Total flavones of Rhododendron simsii Planch flower protect rat hippocampal neuron from hypoxia-reoxygenation injury via activation of BKCa channel.

OBJECTIVES: To study the effects of total flavones of Rhododendra simsii Planch flower (TFR) on hypoxia/reoxygenation (H/R) injury in rat hippocampal neurons and its underlying mechanism. METHOD: Model of H/R was established in newborn rat primary cultured hippocampal neuron. Lactate dehydrogenase (LDH) and neuron-specific enolase (NSE) activity as well as malondialdehyde (MDA) content in cultured supernatants of the neurons were examined. Methyl thiazolyl tetrazolium assay and Hoechst33258 staining were, respectively, used to detect cell viability and apoptosis of neurons. Protein expression and current of BKCa channel were assessed by using Western blotting and whole-cell patch-clamp methods, respectively. KEY FINDINGS: In the ranges of 3.7-300 mg/l, TFR significantly inhibited H/R-induced decrease of neuronal viability and increases of LDH, NSE and MDA in the supernatants as well as apoptosis; TFR 33.3, 100 and 300 mg/l markedly increased current of BKCa channel rather than the BKCa channel protein expression in the neurons. CONCLUSIONS: Total flavones of R. simsii Planch flower had a protective effect against H/R injury in rat hippocampal neuron, and activation of BKCa channel may contribute to the neuroprotection.

Vascular Protection of Hydrogen Sulfide on Cerebral Ischemia/Reperfusion Injury in Rats.

This study was undertaken to demonstrate the vascular protection of exogenous and endogenous hydrogen sulfide (H2S) on cerebral ischemia/reperfusion (I/R) injury. The effect of H2S on cerebrovascular dysfunction in middle cerebral artery (MCA) and neuronal damage were measured after cerebral I/R induced by transient middle cerebral artery occlusion (MCAO) in cystathionine c-lyase (CSE) knockdown and wild-type rats. The effect of sodium hydrosulfide (NaHS, donor of exogenous H2S), L-cysteine (L-Cys, substrate of endogenous H2S), and endothelium cells on the responses of isolated MCA derived from non-ischemic rats was also evaluated to assess the underlying mechanism of H2S-mediate cerebral vasodilation. The results revealed that the contraction and dilation of MCA profoundly decreased after cerebral I/R. The vascular dysfunction became more grievous in CSE knockdown rats than in wild-type rats. Interestingly, this vascular dysfunction was significantly alleviated by NaHS supplementation. Moreover, both NaHS and L-cysteine could induce remarkable relaxation in the isolated MCA, which was eliminated by co-application of potassium channel blockers ChTx and Apamin, or endothelial removal. By contrast, adding endothelium cells cultured in vitro together with ACh into the luminal perfusate could mimic non-NO and non-PGI2 relaxation in endothelium-denuded MCA, once CSE was knocked down from endothelium cells, and its effect on vasorelaxation was abolished. Furthermore, the indexes of neuronal injury were measured after cerebral I/R to confirm the neuroprotection of H2S, and we found that the neurological scores, cerebral infarction volume, brain water content, malondialdehyde content, and serum lactate dehydrogenase activity (a marker of cellular membrane integrity) were significantly higher in CSE knockdown rats than in normal control rats. It is not surprising that NaHS could alleviate the cerebral injury. These findings revealed that H2S has a protective effect on cerebral I/R injury via its upregulation of the endothelium-dependent contraction and dilation function of cerebral vessels, which may be related to activating potassium channel.

Total Flavone of Rhododendron Improves Cerebral Ischemia Injury by Activating Vascular TRPV4 to Induce Endothelium-Derived Hyperpolarizing Factor-Mediated Responses.

