Phytosterol Extract Decreases the Oxidative Damage in the Brains of Diabetic db/db Mice

Hypercaloric diets induce oxidative stress, and consequently induce hyperglycemia and type 2 diabetes mellitus (T2DM). Thus, oxidative stress is significantly increased in T2DM, leading to oxidative damage to brain, which might contribute to cognitive deficits and neurodegenerative diseases. Therefore, reducing the oxidative stress is important to preserving cognitive functions, and it has been suggested that phytosterols may reduce the oxidative stress. The objective of the present study was to determine the effects of phytosterols derived from corn on oxidative damage in the cerebellum, frontal cortex, and hippocampus of diabetic db/db mice. A phytosterol extract was isolated from yellow corn (Zea mays L.) and 100 mg/kg of the extract was administrated daily to diabetic mice for 8 weeks. At the end of the treatment period, tissues were isolated to determine the levels of oxidized lipid and protein. The phytosterol treatment increased body weight in diabetic db/db mice, but this treatment did not have any effects on body weight in wild-type mice. Moreover, the phytosterol treatment decreased levels of oxidized lipids in the cerebellum, frontal cortex, and hippocampus, and also decreased the levels of oxidized proteins in the cerebellum and frontal cortex in diabetic db/db mice. These important results show that phytosterol treatment can reduce oxidative damage in the brains of diabetic mice.