Association between enzymatic and non-enzymatic antioxidant defense with Alzheimer disease

The etiopathogenesis of dementia in Alzheimer's disease [AD] is still unclear. However, long-term oxidative stress is believed to be one of the major contributing factors in progression of neuronal degeneration and decline of cognitive function in AD. In order to assess the presence of oxidative stress in AD, we examined the enzymatic activities of the erythrocyte Cu-Zn superoxide dismutase [Cu-Zn SOD], glutathione peroxidase [GSH-Px], catalase [CAT], and plasma level of total antioxidant status [TAS] in AD and control groups [age and sex-matched]. The results showed that the Cu-Zn SOD activity was significantly higher and the level of GSH-Px and TAS activities were significantly lower in AD subjects than that in the control group [2111 +/- 324 U/grHb, 43.7 +/- 11.6 U/grHb, and 1.17 +/- 0.23 mmol/L compared with 1371 +/- 211 U/gHb; t= -2.17, p=0.036, 56.3 +/- 9.5 U/gHb; t=3.8, p=0.014, and 1.54 +/- 0.2 mmol/L; t=11.18, P<0.001, respectively]. While, the erythrocyte CAT activity was lower in AD subjects compared to the control group, the difference was not statistically significant [t=1.3, P=0.15]. These findings support the idea that the oxidative stress plays an important role in the pathogenesis underlying AD neurodegeneration. In addition, the enzymatic activity of the erythrocyte Cu-Zn SOD and GSH-Px and the plasma level of TAS can be used as a measure of the oxidative stress and a marker for pathological changes in the brain of patients with AD

Facilitating effects of morphine dependence on spatial learning and memory in rat

The effect of morphine on spatial learning and memory is controversial. In the present study, the male rats were used to evaluate the effect of morphine dependence and cold water swimming on spatial learning and memory. Dependent animals received morphine sulfate in drinking water for 25 days. Animals were divided into four groups in simple randomized manner. The first control and dependent groups, were studied in normal water [20 +/- 2 °C], and the second control and dependent groups were studied in cold water [10-12 °C]. Morris Water Maze [MWM] experimentations were begun from 21st to 25th days of morphine administration. In each group of animals, spatial learning and memory parameters were analyzed. The results showed that morphine dependence may facilitates spatial learning and memory in MWM, and cold water reduces swimming speed but facilitating the formation of spatial memory. On the other hand, cold water swimming abolished the effects of morphine on spatial learning but facilitated its effect on spatial memory. The underling mechanism[s] to these phenomenon remains to be elucidated

[Effects of the Papaver rhoeas L. extract on naloxone-induced jumping behavior and diarrhea in morphine-dependent mice]

The prevalance of opioid addiction is releativly high in Iran. Since the mechanism [s] of opioid addiction are not clear, this social problem still remains unresolved. In the present study, the effects of water-alcohol extract of Papaver rhoeas on the acquisition and expression of morphine withdrawal in morphine-dependent N-MARI mice [20-25 g] were investigated. The animals became dependent to morphine and the extract of the Papaver Rhoeas was administered during and after induction of morphine dependence. Then, withdrawal syndroms were tested with naloxone [4 mg/kg] injection. Results showed that administration of naloxone after four days morphine treatment [12.5, 25 and 50 mg/kg], induced diarrhea and also increased the number of jumping in animals. The increase was significant for a dose of 50 mg/kg of morphine. On the other hand, administration of the plant extract [25, 50 and 100 mg/kg] did not induce any changes in the feaces or number of jumping behaviour in the animals. Injection of the same extract [25, 50 and 100 mg/kg] 30 min before morphine [50 mg/kg] administration, caused an increase in number of jumping but reduced the diarrhea in animals. Injection of the plant extract [25, 50 and 100 mg/kg] on the test day, 30 min before naloxone administration also decreased the number of jumping and diarrhea in morphine-dependent animals. It could be concluded that the extract of Papaver rhoeas can amilorates the withdrawal syndrom in morphine-dependent mice. Therefore, the extract might be useful for treatment of withdrawal signs in opioid addicts