The effects of hydroxysafflor yellow A on blood pressure and cardiac function

Aim of the study

This work aims to investigate the effects of HSYA on cardiac function and blood pressure.

Materials and methods

To evaluate changes in mean arterial pressure (MAP) and heart rate (HR), different groups of pentobarbitone-anesthetized normotensive and spontaneously hypertensive rats (SHR) were treated with intravenous HSYA (0.1-3 mg/kg). Isolated WKY rat hearts in Langendorff system were employed for examining the effect of HSYA on hemodynamic. After 30 min equilibration time the isolated hearts were perfused with HSYA (30 μmol/L) in a stepwise fashion. Potassium channel inhibitors were used to determine the role of potassium channel activation in HSYA effect.

Results

Intravenous injection of the HSYA significantly reduced MAP and HR in both normotensive rats and SHR in a dose-dependent manner. HSYA reduced left ventricular systolic pressure (LVSP), left ventricular end-diastolic pressure (LVEDP), the maximum rate of increase of left ventricular pressure (+dp/dt_max) and heart rate (HR) in a dose-dependent manner. HSYA had no remarkable effect on the maximum rate of decrease of left ventricular pressure (−dp/dt_max); BK_Ca and K_ATP blocker can weakened the inhibitory effect of HSYA on heart function and HR, but K_V and K_ACh blocker did not significantly weaken the HSYA effects.

Conclusion

Our results show that HSYA could significantly reduce blood pressure and heart rate, which may be related to activation of BK_Ca and K_ATP channels.     

Gastroprotective and ulcer healing effects of essential oil from Hyptis spicigera Lam. (Lamiaceae)

Aim of the study

Tanshinone IIA (Tan IIA) is one of the key components of Salvia miltiorrhiza Bunge that has been widely used for various cardiovascular and cerebrovascular disorders in Asian countries. Many studies have reported that Tan IIA has antioxidative properties, but whether Tan IIA can rescue neurons from oxidative insult has never been reported. The present study was undertaken to evaluate the possible neuroprotective effects of Tan IIA on hydrogen peroxide (H₂O₂)-induced oxidative stress in rats.

Materials and methods

H₂O₂-induced cytotoxicity was evaluated by the cellular 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay and flow cytometry with PI staining. Calcium imaging experiments were carried out to measure intracellular free calcium concentration. Western blotting was used to determine the expression of Bax and Bcl-2 protein. Electrophysiological studies in hippocampal slices were performed to investigate the effect of Tan IIA on synaptic function and cognitive impairment caused by H₂O₂.

Results

It was found that pretreatment with Tan IIA protected primary rat cortical neurons against H₂O₂-induced cytotoxicity. Furthermore, Tan IIA markedly reduced the elevation of [Ca²⁺]_i evoked by H₂O₂. Western blot analysis indicated that pretreatment with Tan IIA prevented the increase in Bax/Bcl-2 ratio induced by H₂O₂. In addition, preincubation of Tan IIA 20 min prior to H₂O₂ exposure could reverse H₂O₂-induced hippocampal LTP impairment, but without significant alteration in basal synaptic transmission and LTP induction.

Conclusions

These findings demonstrate that Tan IIA might serve as a novel promising therapeutic agent for oxidative stress injury in neurodegenerative diseases.     

Panax notoginseng saponins inhibit ischemia-induced apoptosis by activating PI3K/Akt pathway in cardiomyocytes

Aim of this study

The panax notoginseng saponins (PNS) have been clinically used for the treatment of cardiovascular diseases and stroke in China. Evidences demonstrated that PNS could protect cardiomyocytes from injury induced by ischemia, but the underlying molecular mechanisms of this protective effect are still unclear. This study was aimed to investigate the protective effect and potential molecular mechanisms of PNS on apoptosis in H9c2 cells in vitro and rat myocardial ischemia injury model in vivo.

