Co-administration of lipopolysaccharide and d-galactosamine induces genotoxicity in mouse liver

The acute liver injury (ALI) and hepatic fibrosis caused by the co-treatment of lipopolysaccharide (LPS)/d-galactosamine (D-GalN) have been extensively studied. However, whether LPS/D-GalN are genotoxic has been left unknown. In this study, male mice were divided into eight groups with eight animals in each group. For acute challenge of LPS/D-GalN, the mice in each group received a combination of LPS/D-GalN via intraperitoneal injection at the dose of 25 μg/kg/250 mg/kg, 25 μg/kg/500 mg/kg, or 50 μg/kg/500 mg/kg body weight. An additional group for chronic administration of test compounds was conducted by i.p. injection of LPS/D-GalN (10 μg/kg/100 mg/kg) every other day for 8 weeks. Saline solution (0.9%) and cyclophosphamide (CTX) (50 mg/kg body weight) given by i.p. injection was used as the negative and positive control, respectively. The results of single cell gel electrophoresis (SCGE) assay indicated that acute exposure of the mice to LPS/D-GalN caused severe DNA damage in hepatic cells, but not in the brain, sperm or bone marrow cells, which evidenced the genotoxicity of LPS/D-GalN administrated in combination. Interestingly, the chronic administration of LPS/D-GalN triggered significant genotoxic effects not only in hepatic but also in brain cells, with negative results in sperm and bone marrow cells. Histopathological examination in the liver and brain tissues revealed changes consistent with the SCGE results. The present study indicates genotoxic potential of LPS/D-GalN co-administered in mice, which may serve as an in vivo experimental model for relevant genotoxic study.

The combination of lipopolysaccharide and D-galactosamine administration show positive genotoxic effect in mice liver

Lipopolysaccharide (LPS)/D-galactosamine (D-GalN) co-administration induced acute liver injury (ALI) and hepatic fibrosis have been extensively studied. However, whether LPS/D-GalN show genotoxic effect is current unknown. Male mice were divided into eight groups and each group contain eight animals. For the acute administration of LPS/D-GalN, the mice were given a single intraperitoneal (i.p.) injection of LPS/D-GalN (25 μg/kg + 250 mg/kg, 25 μg/kg + 500 mg/kg, 50 μg/kg + 500 mg/kg body weight) for 6 h, respectively. The chronic administration was conduct by the i.p. injection of LPS/D-GalN (10 μg/kg + 100 mg/kg) every other day for 8 weeks. Saline solution (0.9%) and cyclophosphamide (CTX) (50 mg/kg body weight) injection were used as negative and positive control, respectively. Using single cell gel electrophoresis (SCGE) assay, we found that the acute administration of LPS/D-GalN induces severe DNA damage in mice hepatic cells, but not in brain, sperm and bone marrow cells, implied the genotoxicity of LPS/D-GalN. Interestingly, the chronic treatment of LPS/D-GalN causes significant genotoxic effect in both hepatic and brain cells, but not sperm and bone marrow cells. Histopathological examination in liver and brain section consistent with SCGE results, accordingly. Our study, for the first time, reported the genotoxic potential of LPS/D-GalN co-administration. In addition, LPS/D-GalN administration may serve as an experimental model for further genotoxic study.

Antioxidative, antimitotic, and DNA-damaging activities of Garcinia kola stem bark, Uvaria chamae root, and Olax subscorpioidea root used in the ethnotherapy of cancers

Garcinia kola (GK) stem bark, Uvaria chamae (UC) root, and Olax subscorpioidea (OS) root are components of various indigenous/traditional anticancer regimens. It is, therefore, possible that they might combat oxidative stress and impair cellular proliferation linked to carcinogenesis. In this study, we investigated the antioxidative, mito-depressive, and DNA-damaging activities of the three plant extracts in order to provide further mechanistic insights into their potential anticancer roles in documented cancer remedies that include them. Antioxidative properties were investigated in the 1,1-diphenyl-2-picrylhydrazyl (DPPH) and nitric oxide (NO) radical scavenging assays and an animal model of drug (cisplatin)-induced oxidative stress. The Allium cepa assay and the single cell gel electrophoresis (SCGE) assay were used to assess mito-depressive and DNA-damaging activities. GK and OS showed significantly higher antioxidant activities in the DPPH assay than ascorbic acid; OS had the lowest IC50 of the three plants in the NO assay, comparable to that of ascorbic acid. Pretreatment with the extracts produced an ameliorative and protective effect against the cisplatin-induced oxidative stress as shown by inhibition of lipid peroxidation and improved or restored reduced glutathione and superoxide dismutase levels. In the Allium test, the three extracts produced significant decreases in root growth and also significant cytotoxicity as evidenced by decreased mitotic index. Each of the extracts also showed significantly increased tail DNA (%) in the SCGE assay, indicating the significant DNA-damaging effect. Taken together, this study demonstrates the possible chemopreventive and chemotherapeutic potentials of the three study extracts, which may explain the roles of their source plants in traditional remedies in the therapy of cancers.

