ABSTRACT
AIM: To investigate the effects of auricularia auricular polysaccharide (AAP) on chronic cerebral ischemia injury in rats. METHODS: The chronic cerebral ischemia mode1 was made by permanent middle cerebral artery occlusion (MCAO) on the right side. AAP at different doses (50 mg/kg and 100 mg/kg) was intragastrically administered at the onset of ischemia and in the following days after operation, once a day for 4 weeks. After 4 weeks of MCAO, Morris water maze test was introduced to examine the learning and memory functions. Nissl staining was performed to detect the survival neurons in hippocampal slices. Level of malondialdehyde (MDA) and the activity of superoxide dismutase (SOD) in brain tissue were measured. RESULTS: Rats treated with AAP showed a shorter escaping latency in spacial navigation test because the AAP treated rats spent less time to find the platform in spatial probe test. More survival neurons in hippocampal slices were observed from AAP treated rats. Also, the MDA level in brain tissue was reduced and SOD activity in brain tissue was increased in the AAP treated rats with MCAO. CONCLUSION: AAP protects rats from chronic brain ischemic injury, in which its anti-oxidative effect might be involved.
ABSTRACT
AIM: To investigate the protective effect of auricularia auricular polysaccharide (AAP) on the myocardial injury induced by ischemia and its underlying mechanism. METHODS:AAP was orally administrated to rats at the does of 50, 100 or 200 mg·kg~(-1)·d~(-1) for 20 d. Myocardial injury was induced in anesthetized Sprague - Dawley rats by left anterior descending coronary artery ligation. Myocardial infarct size, the level of lactate dehydrogenase (LDH), the activity of superoxide dismutase (SOD) , the production of lipid peroxidation malondialdehyde (MDA) and protein level of myocardial collagen of the heart were measured. RESULTS: The average myocardial infarct size in AAP groups was significantly smaller than that in ischemia group. The level of serum LDH induced by regional myocardial ischemia was significantly decreased in AAP group compared to ischemia group ( P < 0.01). AAP inhibited the production of MDA and increased the activity of SOD. Furthermore, AAP reduced the protein level of myocardial collagen after ischemia (P < 0.01).CONCLUSION: AAP prevents myocardium from ischemia injury as an antioxidant.
ABSTRACT
AIM: The objectives of the present study were to examine the effect of Jumi(JM) extraction on relaxation of isolated rat aortic rings,and to elucidate its mechanisms.METHODS: The thoracic aortic rings with and without endothelium of male Sprague-Dawley rats were mounted on a bath system.Vasodilatation of aortic rings preconstricted with 10-6 mol/L of phenylephrine(PE) was measured.RESULTS: JM extraction(0.5-8 g/L) caused a concentration-dependent relaxation in aortic rings.The extent of relaxation was larger in endothelium-intact aortic rings than that in endothelium-denuded aortic rings.Both L-NAME [a nitric oxide synthase(NOS) inhibitor] and high potassium(20 mmol/L KCl) partly abolished the relaxation action of JM extraction in endothelium-intact aortic rings.Pretreatment with L-NAME also inhibited the relaxation response to JM extraction in endothelium-denuded aortic rings.After incubation with JM extraction,NOS activities enhanced both in endothelium-intact and endothelium-denuded aortic rings.CONCLUSION: JM extraction causes relaxation of aortic rings through endothelium-dependent and independent pathways.The mechanisms might be involved in NOS and endothelium-derived hyperpolarizing factor.