Chrysophanol accelerates astrocytic mitochondria transfer to neurons and attenuates the cerebral ischemia-reperfusion injury in rats.

Astrocytes transfer extracellular functional mitochondria into neurons to rescue injured neurons after a stroke. However, there are no reports on drugs that interfere with intercellular mitochondrial transfer. Chrysophanol (CHR) was an effective drug for the treatment of cerebral ischemia-reperfusion injury (CIRI) and was selected as the test drug. The oxygen-glucose deprivation/reoxygenation (OGD/R) cell model and the middle cerebral artery occlusion animal model were established to investigate the effect of CHR on CIRI. The result showed that astrocytes could act as mitochondrial donors to ameliorate neuronal injury. Additionally, the neuroprotective effect of astrocytes was enhanced by CHR, the CHR improved the neuronal mitochondrial function, decreased the neurological deficit score and infarction volume, recovered cell morphology in ischemic penumbra. The mitochondrial fluorescence probe labeling technique has shown that the protective effect of CHR is associated with accelerated astrocytic mitochondrial transfer to neurons. The intercellular mitochondrial transfer may be an important way to ameliorate ischemic brain injury and be used as a key target for drug treatment.

An Insight into Antihyperlipidemic Effects of Polysaccharides from Natural Resources.

Hyperlipidemia is a chronic metabolic disease caused by the abnormal metabolism of lipoproteins in the human body. Its main hazard is to accelerate systemic atherosclerosis, which causes cerebrovascular diseases such as coronary heart disease and thrombosis. At the same time, although the current hypolipidemic drugs have a certain therapeutic effect, they have side effects such as liver damage and digestive tract discomfort. Many kinds of polysaccharides from natural resources possess therapeutic effects on hyperlipidemia but still lack a comprehensive understanding. In this paper, the research progress of natural polysaccharides on reducing blood lipids in recent years is reviewed. The pharmacological mechanisms and targets of natural polysaccharides are mainly introduced. The relationship between structure and hypolipidemic activity is also discussed in detail. This review will help to understand the value of polysaccharides in lowering blood lipids and provide guidance for the development and clinical application of new hypolipidemic drugs.

Ginsenoside Rg1-induced antidepressant effects involve the protection of astrocyte gap junctions within the prefrontal cortex.

Ginsenoside Rg1 (Rg1) exhibits antidepressant-like activity by increasing neurogenesis and dendritic spine density without discernible side effects. However, the molecular mechanisms underlying Rg1 antidepressant activity remain poorly understood. As the dysfunction of gap junctions between astrocytes in the prefrontal cortex (PFC) is implicated in major depression disorder, the aim of this study was to investigate the effects of Rg1 on astrocyte gap junctions in the PFC. Rats exposed to chronic unpredictable stress (CUS) were administered Rg1 (5, 10, and 20mg/kg) for 28days and analyzed for depressive symptoms using the sucrose preference and forced swimming tests. Functional and morphological changes of gap junction channels in the PFC were evaluated using dye transfer and electron microscopy, respectively. The expression of connexin 43 (Cx43) was analyzed by western blotting. Rg1 markedly alleviated depression-like behavior in rats. Long-term Rg1 treatment of CUS-exposed rats also significantly prevented the decrease in dye diffusion and improved the ultrastructure of astrocyte gap junctions in the PFC, indicating beneficial effects on the functional activity of gap junction channels in the brain. In addition, Rg1 upregulated Cx43 expression in the PFC reduced by CUS exposure, which significantly correlated with its antidepressant-like effects. The results demonstrate that Rg1-induced antidepressant effects are might be mediated, in part, by protecting astrocyte gap junctions within the prefrontal cortex.

Protective effect and its mechanism of codonopsis pilosula polysaccharide on memory consolidation disorder induced by cycloheximide in mice / 中国药理学与毒理学杂志