BACKGROUND: Total flavonoids of Rhododendron (TFR) is extracted from Rhododendron, a herbal medicine widely used in China. The main components are flavone compounds such as warfarin, rutin, quercetin, and hyperoside. We investigated the role of TRPV4 channel in the TFR induced endothelium-dependent hyperpolarizing factor- (EDHF-) mediated responses against ischemia/reperfusion injury (IR) in cerebral IR (CIR) rats. METHODS: The morphological changes of cerebral cortex, the relaxation of cerebral basal artery (CBA), and cell membrane potential recording were studied in CIR rats. The outward potassium current in smooth muscle cell was recorded by whole-cell patch clamp recording. The protein expression of TRPV4, SKca, and IKca was determined. Confocal laser was used to measure the Ca2+ fluorescence intensity. RESULTS: After treatment with TFR, the number of pyramidal cells in brain tissue increased and the number of empty or lightly stained cells decreased and these effects were eliminated by using HC-067047, Apamin, or TRAM-34. TFR induced and EDHF-mediated dilatation and hyperpolarization in CBA were also attenuated by using these inhibitors. The increased outward current density elicited by TFR in acutely isolated CBA smooth muscle cells was abolished by using TRAM-34 and Apamin. TFR upregulated the protein expression of TRPV4, SKca, and IKca that was also eliminated by these inhibitors. Laser scanning showed that the increased mean fluorescence intensity of Ca2+ by CIR was decreased by using TFR and that this effect was again eliminated by the above inhibitors. CONCLUSIONS: We conclude that in the CBA of the CIR rats the protective effect of TFR on ischemic cerebrovascular injury may be related to the activation of the TRPV4 in both endothelium and smooth muscle by increasing its expression and activity. The activation of TRPV4 channel in the endothelium may be linked to the opening of endothelial IKca/SKca channels that induces EDHF-mediated relaxation and hyperpolarization in the smooth muscle cell. In addition, the activation of TRPV4 in the smooth muscle cell in CBA may be linked with the activation of BKCa channel through a TRPV4-dependent pathway, reduce Ca2+ concentration in the cell, and relaxes the vessel. These findings may form a new therapeutic target for protection of ischemic brain injury and facilitate the use of Chinese medicine in brain protection.

Total flavones of Rhododendron simsii Planch flower protect isolated rat heart from ischaemia-reperfusion injury and its mechanism of UTR-RhoA-ROCK pathway inhibition.

OBJECTIVES: Total flavones of Rhododendron simsii Planch flower (TFR) are an effective part extracted from the flower. The present study was designed to investigate the protective effect of TFR in isolated rat heart following global ischaemia-reperfusion and the possible underlying mechanisms. METHODS: Langendorff perfusion apparatus was used to perfuse isolated rat heart which was subjected to global ischaemia-reperfusion. The hemodynamic parameters were continuously monitored. Coronary flow as well as lactate dehydrogenase (LDH), creatine phosphokinase-MB (CK-MB) and cardiac troponin I (cTnI) in coronary effluents was measured. RhoA activity and urotensin receptor (UTR) and Rho-related coiled-coil-forming protein kinase (ROCK) protein expressions in rat myocardium were examined, respectively. Cardiac dysfunction was indicated by the alterations of hemodynamic parameters and the reduced coronary flow. KEY FINDINGS: Total flavones of Rhododendron simsii Planch flower significantly improved ischaemia-reperfusion-induced cardiac dysfunction and leakages of LDH, CK-MB and cTnI, and inhibited myocardial ischaemia-reperfusion-increased RhoA activity and UTR, ROCK1 and ROCK2 protein expressions. The improvement of TFR in the cardiac dysfunction and the leakage of LDH, CK-MB and cTnI were markedly attenuated under the UTR blockade and ROCK inhibition. TFR-inhibited RhoA activity was decreased under the UTR blockade. CONCLUSIONS: Total flavones of Rhododendron simsii Planch flower had a protective effect on ischaemia-reperfusion injury in isolated rat heart, which may be attributed to the blocking of UTR and subsequent inhibition of the RhoA-ROCK pathway.

Total Flavones of Rhododendron simsii Planch Flower Protect against Cerebral Ischemia-Reperfusion Injury via the Mechanism of Cystathionine-γ-Lyase-Produced H2S.

