Chinese Caterpillar Mushroom, Ophiocordyceps sinensis (Ascomycota), Cold-Water Extract Relaxes the Rat Isolated Bladder.

Ophiocordyceps sinensis is a popular medicinal mushroom used for various health conditions, including alleviation of frequent urination, which is a major symptom of overactive bladder (OAB) syndrome. This study aimed to investigate the effect of O. sinensis (OCS02 cultivar) cold-water extract (CWE) against bladder contractility using the organ bath technique. The bladder was removed from male Sprague-Dawley rats and cut into longitudinal strips of 2 mm × 8 mm. In some experiments, the urothelium was removed to study its role in CWE-induced responses. CWE elicited a biphasic response consisting of an immediate, transient contraction that was followed by a sustained relaxation in bladder strips precontracted with carbachol, a muscarinic agonist. Removal of urothelium did not alter the magnitude of the contractile response but significantly attenuated the relaxation response. In the presence of L-NAME (nitric oxide synthase inhibitor) and sodium nitroprusside (nitric oxide donor), CWE-induced transient contraction was enhanced, whereas the relaxation response was significantly reduced. Following preincubation with CWE, the amplitude and the frequency of the spontaneous myogenic contractions induced by carbachol, as well as the contractile response toward calcium, were significantly suppressed. Findings from this study show that the urothelium plays a role in the relaxant effect of CWE. Its mechanisms of action include the regulation of nitric oxide and inhibition of calcium influx.

Quercetin affects uterine smooth muscle contractile activity in gilts.

Quercetin is a polyphenolic flavonoid occurring in leaves, stems, flowers and fruits of many plants. In traditional Chinese medicine, it is used as a natural therapeutic agent with a broad spectrum of activities (antioxidant, neuroprotective, anti-inflammatory, anticancer, antibacterial and antiviral). Moreover, quercetin affects function of the reproductive tract, however the knowledge of this activity is still fragmentary. Therefore, this study aimed to determine the influence of quercetin on the contractile activity of the porcine myometrium collected from immature (n = 6), cyclic (n = 6) and early pregnant (n = 6) gilts. Strips of the myometrium (comprising longitudinal and circular layer) were resected from the middle part of the uterine horns and the isometric contractions were recorded. After 60-90 min of preincubation, the strips were stimulated with quercetin in increasing (10-13-10-1 M) concentrations and the changes in the tension amplitude and frequency of contractions were measured. Quercetin decreased (P<0.01-0.001) the amplitude of contractions at concentrations 10-11-10-1 M and 10-10-10-1 M in cyclic and early pregnant groups, respectively. The frequency of contractions decreased in all groups but was the highest (at concentrations 10-11-10-1 M; P<0.05-0.001) in the cyclic group and the lowest (at concentrations 10-5-10-1 M; P<0.01) in the immature group. The tension decreased only in the cyclic group after quercetin administration in high concentrations (10-6-10-1 M; P<0.05-0.01). The results indicate that quercetin causes relaxation of the porcine uterine smooth muscle but this activity is strongly related to the physiological status of the gilts.

Receptor-mediated biological effects of extracts obtained from three Asplenium species.

This study reports the effects of aqueous extracts obtained from three fern species of Bulgarian origin: Asplenium ceterach L., Asplenium scolopendrium L., and Asplenium trichomanes L. on the contractility and bioelectrogenesis of rat gastric smooth muscle tissues. In the concentration range 0.015-0.150 mg/mL the three extracts contracted smooth muscle tissues in a concentration-dependent manner. The contractions caused by A. ceterach L. and A. scolopendrium L. extracts (0.150 mg/mL) were reduced by ketanserin (5 × 10-7 and 5 × 10-6 mol/L), an antagonist of serotonin 5-HT2 receptor. The contraction evoked by A. trichomanes L. (0.150 mg/mL) was significantly reduced by 1 × 10-6 mol/L atropine, an antagonist of muscarinic receptors, and turned into relaxation against the background of 3 × 10-7 mol/L galantamine. After combined pretreatment with galantamine and l-arginine (5 × 10-4 mol/L), this relaxation become more pronounced. The study demonstrates that constituents of A. ceterach L. and A. scolopendrium L. extracts act as agonists of 5-HT2 receptors and cause contraction by activating serotonergic signaling system. A. trichomanes L.-induced reaction is an additive result of two opposite-in-character effects. The dominant contraction is initiated by inhibition of acetylcholinesterase activity. The relaxation develops with pre-inhibited acetylcholinesterase, it is significantly potentiated by l-arginine, and therefore associated with nitrergic signaling pathway.