OBJECTIVE To investigate the protective effect of Codonopsis Pilosula Polysaccharide (CPPS) on improving of the memory consolidation disorder induced by Cycloheximide and its possible mechanisms in mice. METHODS The mice was divided into five groups, as normal control group, cycloheximid model group, piracetam positive control group, CPPS 300 mg · kg- 1 group, and CPPS 150 mg·kg-1 group. The mice respectively were given saline, piracetam, and CPPS for 15 d. The memory consolidation disorder model in mice was established by ip. Cyclohexylamine, and orally administered CPPS(300 mg·kg-1 or 150 mg·kg-1) every day. Then experimental groups were subjected Morris Water Maze test. Western blotting analysis were used to analysis the expression of CaMKⅡ/CREB signaling pathways. RESULTS Morris water maze experiment showed that cyclohexylamine can cause memory consolidation disorder(P<0.01), and giving piracetam and CPPS (300 mg · kg- 1) can improve spatial memory impairment in mice(P<0.05, P<0.01). Western blotting experiment results show that compared with normal control group, CaMKⅡ and CREB contents of brain in model group mice had significant decreased(P<0.001); Compared with model group, CaMK Ⅱ and CREB contents of brain tissue in piracetam and CPPS groups increased significantly(P<0.05,P<0.01,P<0.001). CONCLUSION Cyclo?heximide can induce the memory consolidation disorder, and its effect in mice related to CaMK/CREB signaling pathways. CPPS can improved this memory disorder by influence CaMKⅡ/CREB signaling pathways.

[Effects of Jiji decoction on the cognitive function and oxidative stress in mice with vascular dementia induced by cerebral ischemia/reperfusion].

OBJECTIVE: To determine the effects of Jiji decoction (Traditional Chinese Medicine) on the cognitive function and oxidative stress in mice with vascular dementia (VD) induced by cerebral ischemia/reperfusion. METHODS: Thirty-two mice were randomly divided into nonnal group (n = 8), sham group (operation, but no cerebral ischemia/reperfusi6n, n = 8), model group (vascular dementia model induced by cerebral ischemia/reperfusion, n = 8), and Jiji decoction-treated group (vascular dementia model plus treatment with Jiji decoction, n = 8). Fourteen days of treatment after operation, the cognitive behavior was measured in step-through test, spatial probe test and platform test. Afterwards, to assess the levels of oxidative stress, the activity of superoxide dismutase(SOD) and content of malonaldehyde (MDA) in brain of these mice were measured. RESULTS: Data from step-through test indicated that the escaping latency of Jiji decoction-treated group was prolonged and the error counts were decreased significantly ( P <0.01) compared with those of model group. Data from spatial probe test indicated that the time of entering darkroom, the time of climbing height and the time of entering bright room in Jiji decoction-treated group were shortened and the counts of climbing height were increased (P < 0.05-0.01) significantly compared with those of model group. Data from platform test showed that the escaping latency of Jiji decoction-treated group was prolonged significantly (P < 0.01) compared with that of model group. Compared with normal and sham group, the activity of SOD was decreased and the content of MDA was increased in model group significantly (P < 0.01). Compared with those of model group, the levels of SOD and MDA in Jiji decoction-treated group were improved significantly (P < 0.01). CONCLUSION: Jiji decoction could improve cognitive function of VD mice. Its mechanism might be related with the inhibition of oxidative stiess in the brain.

Orthogonal test design for optimizing the extraction of total flavonoids from Inula helenium.

BACKGROUND: Inula helenium, which belongs to thecomposite family, is an important crude drug in traditional Chinese medicine. MATERIALS AND METHODS: The effects of ethanol concentration, liquid to solid ratio, extraction temperature, and duration of microwave irradiation on the flavonoid extraction yield were studied through a single-factor experiment. An orthogonal array (L9(3(4))) was then constructed to achieve the best extraction conditions. RESULTS: Variance analysis revealed that ethanol concentration significantly affected the extraction yield. The optimal conditions were as follows: ethanol concentration, 50% (v/v); liquid to solid ratio, 15:1; duration of microwave irradiation, 240 s; and extraction temperature, 60°C. CONCLUSION: Under these optimal conditions, the total flavonoid yield was 18.34 ± 0.64 mg/g. The use of a microwave-assisted process dramatically reduced the time needed for extraction of flavonoids from I. helenium.

Ultrasound-assisted extraction of total flavonoids from Inula helenium.

BACKGROUND: Inula helenium was a perennial herb belonging to composite family and the roots of I. helenium have been widely used in traditional Chinese medicine. In this study, I. helenium was used as an experimental matrix. MATERIALS AND METHODS: Ultrasound-assisted extraction (UAE) of total flavonoids from I. helenium was studied with dual wavelength UV-VIS spectrophotometer. Effects of various factors including ratio of material to liquid, ultrasonic time, ethanol concentration and extraction times on extraction yield of total flavonoids were evaluated. Then, orthogonal design of four factors at three levels was applied for optimization the extraction yields of flavonoids from the root of I. helenium. RESULT: The optimal extracting process of the total flavonoids from the root of the I. helenium was 1 g plant sample with 20 ml of 60% ethanol, extracting twice and each time for 20 min. CONCLUSION: Under these optimal conditions, the yield of total flavonoids was (17.36±0.94) mg/g. UAE was more efficient and time saving for the extraction of flavonoids from plant materials.