Total flavones of Rhododendron simsii Planch flower (TFR) have a significant protective effect against cerebral ischemia-reperfusion injury. However, its mechanism is unclear. This study investigated the protection of TFR against cerebral ischemia-reperfusion injury via cystathionine-γ-lyase- (CSE-) produced H2S mechanism. CSE-/- mice and CSE-siRNA-transfected rat were used. Relaxation of cerebral basilar artery (CBA), H2S, and CSE mRNA were measured. TFR significantly inhibited cerebral ischemia-reperfusion-induced abnormal neurological symptom and cerebral infarct in the normal rats and the CSE+/+ mice, but not in the CSE-/- mice, and the inhibition was markedly attenuated in CSE-siRNA-transfected rat; TFR elicited a significant vasorelaxation in rat CBA, and the relaxation was markedly attenuated by removal of endothelium or CSE-siRNA transfection or coapplication of NO synthase inhibitor L-NAME and PGI2 synthase inhibitor Indo. CSE inhibitor PPG drastically inhibited TFR-evoked vasodilatation resistant to L-NAME and Indo in endothelium-intact rat CBA. TFR significantly increased CSE mRNA expression in rat CBA endothelial cells and H2S production in rat endothelium-intact CBA. The increase of H2S production resistant to L-NAME and Indo was abolished by PPG. Our data indicate that TFR has a protective effect against the cerebral ischemia-reperfusion injury via CSE-produced H2S and endothelial NO and/or PGI2 to relax the cerebral artery.

The Protective Effect of Total Flavones from Rhododendron simsii Planch. on Myocardial Ischemia/Reperfusion Injury and Its Underlying Mechanism.

OBJECTIVES: Total flavones from Rhododendron simsii Planch. (TFR) are the effective part extracted from the flowers of Rhododendron simsii Planch. and have obvious protective effects against cerebral ischemic or myocardial injuries in rabbits and rats. However, their mechanism of cardioprotection is still unrevealed. Therefore, the present study was designed to investigate the effect of TFR on myocardial I/R injury and the underlying mechanism. METHODS: TFR groups were treated by gavage once a day for 3 days at a dose of 20, 40, and 80 mg/kg, respectively, and then the model of myocardial I/R injury was established. Myocardial infarction, ST-segment elevation, and the expression of UTR, ROCK1, ROCK2, and p-MLC protein in rat myocardium were determined at 90 min after reperfusion. UTR siRNA in vivo transfection and competition binding assay method were used to study the relationship between the protective effect of TFR and UTR. RESULTS: The expression of UTR protein markedly decreased in myocardium of UTR siRNA transfection group rats. TFR could significantly reduce the infarct size and inhibit the increase of RhoA activity and ROCK1, ROCK2, and p-MLC protein expressions both in WT and UTR knockdown rats. The reducing rate of TFR in myocardial infarction area, RhoA activity, and ROCK1, ROCK2, and p-MLC protein expressions in UTR knockdown rats decreased markedly compared with that in WT rats. In addition, TFR had no obvious effect on the increase of ΣST in UTR knockdown rats in comparison with that in model group. In particular, TFR could significantly inhibit the combination of [125I]-hu-II and UTR, and IC50 was 0.854 mg/l. CONCLUSIONS: The results indicate that the protective effect of TFR on I/R injury may be correlated with its blocking UTR and the subsequent inhibition of RhoA/ROCK signaling pathway.

[Quality of realgar and its influencing factors based on toxicity].

The results of a toxicity analysis showed differences from those of the existing experimental data. Therefore, HPLC-ICP-MS was used to analyze the soluble arsenic content at different valences in realgar prepared with water grind processing, which were collected from 3 companies. The results showed that the free arsenic of the 3 companies did not exceed the limit of Chinese Pharmacopoeia. However, if the free arsenic was calculated based on the total value of As(Ⅲ) + As(Ⅴ), free arsenic of 1 company exceeded the limit of Chinese Pharmacopoeia. The method of determining free arsenic in Chinese Pharmacopoeia. was ancient Cai's arsenic detection method, which had a certain limitation and failed to effectively avoid the toxicity of remaining arsenics except for trivalent arsenic. Then, we examined the effects of water and temperature on the content and form of soluble arsenic in realgar. The results showed that the content of soluble arsenic increased with the rise of water content, and the form of soluble arsenic did not change, there were only As (Ⅲ) and As (Ⅴ); With the simple temperature factor, there was an increasing trend in the content of soluble arsenic in the samples, the maximum increment was As (Ⅲ) 2.489 mg•g⁻¹ and As (Ⅴ) 0.546 mg•g⁻¹; When water and temperature played an synergistic effect, the increase of soluble arsenic in the samples significantly changed, the maximum increment was As (Ⅲ) 23.690 mg•g⁻¹, As (Ⅴ) 0.468 mg•g⁻¹, respectively. Through comprehensive analysis, we believed that the quality of realgar was susceptible to water content and temperature. Both of the single effect of water content and the synergistic effect of water and temperature can significantly change the content of soluble arsenic in realgar, and the water content was a high-risk factor. In the current Chinese Pharmacopoeia 2015 version, the free arsenic detection method had limitations, hence new techniques shall be introduced; At the same time, realgar does not have a water content inspection item in the current pharmacopoeia, which shall be added. However, due to the limit of water content, more in-depth studies are required.

