astaxanthine and Infarction--Middle-Cerebral-Artery

Excitotoxicity and oxidative stress are central to the pathology of the nervous system, and inhibition of excitotoxicity induced by glutamate is one of the therapeutic goals determined for stroke. The present study aimed to investigate the effects of Astaxanthin, a potent natural antioxidant, on complications caused by acute cerebral stroke. In this research, 60 male Wistar rats were used which were divided into 5 groups as follow: (1) the sham group (vehicle), (2) the ischemic control group (vehicle), and the ischemic groups treated by Astaxanthin with doses of 25, 45, and 65 mg/kg. In the ischemic groups, ischemic model was performed by middle cerebral artery occlusion (MCAO) method, and the Astaxanthin administration was carried out after the artery occlusion and before opening the artery. The obtained results indicated that Astaxanthin could significantly reduce stroke volume, neurological deficits, and lipid peroxidation. Moreover, it was able to restore total oxidant status (TOS) and caspase 3 level to the normal level. The activity of antioxidant enzyme glutathione peroxidase (GPX), and the expression of catalase, GPx and nuclear factor kappa B (NFκb) genes, which were reduced after ischemia, were increased. This phenomenon was particularly pronounced for glutamate transporter 1 (GLT-1). Furthermore, Astaxanthin decreased the augmented pro-apoptotic gene Bax and restored the reduced Bcl2 expression to the normal level. Significant effects on the P53 and PUMA expression were not observed. Overall, the medium dosage of Astaxanthin appears to be more effective in reducing the complications of ischemia, particularly on our major study endpoints (stroke volume and neurological defects). Longer studies with a more frequent administration of Astaxanthin are required to better understand the precise mechanism of Astaxanthin.

Topics: Animals; Antioxidants; Brain Injuries; Brain Ischemia; Disease Models, Animal; Infarction, Middle Cerebral Artery; Male; Neuroprotective Agents; Rats; Rats, Wistar; Reperfusion; Reperfusion Injury; Stroke; Xanthophylls

The aim of the study was to investigate the effect of astaxanthin and its possible mechanisms on acute cerebral infarction (ACI) in rat model. Male Sprague Dawley rats were randomly divided into sham group, model group, and astaxanthin-treated groups (20, 40, and 80 mg/kg). Neurological examination, the ratio of cerebral edema, and histopathology changes were assessed. Moreover, some oxidative stress markers were obtained for biochemical analysis, and the expression of neurotrophic factors gene was detected by real-time polymerase chain reaction (RT-PCR) method. The results showed that treatment with astaxanthin notably reduced neurological deficit scores and the ratio of cerebral edema compared with the model group. Meanwhile, astaxanthin increased the activity of catalase, superoxide dismutase, and glutathioneperoxidase as well as decreased the content of malondialdehyde in brain tissue. RT-PCR results showed that the expression of brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) mRNA were increased with astaxanthin treatment. The results indicated that astaxanthin could ameliorate ACI followed by suppressing oxidative stress and upregulating the expression of BDNF and NGF mRNA.

Topics: Acute Disease; Animals; Antioxidants; Brain; Brain Edema; Brain-Derived Neurotrophic Factor; Disease Models, Animal; Infarction, Middle Cerebral Artery; Male; Motor Activity; Nerve Growth Factor; Neuroprotective Agents; Oxidative Stress; Rats, Sprague-Dawley; Signal Transduction; Up-Regulation; Xanthophylls

Astaxanthin (AST) is a powerful antioxidant that occurs naturally in a wide variety of living organisms. Much experimental evidence has proved that AST has the function of eliminating oxygen free radicals and can protect organisms from oxidative damage. The present study was carried out to further investigate the neuroprotective effect of AST on oxidative stress induced toxicity in primary culture of cortical neurons and on focal cerebral ischemia-reperfusion induced brain damage in rats. AST, over a concentration range of 250-1000nM, attenuated 50μM H(2)O(2)-induced cell viability loss. 500nM AST pretreatment significantly inhibited H(2)O(2)-induced apoptosis measured by Hoechst 33342 staining and restored the mitochondrial membrane potential (MMP) measured by a fluorescent dye, Rhodamine 123. In vivo, AST prevented cerebral ischemic injury induced by 2h middle cerebral artery occlusion (MCAO) and 24h reperfusion in rats. Pretreatment of AST intragastrically twice at 5h and 1h prior to ischemia dramatically diminished infarct volume and improved neurological deficit in a dose-dependent manner. Nissl staining showed that the neuronal injury was significantly improved by pretreatment of AST at 80mg/kg. Taken together, these results suggest that pretreatment with AST exhibits noticeable neuroprotection against brain damage induced by ischemia-reperfusion and the antioxidant activity of AST maybe partly responsible for it.

Topics: Animals; Apoptosis; Behavior, Animal; Cell Death; Cells, Cultured; Coloring Agents; Fluorescent Dyes; Hydrogen Peroxide; Infarction, Middle Cerebral Artery; Ischemic Attack, Transient; Male; Matrix Metalloproteinases; Neurons; Neuroprotective Agents; Oxidants; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Rhodamine 123; Tetrazolium Salts; Thiazoles; Xanthophylls