Association of genetic polymorphism of glutathione S-transferases with colorectal cancer susceptibility in snuff (Naswar) addicts.

The current study aimed to investigate the relationship between polymorphisms in detoxifying (GSTM1, GSTT1, and GSTP1) genes and their association with colorectal cancer (CRC) in tobacco addicts of Pashtun ethnicity. Polymorphisms in the selected genes were genotyped in a case-control study consisting of 100 histologically confirmed male CRC patients and 100 birth-year and gender-matched healthy controls using the PCR-RFLP method. The GSTM1 null, and GSTT1 null genotypes were significantly contributed to the risk of CRC in the cases (OR= 3.131, 95% CI: 1.451-6.758, P = 0.004, and OR= 3.541, 95% CI: 1.716-7.306, P = 0.001, respectively), whereas the association observed for GSTP1 Val/Val (1.139, 95% CI: 0.356-3.644, P = 0.826) did not show statistical significance. The combined GSTM1 null and GSTT1 null showed a 41-fold increased risk (95% CI: 4.945-351.950, P = 0.001), while, the combined GSTM1 null and GSTP1 Ile/Val or Val/Val variant genotypes exhibited about 3-fold (95% CI: 1.196-7.414, P = 0.019) increased risk to CRC. Similarly, the combined GSTT1 null and GSTP1 Ile/Val or Val/Val variant genotypes showed about a 3-fold (95% CI: 1.285-8.101, P = 0.013) increased risk of CRC. In the combination of three GST genotypes, the GSTM1 null, GSTT1 null, and GSTP1 Ile/Val or Val/Val variant genotypes demonstrated a more than a 22-fold (95% CI: 2.441-212.106, P = 0.006) increased risk of CRC. Our findings suggest that GSTM1 and GSTT1 polymorphism and its combination with GSTP1 may be associated with CRC susceptibility in the Naswar addicted Pashtun population of Khyber Pakhtunkhwa, Pakistan.

Estimating the modulatory effect of cadmium chloride on the genotoxicity and mutagenicity of silver nanoparticles in mice.

Silver (Ag) nanoparticles (nano-Ag) are widely used because of their distinctive antimicrobial properties, but this widespread use increases Ag release into the environment along with many other pollutants such as heavy metals. Therefore, this study was undertaken to study the modulatory effect of cadmium chloride (CdCl2) on the genotoxicity and mutagenicity of nano-Ag in mice liver, kidney and brain tissues. Co-injections of CdCl2 (1.5 mg/kg) with nano-Ag (20, 41, or 82 mg/kg) resulted in significant elevations in both single and double DNA strand breaks that triggered higher apoptotic DNA damage, as revealed by the more fragmented appearance of genomic DNA and the significant increase in apoptotic fractions. Concurrent higher mutation incidence in the presenilin-1 and p53 genes was observed after CdCl2 co-treatment than in nano-Ag-treated groups. Immuno-histochemical localization of p53 protein revealed the overexpression of the p53 gene and the histological examination showed diffusely degenerated, congested blood vessels and the infiltration of leukocytes in the liver, kidney, and brain tissues of the groups co-treated with nano-Ag and CdCl2. Moreover, CdCl2 co-injection with nano-Ag increased reactive oxygen species (ROS) generation, as revealed by increased malondialdehyde levels, decreased glutathione levels, and decreased superoxide dismutase and glutathione peroxidase activity, compared with those induced by nano-Ag particles alone. We concluded that CdCl2 enhanced the nano-Ag-induced genotoxicity via increasing mutation incidence in p53 and presenilin-1 gene.

Nullification of aspirin induced gastrotoxicity and hepatotoxicity by prior administration of wheat germ oil in Mus musculus: histopathological, ultrastructural and molecular studies.

Aspirin (acetyl salicylic acid) is used worldwide to treat various inflammatory conditions and prevent cardiovascular disease, along with reducing the risk of cancer. However, administration of aspirin causes toxic effects, especially in the stomach and liver. Thus, our study examined the protective effect of wheat germ oil on aspirin-induced toxicity in the stomach and liver tissues of Swiss albino mice. Administration of wheat germ oil before aspirin has restored normal hepatic and gastric tissue architecture and DNA integrity has become better than that of a negative health control group compared with the aspirin only treated group. The elevated gastric nitric oxide content in the aspirin only treated group was significantly decreased by wheat germ oil prior administration as a result of reduced the expression of inducible nitric synthase and increased the expression of endothelial nitric oxide synthase compared to their expression in the aspirin administered group. Wheat germ oil pre-administration significantly reduced the level of malondialdehyde, increased the level of glutathione and catalase and superoxide dismutase activities compared with those in aspirin only treated group. We conclude that wheat germ oil has a potential protective effect against aspirin induced gastro- and hepato-toxicity because of its free radical scavenging ability.