[Protective effect against myocardial ischemia reperfusion injuries induced by hyperoside preconditioning and its relationship with PI3K/Akt signaling pathway in rats].

To investigate the protective effect of preconditioning with hyperoside ( Hyp) against myocardial ischemia-reperfusion injury (MIRI) in rats and the role of PI3K/Akt signaling pathway. MIRI was established by ligation of left anterior descending coronary artery for 30 min followed by reperfusion for 120 min in rats. Male SD rats were randomly divided into five groups: sham group,model group (MIRI),Hyp preconditioning group(Hyp), Hyp preconditioning + LY294002 (a PI3K/Akt signaling pathway inhibitor) group (Hyp + LY), and LY294002 group (LY). At the end of reperfusion, hemodynamic parameters were recorded as left ventricular systolic pressure (LVSP) , left ventricular end-diastolic pressure ( LVEDP) and maximal rate of increase and decrease of left ventricular pressure (± dP/dt(max)). Myocardial infaret size, the oxidative stress markers, myocardial enzymes indicators and inflammatory factors were also analyzed. The expressions of Akt, p-Akt, Bax and Bcl-2 proteins was detected by using Western blot method. The results showed that Hyp preconditioning remarkably improved cardiac constriction and relaxation function, reduced myocardial infarct size and enhanced the activities of oxidative stress markers about correlated to MIRI, such as superoxide dismutase (SOD), catalase (CAT) and glutathione-peroxidase (GSH-Px) and decreased the contents of malondialdehyde (MDA) as compared with MIRI group. Simultaneouly, the levels of myocardial enzymes, i. e. creatine kinase ( CK) and creatine kinase MB isoenzyme (CK-MB), and inflammatory factors, for instance tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) were decreased. Hyp pretreatment apparently restrained myocardial apoptosis as evidenced by decreasing the level of Bax expression, increasing the levels of phosphorylation of Akt and Bcl-2 expression. These effects were inhibited by LY294002, a blocker of PI3K/Akt signaling pathway. These findings indicated that the cardioprotection of Hyp preconditioning against MIRI may be related to activating PI3K/Akt signaling pathway, upregulating the expression of BCL-2 protein and down-regulating the expression of Bax protein.

Protective Effect and Mechanism of Total Flavones from Rhododendron simsii Planch Flower on Cultured Rat Cardiomyocytes with Anoxia and Reoxygenation.

Many flavonoids have cardioprotection against myocardial ischemia/reperfusion (I/R) injury. Total flavones from Rhododendron simsii Planch flower (TFR) can protect myocardial ischemic injuries. However, its protective mechanism is still unknown. The present study was designed to investigate the mechanism of TFR on myocardial I/R and anoxia/reoxygenation (A/R) injuries. Rat model of myocardial I/R injury was made, and myocardial infarction was determined. A/R injury was induced in cultured rat cardiomyocytes; cellular damage was evaluated by measuring cell viability, LDH and cTnT releases, and MDA content. Expressions of ROCK1 and ROCK2 protein were examined by Western blot analysis, and K(+) currents were recorded by using whole-cell patch clamp technique. TFR 20~80 mg/kg markedly reduced I/R-induced myocardial infarction. TFR 3.7~300 mg/L significantly inhibited A/R-induced reduction of cell viability, LDH and cTnT releases, and MDA production. Exposure to A/R significantly increased ROCK1 and ROCK2 expressions in rat cardiomyocytes, but TFR 33.3~300 mg/L obviously inhibited this increase. 300 mg/L TFR significantly augmented inward rectifier K(+) current and other K(+) currents in rat cardiomyocytes. These results indicate that TFR has a protective effect on rat cardiomyocytes A/R damage, and the protective mechanism may be engaged with the inhibition of ROCK1 and ROCK2 and activation of K(+) channels.

Protective effects of Sapindus saponins in spontaneously hypertensive rats.

