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ABSTRACT: Diabetes mellitus can cause dysfunction of the central nervous system called "diabetic encephalopathy". Although various oral drugs are used to treat diabetes, they do not prevent the development of diabetes-associated cognitive decline in rats, and novel strategies for the prevention and treatment are urgently needed. Luteolin, a flavonoid isolated from Cirsium japonicum, has antioxidant, anti-inflammatory and neuroprotective activities. However, no report is available on influence of luteolin on streptozotocin-induced memory impairment. Therefore, we tested its influence against cognitive dysfunction in streptozotocin-induced diabetic rats using Morris water maze test. Nissl's staining, choline esterase (ChE) activity as marker of cholinergic function and oxidative stress were assessed in the cerebral cortex and hippocampus to evaluate the neuropathological changes and the effects of luteolin on diabetic rats. The results showed that streptozotocin-induced diabetes produced obvious neuron damage and cognitive dysfunction coupling with markedly increased oxidative stress and ChE activity in the brain. In contrast, chronic treatment with luteolin (50 and 100mg/kg) improved neuronal injury and cognitive performance by attenuating oxidative stress and ChE activity in diabetic rats. In conclusion, the present study suggested that oral supplementation of luteolin might be a potential therapeutic strategy for the treatment and/or prevention of diabetic encephalopathy.
Brain research bulletin 02/2013; 94C:23-29. · 2.18 Impact Factor
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ABSTRACT: The present work was aimed to study the protective effect of L-theanine on chronic restraint stress (CRS)-induced cognitive impairments in mice. The stress was produced by restraining the animals in well-ventilated polypropylene tubes (3.2cm in diameter ×10.5cm in length) for 8h once daily for 21 consecutive days. L-theanine (2 and 4mg/kg) was administered 30 minutes before the animals subjected to acute immobilized stress. At week 4, mice were subjected to Morris water maze and step-through tests to measure the cognitive function followed by oxidative parameters and corticosterone as well as catecholamines (norepinephrine and dopamine) subsequently. Our results showed that the cognitive performances in CRS group were markedly deteriorated, accompanied by noticeable alterations in oxidative parameters and catecholamine levels in the hippocampus and the cerebral cortex as well as corticosterone and catecholamine levels in the serum. However, not only did L-theanine treatment exhibit a reversal of the cognitive impairments and oxidative damage induced by CRS, but also reversed the abnormal level of corticosterone in the serum as well as the abnormal levels of catecholamines in the brain and the serum. This study indicated the protective effect of L-theanine against CRS-induced cognitive impairments in mice.
Brain research 02/2013; · 2.46 Impact Factor
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ABSTRACT: The present study was aimed to investigate the effects of nizofenone administration on the chronic restraint stress-induced cognitive impairments in mice. Adult male mice were randomized into five groups: control group, nizofenone control group, chronic restraint stress group, and nizofenone treatment groups (3.0mg/kg and 9.0mg/kg). The changes of cognitive performances were examined by Morris water maze (MWM), open field and step-through tests. Our results showed that the cognitive performances in CRS group were markedly deteriorated, accompanied by noticeable alterations in oxidative parameters, acetylcholinesterase activity and catecholamines levels in the hippocampus and the prefrontal cortex. These changes could be reversed by nizofenone treatment. Moreover, CRS group showed higher corticosterone levels and lower catecholamine levels in the serum, which were reversed in the nizofenone treatment groups. Collectively, the present results suggested the potential of nizofenone in attenuating the CRS-induced cognitive impairments.
Pharmacology Biochemistry and Behavior 09/2012; · 2.53 Impact Factor
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ABSTRACT: We examined the protective effect of l-citrulline on ethanol-induced gastric ulcer in rats. Administration of l-citrulline at doses of 300, 600 and 900mg/kg body weight prior to ethanol ingestion protected the stomach from ulceration. The gastric lesions were significantly attenuated by all doses of l-citrulline as compared to the ethanol group. Pre-treatment with l-citrulline prevented the oxidative damage and the decrease of nitric oxide content as well as the increase of the myeloperoxidase activity. Consequently, significant changes observed included the attenuation in the elevation in total nitric oxide synthase activity and inducible nitric oxide synthase activity as well as the decrease in constitutive nitric oxide synthase activity in the gastric mucosa induced by ethanol. Analysis of serum cytokines of ethanol-induced rats showed a moderate decrease in interleukin-10 with considerable increase of interleukin-6 while l-citrulline inhibited the acute alteration of cytokines. These results suggested the gastroprotective effect of l-citrulline.
Environmental toxicology and pharmacology. 05/2012; 34(2):280-287.