In Vitro Contraction of Isolated Cauda Epididymal Duct Smooth Muscle as a Complimentary Approach to Physiological, Pathological, Toxicological, and Pharmacological Studies on Epididymal Function.

Contraction of cauda epididymal duct (CE) smooth muscle is one of the very first events of the seminal emission phase of ejaculation. The contraction of CE smooth muscle is governed by a complex interaction of hormones, autacoids, and by the neurotransmitters released from the epididymal intramural nerve endings, and any impairment in the CE smooth muscle contraction has the potential to impair male fertility. Apart the obvious pathophysiological and toxicological importance of CE smooth muscle contraction, modulation of CE contraction has pharmaceutical interest offering a druggable target to development of drugs to improve/impair male fertility. The in vitro contraction experiments constitute a valuable approach to an in-depth evaluation of functional and molecular changes resulting from pathologies or drug exposure. Therefore, this chapter consists in a description of in vitro pharmacological reactivity contractility of the epididymal duct in a controlled medium, maintained at 30 °C of temperature and continuously bubbled with 95% O2 and 5% CO2 to obtain cumulative concentration-response curves that has been fundamental to some of our investigations on epididymal physiology, toxicology, and pharmacology.

Identification and Characterization of a Novel Large-Conductance Calcium-Activated Potassium Channel Activator, CTIBD, and Its Relaxation Effect on Urinary Bladder Smooth Muscle.

The large-conductance calcium-activated potassium channel (BKCa channel) is expressed on various tissues and is involved in smooth muscle relaxation. The channel is highly expressed on urinary bladder smooth muscle cells and regulates the repolarization phase of the spontaneous action potentials that control muscle contraction. To discover novel chemical activators of the BKCa channel, we screened a chemical library containing 8364 chemical compounds using a cell-based fluorescence assay. A chemical compound containing an isoxazolyl benzene skeleton (compound 1) was identified as a potent activator of the BKCa channel and was structurally optimized through a structure-activity relationship study to obtain 4-(4-(4-chlorophenyl)-3-(trifluoromethyl)isoxazol-5-yl)benzene-1,3-diol (CTIBD). When CTIBD was applied to the treated extracellular side of the channel, the conductance-voltage relationship of the channel shifted toward a negative value, and the maximum conductance increased in a concentration-dependent manner. CTIBD altered the gating kinetics of the channel by dramatically slowing channel closing without effecting channel opening. The effects of CTIBD on bladder muscle relaxation and micturition function were tested in rat tissue and in vivo. CTIBD concentration-dependently reduced acetylcholine-induced contraction of urinary bladder smooth muscle strips. In an acetic acid-induced overactive bladder (OAB) model, intraperitoneal injection of 20 mg/kg CTIBD effectively restored frequent voiding contraction and lowered voiding volume without affecting other bladder function parameters. Thus, our results indicate that CTIBD and its derivatives are novel chemical activators of the bladder BKCa channel and potential candidates for OAB therapeutics. SIGNIFICANCE STATEMENT: The novel BKCa channel activator CTIBD was identified and characterized in this study. CTIBD directly activates the BKCa channel and relaxes urinary bladder smooth muscle of rat, so CTIBD can be a potential candidate for overactive bladder therapeutics.

Pharmacological screening of the phenolic compound caffeic acid using rat aorta, uterus and ileum smooth muscle.

