Vascular relaxing effect of Hydrocotyle umbellata L. is mediated by blocking of l-type Ca2+ channels.

ETHNOPHARMACOLOGICAL RELEVANCE: Hydrocotyle umbellata L. is a medicinal herb for the treatment of some health problems including hypertension, according to traditional medicine. Even so, its vascular effects and the pharmacological action mechanisms have not been analyzed. AIM OF THE STUDY: This experiment aimed to analyze the effects of hydroalcoholic extract of Hydrocotyle umbellata L. (HEHU) on isolated vessels and verify the interaction of hibalactone (chemical marker) against Cav1.2 channels using molecular docking. MATERIALS AND METHODS: Vascular reactivity experiments were performed using rat aortas with (E+) or without endothelium (E-) in an isolated organ bath. Computational molecular docking approaches were used to show the direct effect on L-type Ca2+ Channels. RESULTS: HEHU (0-560 µg/mL) induced relaxation of the pre-contracted arteries in a concentration-dependent manner. The maximum effect was higher in E+ (76.8 ± 4.1%) as compared to E- (47.3 ± 5.5%). Pre-treatment of E+ arteries with L-NAME or ODQ reduced the relaxation to similar level of E- arteries. The treatment of arteries with MDL-12,330 A, diclofenac, propranolol and atropine did not change the relaxation induced by HEHU. The contraction caused by internal Ca2+ release induced by caffeine was reduced after HEHU treatment. Moreover, the HEHU also impaired the contraction induced by Ca2+ influx stimulated with phenylephrine or high KCl. The docking study demonstrated the effectiveness of hibalactone in blocking the Cav1.2 channel. CONCLUSIONS: These findings show that HEHU induces vascular relaxation which is potentiated (but not dependent) by endothelial cells. Blocking of Ca2+ influx seems to be the main mechanism for the vascular effects of HEHU.

The mechanisms of calcium mobilization by procyanidins, flavonols and flavonoids from Cecropia glaziovii Sneth in pulmonary endothelial cell cultures endorse its popular use as vasodilator phytomedicine.

The hypotensive and antihypertensive activities of the aqueous extract (AE) and butanolic fraction (ButF) isolated from Cecropia glaziovii Sneth have been demonstrated in previous studies in animal models. This study aimed to evaluate the molecular mechanism of action responsible for the vasodilatory effect of procyanidins, flavanols, and flavonoids found in C. glaziovii in endothelial cell culture. For this purpose, we analyzed the effect of procyanidin B2 and B3 compounds, catechin, epicatechin, orientin, isoorientin, and isovitexin in the mobilization of Ca2+ in rat endothelial cell cultures. Parallel associations with different antagonists were examined by considering the following in vivo hypotensive mechanisms: blockage of L-type calcium channels, action on ß-2 adrenergic receptors, and vasodilation via the nitric oxide pathway. All measurements of calcium mobilization were carried out by using the fluorescence measurement methodology in a Flexstation M3 spectrophotometer. The results indicate that some of the compounds have mixed actions, acting through different calcium mobilization pathways. The mobilization induced by such compounds significantly decreased when they were incubated with their corresponding antagonists. Taken together, our data suggest that the beneficial effects seen with the popular use of Cecropia glaziovii Sneth in pathological conditions, such as systemic arterial hypertension, seem to be related to the plant's hypotensive effect, very probably promoted by the actions of flavonols, flavonoids, and procyanidins, by different pathways of calcium mobilization.

Vasorelaxant and Antihypertensive Effects of Mentha pulegium L. in Rats: An In vitro and In vivo Approach.

Aims The aim of the study was to investigate the effect of aqueous aerial part extract of Mentha pulegium L. (Pennyrile) (MPAE) on arterial pressure parameters in rats. BACKGROUND: Mentha pulegium is a medicinal plant used to treat hypertension in the Moroccon population. METHODS: In the current study, MPAE was prepared and its antihypertensive activity was pharmacologically investigated. L-NAME-hypertensive and normotensive rats received MPAE (180 and 300 mg/kg) orally for six hours for acute experiment and during seven days for the sub-chronic treatment. Thereafter, systolic, diastolic, mean arterial blood pressure and heart rate were evaluated. In the in vitro experiment, isolated denuded and intact thoracic aortic rings were suspended in a tissue bath system and the tension changes were recorded. RESULTS: A fall in blood pressure was observed in L-NAME-induced hypertensive treated with MPAE. The extract also produced a dose-dependent relaxation of aorta pre-contracted with NE and KCl. The study showed that the vasorelaxant ability of MPAE seems to be exerted through the blockage of extracellular Ca2+ entry. CONCLUSION: The results demonstrate that the extract of pennyrile exhibits antihypertensive activity. In addition, the effect may be, at least in part, due to the dilation of blood vessels via blockage of Ca2+ channels.

