Glutathione S-transferase-pi in malignant tissues and plasma of human colorectal and gastric cancers

Purpose: In this study, 16 paired samples of colorectal and gastric cancers and adjacent non-neoplastic tissues were analysed for the determination of glutathione S-transferase (GST) activities and the expression of GST-pi. Methods: Western blotting procedure as well as plasma GST-pi levels were used. Results: GST activities were found to be increased in malignant tissues of patient compared with adjacent normal tissues. A significant correlation was detected between GST activity and GST-pi expression in malignant tissues of patients. Plasma GST-pi levels increased in patients compared to aged-matched control subjects. When the patients were grouped according to TNM stage, GST-pi expression in malignant tissues as well as plasma GST-pi levels were higher in patients with more advanced tumor stages. Conclusions: Our results indicate that GST-pi expression in malignant tissues and plasma GST-pi levels in human colorectal and gastric cancers increased depending on the stages of tumor

The effects of N-acetyl cysteine treatment and nitric oxide synthase inhibition on oxidative stress induced by E-coli endotoxin

In the present study, we have examined the effects of N-acetyl cysteine (NAG) on hepatic lipid peroxidation and glutathione levels in lipopolysaccharide (LPS) and N-nitro-L-arginine (L-NAME) treated rats. LPS treatment to rats resulted in increased lipid peroxide levels and decreased glutathione (GSH) content in the liver homogenate and mitochondria. NAC plus L-NAME administration attenuated all the abnormalities caused by LPS. In conclusion, it has been suggested that NAC may have some beneficial effects in LPS + L-NAME treated rats

Do vitamin E and Selenium have beneficial effects on trinitrobenzenesulfonic acid-induced experimental colitis

The balance between oxidant and antioxidant systems may be important in the pathogenesis and/or maintenance of tissue injury in ulcerative colitis. This study was designed to evaluate the effects of vitamin E and selenium supplementations on tissue injury and oxidative stress in trinitrobenzenesulfonic acid-induced ulcerative colitis in rats. Trinitrobenzenesulfonic acid administration severely changed the normal architecture of the colon and significantly increased the levels of malondialdehyde, protein carbonyl, and xantine oxidase (P < 0.001) in the colon homogenates of these rats. Supplementation of selenium to the trinitrobenzenesulfonic acid-treated rats neither improved the histopathological findings nor decreased the levels of malondialdehyde and protein carbonyl. Vitamin E supplementation reduced the levels of malondialdehyde and protein carbonyl but did not improve the colonic lesions. Supplementation of vitamin E + selenium significantly reduced both the severity of colonic lesions and the levels of malondialdehyde and protein carbonyl. In conclusion, we suggest that antioxidants and specific micronutrients may have beneficial effects in the treatment of ulcerative colitis