Oxidative stress and antioxidant status in cancer patients and healthy subjects, a case-control study.

Since raised oxidative stress (OS) or weak antioxidant defence or both are considered to be important players in multimechanistic pathogenesis of cancer, the present study was undertaken to evaluate their possible involvement in the pathogenesis of this disease in the local population. Levels of plasma vitamin C, vitamin E, total antioxidant activity (TAA) and thiobarbituric acid reacting substances (TBARS) as a marker of OS were measured in 20 cancer patients (Mean age 63.1 + 9.3 yr.) and 20 age, sex and socioeconomically matched healthy subjects (Mean age 63.7+7.8 yr.). Significantly low level of vitamin C (p <0.001), vitamin E (p <0.001) and TAA (p <0.003) were observed in cancer patients, whereas OS was significantly increased in patients as compared to control (p <0.003). Smokers had significantly lowered TAA and significantly raised OS than non-smokers, in both case and control groups. Tobacco chewer patients had raised OS as compared to control. This study supports the thesis that OS is a risk factor in carcinogenesis and that smoking, an established risk factor in cancer, at least partly appears through it.

Effects of alpha-tocopherol on bacterial translocation and lipid peroxidation in rats with intestinal obstruction

PURPOSE: Investigate if alpha-tocopherol has a protective effect on intestinal mucosa after obstruction and to evaluate the potential relations between lipid peroxidation and bacterial translocation. METHODS: Ten rats were submitted to a sham laparotomy and six served as control group. A small bowel obstruction was done in sixteen animals and among them eight were pretreated with alpha-tocopherol. Forty-eight hours later, mesenteric lymph node, spleen, liver and blood cultures and also samples from ileal mucosal were obtained, Thiobarbituric acid reactive substances (TBARS) levels were determined and intestinal histological assessment was performed. RESULTS: Bacterial translocation was significantly increased in the obstructed rats compared with the control, sham and antioxidant pretreated groups (p< 0,05). TBARS (nmol/100mg) in untreated obstructed rats increased from 49,0 ± 13,3 in control group to 128,8 ± 40 after 48 hours of intestinal obstruction and achieved 72,3 ± 24,6 in alpha-tocopherol group (p< 0,05). Bacterial adherence to the intestinal epithelial cells surface and mucosal necrosis were significantly increased in the obstructed compared with nonobstructed rats. CONCLUSION: Alpha-tocopherol reduce the deleterious effects of the TBARS over the intestinal mucosal suggesting that in such circumstances there might be an association between bacterial translocation and lipid peroxidation after an intestinal occlusion.