[Optimization of processing technology for semen cuscuta by uniform and regression analysis].

OBJECTIVE: To optimize the best preparation technology for the contains of total flavornoids, polysaccharides, the percentage of water and alcohol-soluble components in Semen Cuscuta herb processing. METHODS: UV-spectrophotometry was applied to determine the contains of total flavornoids and polysaccharides, which were extracted from Semen Cuscuta. And the processing was optimized by the way of uniform design and contour map. RESULTS: The best preparation technology was satisfied with some conditions as follows: baking temperature 150 degrees C, baking time 140 seconds. CONCLUSION: The regression models are notable and reasonable, which can forecast results precisely.

Differential gene expression profiles of DNA repair genes in esophageal cancer cells after X-ray irradiation.

BACKGROUND AND OBJECTIVE: Various factors affect the radioresistance of tumor cells, with unknown molecular mechanism(s). Many genes have been found to associate with the radioresistance of tumor cells, however, the precise mechanism of these genes have not been elucidated. This paper was to analyze the differential expressions of DNA repair genes in esophageal carcinoma cells at different time after X-ray irradiation, and to investigate the role of these DNA repair genes in radiation resistance. METHODS: Esophageal cancer parental cells Seg-1 were treated with continuous 2 Gy of fractionated irradiation until the total dose reached 60 Gy to establish the radioresistant cell line Seg-1R. Total RNA was extracted from each cell line at 0, 8, and 24 h after irradiation. Illumine Human-6 V3 microarray was used to identify differentially expressed genes between parental and radioresistant cells. Ten genes involved in DNA repair were obtained and their expressions at different time points after irradiation were analyzed by Gene Ontology analysis. RESULTS: Ten DNA repair associated genes were found to be differentially expressed. Three of these genes, SLK, HMGB1, and PMS1, were not only differentially expressed between parental and radioresistant cell lines, but also expressed differently at different time points after irradiation in the same cell line. CONCLUSIONS: PMS1 may be an important factor involved in the mechanism of radioresistance of esophageal carcinoma cells.

[Study on the optimal extraction process of chaihushugan powder].

OBJECTIVE: To study the optimal extraction process of chaihushugan powder by orthogonal design. METHODS: RP-HPLC method was developed for the determination of saikosaponin a, ferulic acid, hesperidin and paeoniflorin in chaihushugan powder. The contents of the components and the extraction yield were selected as assessment indices. Four factors were study by L9 (3(4)), including the alcohol concentration, amount of alcohol, duration of extraction and times of extraction. RESULTS: The optimal extracting condition was 80% alcohol consumed as 10 times of crude herb amount, and extracting two times for 90 min each time. CONCLUSION: This study supplies theoretical base for the development of chaihushugan powder formulation.

[High throughput screening for glutathione S-transferase inhibitors].

To identify the inhibitor of glutathione S-transferase (GST), a high-throughput screening method was established in a 384-well microplate with total 35 microL volume, and the absorbance at 340 nm is detected. The concentrations of substrates, CDNB and GST were determined by chromatometry. The optimal enzyme kinetics reaction time and temperature are 2 h and 30 degrees C , respectively. The established model was evaluated by NaOCl, a known GST inhibitor, and the parameter Z' was 0.77, which showed a high feasibility and stability of the assay. A total of 31,098 compounds were screened, of which 4 compounds were shown to inhibit GST activity, high inhibiting activity for their IC50 of GST inhibition was 3.94, 4.05, 74.85, and 77.41 mg x L(-1), separately. The results indicated that the colorimetric method by using CDNB and GSH as substrate is stable, sensitive, reproducible and also suitable for high throughput screening.

[Relation between adenosine A1 receptor and NMDA receptor on synaptic transmission in dentate gyrus of hippocampus].

