RESUMO
Colon cancer is one of the most common malignancies with significant importance. Recent theories believe that cancers are metabolic diseases. Therefore, the role of metabolism in the prevention and treatment of cancer has been considered and the ketogenic diet is one example. In the present study, we evaluated the effect of the ketogenic diet and a high carbohydrate diet on tumor size and number, histopathology, and insulin level as well as VEGF level in 1, 2 dymethylhydrazine (DMH)-induced colon cancer in rats. Forty adult male Wistar rats were divided into four groups as follows: control, colon cancer, ketogenic diet, and high carbohydrate diet groups. For induction of colon cancer, 30 mg/kg of 1,2 DMH solution was injected subcutaneously twice a week for 24 weeks. The results showed that the ketogenic diet reduced tumor size, number, and histopathological changes as well as VEGF level (P<0.01) compared to the colon cancer group. The ketogenic diet also increased the levels of beta hydroxyl butyrate (P<0.001) and decreased those of glucose, insulin and HbA1c (P<0.001). Furthermore, a high carbohydrate diet did not show any protective effects on colon cancer prevention. In conclusion, the ketogenic diet demonstrated prophylactic effects on colon cancer, and this anti-cancer effect could be partially attributed to the reduction in VEGF and insulin levels.
RESUMO
Myocardial infarction (MI) refers to the loss of cardiomyocytes due to inadequate coronary blood flow and subsequently a reduced oxygen supply. Activation of N-methyl-D-aspartate (NMDA) receptors has been linked to myocardial infarction. The aim of the present study was to determine the cardioprotective effects of memantine, in myocardial infarction both in ex vivo and in vivo models. Effects of memantine on the electrocardiogram (ECG) pattern, cardiodynamic parameters, infarct size and lipid peroxidation were evaluated in the isolated perfused rat heart. Moreover, in in vivo studies in rats, the protective effects of memantine on isoproterenol-induced myocardial infarction model (administration of 100 mg/kg isoproterenol subcutaneously for 2 consecutive days) was evaluated by measuring ECG pattern, mean arterial pressure, malondialdehyde (MDA) levels, myeloperoxidase (MPO) activity, cardiac tumor necrosis factor-alpha (TNF-α) level and cardiac remodeling. The results from the ex vivo isolated perfused heart showed that memantine treatment increased heart rate, left ventricular systolic pressure and left ventricular maximal rate of pressure increase, and decreased cardiac arrhythmia, MDA level and infarct size in comparison to ischemia/reperfusion (IR) group. The isoproterenol-induced MI (Iso) as used in the in vivo model demonstrated that MDA levels and MPO activity were decreased in memantine groups. Memantine treatment reduced the expression of cardiac TNF-α in comparison to Iso group. Cardiac fibrosis and hypertrophy were lower in memantine groups. In conclusion, memantine exerts cardioprotective effects in models of myocardial infarction, which may be attributed to reduction of pro-inflammatory and oxidative stress factors and subsequently a decrease in cardiac remodeling.