OBJECTIVES: To investigate the protective effects of Sapindus saponins in spontaneously hypertensive rats, and the possible cellular and molecular mechanisms. METHODS: Thirty-two 16-week-old spontaneously hypertensive rats were randomly divided into four groups (8 in each group): model group (placebo), positive control group (27 mg/kg of Captopril Tablets), Sapindus saponins groups (27 mg/kg and 108 mg/kg, respectively). Another 8 healthy Wistar-Kyoto strain (WKY) rats were used as the normal group. The animals were treated for 8 weeks. Blood pressure of rats was determined by non-invasive blood pressure meter (BP-6). Furthermore, the contents of angiotensin II (Ang II) in plasma and myocardial tissue were determined by enzyme-linked immunosorbent assay (ELISA), the gene expression of receptor angiotensin type 1 (AT1R) in aorta was determined by quantitative realtime polymerase chain reaction (qRT-PCR). The protein expression of transforming growth factor-ß1 (TGF-ß1) and AT1R in heart was determined by immunohistochemical staining. The protein expression of p-phosphorylation of p38 mitogen-activated protein kinase (p-p38MAPK) was determined by Western blotting. The contents of interleukin (IL)-1, IL-6 and tumor necrosis factor (TNF) in serum were determined by radioimmunoassay. And the histopathological and morphological changes of aorta and heart tissue samples were assessed semi-quantitatively by hematoxylin-eosin (HE) or Masson staining. RESULTS: Thirty minutes after single or continuous treatment, systolic blood pressure (SBP) was reduced significantly in Sapindus saponins groups. And the contents of AngII, IL-1, IL-6 and TNF-α in serum, the expression of AT1R mRNA, p-p38MAPK and TGF-ß1 were significantly suppressed dose-dependently (P<0.05 or P<0.01). With the Sapindus saponins treatment, compared with those of the model group, the cardiac and aortic pathological changes were ameliorated significantly. CONCLUSIONS: Our findings suggest that Sapindus saponins might have protective effects in spontaneously hypertensive rats, the cellular and molecular mechanisms of which might be relevant to the regulation of inflammatory responses mediated by p-p38MAPK signal pathway based on activated Ang II and AT1R.

Protective Effect and Mechanism of Total Flavones from Rhododendron simsii Planch on Endothelium-Dependent Dilatation and Hyperpolarization in Cerebral Ischemia-Reperfusion and Correlation to Hydrogen Sulphide Release in Rats.

We for the first time investigated the effect and mechanism of the total flavones of Rhododendron simsii Planch (TFR), a widely-used Chinese herb for a thousand years, on vasodilatation and hyperpolarization in middle cerebral artery (MCA) of rats subject to global cerebral ischemia-reperfusion (CIR). TFR (11~2700 mg/L) evoked dose-dependent vasodilation and hyperpolarization in MCA of both sham and CIR that were partially inhibited by 30 µM N-nitro-L-arginine-methyl-ester and 10 µM indomethacin and further attenuated by endogenous H2S synthese-CSE inhibitor PPG (100 µM) or Ca(2+)-activated potassium channel (Kca) inhibitor TEA (1 mM). In whole-cell patch clamp recording, TFR remarkably enhanced the outward current that was inhibited by TEA. CIR increased CSE mRNA expression and the contents of H2S that were further increased by TFR. We conclude that, in MCA of CIR rats, TFR induces non-NO and non-PGI2-mediated effects of vasodilatation and hyperpolarization involving Kca and increases CSE mRNA expression level in endothelial cells and H2S content in the cerebrum. These findings suggest that the response induced by TFR is potentially related to endothelium-derived hyperpolarizing factor mediated by the endogenous H2S and promote the use of TFR in protection of brain from ischemia-reperfusion injury.

[Effects and mechanisms of hyperoside on vascular endothelium function in middle cerebral arteries of rats ex vivo].