AIM: To observe the effect of adenosine A, receptor antagonist on synaptic transmission in the dentate gyrus of hippocampus and its relations with NMDA receptor. METHODS: Using electrophysiological technique to record the long-term potentiation (LTP), the relation between selective adenosine A1 receptor antagonist 8-cyclopentyl-1,3-dipropylxanthine (DPCPX) and NMDA receptor agonist/antagonist, in both basic synaptic transmission and 200 Hz high-frequency stimulation (HFS) induced LTP of the dentate gyrus of hippocampus in anesthetized rats, was studied. RESULTS: DPCPX (6 mg x L(-1), 5 microL, icv) or NMDA (0.2 mg x L(-1), 5 microL, icv) was shown not to affect the synaptic transmission in the dentate gyrus in rats. DPCPX was found not to affect the keeping of LTP induced by HFS after icv NMDA. But the basic synaptic transmission and the magnitude of LTP induced by HFS in the dentate gyrus after icv NMDA could be enhanced significantly by icv DPCPX in advance. DPCPX could not affect the magnitude of LTP inhibited by AP5 (0.5 mg x L(-1), 5 microL) NMDA receptor antagonist, but the inhibitory effect of AP5 on LTP could be antagonized by icv DPCPX in advance. CONCLUSION: The selective adenosine A1 receptor antagonist DPCPX could not affect the synaptic transmission in the dentate gyrus of hippocampus, but could significantly enhance the effect of NMDA receptor in both basic synaptic transmission and HFS induced LTP in the dentate gyrus of hippocampus in anesthetized rats.

[Pharmacokinetics of osthole in rabbits].

AIM: To investigate the pharmacokinetics of osthole in rabbits and obtain the main pharmacokinetic parameters. METHODS: A simple high-performance liquid chromatography (HPLC) method was developed to study the pharmacokinetics of osthole in rabbits by joining an internal standard (paeonal). Methanol-water (80:20) was used as the mobile phase. According to the 3P87 pharmacokinetic program, the main parameters were calculated. RESULTS: The osthole pharmacokinetics conforms to a two compartment open model after i.v. administration, T1/2 alpha = 5.81 min, T1/2 beta = 42.2 min, K21 = 0.036 0.min-1, K12 = 0.045 0.min-1, K10 = 0.054 0.min-1, AUC = 235 mg.min.L-1, CLs = 0.043 0 L.min-1.kg-1, Vc = 0.780 L.kg-1. CONCLUSION: The pharmacokinetics of osthole after i.v. administration showed a rapid distribution and elimination process in rabbits.

[Effect of adenosine A1 receptor antagonist on learning and memory and analysis of its mechanism].

AIM: To study the effect of blocking adenosine A1 receptors on learning and memory and the relation with cholinergic and aminoacidergic nerve. METHODS: Using step through test, spectrophotometry and HPLC method, the effect of selective adenosine A1 receptor antagonist 8-cyclopentyl-1,3-dipropylxanthine (DPCPX, 0.3, 0.15, 0.075, 0.03, 0.015 microgram, icv) on memory impairment by scopolamine (Scop, 3 mg.kg-1 i.p.) or 2-amino-5-phosphonovaleric (AP5, 2.5 ng, icv), acetylcholinesterase (AChE) activity and aminoacid level in brain of mice was studied. RESULTS: DPCPX was shown to significantly improve scopolamine-induced memory impairment, but not AP5-induced. The activity of AChE in mouse brain was significantly inhibited by large doses of DPCPX in vitro and in vivo test. DPCPX(0.3 microgram, icv) was shown to significantly increase the content of glutamate and aspartic acid in brain of mice. DPCPX (0.3, 0.15 microgram, icv) significantly decrease GABA and increase Glu/GABA in brain of mice. CONCLUSION: The selective adenosine A1 receptor antagonist DPCPX was shown to significantly improve scopolamine but not AP5-induced memory impairment. Large doses of DPCPX was shown to influence the AChE activity and the changes in aminoacid level in brain, especially increase Glu/GABA.

[Effect of osthol on memory impairment of mice in AlCl3-induced acute senile model].

AIM: To study the protective effect and mechanism of osthol on learning and memory impairment of mice with acute senile model induced by AlCl3. METHODS: After s.c. AlCl3 60 mg.kg-1 for 7 d and i.p. osthol 15 and 7.5 mg.kg-1 for 12 d, using step-through test and step-down test, the effect of osthol on learning and memory was observed and the glutathione peroxidase (GSH-PX) activities in blood and superoxide dismutase (SOD) activities in plasma and cerebrum were measured. RESULTS: Osthol 15 and 7.5 mg.kg-1 significantly improved the capability of memory and enhanced the activities of GSH-PX and SOD in AlCl3 treated mice. CONCLUSION: Osthol shows protective effect on brain memory impairment of mice in acute senile model induced by AlCl3. Perhaps the mechanism is involved in enhancing the activities of GSH-PX and SOD, clearing away the free radical, protecting the brain neuron from the harm of lipoperoxide.