, and building foundation soils. The article aims to provide a theoretical basis for predicting the impact of indoor air pollution on human health (DNA oxidative damage and related diseases) by measuring the concentration of 8-OHdG in human urine.
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To study the protective effects of Wuzi Yanzong recipe on DNA oxidative damage of testis germ cells in natural ageing rats based on Nrf2/HO-1 signaling pathway and base excision repair (BER). In the study, 16-month-old SPF grade male SD rats were randomly divided into three groups, namely ageing model group, and low and high-dose Wuzi Yanzong recipe groups (WZ, 1, 4 g·kg⁻¹). In addition, 2-month-old SD rats were used as adult control group (10 rats in each group). The ageing model group and the adult control group were fed with normal diet for 4 months. WZ groups were given medicated feed for 4 months. After fasting for 12 hours, the rats were put to death. Then, the testes were immediately removed. The vitality of superoxide dismutase (SOD) and malondialdehyde (MDA) content in testis were detected by xanthine oxidase method and thiobarbituric acid (TBA) method. The levels of Nrf2 and 8-OHdG were detected by immunofluorescence. The protein expression levels of Nrf2, HO-1, NQO1, APE1, OGG1 and XRCC1 were detected by Western blot. Compared with the ageing model group, WZ significantly increased the SOD vitality and decreased MDA content of testis. In addition, immunofluorescence results showed that WZ significantly attenuated testicular DNA oxidative damage and improved antioxidant capacity. Such changes were accompanied by the down-regulation of DNA oxidative damage response protein 8-OHdG levels and the up-regulation of Nrf2 levels. Moreover, Western blot results showed that WZ significantly increased the protein expression levels of Nrf2, HO-1 and NQO1 of the testis germ cells, when compared with ageing model group. In parallel, the protein expression levels of APE1, OGG1 and XRCC1 were significantly decreased. In conclusion, WZ improves ageing-related DNA oxidative damage via Nrf2/HO-1 and BER pathways.
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OBJECTIVE: To investigate the relationship of polycyclic aromatic hydrocarbons( PAH) metabolites,DNA oxidative damage and ring finger protein 2( RING2) expression in coke oven workers. METHODS: A judgment sampling method was used to select 497 coke oven workers in a steel plant as exposure group and 175 water treatment workers in the same plant as control group. The levels of urinary 1-hydroxypyrene, 2-hydroxynathalene, 2-hydroxyfluorene,9-hydroxyphenanthrene and 8-hydroxy deoxyguanosine(8-OHd G) were detected by high performance liquid chromatography.The RING2 expression in whole blood was measured by reverse transcription-polymerase chain reaction. RESULTS: The relative expression of urinary 1-hydroxypyrene,2-hydroxynathalene,2-hydroxyfluorene,9-hydroxyphenanthrene and RING2 in exposure group were higher than that in control group( P < 0. 01). The logistic regression analysis indicated that the higher the level of 1-hydroxypyrene,the higher the risk of high-RING2 expression( P < 0. 05) after adjusting for factors such as sex,age,smoking status,alcohol drinking,2-hydroxynathalene,2-hydroxyfluorene and 9-hydroxyphenanthrene.In 1-hydroxypyrene middle and high level groups,the 8-OHd G concentration of high-RING2 expression workers was significantly higher than those of low-RING2 expression workers( P < 0. 05). CONCLUSION: With the increase of urinary1-hydroxypyrene,the risk of high-RING2 expression was elevated,the degree of DNA oxidative damage was gradually increased.
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Objective To study the effect of DNA damage induced by H2 O2 on the micronucleus frequency in lymphocytes. Methods Resting lymphocytes were treated with different levels of H2 O2 (10,50,100,1 000 μmol/L).1 000 μmol/L H2 O2 was added into mitogen-stimulated lymphocyte cultures at different time intervals.Then micronucleus rate was examined by the conven-tional culture method.Results There was no significant change of the micronucleus frequency in the experimental groups.Conclu-sion H2 O2 could induce lymphocyte DNA damage rapidly,but exerts no effect on the formation of micronuclei,which may be relat-ed to the type of DNA damage and rapid DNA repair.
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Objective To study the effects of UVR or H2O2 on the expression of p53 in human melanocytes,and that of nutlin-3 and PFT-α on the DNA oxidative damage,and to investigate the role of p53 in the antioxidative stress.Methods The effect of UVR,H2O2,nutlin-3 and PFT-α on the expression of p53 of human melanocytes was detected by Western blot analysis,and that of nutlin-3 and PFT-α on UVR or H2O2 DNA damage assessed by single cell electrophoresis (comet assay).Determination of the effect of nutlin-3 on H2O2 DNA damage was detected by γ-H2AX immunofluorescence.Results UVR and H2O2 could induce p53 protein expression,accompanied by increased phosphorylation of p53 on serine 15 residue,and nutlin-3 and PFT-α could induce and inhibit p53 protein in human melanocytes respectively; nutlin-3 decreased the tail moment of DNA oxidative damage of UVR or H2O2 in human melanocytes,but PFT-α increased the tail moment of DNA oxidative damage of UVR or H2O2 in human melanocytes,and there were significant differences among the control and exposed groups; nutlin-3 decreased expression of γ-H2AX.Conclusions p53 plays a very important role in the antioxidative stress in melanocyte exposed to UV or H2O2.
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A preliminary study was conducted to determine the level of oxidative DNA damage, fruits and vegetables intake among 50 breast cancer patients (cases) as compared to 50 healthy women (controls) with no known medical history of breast cancer in Klang Valley. Both groups were matched for age and ethnicity. Data on socio-demographic, health status and medical history, fruits and vegetables intake, and supplements intake were obtained through an interviewbased questionnaire. Anthropometry measurements included weight, height, and waist and hip circumference were also carried out on subjects. A total of 3mL fasting venous blood was drawn to assess lymphocytes oxidative DNA damage using Alkaline Comet Assay. Results indicated that the mean intake of fruits and vegetables was lower in cases (4.09 ± 1.17 servings/d) than controls (4.77 ± 0.90 servings/d)(p < 0.05) The intake of fruits and vegetables from family groups of solanaceae, myrtaceae, caricaceae, apiaceae, brinjal, rutaceae, broccoli, orange, carrot, watermelon were 0.5 - 1 servings/week significantly higher among controls as compared to cases (p < 0.05 for all parameters). However, the intake of fruits from rosaceae family and apple was higher among controls than cases (p < 0.05). The estimated intake of β-carotene, carotenoids, vitamin A, vitamin C (p < 0.001), α-carotene and lycopene (p < 0.05) from fruits and vegetables were higher among controls than cases. Mean DNA damage level of cases (4.55 ± 1.78 % DNA in tail, %TD; 0.35 ± 0.21 tail moment, TM) were 3.5 and 3.9 times higher than the value of controls (1.3 ± 0.70% TD; 0.09 ± 0.09 TM) (p < 0.001) and the damage increased with higher values of waist hip ratio (% TD, r = 0.396, p < 0.05; TM, r = 0.349, p < 0.05) and waist circumference (% TD, r = 0.334, p < 0.05; TM, r = 0.360, p < 0.05). There was an inverse relationship between oxidative DNA damage with intake of total fruits and vegetables, cauliflowers and water convolvulus and also consumption from rutaceae and solanaceae families. Similar trend was noted for estimated intake of vitamin A, carotenoids, vitamin C, β-carotene and lycopene. In conclusion, the intake of fruits and vegetables of five servings/d and the consumption of specific families and types of fruits and vegetables might protect against oxidative DNA damage and further reduce breast cancer risk.