Effect of Rhizoma Corydalis on focal cerebral infarct in ischemia-reperfusion injured rats.
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AIM: To investigate the effect of Rhizoma Corydalis (RC) on focal cerebral infarct. METHODS: A total of 30 Sprague-Dawley (SD) rats were studied. Focal cerebral infarct was established b y occluding the bilateral common carotid arteries and the right middle cerebral artery for 90 min. After 24 h reperfusion, the neurological status was evaluated and then the rats were killed and the brain tissue was stained with 2,3,5-triphenyl-tetrazolium chloride. The neurological status and the changes in the area of cerebral infarct were used as an index to evaluate the effect of RC on cerebral infarct. In addition, the whole blood was examined 24 h after RC treatment in the other 24 SD rats. RESULTS: Pretreatment with RC 100 mg/kg can improve neurological status and also can reduce the area of cerebral infarct in ischemia-reperfusion injured rats. The counts of erythrocyte and the amount of hematocrit increased in whole blood of RC-treated rats. CONCLUSION: RC can improve neurological status and reduce the area of cerebral infarct in ischemia-reperfusion injured rats. (+info)
Modulation of Corydalis tuber on glycine-induced ion current in acutely dissociated rat periaqueductal gray neurons.
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Traditionally, Corydalis tuber has been used for the control of pain including headache, stomach ache, and neuralgia. In the present study, modulation of the Corydalis tuber on glycine-activated ion current in the acutely dissociated periaqueductal gray (PAG) neurons was studied by a nystatin-perforated patch-clamp technique. High concentrations of Corydalis tuber elicited ion current, which was suppressed by strychnine application, while low concentrations of Corydalis tuber reduced glycine-induced ion current in the PAG neurons. Inhibitory action of Corydalis tuber on glycine-activated ion current was partially abolished by treatment with naltrexone, a non-selective opioid antagonist. Application of N-methylmalemide (NEM), a sulfhydryl alkylating agent, also partially abolished the inhibitory action of Corydalis tuber on glycine-activated ion current in the PAG neurons. These results suggest that the inhibitory effect of Corydalis tuber on glycine-activated ion current in the PAG neurons is one of the analgesic mechanisms of the Corydalis tuber. (+info)
The combination of rat mast cell and rabbit aortic smooth muscle is the simple bioassay for the screening of anti-allergic ingredient from methanolic extract of Corydalis tuber.
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We have assessed the release of histamine from mast cells by smooth muscle contraction. 0.3 microg/ml compound 48/80 showed no effect on concentration-response relationship of histamine in rabbit aorta. Compound 48/80 induced release of histamine from rat mast cells. When aorta was stimulated by compound 48/80 in the presence of mast cells, contraction was evoked in concentration-dependent manner. This mast cell-dependent contraction was completely blocked by H1 receptor antagonist, 1 microM diphenhydramine. When mast cells was treated with compound 48/80 inhibitor benzalkonium chloride, mast cell-dependent contraction was inhibited, although benzalkonium chloride itself showed no effect on concentration-response relationship of histamine in rabbit aorta. At high concentration of 10 microg/ml, benzalkonium chloride itself evoked histamine release from mast cells and indeed inhibitory effect of 10 microg/ml benzalkonium chloride on mast cell-dependent contraction was lower than that of 3 microg/ml. We have applied this bioassay to search anti-allergic ingredient from a total methanolic extract of Corydalis tuber (Corydalis turtschaninovii BESSER forma yanhusuo Y. H. CHOU et C. C. HSU). Successively, we have isolated five fractions. The fractions I-IV are identified to be corybulbine (1), tetrahydropalmatine (2), corydaline (3) and yuanhunine (4), respectively. Main component of fraction V is the mixture of 3 and canadine (5). Fractions II and V significantly inhibited mast cell-dependent contraction in rabbit aorta as well as inhibited histamine release from rat mast cells. Furthermore, fractions I, III and V inhibited histamine-induced contraction in rabbit aorta at non-competitive manner. From these results, combination of rat mast cells and rabbit aorta is good bioassay to search the anti-allergic ingredient, and we have obtained effective fractions from Corydalis tuber using this assay. (+info)
Effects of l-tetrahydropalmatine on locomotor sensitization to oxycodone in mice.