To investigate the effects and potential mechanisms of hyperoside (Hyp) on the vascular endothelium function in middle cerebral artery (MCA) ex vivo in rats. Isolated arterial segments from MCAs of rats were used for surveying vasomotoricity in a pressurized chamber. Transmembrane potential was recorded by using glass microelectrodes to evaluate hyperpolarization. Hyp (1 x 10(-6)-1 x 10(-4) mol . L-1) was utilized to observe the effect on 1 x 10(-7) mol . L-1 U46619-preconstricted MCA in rats. The results showed that 1 x 10(-6)-1 x 10(-4) mol . L-1 Hyp significantly induced concentration-dependent vasodilatation and hyperpolarization, leading to the maximal diastolic ratio of (73. 2 ± 6. 1)% and maximal changes in membrane potentials of (-13. 2 ± 2. 2) mV. Hyp still elicited vasorelaxation and hyperpolarization by removal of endothelium in MCA of rat, which was notably attenuated as compared with vascular endothelium-intact group (P <0. 01). In the MCAs preconstricted by U46619 (1 x 10(-7) mol . L-1), Hyp (1 x 10(-6)-1 x 10(-4) mol . L-1) produced concentration-dependent vasorelaxation and hyperpolarizition that were partially attenuated by 3 x 10(-5) mol . L-1 L-NAME(a NOS inhibitor) plus 1 x 10(-5) mol . L-1 PGI2 ,(a synthetase inhibitor). The residual effects were further decreased by 1 x 10(-3) mol . L-1 TEA (an inhibitor of Ca2+-activated potassium channel) or 1 x 10(-5) mol . L-1 PPG (a blocker of endogenous H2S synthese-CSE). Similarly, 1 x 10(-5)-1 x 10(-3) mol . L-1 NaHS (a donor of exogenous H2S) or 1 x 10(-5)-1 x 10(-3) mol . L-1 L-Cys (the substrate of endogenous H2S synthesis) obviously evoked dose-dependent vasodilatation and hyperpolarization of MCA in rats. These findings indicated that Hyp may induce endothelium-dependent and endothelium-independent responses. And the endothelium-dependent vasodilatation may be related to the increases of endogenous H2S that has been promoted Hyp in the endotheliocyte of MCAs, and activated Kca and opening of Kca channels, resulting in the hyperpolarization of vascular smooth muscle cell membrane and subsequent reduction of Ca2+ influx and vasodilation.

[Effect of Sapindus saponins on myocardial inflammation and left ventricular remodeling in spontaneously hypertensive rats].

OBJECTIVE: To investigate the effect of Sapindus saponins on myocardial inflammation and left ventricular remodeling in spontaneously hypertensive rats. METHODS: Forty 16-week-old spontaneously hypertensive rats were randomly divided into five groups, placebo as model group, captopril tablets (27 mg/kg) as positive control, low-dose Sapindus saponins (27 mg/kg), medium-dose (54 mg/ kg) and high-dose (108 mg/kg) groups. And another eight healthy Wistar-Kyoto strain (WKY) rats were used as the normal group. The animals were treated for eight weeks, and the detection indexes were as follows: (1) Calculated left ventricular mass index (LVMI); (2) Observed the morphological changes on left ventricular myocardial tissue by HE staining; (3) Observed the collagen distribution in left ventricular myocardial by Masson staining; (4) Detected the protein expression of TGF-beta1 by immunohistochemical assay. RESULTS: Sapindus saponins could effectively reverse the left ventricular hypertrophy phenomenon in SHR, lowered LVMI, inhibited the myocardial cell hypertrophy and hyperplasia of collagen fibers, and blocked the expression level of TGF-beta1 in myocardial when compared with the SHR model group, there were significant differences (P < 0.05 or P < 0.01). CONCLUSION: Sapindus saponins can reserve the left ventricular remodeling in pathological conditions, its possible mechanism may be related to the inhibition of myocardial tissue inflammation factor of TGF-beta1.

[Effects of sapindus saponins on inflammatory response mediated by Ang II/p38MAPK pathway and cardiac hypertrophy in spontaneously hypertensive rats].

OBJECTIVE: To investigate the effects of sapindus saponins on myocardial inflammation mediated by Ang II/ p38MAPK signal pathway and cardiac hypertrophy in spontaneously hypertensive rats. And also to explore the correlation of cardiac hypertrophy and inflammation. METHOD: Thirty-two 16-week-old spontaneously hypertensive rats (SHR) were randomly divided into four groups, one with placebo as model group, one with captopril tablets (27 mg x kg(-1)) as positive control, one with low-dose sapindus saponins (27 mg x kg(-1)), one with high-dose (108 mg x kg(-1)). And another eight healthy Wistar-Kyoto strain (WKY) rats were used as the normal group. The animals were treated for eight weeks, and the indicators detected were as follows: (1) left ventricular mass index (LVMI); (2) the content of Ang II and hs-CRP in plasma were determined by ELISA; (3) the protein expression of AT1R and VEGF were determined by immunohistochemical method; (4) the protein expression of p-p38MAPK in myocardial cells was determined by Western blot. RESULT: Sapindus saponins reduced LVMI, and blocked the expression level of Ang II, AT1R, p-p38MAPK, VEGF and hs-CRP in myocardial tissue. Vs the SHR model group, there were significant differences (P < 0.05 or P < 0.01). CONCLUSION: Our findings suggested that sapindus saponins could inhibited cardiac hypertrophy, the possible mechanisms may be related to the inhibition on inflammatory response mediated by Ang II/p38MAPK pathway.