Materials and methods

H9c2 cells subjected to serum, glucose and oxygen deprivation (SGOD) were used as in vitro models and SD rats subjected to left anterior descending (LAD) coronary artery ligation were used as in vivo models. The anti-apoptotic effect of PNS was evaluated by Annexin V/PI analysis or TUNEL assay. Mitochondrial membrane potential (Δψm) was detected by JC-1 analysis. The expression of Akt and phosphorylated Akt (p-Akt) were detected by western blot assay.

Results

PNS exhibited anti-apoptotic effect both in H9c2 cells and in ischemic myocardial tissues. However, the effect was blocked in vitro by LY294002, a specific PI3K inhibitor. The anti-apoptotic effect of PNS was mediated by stabilizing Δψm in H9c2 cells. Furthermore the indices of the left ventricular ejection fractions (EF), left ventricular fractional shortening (FS), left ventricular dimensions at end diastole (LVDd) and left ventricular dimensions at end systole (LVDs) suggested that PNS improved rats cardiac function. PNS significantly increased p-Akt both in H9c2 cells and in ischemic myocardial tissues and this effect was also blocked by LY294002 in H9c2 cells.

Conclusion

Results of this study suggested that PNS could protect myocardial cells from apoptosis induced by ischemia in both the in vitro and in vivo models through activating PI3K/Akt signaling pathway.     

Baicalein, an active component of Scutellaria baicalensis Georgi, improves cardiac contractile function in endotoxaemic rats via induction of heme oxygenase-1 and suppression of inflammatory responses

Aim of the study

To evaluate the protective effect of baicalein on myocardial dysfunction caused by endotoxaemia in rats and to explore the possible mechanisms.

Materials and methods

Baicalein (10 mg/kg, intravenous) was administered to conscious Wistar rats 30 min after lipopolysaccharide (LPS; 10 mg/kg, intravenous) challenge. Six hours after LPS administration, the contractile function of the isolated heart was examined using the Langendorff technique. Cardiac protein expression related to inflammatory responses, superoxide anion production and caspase-3 activity were measured.

Results

Post-treatment with baicalein significantly attenuated the LPS-induced hypotension with accompanying tachycardia. The contractile function of isolated heart was significantly preserved 6 h after LPS administration, following treatment with baicalein. Furthermore, baicalein induced the expression of heme oxygenase-1 protein and reduced superoxide anion formation in the myocardium of LPS-treated rats. Cardiac levels of inducible nitric oxide synthase, monocyte chemoattractant protein-1, phospho-IκBα and phospho-p65 protein and caspase-3 activity significantly increased 6 h after LPS challenge but baicalein significantly attenuated these LPS-induced changes.

Conclusions

Baicalein improves myocardial contractility in LPS-induced sepsis, which may be related to reductions in oxidative stress, myocardial inflammatory responses and apoptosis.     

Activation of the nuclear receptor PPARγ by metabolites isolated from sage (Salvia officinalis L.)

Ethnopharmacological relevance

Salvia officinalis has been used as a traditional remedy against diabetes in many countries and its glucose-lowering effects have been demonstrated in animal studies. The active compounds and their possible mode of action are still unknown although it has been suggested that diterpenes may be responsible for the anti-diabetic effect of Salvia officinalis.

Aim of the study

To investigate whether the reported anti-diabetic effects of Salvia officinalis are related to activation of the nuclear receptor peroxisome proliferator-activated receptor (PPAR)γ and to identify the bioactive constituents.

Materials and methods

From a dichloromethane extract of Salvia officinalis able to activate PPARγ several major metabolites were isolated by chromatographic techniques. To assess bioactivity of the isolated metabolites a PPARγ transactivation assay was used.

Results

Eight diterpenes were isolated and identified including a new abietane diterpene being the epirosmanol ester of 12-O-methyl carnosic acid and 20-hydroxyferruginol, which was isolated from Salvia officinalis for the first time, as well as viridiflorol, oleanolic acid, and α-linolenic acid. 12-O-methyl carnosic acid and α-linolenic acid were able to significantly activate PPARγ whereas the remaining metabolites were either unable to activate PPARγ or yielded insignificant activation.