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AIM: Recent studies have shown that l-tetrahydropalmatine (l-THP), an active component of Corydolis yanhusuo, can inhibit the development of the conditional place preference induced by opioid receptor agonists, but the effects of l-THP on locomotor sensitivity induced by opioid receptor agonists have not been documented. In the present study, the effects of l-THP on locomotor sensitization to oxycodone, which is an opioid receptor agonist, were studied. METHODS: Mice treated daily for 7 d with 5 mg/kg oxycodone and challenged with the same dose after 5 days of washout showed locomotor sensitization. In order to study the effects of l-THP on locomotor sensitization induced by oxycodone, l-THP was administered at doses of 6.25, 12.5, and 18.75 mg/kg, 40 min prior to treatment of oxycodone. RESULTS: l-THP per se did not affect the locomotor activity at the doses of 6.25, 12.5, and 18.75 mg/kg, but could antagonize the hyperactivity induced by oxycodone (5 mg/kg). Co-administration of l-THP (18.75 mg/kg), 40 min prior to oxycodone, could inhibit the development of sensitization to oxycodone. In addition, l-THP (6.25, 12.5, and 18.75 mg/kg, i.g.) dose-dependently prevented the expression of oxycodone sensitization. CONCLUSION: These results suggested that l-THP could attenuate the locomotor-stimulating effects of oxycodone and inhibit the development and expression of oxycodone behavioral sensitization. (+info)
Regulation of glutamate level in rat brain through activation of glutamate dehydrogenase by Corydalis ternata.
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When treated with protopine and alkalized extracts of the tuber of Corydalis ternata for one year, significant decrease in glutamate level and increase in glutamate dehydrogenase (GDH) activity was observed in rat brains. The expression of GDH between the two groups remained unchanged as determined by Western and Northern blot analysis, suggesting a post-translational regulation of GDH activity in alkalized extracts treated rat brains. The stimulatory effects of alkalized extracts and protopine on the GDH activity was further examined in vitro with two types of human GDH isozymes, hGDH1 (house-keeping GDH) and hGDH2 (nerve-specific GDH). Alkalized extracts and protopine activated the human GDH isozymes up to 4.8-fold. hGDH2 (nerve- specific GDH) was more sensitively affected by 1 mM ADP than hGDH1 (house-keeping GDH) on the activation by alkalized extracts. Studies with cassette mutagenesis at ADP-binding site showed that hGDH2 was more sensitively regulated by ADP than hGDH1 on the activation by Corydalis ternata. Our results suggest that prolonged exposure to Corydalis ternata may be one of the ways to regulate glutamate concentration in brain through the activation of GDH. (+info)
Anti-amnestic activity of pseudocoptisine from Corydalis Tuber.
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Pseudocoptisine, a quaternary alkaloid with benzylisoquinoline skeleton, was isolated from Corydalis Tuber, one of the important medicinal plants in traditional medicine. Pseudocoptisine inhibited acetylcholinesterase (AChE) activity in a dose-dependent manner, and the concentration required for 50% inhibition was 12.8 microM. In further study, the anti-amnesic activities of pseudocoptisine in mice on the learning and memory impairments induced by scopolamine (1.0 mg/kg, i.p.) were examined. This alkaloid (2.0 mg/kg, p.o.) administration significantly reversed cognitive impairments in mice by passive avoidance test (p<0.05). It also reduced escape latencies in training trials and prolonged swimming times in the target quadrant during the probe trial in the water maze task (p<0.05). These results indicate that pseudocoptisine has anti-cholinesterase and anti-amnesic activities that may be useful for cognitive impairment treatment. (+info)
Isoquinoline alkaloids isolated from Corydalis yanhusuo and their binding affinities at the dopamine D1 receptor.
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Bioactivity-guided fractionation of Corydalis yanhusuo has resulted in the isolation of eight known isoquinoline alkaloids - tetrahydropalmatine, isocorypalmine, stylopine, corydaline, columbamine, coptisin, 13-methylpalmatine, and dehydrocorybulbine. The tertiary alkaloids were further analyzed by chiral HPLC to determine the ratios of d-and l-isomers. The isolated compounds were screened for their binding affinities at the dopamine D(1) receptor. Isocorypalmine had the highest affinity (K(i) = 83 nM). The structure-affinity relationships of these alkaloids are discussed. (+info)
Differential effects of nectar robbing by the same bumble-bee species on three sympatric Corydalis species with varied mating systems.
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