Pharmacological basis of the anxiolytic and antidepressant properties of Silexan®, an essential oil from the flowers of lavender.

Silexan®, a proprietary essential oil manufactured by steam distillation from Lavandula angustifolia flowers showed pronounced anxiolytic effects in patients with subthreshold anxiety disorders and was also efficacious in patients with Generalized Anxiety disorder (GAD). Moreover, evidences for antidepressant-like properties of Silexan® have been observed in anxious patients suffering from comorbid depressive symptoms and in patients with mixed anxiety-depression disorder (ICD-10 F41.2). In accordance with the clinical data Silexan® is active in several behavioral models in rodents at rather low concentrations indicating potent anxiolytic and antidepressive properties. As possible mechanism of action a moderate inhibition of voltage dependent calcium channels (VDCC) has been found showing some similarities to the anxiolytic drug pregabalin. However, while pregabalin mainly inhibits P/Q-type channels by binding to a modulatory subunit, Silexan® moderately inhibits mainly T-type and N-type channels and to some extent P/Q-type channels. Unlike pregabalin Silexan® is free of hypnotic or sedative side effects and seems to be devoid of any abuse potential. With respect to its specific antidepressant like properties Silexan® improves several aspects of neuroplasticity which seems to be the common final pathway of all antidepressant drugs. As a potential mechanism of its effects on neuroplasticity an activation of the transcription factor CREB via activation of intracellular signaling kinases like PKA and MAPK has been found. Since the concentrations of Silexan® needed to inhibit VDCC function and to improve neuroplasticity are quite similar, the effects of Silexan® on PKA or MAPK could constitute a common intracellular signaling cascade leading to VDCC modulation as well as CREB activation and improved neuroplasticity.

Antihypertensive and vasorelaxant mode of action of the ethanol-soluble extract from Tagetes lucida Cav. aerial parts and its main bioactive metabolites.

ETHNOPHARMACOLOGICAL RELEVANCE: Tagetes lucida Cav. commonly known as "yauhtli" or "pericón" is used in Mexican traditional medicine for the treatment of anxiety, depressant diseases, pain, hypertension, among others. AIM: To evaluate the antihypertensive and vasorelaxant modes of action of a crude ethanolic extract from T. lucida aerial parts and to isolate the bioactive compounds. MATERIALS AND METHODS: Ethanolic extract was tested in an in vivo assay in SHR rats by intragastric administration at 10 and 100 mg/kg dosages, to measure and to compare hemodynamic parameters like diastolic and systolic blood pressure and heart rate. Also, extract (3.03-1000 µg/ml), fractions (3.03-1000 µg/ml) and pure isolated compounds (1.75-550 µM) were evaluated on isolated aortic rings contracted with noradrenaline (0.1 µM) to determine their vasorelaxant effect and extract-mode of action. RESULTS: Ethanolic extract of T. lucida lowered systolic and diastolic blood pressure on SHR rats without heart rate modification (P > 0.05). Moreover, the extract showed concentration-dependent relaxant effect in a partially endothelium-dependent manner (P < 0.05), through NO/cGMP system activation and calcium channel blockade. 6,7,8-trimethoxycoumarin (1), 6,7-dimethoxycoumarin (2), and 7-methoxycoumarin (3) from T. lucida are the main bioactive compounds of the extract and showed significant vasorelaxant activity. CONCLUSIONS: Results provide evidence and endorsed the antihypertensive properties attributed to T. lucida in traditional medicine, which is produced by vasorelaxant effect mainly through multitarget NO/cGMP system activation and calcium channel blockade. Coumarin derivatives 1, 2 and 3 are the responsible of the vasorelaxant activity.

Tracheal relaxation through calcium channel blockade of Achillea millefolium hexanic extract and its main bioactive compounds.