Conclusions

Selected metabolites from Salvia officinalis were able to activate PPARγ and hence, the anti-diabetic activity of this plant could in part be mediated through this nuclear receptor.     

Aqueous extract of Gleditsia sinensis Lam. fruits improves serum and liver lipid profiles and attenuates atherosclerosis in rabbits fed a high-fat diet

Ethnopharmacological relevance

Gleditsia sinensis Lam. has been used in the traditional Chinese medicine as a chief ingredient of many polyherbal formulations for the treatment of obesity and thrombosis.

Aim of the study

To evaluate the effects of Gleditsia sinensis Lam. fruit aqueous extract (GAE) on hyperlipidemia and atherosclerosis in Japanese white rabbits on a high fat diet.

Materials and methods

Rabbits were divided into four groups: the normal control with a normal diet, and high-fat diet-fed model group and GAE-treated groups supplemented with GAE (6 or 12 mg/kg/day, p.o.), respectively. The groups fed high-fat diets were given i.v. with bovine serum albumin (BSA) on the 4th week to induce atherosclerosis. The serum lipid profile, including triglycerides (TG), total cholesterol (TC) and low density lipoprotein cholesterol (LDL-C), was determined on the 0th, 4th, 8th and 14th week, respectively. And the activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and creatine kinase (CK) were measured simultaneously. At the end of the experiment, the rabbits were sacrificed, and the atherosclerotic plaques as well as the histopathological changes of aorta and liver were assessed by oil-red or HE staining, respectively, and the aorta and liver lipid profiles were also assayed.

Results

Results showed that the prophylactic treatment with GAE could significantly decrease the lipid levels of serum, aorta and liver, attenuate aortic atherosclerosis and improve aortic remodeling without the significant liver and muscle toxicity.

Conclusion

The present findings suggest that GAE can effectively attenuate the atherosclerotic at least through anti-hyperlipidemic activity and thus has the therapeutic potential in treating hyperlipidemia-related cardiovascular diseases.     

The absorption characterization effects and mechanism of Radix Angelicae dahuricae extracts on baicalin in Radix Scutellariae using in vivo and in vitro absorption models

Ethnopharmacological relevance

Angelicae Dahurica(Hoffm.)Benth.&Hook.f.ex Franch.&Sav combined with Scutellaria baicalensis Georgi. has been widely used as herb-pairs in traditional Chinese medicine (TCM) to treat migraine headache and cataract, but the underlying compatibility mechanism of the two herbs remains unknown.

Aim of study

In the present work, we investigated the additive or synergistic effects of absorption behavior of Radix Angelicae dahuricae extracts on baicalin, and the absorption-enhancing mechanism of Radix Angelicae dahuricae extracts on baicalin.

Materials and methods

Total coumarins (Cou) and volatile oil (VO), as the two main components of Radix Angelicae dahuricae, were extracted by supercritical fluid extraction (SFE) further treated with liquid-liquid separation method. The absorption behavior was investigated by applying the everted gut sac technique and in situ single-pass intestinal perfusion method.

Results and conclusions

The results showed that both the Cou and the VO could improve the intestinal absorption of baicalin in vivo, and had synergistic action the enhanced absorption of baicalin. Since verapamil did not affect the P_app and K_a of baicalin significantly, we concluded that the absorption of Baicalin could not be an active transportation in dependent of P-glycoprotein-Mediated efflux systems. Based on intestinal absorption of drug studying was one of the efficacious methods to clarify the compatibility of principles of herb-pairs. The everted gut sac technique and in situ single-pass intestinal perfusion technique model were the effective methods to study the absorption of drug, the application of the animal model to investigating the absorption of herb-drug interactions or other relevant research purposes is envisioned.     

Actions of Artemisia vulgaris extracts and isolated sesquiterpene lactones against receptors mediating contraction of guinea pig ileum and trachea

Aim of the study

The present study evaluates the Philippine medicinal plant Artemisia vulgaris for antagonistic activity at selected biogenic amine receptors on smooth muscle of the airways and gastrointestinal tract in order to explain its traditional use in asthma and hyperactive gut.