[Effect of total flavones of Rhododendra simsii on the activation of ERK induced by cerebral ischemia-reperfusion in rats].

OBJECTIVE: To study the effect of total flavones of Rhododendron simsii (TFR) on the activation of ERK induced by cerebral ischemia-reperfusion in rats and its possible mechanism. METHODS: Cerebral ischemia-reperfusion were induced by 4-vessel occlusion in rats. Changes in electroencephalogram were recorded before and 10 min after ischemia and 5,10,15,30,45 and 60 min after reperfusion. The activation of ERK1/2 and p-ERK1/2 of cerebral cortex and hippocampus was investigated by western blot. RESULTS: Compared with sham-operate group, EEG amplitude decreased significantly after ischemia and recovered after reperfusion in NS control and at 45 min and 60 min, EEG amplitude of TFR (15, 30, 60 mg/kg) groups was significantly higher than that of NS control (P < 0.05 or P < 0.01). TFR (30, 60 mg/kg) could increase the activation of ERK1/2 after cerebral ischmia-reperfusion. CONCLUSION: TFR (15, 30, 60 mg/kg) could significantly promote the recovery of EEG and the mechanism might be associated with the increase of the activation of ERK1/2 after cerebral ischemia-reperfusion.

[Research of sapindus saponins on endothelial function in spontaneously hypertensive rats].

OBJECTIVE: To investigate the regulation on endothelial function of sapindus saponins in spontaneously hypertensive rats by studying the reactivity on different vasoconstrictor and dilator, and the content of the active substances. METHOD: Forty 16-week-old spontaneously hypertensive rats were randomly divided into five groups, one with placebo as model group, one with captopril tablets (27 mg x kg(-1)) as positive control, one with low-dose sapindus saponins (27 mg x kg(-1)), one with medium-dose (54 mg x kg(-1)), one with high-dose (108 mg x kg(-1)). And another eight healthy Wistar-Kyoto strain (WKY) rats were used as the normal group. The animals were treated for eight weeks, and the indicators to be detected were as follows: (1) the response of thoracic aorta on different vasoconstrictors Ang II (1 x 10(-9) -1 x 10(-5) mol x L(-1)), PE (1 x 10(-8) 1 x 10(-4) mol x L(-1)), KCl (20 -120 mmol x L(-1)); (2) the endothelium-dependent or non-endothelium-dependent vasodilation response of thoracic aorta on Ach (1 x 10-(10)-1 x 10(-5) mol x L(-1)) or SNP (1 x 10(-8)-1 x 10(-3) mol x (L(-1); (3) the content of NO, 6-KPG1alpha, ET-1 and TXB2 in serum was determined by Elisa. RESULT: In SHR model group, the response of thoracic aorta on Ang II, PE and KCl was increased, the endothelium-dependent vasodilation on Ach was reduced, but the effects on SNP was not obvious, the content of ET-1 and TXB2 was increased, and the content of NO and 6-KPG1alpha was reduced, Vs the normal control group, there were significant differences (P < 0.05 or P < 0.01); in the treatment groups, the response of thoracic aorta on Ang II, PE and KCl was reduced, the endothelium-dependent vasodilation of thoracic aorta on Ach was improved, the content of ET-1 and TXB2 was reduced, and the content of NO and 6-KPG1alpha was increased, Vs the SHR model group, there were significant differences (P < 0.05 or P < 0.01). CONCLUSION: Our findings suggested that sapindus saponins protected the endothelial function in SHR, the mechanisms were relevant to the protection of endothelial function.

Cellular mechanisms underlying Hyperin-induced relaxation of rat basilar artery.