ETHNOPHARMACOLOGICAL IMPORTANCE: Achillea millefolium L. (Asteraceae) is used for the treatment of respiratory diseases, diabetes, and hypertension. AIM: to explore its tracheal relaxant properties and clarify its functional mechanism of action on smooth muscle cells, which allow us to propose it as a potential anti-asthmatic drug. MATERIAL AND METHODS: organic and hydro-alcoholic extracts from A. millefolium were obtained by macerations, then their relaxing effect on ex vivo isolated rat trachea rings was determined. Most active extract (hexanic extract, EHAm) was studied to determine its functional mechanism of action using synergic, antagonist and inhibitor agents related with the contraction/relaxation process of the smooth muscle. Also, EHAm was subjected to bio-guided fractionation by open-column chromatography (on silica gel) using cyclohexane-EtOAc (80:20) in an isocratic way to isolate main bioactive compounds. RESULTS: organic and hydro-alcoholic extracts showed relaxant effect in a concentration-response dependent manner, being EHAm the most active. The functional mechanism of action indicates that EHAm induced a non-competitive antagonism to the muscarinic receptors ; in addition, the NO/cGMP pathway is involved in the relaxation process of the tracheal smooth muscle. However, the most important mechanism of action showed by EHAm was related with the calcium channel blockade influx into the smooth muscle cells. On the other hand, epimeric sesquiterpene lactones leucodin (1) and achillin (2) were isolated and purified, which are responsible for the observed smooth muscle relaxant activity of the extract. CONCLUSION: hexanic extract of A. millefollium induced a significant relaxant effect on tracheal rat rings by calcium channel blockade and NO release.

Influence of Echeveria gibbiflora DC aqueous crude extract on mouse sperm energy metabolism and calcium-dependent channels.

ETHNOPHARMACOLOGY RELEVANCE: In traditional Mexican medicine, Echeveria gibbiflora DC has been used as a vaginal post-coital rinse to prevent pregnancy. The aqueous crude extract (OBACE) induces sperm immobilization/agglutination and a hypotonic-like effect, likely attributed to the high concentration of calcium bis-(hydrogen-1-malate) hexahydrate [Ca2+ (C4H5O5)2•6H2O]. Likewise, OBACE impedes the increase of [Ca2+]i during capacitation. AIM OF THE STUDY: Evaluate the effect of OBACE on sperm energy metabolism and the underlying mechanism of action on sperm-specific channel. MATERIAL AND METHODS: In vitro, we quantified the mouse sperm immobilization effect and the antifertility potential of OBACE. The energetic metabolism status was also evaluated by assessing the ATP levels, general mitochondrial activity, mitochondrial membrane potential, and enzymatic activity of three key enzymes of energy metabolism. Furthermore, the effect of the ion efflux of Cl- and K+, as well as the pHi, were investigated in order to elucidate which channel is suitable to perform an in silico study. RESULTS: Total and progressive motility notably decreased, as did fertility rates. ATP levels, mitochondrial activity and membrane potential were reduced. Furthermore, the activities of the three enzymes decreased. Neither Cl- or K+ channels activities were affected at low concentrations of OBACE; nevertheless, pHi did not alkalinize. Finally, an in silico analysis was performed between the Catsper channel and calcium bis-(hydrogen-1-malate) hexahydrate, which showed a possible blockade of this sperm cation channel. CONCLUSION: The results were useful to elucidate the effect of OBACE and to propose it as a future male contraceptive.

Searching for calcium antagonists for hypertension disease therapy from Moutan Cortex, using bioactivity integrated UHPLC-QTOF-MS.

INTRODUCTION: Calcium channel blockers (CCBs) are currently the most commonly used drugs for the treatment of hypertension. Moutan Cortex (MC), a traditional Chinese herb, has been found to have an anti-hypertensive effect. However, its potential mechanisms in the regulation of intracellular calcium concentration ([Ca2+ ]i ) remain poorly understood. OBJECTIVE: The main objective of this work was to identify the potential calcium antagonists from MC and study their molecular mechanisms. METHODS: Ultra-high performance liquid chromatography-quadrupole-time-of-fight-mass spectrometry (UHPLC-QTOF-MS) analysis combined with a dual-luciferase reporter assay was utilised to systematically screen the calcium antagonistic active ingredients in the methanol extract of MC. Additionally, the molecular mechanism of these compounds was further studied using live-cell imaging analysis with the calcium ion (Ca2+ ) probe dye fluo-4/AM to monitor changes in [Ca2+ ]i . RESULTS: Three monoterpenoids (paeoniflorin, benzoylpaeoniflorin and mudanpioside C), one phenolic acid (paeonol) and one gallotannin (1,2,3,4,6-O-pentagalloylglucose) were screened out as potential calcium antagonists in MC. Among them, the calcium antagonistic activity of benzoylpaeoniflorin, mudanpioside C and 1,2,3,4,6-O-pentagalloylglucose is first reported. Additionally, paeoniflorin, benzoylpaeoniflorin, mudanpioside C and paeonol can effectively block voltage-operated Ca2+ channels (VOCCs) to exert calcium antagonism, while 1,2,3,4,6-O-pentagalloylglucose plays a role in blocking inositol 1,4,5-trisphosphate receptors (IP3Rs). CONCLUSION: This work indicated that the anti-hypertensive efficacy of MC acted through multiple components selectively antagonising multiple cell signalling pathways to regulate [Ca2+ ]i . Furthermore, they could be considered as a reference standard for controlling the quality of Chinese medicinal materials.