Materials and methods

The antagonistic activity of chloroform crude extract (AV-CHCl₃) and methanol crude extract (AV-MeOH) of Artemisia vulgaris was studied against concentration-response curves for contractions of the guinea pig ileum and trachea to 5-hydroxytrptamine (5-HT₂ receptors), methacholine (M₃ muscarinic receptors), histamine (H₁ receptors) and β-phenylethylamine (trace amine-associated receptors, TAAR1).

Results and discussion

The Artemisia vulgaris chloroform (AV-CHCl₃) and methanol (AV-MeOH) extract showed histamine H1 antagonism in the ileum and trachea. Further analysis of AV-CHCl₃ isolated two major components, yomogin and 1,2,3,4-diepoxy-11(13)-eudesmen-12,8-olide. Yomogin, a sesquiterpene lactone, exhibited a novel histamine H1 receptor antagonism in the ileum.

Conclusion

The presence of a specific, competitive histamine receptor antagonist and smooth muscle relaxant activity in Artemisia vulgaris extracts on the smooth muscle in ileum and trachea explains its traditional use in the treatment of asthma and hyperactive gut.     

Antihypertensive effect of total flavone extracts from Puerariae Radix

Aim of the study

To evaluate the antihypertensive effect of total flavone extracts from Puerariae Radix (FEPR). To explore the hemodynamic profiles and pertinent mechanism of the extracts.

Materials and methods

Acute and chronic antihypertensive effects of FEPR were examined in spontaneous hypertensive rats (SHRs) and reno-hypertensive rats (two kidneys one clip model, 2K1C). Anesthetized dogs were used to evaluate the hemodynamic effects of FEPR. The determination of angiotensin converting enzyme (ACE) activity in vitro and plasma renin activity (PRA) and endothelin (ET) in vivo were used to study the pilot mechanism of FEPR. Moreover, the toxicity study of FEPR was evaluated.

Results

FEPR (100, 200 and 400 mg/kg, i.v.) notably reduced the blood pressure of SHRs in a short time period. A two-week administration of FEPR (45, 90 and 180 mg/kg, p.o.) decreased the blood pressure of both 2K1C rats and SHRs. The results of hemodynamic study in anesthetized dogs showed that, left ventricular end systolic pressure and left ventricular dP/dt_max had shown no significant difference between FEPR-treated dogs and those from the control group, while the cerebral blood flow increased significantly in FEPR-treated groups. FEPR significantly inhibited the ACE activities in vitro dose dependently, and inhibited the PRA in vivo, while the content of ET showed no difference in the FEPR treated group comparing with the control group.

Conclusions

FEPR shows significantly blood pressure lowering and cerebral vascular resistance (CVR) decreasing effect, which can partly be explained by the involvement of the Renin-Angiotensin-System (RAS).     

Biomarkers in the early period of acute myocardial infarction in rat serum and protective effects of Shexiang Baoxin Pill using a metabolomic method

Ethnopharmacological relevance

To identify the biomarkers in early period of acute myocardial infarction (AMI) in rat serum and reveal the effective mechanism of a Traditional Chinese Medicine (TCM) named Shexiang Baoxin Pill (SBP).

Material and method

A metabolomic approach using reversed-phase liquid chromatography/quadrupole time-of-flight mass spectrometry (LC-Q-TOF-MS) was developed.

Results

Fourteen biomarkers in the early period of acute myocardial infarction (AMI) in rat serum were identified. These biomarkers include 5-methylcytosine, cystathionine ketimine, 2-oxoadipic acid, thymidine, epinephrine, homocystine, uric acid, 12(S)-hydroperoxyeicosatetraenoic acid (12s-HPETE), 11-dehydrocorticosterone, 12(S)-hydroxyeicosatetraenoic acid (12s-HETE), deoxycorticosterone, corticosterone, aldosterone and cortisol. Through pathway analysis of these biomarkers, inflammation, hypertrophy and oxidative injury were considered the most relevant pathological changes in early period of AMI.

