Résumé
Objective: To investigate the neuroprotective efficacy of pomegranate and ellagic acid on the histopathological changes in the hippocampus of an aluminium chloride (AlCl3) induced rat model of Alzheimer's disease. Methods: Sprague Dawley rats were divided into 4 groups (n=10 each): Group I : serving as negative control; Group II, Alzheimer model, induced by administration of 17 mg/kg bw AlCl3; Group III, administered the same dose of AlCl3 with 50 mg/kg of pomegranate peel extract and Group IV : administered ellagic acid (50 mg/kg) in addition to the same dose of AlCl3. The medication given to all groups continued for 28 days. All were given the compounds by gastric gavage. Radial arm maze test, hippocampus antioxidant markers, histopathology of the dentate gyrus, and CA3 of the hippocampus were evaluated. Results: Rats treated with pomegranate peel extract exposed to radial arm maze test showed less number of errors and reduced time needed to reach the criterion. There was an increase in the levels of glutathione, catalase, and total antioxidant capacity and decreased lipid peroxidation products. Histopathological features in dentate gyrus and CA3 as apoptosis and chromatolysis of pyramidal cells and granular layer, respectively, were decreased. Alzheimer characteristic neurofibrillary tangles and senile plaques were reduced. Treatment with ellagic acid ameliorated the pathological results but to a statistically lower level. Conclusions: Pomegranate peel extract alleviates memory deficit and restores antioxidant homeostasis following degenerative changes in the hippocampus induced by aluminium chloride in rats..
Résumé
Combined topical and intracameral anesthesia proved to be an alternative to peribulbar and retrobulbar anesthesia in cataract surgery especially in phacoemulsification approach. So, in the present work the effect of intracameral injection of different concentrations of lidocaine on the structure of rabbit's cornea was studied using the freez-fracture technique and the scanning electron microscope. Fourteen baladi rabbits of both sexes weighing 2-3 kg. were used and divided into two groups according to the concentration of lidocaine .One eye of the animals of the first group was injected with 0.2 ml. of 0.5% lidocaine into the anterior chamber and the other eye with balanced salt solution [BSS] and served as control . In the second group, one eye was injected with 0.2 ml. of 2% lidocaine and the other eye with [BSS] .In both groups the duration of injection was 10 minutes. Parts of the cornea were prepared for scanning electron microscopic examination. The control specimens showed polygonal epithelial cells with surface microvilli, micro plicae and craters. The craters had raised edges with fenestrations and / or microvilli on their floor. Bowman's membrane was acellular homogenous layer. The stromal lamellae were arranged in zip pattern. The keratocytes were spindle-shaped with irregular surface. Descemet's membrane appeared to be splitted. The endothelium was seen as polygonal cells with raised edges and surface micrvilli. With the use of 0.5% lidocaine the endothelial cells became oedematous. On the other hand, with the use of 2% lidocaine there was excessive blebs, bullae and marked oedema of the endothelium with sloughing of some cells. So, the injection of high concentration of lidocaine into the anterior chamber during cataract operation is a potential risk for endothelial injury that may lead to loss of corneal transparency. However using the low concentration of lidocaine appeared to be safe· with no adverse effects