Objective: To investigate the effects of Zhengtian Pills (ZTP) on long term potentiation (LTP) both in Schaffer-CA1 in vitro and perforant path-dentate gyrus (PP-DG) synapses in vivo. Methods: Sprague-Dawley rats were randomly divided into five groups: control, positive control, migraine model, low-, and high-dose ZTP groups. Glyceryl trinitrate (10 mg/kg) was injected subcutaneously to make migraine rat model. Flunarizine (0.9 mg/kg) was set as positive control. Extracellular recording technique in vivo was used to record the effects of ZTP on LTP of PP-DG pathway in anesthetized rats; Using extracellular recording technique in vitro, the effects of ZTP on LTP of Schaffer Collateral-CA1 pathway in rat hippocampal slices were investigated. Results: Compared to the control group, ZTP (1.08 g/kg) significantly enhanced population spike amplitude in PP-DG pathway; Glyceryl trinitrate (10 mg/kg) significantly reduced population spike amplitude in PP-DG pathway; Neither ZTP (0.54 g/kg) nor Flunarizine (0.9 mg/kg) had significant effects on LTP in PP-DG pathway. Compared to the model group, ZTP (1.08 g/kg), ZTP (0.54 g/kg), and flunarizine (0.9 mg/kg) significantly enhanced population spike amplitude in PP-DG pathway. Compared to the control group, ZTP (1.08 g/kg) significantly enhanced field excitatory postsynaptic potential (fEPSP) slope in Schaffer Collateral-CA1 pathway; Glyceryl trinitrate (10 mg/kg) significantly reduced fEPSP slope in Schaffer Collateral-CA1 pathway; Neither ZTP (0.54 g/kg) nor flunarizine (0.9 mg/kg) significant effects on LTP in Schaffer Collateral-CA1 pathway, Compared to the model group, ZTP (1.08 g/kg), ZTP (0.54 g/kg), and Flunarizine (0.9 mg/kg) had significantly enhanced fEPSP slope in Schaffer Collateral-CA1 pathway. Conclusion: Combined with the previous study, the results gave a clue that the effects of ZTP on TRPV1 and hippocampal LTP or their interactions could be the important molecular mechanisms of ZTP acting as migraine and headache medication. (C) 2018 Published by Elsevier B.V. on behalf of Tianjin Press of Chinese Herbal Medicines.
Vascular dementia (VaD) is the common cognitive disorder derived mainly from lacunar stroke. The neurovascular coupling (NVC) dysfunction involves in its pathogenesis. VaD lacks suitable animal models for developing preventive therapies. This study aimed to confirm a model for preventing VaD via maintaining NVC sensitivity in rats. The model was replicated with autologous microthrombi against the background of hypercholesterolemia. A phosphodiesterase inhibitor (pentoxyfylline) was preventively administrated to confirm the role of NVC sensitivity. Cognitive function was evaluated as exploratory, learning and memorizing abilities. NVC sensitivity was defined as the ratio of microcirculative cerebral blood flow (∆CBF) to the quantitative electroencephalograph (∆qEEG) before and after penicillin stimulation. The pathogenesis of NVC dysfunction was explored as expressions of neuronal (nNOS), inducible (iNOS) and endothelial nitric oxide synthase (eNOS) in cerebral cortex. The model rats showed cognitive impairment, microvascular edema (2.54 ± 0.30%, P < 0.01), neuronal edema (1.24 ± 0.48%, P < 0.01) and nissl body loss (0.03 ± 0.003%, P < 0.01) in cerebral cortex, and neuronal necrosis in hippocampal CA1 region (neuronal cell number 41.76 ± 10.04 cells, P < 0.01) compared with sham group. The NVC dullness in model rats was confirmed as significantly decreased ratio of ∆CBF/∆qEEG (0.05 ± 0.02%, P < 0.01) compared with sham group (0.20 ± 0.06%). The underlying mechanism of NVC dysfunction was found as imbalanced NOS expressions (decreased nNOS and eNOS, while increased iNOS levels in cerebral cortex). The NVC dullness was significantly relieved in pentoxyfylline administrated rats (0.12 ± 0.06%, P < 0.01). It indicated that this model was suitable to evaluate candidates for preventing VaD via maintaining NVC sensitivity.
