Vitamin E and Selenium Reduce Prednisolone Side Effects in Rat Hearts.

Aim of this work was to determine the effects of dietary intake vitamin E and Se on lipid peroxidation (LPO) as Thiobarbituric acid reactive substances (TBARS) and on the antioxidative defense mechanisms in heart tissues of rats treated with high doses of prednisolone. 250 adult male Wistar rats were randomly divided into 5 groups and fed with normal diet. Additionally groups 3, 4, and 5 received a daily supplement in their drinking water of 20 mg vitamin E, 0.3 mg Se, and a combination of vitamin E and Se (20 mg/ 0.3 mg), respectively, for 30 days. For 3 d subsequently, control group was treated with placebo, and remaining four groups were injected intramuscularly with 100 mg/kg prednisolone. After last administration of prednisolone, 10 rats from each group were killed at 4, 8, 12, 24, and 48 h and the activities of antioxidant enzymes and the levels of GSH and TBARS were measured. GSH-Px, CAT activities and GSH levels decreased starting from 4th hour to 48% and 65% of control levels by 24th hour, respectively and it reincreased to control levels at 48th hour in the prednisolone group (p < 0.001, p < 0.001). In addition, prednisolone administration led 2-fold increase in heart TBARS levels at 24th hour (p < 0.001). E vitamins and Se inhibited the increase in heart TBARS and the decrease in antioxidative enzymes levels. Therefore, It is concluded that vitamin E and Se may have a preventive role in decreasing the increase of TBARS caused by prednisolone administration in our study.

Effects of Cinnamomum cassia extract on oxidative stress, immunreactivity of iNOS and impaired thoracic aortic reactivity induced by type II diabetes in rats

Type II diabetes is known to cause neuropathy, nephropathy and retinopathy. However, cardiovascular disorders associated with diabetes have been ignored. In traditional medicine, cinnamon (Cinnamomum cassia) bark has been used for its abilities to relieve fever, inflammation and chronic bronchitis. In the present study, the effect of Cinnamomum cassia extract (CN) on the thoracic aorta in an experimental type II diabetes model was investigated. In rats administered with nicotinamide + streptozotocin, significant endothelial dysfunction and oxidative stress were characterised by increased inducible nitric oxide synthase (iNOS) and decreased insulin/proinsulin levels. This impairment was prevented by administering 1000 mg/kg metformin or 500-1000-1500 mg/kg CN. CN administration attenuated the inflammatory response by decreasing the levels of malondialdehyde (MDA), Nitric oxide (NO) and increasing Glutathione peroxidase (GPx), glutathione (GSH). In addition, CN administration was shown to cause down-regulating effects on iNOS in thoracic aorta. These findings reveal that CN could prevent chronic complications of experimentally induced type II diabetes by attenuating inflammation, oxidant/antioxidant imbalance, and normalised contraction and relaxion responses in the thoracic aorta.