Conclusion

Identification of AMI biomarkers not only supplied a systematic view of the progression of AMI in the early period but also provided the theoretical basis for the prevention or treatment of AMI. The results demonstrated that SBP pretreatment could offer protective effects for AMI through regulating the pathway of steroid hormone biosynthesis.     

Inhibition of matrix metalloproteinases related to metastasis by diosgenyl and pennogenyl saponins

Ethnopharmacological relevance

Diosgenyl and pennogenyl saponins isolated from Rhizoma Paridis, showed pro-apoptosis and immunoregulation with antitumor activity in cultured cells and animal systems.

Aim of the study

To evaluate their anti-metastatic mechanism on cancer cells and discuss their structure-activity relationship on anti-tumor effect.

Materials and methods

This research used the wound healing and migration assay to detect their anti-invasive effect on B16 melanoma cells. Through the gelatin zymography assay, immunofluorescence analysis and western blot, saponins exhibited different levels of protein expression inhibition of MMP-1, -2, -3, -9 and -14.

Results

Through the analysis, diosgenyl and pennogenyl saponins inhibited the metastasis of B16 melanoma cells. Diosgenyl saponins also showed strong suppression of enzyme activity of MMP-2 and -9. Different saponins exhibited different levels of inhibition on MMP expression.

Conclusions

17-α OH increases the sensitivity of diosgenyl saponins to the membrane-bound protease which can stimulate proMMP-2 activation, but it also decreases the anti-metastatic activity of diosgenyl saponin. Furthermore, their combination might provide a potential therapeutic modality for metastasis.     

Antiplatelet effects of Spatholobus suberectus via inhibition of the glycoprotein IIb/IIIa receptor

Ethnopharmacological relevance

The vine stem of Spatholobus suberectus is a widely used blood-activating and stasis-dispelling medicine for the treatment of diseases related to blood stasis syndrome in traditional medicine in Korea, Japan, and China.

Aim of the study

To demonstrate the clinical effects of Spatholobus suberectus against blood stasis syndromes using in vitro and in vivo platelet aggregation studies and to investigate its exact mechanisms.

Materials and methods

We extracted vine stems of Spatholobus suberectus, using 95% EtOH (SSE) and investigated its antiplatelet activity on platelet aggregation induced by collagen and ADP in human platelet-rich plasma (PRP). For the mechanism study, a glycoprotein IIb/IIIa (GP IIb/IIIa) assay using flow cytometric analysis and a thromboxane A₂ (TXA₂) assay were performed. In addition, we investigated the effects of SSE in a thromboembolic mouse model.

Results

SSE significantly inhibited ADP- and collagen-induced platelet aggregation in human PRP concentration-dependently without affecting plasma clotting time. It also significantly inhibited fibrinogen binding to the GP IIb/IIIa receptor and partly inhibited the formation of TXA₂. In the in vivo study, oral administration of SSE dose-dependently suppressed the death of thromboembolism model mice induced by intravenous injection of collagen plus epinephrine.

Conclusions

SSE showed antiplatelet activity without anticoagulant effects mainly through the inhibition of fibrinogen binding to the GP IIb/IIIa receptor. Our current results support the clinical usage of SSE in the East Asian region treating atherothrombotic diseases and may represent a new natural source to develop antiplatelet agents.     

Inhibition of the inflammatory and coagulant action of Bothrops atrox venom by the plant species Marsypianthes chamaedrys

Aim of the study

This study investigated the efficacy of Marsypianthes chamaedrys Vahl (Lamiaceae) inflorescence and leaf extracts in inhibiting the inflammatory and coagulant actions of Bothrops atrox venom.

