NeuropharmacologyResearch PaperLutein and docosahexaenoic acid prevent cortex lipid peroxidation in streptozotocin-induced diabetic rat cerebral cortex
Section snippets
Experimental design
Male Wistar rats were used in the study. Diabetes was induced in animals by a single i.p. injection of STZ (65 mg/kg) in 0.1 M citrate buffer, pH 4.5. Another set of rats, which received only vehicle, served as the control. Fasting blood glucose levels were measured 72 h after STZ injection. Animals having blood glucose levels>200 mg/dl were considered diabetic. Animals were randomly divided into the following experimental groups: control rats (group C); control animals treated with lutein (0.5
Results
Table 1 shows body weight, blood glucose and glycated haemoglobin levels of diabetic and age-matched control rats. The body weight of STZ diabetic rats was significantly lower than that of controls, 3 months after injection of STZ. Blood glucose and HbA1c levels differed significantly between diabetic and control mice and treatment with lutein and DHA did not affect these values. Insulin administration to diabetic rats significantly reversed all these changes to near normal levels.
Discussion
Streptozotocin-induced diabetes is a well-documented model of experimental diabetes that provides a relevant example of endogenous chronic oxidative stress as a result of hyperglycemia (Low et al., 1997). In the present study, STZ treatment produced significant increase in glucose levels along with reduction in body weight in diabetic animals. In addition, there was marked increase in water intake (data not shown) and polyuria which are hallmark clinical findings in diabetes. On the other hand,
Conclusion
In conclusion, this study shows neuroprotective effect of two treatments, lutein and DHA, in cortical neurons of diabetic animals. Further research is needed on the neuroprotective effect of lutein and DHA in relationship to apoptosis and cell survival in cerebral cortex in the diabetic condition.
Acknowledgments
Partially supported by the project PI03/1710 from FIS to F.B.-M., and PRUCHA06/29 from FUSP, and Copernicus-Santander program to F.J.R. We thank David Smith (Oxford University) for his careful reading and correction of the manuscript.
References (49)
- et al.
Water maze learning and hippocampal synaptic plasticity in streptozotocin-diabetic rats: effects of insulin treatment
Brain Res
(1998) Polyunsaturated fatty acids and inflammatory processes: new twists in an old tale
Biochimie
(2009)- et al.
Differential tissue dose responses of (n-3) and (n-6) PUFA in neonatal piglets fed docosahexaenoate and arachidonoate
J Nutr
(2007) - et al.
Oxidant-mediated repression of the mitochondrial transcription in diabetic rats
Free Radic Biol Med
(1997) - et al.
Curcumin attenuates diabetic encephalopathy in rats: behavioural and biochemical evidence
Eur J Pharmacol
(2007) - et al.
Hepatic cytosolic non-selenium dependent glutathione peroxidase activity: its nature and the effect of selenium deficiency
J Nutr
(1978) - et al.
Protein measurement with the Folin phenol reagent
J Biol Chem
(1951) Modfication of ion homeostasis by lipid peroxidation: roles in neuronal degeneration and adaptive plasticity
Trends Neurosci
(1998)- et al.
Lutein effect on retina and hippocampus of diabetic mice
Free Radic Biol Med
(2006) - et al.
Dietary lutein absortion from marigold extract is rapid in BALB/c mice
J Nutr
(1998)