Caffeic acid is a phenolic compound widely found in commonly consumed foods such as pears, apples and coffee, and is pharmacologically known for its antioxidant, anti-inflammatory and anti-asthmatic properties. However, its relaxant activity in the aorta, uterus and ileum smooth muscle has not been investigated. This study aimed to comparatively evaluate the effect of caffeic acid on smooth muscle from different organs (aorta, uterus and ileum), and the contractions of this different organ were induced by different agonists. The organ bath technique was used, where the organs were placed in different cuvettes with 10 mL of Tyrode solution for 1 h to stabilize, then, myometrial, intestinal strip and aortic ring contractions were evoked using different contractile agonists (KCl 60 mM, PHE 0.1 µM, OT 10-2 IU/mL, CCh 10-6 M and BaCl2 0.1-30 mM); increasing concentrations of caffeic acid (0.03-7 mM) were administered in the experimental preparations. In the presence of KCl (60 mM), caffeic acid caused relaxations with the following EC50 values: 2.7 ± 0.26 mM/mL (aorta), 5.7 ± 0.71 mM/mL (uterus) and 2.1 ± 0.39 mM/mL (ileum). When in the presence of different agonists, PHE (0.1 µM) for the aorta, OT (10-2 IU/mL) for the uterus and CCh (10-6 M) for the ileum, caffeic acid caused relaxations with EC50 values of: 2.7 ± 0.31 mM/mL; 2.2 ± 0.34 mM/mL and 2.0 ± 0.28 mM/mL, respectively. The inhibitory effect of caffeic acid on serotonergic (aorta and uterus) and muscarinic receptors (uterus and ileum), as well as its possible involvement with L-type Ca2+ channels, was also observed. This study reports the pharmacological characterization of caffeic acid on smooth muscle from different organs, for which caffeic acid was more potent in the ileum. A diverse understanding of its performance as a possible therapeutic product is attributed to its relaxant effect.

Curcumin analogs (B2BrBC and C66) supplementation attenuates airway hyperreactivity and promote airway relaxation in neonatal rats exposed to hyperoxia.

BACKGROUND: This study was undertaken to test the hypothesis that the newly synthesized curcuminoids B2BrBC and C66 supplementation will overcome hyperoxia-induced tracheal hyperreactivity and impairment of relaxation of tracheal smooth muscle (TSM). MATERIALS AND METHODS: Rat pups (P5) were exposed to hyperoxia (>95% O2 ) or normoxia for 7 days. At P12, tracheal cylinders were used to study in vitro contractile responses induced by methacholine (10-8 -10-4 M) or relaxation induced by electrical field stimulation (5-60 V) in the presence/absence of B2BrBC or C66, or to study the direct relaxant effects elicited by both analogs. RESULTS: Hyperoxia significantly increased contraction and decreased relaxation of TSM compared to normoxia controls. Presence of B2BrBC or C66 normalized both contractile and relaxant responses altered by hyperoxia. Both, curcuminoids directly induced dose-dependent relaxation of preconstricted TSM. Supplementation of hyperoxic animals with B2BrBC or C66, significantly increased catalase activity. Lung TNF-α was significantly increased in hyperoxia-exposed animals. Both curcumin analogs attenuated increases in TNF-α in hyperoxic animals. CONCLUSION: We show that B2BrBC and C66 provide protection against adverse contractility and relaxant effect of hyperoxia on TSM, and whole lung inflammation. Both analogs induced direct relaxation of TSM. Through restoration of catalase activity in hyperoxia, we speculate that analogs are protective against hyperoxia-induced tracheal hyperreactivity by augmenting H2 O2 catabolism. Neonatal hyperoxia induces increased tracheal contractility, attenuates tracheal relaxation, diminishes lung antioxidant capacity, and increases lung inflammation, while monocarbonyl CUR analogs were protective of these adverse effects of hyperoxia. Analogs may be promising new therapies for neonatal hyperoxic airway and lung disease.

Acanthopanax senticosus Root Extract Exerts Dual Action on Mouse Ileal Smooth Muscle Function, Leading to Modulation of Gastrointestinal Motility.

