Activities of erythrocyte antioxidant enzymes in cancer patients

Abstract

We measured the activities of erythrocyte superoxide dismutase (SOD) and glutathione peroxidase (GPX) before therapy in 97 patients with cancer in various sites (gastrointestinal tract (GIT) (n=40), breast (n=30), and others (n=27)), and in 60 matched controls to assess antioxidant enzyme protection. Hemolysate hemoglobin (Hb) was measured spectrophotometrically. The activity of SOD (U/g Hb) was significantly lower in all sites (when all the cancer sites were considered as a group), GIT, breast, and other sites compared to the controls (P<0.0001, P<0.0001, P<0.0001 and P<0.0001, respectively). The activity of GPX (U/g Hb) was significantly decreased in all sites, GIT, and breast cancer sites than in the controls (P=0.024, P=0.033, and P=0.043, respectively). Age showed a weak negative correlation with enzyme activities in controls and patients. There was no significant association between SOD and GPX activities in either the controls or the patients. These results suggest that there may be a greater antioxidant burden for SOD than GPX in cancer, and that a weak association exists between the activities of the two enzymes in antioxidant protection.

Total antioxidative capacity and zinc concentration in dogs suffering from perianal tumours

“…Although the healthy control group of dogs was not included in the current study, clinical examinations and observations following the AHT of animal patients from non-malignant group enabled to consider all these animals as healthy. Another study on humans demonstrated significantly lower values of erythrocyte SOD and GPx activity in patients suffering from various types of cancers when compared to the values observed in the controls (2). Moreover, the evaluation of erythrocyte lysate in women suffering from fibroadenoma and adenocarcinoma of the breast has also revealed poor antioxidative capacity expressed by a significantly decreased activity of SOD, GPx, catalase, and reduced glutathione when compared to age-matched healthy controls (17).…”

Effects of physical activity on systemic oxidative/DNA status in breast cancer survivors

“…The present data demonstrated that enhanced oxidative stress was present at time of diagnosis in all enrolled subjects, which is in agreement with data from a number of previous studies (28,29), affecting both components of SOS. Certain authors have reported that the activities of all the studied antioxidant enzymes (SOD, catalase, GPx and glutathione S-transferases) and the levels of reduced GSH were significantly increased in breast cancer patients compared with their healthy control group (30); whereas others have reported reduced SOD and GPx activities in breast cancer patients (31). In the present study, the oxidative stress level was improved marginally following surgical treatment, and was positively affected by physical activities, but in different ways in the two survivor groups who undertook training programs.…”

Lipid peroxidation and antioxidant status in blood of patients with uterine myoma, endometrial polypus, hyperplastic and malignant endometrium

“…Although it is not clear whether oxidative stress and tumor result from an increased oxidant production or from a failure of antioxidant defense system (Toyokuni et al, 1995), impairment of the AOS is considered to be critically involved in such conditions. In neoplastic transformation, antioxidant enzyme activities have shown different patterns and they are highly variable in tissues and blood of patients with different types of cancer (Ahmed et al, 1999;Hristozov et al, 2001;Abiaka et al, 2002).…”