Ex-vivo antihypertensive and calcium channel blocking activity of Androsace foliosa n-hexane leaves fraction on isolated rabbit aorta.

Hypertension is persistent elevation in blood pressure for 3-4 weeks. Estimated global prevalence of hypertension suggested that by the Year 2025 (29%) of adult worldwide are suffering from hypertension (1.56 billion). Hypertension complications are hemorrhage, atherosclerosis, renal artery stenosis, angina pectoris end organ damage, cardiomyopathy, myocardial infarction and retinopathy. Along with other drug class Calcium channel blocker are also used for the treatment of hypertension. In this study the possible action of the n-hexane leaves fraction of the Androsace foliosa on isolated rabbit aorta was examined. Antihypertensive activity was examined in the existence of standard agonist like phenylephrine and antagonist like Verapamil. Phenylephrine (PE 1µM) high K+ was used to steady the tissue materials. Additionally to observe the calcium channel blocking effect the tissues were treated with n-hexane segment of A. foliosa leaves. Aortic tissues were treated 4-5intervals with Ca+2- free preparation earlier to control calcium reaction curve (CRCs). Verapamil is utilized as standard calcium channel inhibitory mediator and is used as an antagonist. The Af. n-hexane leaves fraction completely inhibited the precontractions induced by Phenylephrine (1µM) and K+ (80 mM) precontractions, with EC50 standards of 1.0mM (0.3-1.0mg/mL) and 4.90mM (1-3mg/mL), respectively. Androsace foliosa n-hexane leaves fraction was tested for calcium channel inhibitory effect on isolated rabbit aorta. A. foliosa n- hexane leaves segment at the dosage of 1mg/mL block the calcium channel approximately (35±5%). Consequence indicates that A. foliosa n-hexane leaves segment block calcium channel in the similar manner as compared to the standard calcium channel blocker drug (verapamil).

Blockade of T-type calcium channels by 6-prenylnaringenin, a hop component, alleviates neuropathic and visceral pain in mice.

Since Cav3.2 T-type Ca2+ channels (T-channels) expressed in the primary afferents and CNS contribute to intractable pain, we explored T-channel-blocking components in distinct herbal extracts using a whole-cell patch-clamp technique in HEK293 cells stably expressing Cav3.2 or Cav3.1, and purified and identified sophoraflavanone G (SG) as an active compound from SOPHORAE RADIX (SR). Interestingly, hop-derived SG analogues, (2S)-6-prenylnaringenin (6-PNG) and (2S)-8-PNG, but not naringenin, also blocked T-channels; IC50 (µM) of SG, (2S)-6-PNG and (2S)-8-PNG was 0.68-0.75 for Cav3.2 and 0.99-1.41 for Cav3.1. (2S)-6-PNG and (2S)-8-PNG, but not SG, exhibited reversible inhibition. The racemic (2R/S)-6-PNG as well as (2S)-6-PNG potently blocked Cav3.2, but exhibited minor effect on high-voltage-activated Ca2+ channels and voltage-gated Na+ channels in differentiated NG108-15 cells. In mice, the mechanical allodynia following intraplantar (i.pl.) administration of an H2S donor was abolished by oral or i.p. SR extract and by i.pl. SG, (2S)-6-PNG or (2S)-8-PNG, but not naringenin. Intraperitoneal (2R/S)-6-PNG strongly suppressed visceral pain and spinal ERK phosphorylation following intracolonic administration of an H2S donor in mice. (2R/S)-6-PNG, administered i.pl. or i.p., suppressed the neuropathic allodynia induced by partial sciatic nerve ligation or oxaliplatin, an anti-cancer agent, in mice. (2R/S)-6-PNG had little or no effect on open-field behavior, motor performance or cardiovascular function in mice, and on the contractility of isolated rat aorta. (2R/S)-6-PNG, but not SG, was detectable in the brain after their i.p. administration in mice. Our data suggest that 6-PNG, a hop component, blocks T-channels, and alleviates neuropathic and visceral pain with little side effects.