Materials and methods

Marsypianthes chamaedrys, which is used in Brazil as a folk medicine to treat snakebites and local inflammatory reactions, was tested in vitro to determine its ability to block indirect phospholipase A₂ and direct coagulant activities and in vivo to determine its ability to inhibit leukocyte migration and cytokine release.

Results

In vitro, Marsypianthes chamaedrys showed antiphospholipase A₂ and anticoagulant activities; the latter activity was also confirmed by prothrombin time (PT) and activated partial thromboplastin time (aPTT) in the absence of venom. Of the extracts used, those obtained from the crushed plant had the greater inhibitory activity in in vitro tests, showing that biological activity is affected by the way extracts are obtained. In vivo, Marsypianthes chamaedrys inhibited leukocyte migration and the release of the proinflammatory cytokines IL-6 and TNF-α without altering the concentration of the anti-inflammatory cytokine IL-10.

Conclusions

As specific antivenoms are not effective in neutralizing the local action of Bothrops venoms, characterization of the anti-inflammatory mechanisms induced by Marsypianthes chamaedrys is of vital importance if the extracts of this plant species are to be used in future as adjuvants in the treatment of snakebites.     

Wound healing and anti-inflammatory activities of the Michauxia L'Hérit (Campanulaceae) species native to Turkey

Ethnopharmacological relevance

The leaves of Michauxia species are used for the treatment of wounds in Turkish traditional medicine. In the present study, wound healing, anti-inflammatory and antioxidant activities of the extracts obtained from the root and herb of 5 species of Michauxia collected in different parts of Turkey were evaluated.

Material and methods

In vivo incision and excision wound models were used in order to assess the wound healing effects of the methanolic extracts of the plants. Skin samples were also evaluated histopathologically. In vivo inhibitory effect of the extracts on acetic acid-induced increase in capillary permeability was studied for the assessment of anti-inflammatory activity. TBA (thiobarbituric acid) test, qualitative and quantitative DPPH (2,2-diphenyl-1-picrylhydrazyl) tests were used to evaluate the antioxidant activity.

Results

Noteworthy wound healing activity was observed for the ointment formulation prepared with 1% Michauxia nuda (root) and Michauxia tchihatchewii (herb) extracts. The results of histopathological evaluation supported the outcome of incision and excision wound models. Moreover, the Michauxia nuda (root) exerted remarkable anti-inflammatory effect. The highest antioxidant activity was observed with the ethyl acetate extract of Michauxia tchihatchewii herb.

Conclusion

The experimental study revealed that Michauxia displays remarkable wound healing and anti-inflammatory and antioxidant activities.     

Blocking effects of acehytisine on pacemaker currents (I(f)) in sinoatrial node cells and human HCN4 channels expressed in Xenopus laevis oocytes

Ethnopharmacological relevance

The root of Aconitum coreanum (Levl.) Raipaics has been extensively used to treat various kinds of disorders including cardiovascular disease in China for a long time. According to recent studies, its antiarrhythmic actions are attributable to the active component, acehytisine. However, the underlying mechanism remains poorly understood.

Aim of the study

The effects of acehytisine on the spontaneous activity in sinoatrial nodes and the electropharmacological action of this drug on I_f in pacemaker cells and hHCN4 channels in oocytes were to be investigated.

Materials and methods

Sinoatrial nodes were cut from rabbit heart, and transmembrane potentials were recorded by standard microelectrode technique. A whole-cell patch clamp technique was employed to record I_f isolated enzymatically from rabbit sinoatrial node pacemaker cells. Human HCN4 channels were heterologously expressed in Xenopus oocytes and studied using the two-electrode voltage clamp technique.

Results

Acehytisine decreased the pacemaker rate of firing and slope of diastolic depolarization, modified the action potential configurations and blocked I_f in rabbit sinoatrial node cells and hHCN4 channels expressed in Xenopus oocytes in a concentration-dependent, voltage-independent and non-use-dependent manner. Its electropharmacological properties were consistent with those of a close-state blocker.

Conclusion

Our findings are likely to shed light on the clinical application of acehytisine in the treatment of cardiovascular disorders.