A Chinese Traditional Therapy for Bleomycin-Induced Pulmonary Fibrosis in Mice

Pulmonary fibrosis is a chronic and fatal disease of lung tissue with high incidence and mortality in the world. The exploration of effective treatment for pulmonary fibrosis remains an urgent challenge. In our study, Qingfei Xieding was investigated as a novel Chinese traditional patent medicine against pulmonary fibrosis. A pulmonary fibrosis mouse model was constructed by injecting with bleomycin sulfate. Following Qingfei Xieding administration, lung samples were collected to assess pulmonary phenotype changes by analyzing lung coefficient, wet/dry, and histopathologic section. Levels of nitric oxide (NO), hydroxyproline (HYP), malondialdehyde (MDA), and total antioxidant capacity were measured to evaluate the degree of oxidation. A single-cell gel electrophoresis (SCGE) assay was used to evaluate bleomycin-induced DNA damage. Western blotting and real-time quantitative PCR were performed to determine the abundance of inducible nitric oxide synthase (iNOS), connective tissue growth factor (CTGF), alpha smooth muscle actin (α-SMA), and fibronectin (FN). In the present study, Qingfei Xieding administration significantly attenuated bleomycin-induced pulmonary fibrosis in mice by reducing lung coefficient, wet/dry, NO, HYP, and MDA as well as the expression of iNOS, CTGF, α-SMA, FN, and DNA damage. The results indicated that Qingfei Xieding is effective to resist oxidative damage and histopathologic lesion, serving a protection role on bleomycin-induced pulmonary fibrosis.

Assessment of DNA Damage in Leukoplakia Patients with Different Degrees of Dysplasia

ABSTRACT Background Single cell gel electrophoresis (SCGE) assay also known as comet assay is a rapid and highly sensitive fluorescent molecular technique for detecting various forms of deoxyribonucleic acid (DNA) damage at individual cellular level. Materials and methods The present study was done to detect the extent of DNA damage in oral leukoplakia (OL) and compare with normal individuals. The sample population was obtained from an outpatient clinic of a tertiary teaching dental institute. A total of 36 consecutive patients with leukoplakia and 10 healthy normal volunteers were recruited for the study and assessed for the extent of DNA damage using SCGE following clinical diagnosis and histological grading. Peripheral blood was obtained by venipuncture and SCGE assay was performed. Mean comet tail length was recorded and analyzed statistically to compare the extent of damage in each group. Results The mean comet tail length seen in leukoplakia patients with moderate to severe dysplasia was 1.25 ± 0.14 mm while for the control subjects, it was 0.31 ± 0.10 mm. The difference was statistically significant (p = 0.000). On comparing within the grades of leukoplakia, a progressive trend of increasing tail length was observed with increasing grades of dysplasia. Conclusion Deoxyribonucleic acid damage as measured by SCGE is seen in leukoplakia. A stepwise increase in DNA damage levels from healthy controls, through patients with non-dysplastic epithelium to varying grades of dysplasia has been observed indicating the extent of DNA damage in this high risk group. How to cite this article Vellappally S, Binmgren MA, Huraib SB, Hashem MI, Patil S, Anil S. Assessment of DNA Damage in Leukoplakia Patients with Different Degrees of Dysplasia. J Contemp Dent Pract 2015;16(12):971-976.

Genotoxicity of Organic Extracts in Water from Jilin City Section of the Second Songhua River

The second Songhua River has severe organic contamination due to domestic sewage and industrial wastewater. It is important to determine its genotoxic activity, which is a potential hazard for human health. The micronucleus assay and lymphocytes SCGE assay were employed to examine the genotoxic activity of organic extracts of water samples taken from upstream, midstream and downstream in Jilin City section of the second Songhua River in dry season and in wet season, respectively. Micronucleus assay results showed that there were significant increases in water samples at doses of 25L/kg and 50L/kg. The genotoxicity seemed to be less when compared with the results from dry season to wet season and to be strong from upstream to downstream. A similar result was also obtained in DNA damage on lymphocytes by SCGE assay. These results indicate that the organic extracts of water samples taken from the Songhua River show genotoxic activity. The risks of potential harm for human health in the Songhua River should be studied further.

The Effects of Perfluorooctane Sulfonate (PFOS) on Proliferation of Mouse Leydig Cells In Vitro

To evaluate the male reproductive toxicity of PFOS on mammal animals at cellular level, mouse leydig cells were isolated from healthy mouse testis tissue and cultured in vitro. Adherent cells were treated with a serial concentration of PFOS for 4 more days of culture. Proliferation and DNA damage of the cells were analyzed by CCK assay and SCGE assay respectively. Forty-eight hours of treating with PFOS≧25μg/mL all inhibited the proliferation of the cells (p<0.05). PFOS seemed not to change the time for the cells to reach platform phase. DNA damage was also observed in the groups treated with PFOS dependent on dose and exposure time. The highest DNA damage level was averagely 17 cells per well in 96-well plates, which occurred to 62.5μg/mL group at 72h.

Correlation between folate and vitamin B₁₂ and markers of DNA stability in healthy men: preliminary results.

The aim of this study was to find correlations between folate and vitamin B₁₂ on baseline damage in white blood cells and their association with smoking, alcohol consumption and ageing. Thirty-six healthy vitamin non-deficient male subjects were selected in a randomized study. Comet assay (SCGE) and micronucleus (MN) assay were used as biomarkers of DNA damage. The amount of DNA damage was correlated with vitamin B₁₂ and folic acid concentration. Positive, but non-significant correlation (canonical R = 0.61; χ²=28.97; P=0.253) was found between micronucleus (MN) frequency or comet assay parameters (SCGE) and five covariates (age, smoking, alcohol consumption, vitamin B₁₂ and folate blood serum concentration). The highest MN frequency was observed in the group with the lowest vitamin B₁₂ concentration (F=3.59; P=0.024). The SCGE assay failed to show significant correlation with vitamin B₁₂ or folic acid concentration. Concentration of vitamin B₁₂ was significantly correlated with incidence of micronuclei. Our results present background data that could be valuable for future genotoxicological monitoring.