Objective To investigate the effects and molecular mechanism of Zhengtian Pills(ZTP) on migraine headache. Methods All rats were randomly divided into control, positive control, migraine model, low- and high-dose ZTP groups, and glyceryl trinitrate was injected to induce migraine headache. The time of ears turning red, frequency of scratching head, climbing the cage, and head-twitching were used to evaluate rat behaviors. After 10 d administration of ZTP, the expression levels of transient receptor potential vanilloid 1(TRPV1) both in cortex and hippocampus were determined by Western blotting. Results After 2 min of glyceryl trinitrate injection, rats showed headache phenomena that parallels the clinical symptoms of migraine, which peaked in 30 min, and lasted for 60 min. Frequency of head-twitching and numbers of scratching head in glyceryl trinitrate(GTN) group were significantly increased. In contrast, after ZTP(1.08 g/kg, ig) treatment, the numbers of scratching head with fore-limb, hind-limb and the frequency of head-twitching were significantly decreased. Flunarizine(FLU) and low-dose ZTP(0.54 g/kg) also showed a trend to decrease the numbers of scratching head and head-twitching frequency, but no significant difference. Besides, ZTP significantly decreased the up-regulated TRPV1 protein expression level both in cortex and hippocampus. Conclusion The present study shows that ZTP could significantly improve the migraine symptoms of headache in rats and TRPV1 might be one of the important molecular mechanisms. This is the first report about the effect of ZTP on TRPV1 protein expression level both in cortex and hippocampus of rats.
To develop a new model of vascular dementia for evaluating Chinese medicine prescriptions.
Objective To investigate the effect of oleuropein (OE) on long term potentiation (LTP) at hippocampal perforant path-dentate gyrus synapses in vivo. Methods An outer guide cannula, a monopolar recording electrode, and a bipolar stimulating electrode were implanted in the skull and extracellular recording technique was used to record the population spike in the dentate gyrus of anesthetized rats. Results Oleuropein significantly increased the basal synaptic transmission and the amplitude of population spike was increased from (117.6 +/- 2.3)% to (134.9 +/- 3.7)% after administration with OE. OE also accelerated LTP induction and maintenance, the population spike amplitude after high frequency stimulation was increased from (167.2 +/- 12.8)% to (225.5 +/- 15.5)% and the maintenance phase of LTP was from (182.1 +/- 15.1)% to (210.5 +/- 9.0)% respectively after administration with OE. Conclusion Present study showed that OE significantly improved different stages of LTP, which could be the molecular mechanism of its efficacy on attenuating AD-like pathology and delaying cognitive decline. OE can be a promising drug for AD and dementia.
There are a wide variety of spiders on the earth and most them can secrete venom,which contains a variety of chemi-cal compositions that have multiple influences on organism be-sides toxic effects.The pharmacological efficiency includes cardi-ovascular and cerebrovascular activities,analgesic activities,an-tibacterial and anticancer activities etc.Ion channels are one of the important targets of spider toxins.They act on different ion channels,such as potassium channel,calcium channel and differ-ent subtypes of sodium channels.Therefore the spider toxins pres-ent different pharmacological activities and potential medicinal value.The venoms of spiders are less well studied than those from other venomous taxa such as conotoxin,scorpions and snakes etc. However,in recent years,spider toxins are turning to a new hot subject in related research areas.This review summarizes the lat-est progress in biological activities of spider toxins as well as its application in medical practice and development.
The goal of this study is to investigate the biotransformation of ginsenoside Rg1 in vivo. A highly sensitive and specific LC-MS/MS method was developed and used for metabolite identification in rat feces and urine after oral administration of ginsenoside Rg1 . Four metabolites of Rg1 were detected in rat feces and three metabolites of Rg1 were detected in rat urine. Deglycosylation and oxygenation were found to be the major metabolic pathways of ginsenoside Rg1 after oral administration in rat. Except for the reported metabolites Rh1 and protopanaxatriol, mono-oxygenated Rg1 and mono-oxygenated protopanaxatriol were detected for the first time after oral administration of Rg1. The in vivo metabolite profiling of ginsenoside Rg1 in rat was proposed. Viewed collectively, Rg1 was metabolized to mono-oxygenated Rg1, Rh1, protopanaxatriol and the secondary metabolite mono-oxygenated protopanaxatriol in rat.