Lipid peroxidation and scavenging enzyme activity in streptozotocin-induced diabetes

Abstract

The aim of this study was to evaluate lipid peroxidation and scavenging enzyme activity in streptozotocin-induced diabetes, and then to establish whether moderate doses of nonenzymatic antioxidant vitamin E play a role in the antioxidant defence system in diabetic pregnant rats and their offspring. The study group consisted of 30 normal female Wistar rats, which were given a single dose of streptozotocin (40 mg/kg) and were mated 7 days later. Subsequently, the diabetic animals were divided into two matched groups: the first supplemented with vitamin E (30 mg/100 g chow), and the other fed with a standard diet lacking vitamin E. Controls consisted of 15 pregnant rats. On the first day after delivery, the rats were decapitated and homogenates of maternal liver and uterus as well as neonatal lungs and liver were prepared. Then the following parameters were measured: malondialdehyde (MDA) concentrations in the homogenates and blood serum, glutathione (GSH) levels, the activity of CuZn-superoxide dismutase (SOD) and glutathione peroxidase (GPx), and glycaemia. The neonates of diabetic rats were smaller than the healthy ones and serum glucose concentration was markedly higher in the diabetic animals. MDA levels were significantly increased, whereas GSH, SOD and GPx were markedly diminished in the diabetic adult rats and their offspring in comparison to the control group. In the animals supplemented with alpha-tocopherol, MDA concentrations were significantly lower, GSH content and SOD activities were markedly elevated most tissues studied, whereas GPx remained unchanged. We conclude that, by monitoring the activity of selected scavenging enzymes, information on ongoing biological oxidative stress and thereby on the fetus/neonate status may be obtained. Our results suggest that diabetic pregnant rats and their neonates are exposed to an increased oxidative stress and that vitamin E supplementation may reduce its detrimental effects.

Antioxidant Enzymes in Gestational Diabetes: A Study on a Kuwaiti Population

“…These observations are in contrast to some previous reports on GPX in diabetes where GPX showed either no change or paralleled SOD, both showed a reciprocal relationship with MDA or RBARS levels [19,32,37,38]. The unexpected increase in the GPX activities here can only be evaluated in the context of a full spectrum of the levels of antioxidant components.…”

Lipid Peroxidation and Resistance to Oxidation in Patients with Type 2 Diabetes Mellitus

“…The levels of these reactive oxygen species are controlled by antioxidant enzymes namely, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSHPx) and nonenzymatic scavengers like reduced GSH, vitamin E, selenium, β -carotene, coenzyme Q. The reports indicate increased or decreased lipid peroxidation, SOD, GSH-Px and CAT activity in various tissues; like liver, kidney, blood vessels, heart, lymphoid organs, lungs and uterus (Ramanathan et al 1999;Kinalski et al 2000). Merzouk et al (2003) investigated plasma vitamin A, C and E levels and erythrocyte antioxidant enzyme activities in type I and type II diabetic subjects with and without complications.…”

Effects of Chard (Beta vulgarisL. var cicla) on the Liver of the Diabetic Rats: A Morphological and Biochemical Study

“…Lipid peroxidation has been implicated in the pathogenesis of many degenerative disorders, including chemically induced diabetes. 45) In diabetes, increases in lipid peroxidation can cause tissue damage. 46) Lipid peroxide levels increased in STZ diabetic rat tissue.…”