Pharmacological validation of the folkloric uses of Cyperus rotundus L. in different ailments: An in vivo and in vitro research.

In vivo and in vitro research study was conducted on Cyperus rotundus to evaluate the sound mechanistic background in the treatment of gastrointestinal, bronchial and vascular disorders as well as in pain, emesis, pyrexia and bacterial infections. Results showed that crude extract of Cyperus rotundus (Cr.Cr) exhibited the dose-dependent spasmolytic effect in rabbit jejunum by inhibiting the spontaneous and K+ (80 mM)-induced contractions. Pretreatment of tissue with Cr. Cr caused the rightward shift of calcium concentration response curves, similar to verapamil. Cr. Cr also caused the relaxation of K+(80 mM)- and carbachol (1 µM)-induced contractions of trachea preparations, similar to that of verapamil. Moreover, Cr. Cr also relaxed the contraction induced by the K+ (80 mM) and phenylephrine (1 µM) of aorta preparations. Data show that C. rotundus possess the spasmolytic, bronchodilator and vasodilator activities possibly through calcium channels blockade; validating its folkloric use in diarrhea, dyspepsia, bronchitis, asthma and hypertension in addition to antibacterial, antiemetic, antipyretic and analgesic activities.

Spasmolytic activity of Aquilariae Lignum Resinatum extract on gastrointestinal motility involves muscarinic receptors, calcium channels and NO release.

CONTEXT: Aquilariae Lignum Resinatum (ALR), the dry rhizome of Aquilaria agallocha R. (Thymelaeaeeae), has been widely used to treat emesis, stomachache and gastrointestinal dysfunction. OBJECTIVE: This study evaluates the effects of ALR methanol extract on gastrointestinal motility (GIM) and possible mechanisms of the action involved. MATERIALS AND METHODS: In vivo, the study evaluated the effects of ALR (200-800 mg/kg) on gastric emptying and small intestinal motility in normal and neostigmine-induced adult KM mice. The in vitro effects of ALR (0.2-1.6 mg/mL) on GIM were performed on isolated jejunum of Wistar rats, pretreated with acetylcholine (ACh), KCl, CaCl2, and pre-incubation with l-NAME (a selective inhibitor of the nitric oxide synthase). RESULTS: In vivo, ALR (800 mg/kg) decreased gastric emptying (70.82 ± 9.81%, p < 0.01, compared with neostigmine group 91.40 ± 7.81%), small intestinal transit (42.82 ± 3.82%, p < 0.01, compared with neostigmine group 85.53 ± 5.57%). In vitro, ALR concentration dependently decreased the contractions induced by ACh (10-5 M) and KCl (60 mM) with respective EC50 values of 0.35 and 0.32 mg/mL. The Ca2+ concentration-response curves were shifted by ALR to the right, similar to that caused by verapamil (the positive). The spasmolytic activity of ALR was inhibited by pre-incubation with l-NAME. DISCUSSION AND CONCLUSIONS: ALR played a spasmolytic role in GIM, which is probably mediated through inhibition of muscarinic receptors, blockade of Ca2+ influx and NO release. This is the first study presenting a comprehensive description of the effects of ALR on GIM.

Patchouli alcohol isolated from Pogostemon cablin mediates endothelium-independent vasorelaxation by blockade of Ca2+ channels in rat isolated thoracic aorta.