BACKGROUND AND AIM: Hyperin, a flavonol compound extracted from the Chinese herb Abelmoschus manihot L. Medic, is reported to exert protective actions in cerebral ischemic injury. The specific aim of the present study was to study the relaxation of Hyperin in rat isolated basilar artery and identify the underlying cellular mechanisms. METHODS: Rat isolated basilar artery segments were cannulated and perfused while being superfused with PSS solution. Vessel images were recorded by video microscopy and diameters measured. Membrane potential was recorded using glass microelectrodes to evaluate the basilar artery smooth muscle cell hyperpolarization. RESULTS: Perfusion of Hyperin (1~100 µM) elicited a concentration-dependent relaxation of basilar artery segments preconstricted with 0.1 µM U46619. The response was significantly inhibited by the removal of the endothelium. Hyperin also elicited marked and concentration-dependent hyperpolarization of smooth muscle cells. 30 µM nitro-L-arginine (an inhibitor of nitric oxide synthase) and indomethacin (an inhibitor of cyclooxygenase), partially inhibited Hyperin-induced relaxation and hyperpolarization leaving an attenuated, but significant, endothelium-dependent relaxation and hyperpolarization. This remaining effect was almost completely blocked by 1mM tetraethylammonium (an inhibitor of Ca(2+)-activated K(+) channels), or by 100 µM DL-propargylglycine, an inhibitor of cystathionine-γ-lyase (a synthase of the endogenous H(2)S). CONCLUSION: These findings show that Hyperin produces significant hyperpolarization in rat basilar artery smooth muscle cells and relaxation through both endothelium-dependent and endothelium-independent mechanisms. The underlying mechanisms appeared to be multi-factorial involving nitric oxide, prostacyclin, and endothelium-derived hyperpolarizing factor (EDHF). Our data further suggest that endogenous H(2)S is a component of the EDHF-mediated hyperpolarization and relaxation to Hyperin.

Protective effects of total flavones of rhododendra against global cerebral ischemia reperfusion injury.

The purpose of this research was to demonstrate the protective effects and possible mechanisms of total flavones of rhododendra (TFR) against global cerebral ischemia reperfusion injury in rats. Global cerebral ischemia/reperfusion injury was caused by four vessel occlusion (bilateral vertebral arteries and bilateral carotid arteries, 4-VO). The electroencephalographic (EEG) changes were recorded. The EEG, brain water content, levels of malondialdehyde (MDA) and lactate dehydrogenase (LDH) activity in plasma, aggregation of platelets induced by ADP, and the resting and CaCl(2)-induced increase of free intracellular calcium concentration ([Ca(2+)](i)), were also evaluated. TFR dramatically elevated EEG amplitude, reduced the brain water content and the resting cytoplasmic free calcium concentration, inhibited the increase of [Ca(2+)](i) induced by CaCl(2) and had an inhibitory effect on platelet aggregation. The LDH activity and the MDA content in plasma were also decreased. These results indicate that TFR has protective effects against cerebral injury in rats, which might be associated with its antioxidant properties, antiplatelet effects and possible inhibition of Cal(2+) influx to reduce [Ca(2+)](i).

[Experimental study on effect of total flavone of Ginkgo biloba on delaying cell senescence].

OBJECTIVE: To investigate the mechanism of delaying the senescence of human diploid fibroblast (2BS) by total flavone of Ginkgo biloba (FG). METHODS: The drug sera of FG was used to treat the 2BS. The population doublings of 2BS cells were observed, the mRNA expression of P16 gene was determined by fluorescence real-time quantitative PCR. RESULTS: FG significantly extended the population doublings of 2BS cells, and decreased the expression of P16 mRNA. CONCLUSION: FG can delay the senescence of cells by inhibiting the P16 gene expression.

[Protective effect of injection of Danhong against acute myocardial ischemia in dogs].

OBJECTIVE: To investigate the protective effects of injection of Danhong against acute myocardial ischemia in dogs. METHOD: The myocardial ischemia model were established by ligation of coronary artery in dogs. The degree of myocardial ischemia and the myocardial infarction size were observed before and after giving injection of Danhong. The serum creatine phosphokinase (CK) and lactate dehydrogenase (LDH) activities were also determined. RESULT: Injection of Danhong (1, 2, 4 g x kg(-1)) could significantly decreased the damage degree of myocardial ischemia, redused myocardial infarction size and also reduced the serum LDH and CK activities. CONCLUSION: Injection of Danhong had protective action on myocardial ischemia.