ETHNOPHARMACOLOGICAL RELEVANCE: The aerial parts of Pogostemon cablin (Blanco) Benth. for the treatment of cardiodynia have been documented in Mingyi Bielu of late Han Dynasty, in addition to that the Ca2+ antagonized activities of P. cablin and its critically pharmacological ingredient patchouli alcohol (PA) were reported previously. AIM OF THE STUDY: To investigate the relaxant effects of PA on rat isolated thoracic aortas and further explore its potential mechanisms of actions. MATERIALS AND METHODS: The aortas with endothelium and without endothelium were prepared and suspended in the organ bath for isometric tension recordings. The responses to accumulative concentrations of PA in endothelium-intact (E + ) aortas with basal tension and in different treated aortas pre-contracted with potassium chloride (KCl) or phenylephrine (PHE) were observed; the effects of L-NAME and indomethacin in aortas with intact endothelium, and of L-NAME, propranolol, tetraethtylamine (TEA), 4-aminopyridine (4-AP), barium chloride (BaCl2), glyburide in aortas with endothelial denudation on PA-produced vasorelaxation were assessed; the influences of PA on extracellular Ca2+ influx and intracellular Ca2+ release were measured in Ca2+-free medium. Finally, the abilities of PA to inhibit KCl- and PHE-induced contractions were compared to that of verapamil in E- aortas. RESULTS: PA produced vasorelaxant effects in KCl- and PHE-precontracted E + aortas in a concentration-dependent manner, which had no statistically different from that in KCl- and PHE-precontracted E- aortas. PA (10 µM) significantly reduced KCl-induced contractions while PHE-induced contractions were significantly reduced by 100 µM of PA instead of 10 µM and 30 µM in aortas with endothelium. Pre-incubation of E + aortas with L-NAME as well as indomethacin and of E- aortas with L-NAME, propranolol, TEA, 4-AP, BaCl2 and glyburide had no obvious effects on vasorelaxation of PA. In endothelium-removed aortas around Ca2+-free solution, PA remarkably lowered the contractions stimulated with Ca2+ and PHE, and application of ruthenium red and heparin further enhanced the abilities of PA to reduce PHE-caused contractions. In aortas without endothelium, 100 µM of PA markedly attenuated KCl-induced contractions but not affect PHE-induced contractions. Verapamil at the equal dose markedly attenuated KCl- and PHE-induced contractions, and the inhibitory effects on KCl-induced contractions were more forceful than that on PHE-induced contractions. In combined usage, the inhibitory effects on the contractions elicited by KCl were evidently weaker than that of verapamil alone and indifferently stronger than that of PA alone, and the inhibitory effects on the contractions elicited by PHE were evidently weaker than that of single verapamil but stronger than that of single PA. CONCLUSION: PA may act as a Ca2+ antagonist to exert an intensively vasorelaxant effects through endothelium-independent pathway, and its mechanisms underlying the vasoactivities seem to be associated with the blockade of extracellular Ca2+ influx through VDCCs and ROCCs in vascular smooth muscle cells (VSMCs) membrane and intracellular Ca2+ releases through IP3R- and RYR-mediated Ca2+ channels in sarcolemma.

Airways and vascular smooth muscles relaxant activities of Gaultheria trichophylla.

The aim of this experimental work was to explore the potential pharmacological activities of Gaultheria trichophylla Royle in hyperactive respiratory and vascular conditions. Gaultheria trichophylla was extracted with solvents, phytochemical detection tests were performed, and rabbit trachea and aorta strips were used to evaluate its effects on airways and vascular smooth muscles. Qualitative phytochemical tests showed the presence of flavonoids, alkaloids, anthraquinones, saponins, terpenoids, and condensed tannins. The methanol extract caused inhibition (EC50 values of 3.12 mg/mL) of carbachol (1 µM) and partial relaxation of K+(80 mM) caused contractions in tracheal strips. The chloroform extract was comparatively more potent against carbachol than K+ induced contraction with EC50 values of 0.64 and 2.26 mg/mL, respectively. However, the n-hexane extract showed more potency against K+ than cabachol induced contractions, as in case with verapamil, with EC50 values of 0.61 and 6.58 mg/mL, respectively. In isolated prepared trachea, the extracts displaced the carbachol concentration response curves and maximum response was suppressed. In rabbit aorta preparations, methanol and n-hexane extracts partially relaxed phenylephrine (1 µM) and K+ induced vasoconstrictions. However, the chloroform extract inhibited phenylephrine induced contractions and exhibited a vasoconstrictor effect at lower concentrations and a relaxant effect at higher concentrations against K+ precontractions. The data indicates that, in addition to others, the extracts of G .trichophylla possess verapamil like Ca++ channel blocking components which explain the possible role of this plant in respiratory and vascular conditions.

Antispasmodic and bronchorelaxant activities of Salsola imbricata are mediated through dual Ca+2 antagonistic and ß-adrenergic agonistic effects.

CONTEXT: Salsola imbricata Forssk. (Chenopodiaceae) has folkloric repute for the treatment of various gastrointestinal and respiratory ailments. OBJECTIVE: The present study investigates spasmolytic and bronchorelaxant effects of S. imbricata. MATERIALS AND METHODS: The crude aqueous-ethanol extract of the aerial parts of S. imbricata and its fractions, in cumulative concentrations (0.01-10 mg/mL), were tested on contractions of isolated rabbit jejunum and tracheal preparations. Furthermore, concentration response curves (CRCs) of Ca+2 and carbachol were constructed in the absence and presence of the extract. Standard organ bath methods were used. RESULTS: The crude extract relaxed spontaneous, K+ (80 mM) and carbachol (1 µM)-induced contractions in jejunum preparations with respective EC50 values of 0.40 (0.35-0.46), 0.69 (0.60-0.79) and 0.66 (0.57-0.75) mg/mL. It shifted Ca+2 CRCs rightward in nonparallel manner. In isolated tracheal preparations, the crude extract caused relaxation of K+ (80 mM) and carbachol (1 µM)-induced contractions with EC50 values of 0.86 (0.75-0.98) and 0.74 (0.66-0.84) mg/mL, respectively. It displaced carbachol CRCs rightward with suppression of maximal response. In both tissues, pretreatment with propranolol (1 µM) caused rightward shift in inhibitory CRCs of the extract against carbachol-induced contractions. The ethyl acetate fraction was found more potent in relaxing smooth muscle contractions than the parent extract and its aqueous fraction. DISCUSSION AND CONCLUSION: The results suggest that the spasmolytic and bronchorelaxant activities of S. imbricata are related to Ca+2 antagonistic and ß-adrenergic agonistic effects, thus justifying some of the traditional uses of the plant.

Characterization of Vasorelaxant Principles from the Needles of Pinus morrisonicola Hayata.

Pinus morrisonicola Hayata, usually called Taiwan five-leaf pine (5LP), is an endemic species in Taiwan and is traditionally used to relieve hypertension symptoms and improve cardiovascular function. In this study, the needle extract of 5LP was fractionated and analyzed by LC/MS/MS to search for possible antihypertensive candidates. In addition, bioassay-guided purification of the bioactive components was performed by Ca2+ fluorescent signal (Fluo 4-AM) assays. Two dihydrobenzofuran lignans, pinumorrisonide A (1) and icariside E4 (2), and one acylated flavonoid glycoside, kaempferol 3-O-α-(6‴-p-coumaroylglucosyl-ß-1,4-rhamnoside) (3) were characterized from the active fractions. The structure of a new compound 1 was established on the basis of 2D NMR spectroscopic and mass spectrometric analyses, and the known compounds 2 and 3 were identified by comparison of their physical and spectroscopic data with those reported in the literature. The purified compounds 1-3 exhibited significant inhibition of Ca2+ fluorescence with IC50 values of 0.71, 0.36, and 0.20 mM, respectively. A mechanism study showed that these compounds showed vasorelaxant effects by blocking the voltage-operated Ca2+ channel (VOCC) and inhibiting Ca2+ influx to the cytoplasmic. These results suggested that 5LP and the three characterized components could be promising antihypertensive candidates for the use as VOCC blockers.

Anti-cholinergic and Ca2+-antagonist mechanisms explain the pharmacological basis for folkloric use of Sisymbrium irio Linn. in gastrointestinal, airways and vascular system ailments.

ETHNOPHARMACOLOGICAL RELEVANCE: Seeds of Sisymbrium irio Linn has been used traditionally in different regions of Pakistan for the treatment of gastrointestinal, airways and vascular system ailments. To insight the pharmacological basis, in vitro study was conducted in order to validate its folkloric uses. MATERIAL AND METHODS: 70% aqueous-methanolic extract of seeds from S. irio (Si.MEs) was tested on isolated rabbit aorta, jejunum and trachea strip hanged in tissue bath having physiological solutions aerated with carbogen and their responses were measured and recorded via Power Lab. RESULTS: The Si.MEs exhibited the transient spasmogenic effect (0.01-1.0mg/mL) on spontaneous jejunum contractions, followed by the spasmolytic effect. The addition of atropine resulted in blocking in spasmogenic effect while the spasmolytic effect was originated, suggesting the presence of an antimuscarinic effect. Likewise verapamil, Si.MEs (0.03-5mg/mL) repressed the high concentration K+(80mM)-induced contraction and also drifted the Ca2+ concentration-response curves toward right (0.3-3.0mg/mL), possibly signifying the Ca2+ channel blockade. Furthermore, Si.MEs exhibited nonspecific relaxant effect on carbachol (1µM)- and high concentration K+(80mM)-induced tracheal contractions in a way comparable to dicyclomine, suggesting the coexistence of Ca2+-antagonistic and/or antimuscarinic properties. Additionally, Si.MEs also relaxed the phenylephrine(1µM)- and high concentration K+(80mM)-induced aortic contraction (0.01-3mg/mL), suggesting blockade of Ca2+ channel. Moreover, oral administration of Si.MEs, as high as 6g per kg, did not produce lethality among the treated groups of mice. CONCLUSIONS: Aqueous-methanolic extract of seeds from S. irio (Si.MEs) exhibited the bronchodilator and gut modulator (spasmogenic and spasmolytic) activities, probably through dual blockade of muscarinic receptors and Ca2+ channels, whereas, vasodilator effect may be due to Ca2+ channels blockade.

Selective tools for the solid-phase extraction of Ochratoxin A from various complex samples: immunosorbents, oligosorbents, and molecularly imprinted polymers.

The evolution of instrumentation in terms of separation and detection has allowed a real improvement of the sensitivity and the analysis time. However, the analysis of ultra-traces of toxins such as ochratoxin A (OTA) from complex samples (foodstuffs, biological fluids…) still requires a step of purification and of preconcentration before chromatographic determination. In this context, extraction sorbents leading to a molecular recognition mechanism appear as powerful tools for the selective extraction of OTA and of its structural analogs in order to obtain more reliable and sensitive quantitative analyses of these compounds in complex media. Indeed, immunosorbents and oligosorbents that are based on the use of immobilized antibodies and of aptamers, respectively, and that are specific to OTA allow its selective clean-up from complex samples with high enrichment factors. Similar molecular recognition mechanisms can also be obtained by developing molecularly imprinted polymers, the synthesis of which leads to the formation of cavities that are specific to OTA, thus mimicking the recognition site of the biomolecules. Therefore, the principle, the advantages, the limits of these different types of extraction tools, and their complementary behaviors will be presented. The introduction of these selective tools in miniaturized devices will also be discussed.

Spasmolytic and Ca++ Channel Blocking Potential of Nepetolide: Isolated from Nepeta suavis.

Nepeta suavis is used in traditional medicine for treatment of abdominal spasm (colic). The tricyclic clerodane type diterpene, nepetolide, isolated for the first time from Nepeta suavis, was evaluated for Ca++ antagonist and antispasmodic activities. When studied in isolated rabbit jejunum, nepetolide caused concentration-dependent (0.03-100 µM) relaxation of spontaneous and high K+ (80 mM)-induced contractions, like that caused by verapamil, indicating that nepetolide exhibits spasmolytic activity, possibly mediated through Ca++ channel blocking action, which provides scientific explanation for the medicinal application of Nepeta suavis as an antispasmodic agent.

Antihypertensive activity of 80% methanol seed extract of Calpurnia aurea (Ait.) Benth. subsp. aurea (Fabaceae) is mediated through calcium antagonism induced vasodilation.

ETHNOPHARMACOLOGICAL RELEVANCE: Calpurnia aurea (Ait.) Benth. subsp. aurea (CASA) (Fabaceae) seeds are used to treat hypertension in Ethiopian folklore medicine, particularly by Shinasha, Agew-awi and Amhara people in northwest Ethiopia. However, the claim has so far not been substantiated scientifically. AIM OF THE STUDY: The study was conducted to evaluate the antihypertensive activity of 80% methanol extract of CASA in animal model of hypertension as well as its vasorelaxant effect and possible underlying mechanisms in isolated guinea pig aorta. MATERIAL AND METHODS: Hypotensive and antihypertensive effect of CASA extract was determined in vivo through the intravenous (iv) route in normotensive and hypertensive anesthetized rats using 2-kidney-1-clip (2K1C) rat model. Ex vivo, guinea pig thoracic aortic rings were isolated and suspended in organ bath, and the vasodepressor effects as well as the mechanism of action of the extract were studied by means of isometric tension recording experiments. RESULTS: The blood pressure fell dose-dependently and significantly in renal hypertensive and normotensive rats following i.v. administration, suggesting that the hydroalcoholic extract possesses hypotensive and antihypertensive effects. The extract also caused a dose-dependent relaxation of aorta pre-contracted with KCl at a concentration of 5-250mg/L, with a maximum relaxation of 92.1% achieved at 250mg/L. The relaxation mechanism was found to be independent of the muscarinic receptors, histamine receptors, ATP dependent K(+) channels, cyclooxygenase enzymes, cGMP/NO pathway and the endothelium system. The extract caused rightward shift of the Ca(++) dose-response curves, similar to that caused by verapamil, indicating that it produced vasorelaxation by inhibiting extracellular Ca(2+) influx. CONCLUSIONS: The findings demonstrate that the plant is endowed with antihypertensive effect, providing evidence for its traditional use. The effect may be, at least in part, due to dilation of blood vessels through blockage of Ca(2+) channels.