Diarrhea is often caused by changes in lifestyle, stress, or side effects of drugs. Acanthopanax senticosus root extract (ASRE) has long been used as a functional food remedy with anti-fatigue, neuroprotective, and immunomodulatory activities. However, it is unclear whether ASRE has beneficial effects on gastrointestinal (GI) motility. Therefore, we first investigated whether ASRE directly affects contractile functions of the isolated mouse ileum, and then assessed its effects on GI transit of a charcoal meal in normal mice and a carbachol (CCh)-induced diarrhea mouse model. ASRE caused contraction of the isolated mouse ileum and the maximum contraction was approximately half of that induced by acetylcholine (ACh) administration. In the presence of atropine, this ASRE-induced contraction disappeared, while relaxation responses were observed. However, ASRE reduced potassium chloride- and ACh-induced contractions, and the inhibitory effect was not counteracted by a ß-blocker. Administration of a nitric oxide synthase inhibitor or potassium channel blockers did not affect the ASRE-induced relaxation. Oral administration of ASRE for 1 and 4 d reduced the increased GI transit in CCh-treated but did not affect the GI transit of normal mice. These results indicate that ASRE exhibited dual effects of contraction via muscarinic receptors and direct relaxation on mouse ileal function, and its relaxant effect could be useful in treating diarrhea symptoms, resulting in an increase in the parasympathetic nerve activities.

A 12-Week-Long Intake of Bilberry Extract (Vaccinium myrtillus L.) Improved Objective Findings of Ciliary Muscle Contraction of the Eye: A Randomized, Double-Blind, Placebo-Controlled, Parallel-Group Comparison Trial.

A 12-week-long randomized, double-blind, placebo-controlled, parallel-group comparison trial was conducted to determine the effects of long-term standardized bilberry extract (SBE) intake on tonic accommodation of ciliary muscle caused by visual display terminal (VDT) tasks. This study was compliant with the accordance with CONSORT 2010 statement. A total of 109 healthy adult men and women aged 20-60 years were recruited and randomized into SBE and placebo groups. The subjects in the SBE and placebo groups were administered 240 mg of SBE and placebo, respectively, once daily for 12 weeks. Tests were performed before and after VDT tasks at week 0, 4, 8, and 12; high-frequency component (HFC)-1 value was the evaluation outcome. Results showed that post-load HFC-1 values at weeks 8 and 12 were significantly improved in the SBE group than in the placebo group (p = 0.014 and 0.017, respectively). Regarding the difference between before and after the task load (ΔHFC-1), the values were significantly better in the SBE group than in the placebo group at week 4 and 12 (p = 0.018 and 0.049, respectively). This study shows that oral consumption of 240 mg SBE extract for 12 weeks relieves the tonic accommodation of the ciliary muscle caused by VDT tasks and near-vision tasks.

Study of Magnesium Formulations on Intestinal Cells to Influence Myometrium Cell Relaxation.

Background: Magnesium is involved in a wide variety of physiological processes including direct relaxation of smooth muscle. A magnesium imbalance can be considered the primary cause or consequence of many pathophysiological conditions. The smooth muscle tissue of the uterus, i.e., the myometrium, undergoes numerous physiological changes during life, fundamental for uterine activities, and it receives proven benefits from magnesium supplementation. However, magnesium supplements have poor absorption and bioavailability. Furthermore, no data are available on the direct interaction between intestinal absorption of magnesium and relaxation of the myometrium. Methods: Permeability in human intestinal cells (Caco-2 cells) and direct effects on myometrial cells (PHM1-41 cells) of two different forms of magnesium, i.e., sucrosomial and bisglycinate, were studied in order to verify the magnesium capacity of modulate contractility. Cell viability, reactive oxygen species (ROS) and nitric oxide (NO) production, magnesium concentration, contractility, and pathways involved were analyzed. Results: Data showed a better influence of buffered chelate bisglycinate on intestinal permeability and myometrial relaxation over time with a maximum effect at 3 h and greater availability compared to the sucrosomial form. Conclusions: Magnesium-buffered bisglycinate chelate showed better intestinal absorption and myometrial contraction, indicating a better chance of effectiveness in human applications.

Characterization of ethyl acetate and n-butanol extracts of Cymbopogon schoenanthus and Helianthemum lippii and their effect on the smooth muscle of the rat distal colon.

ETHNOPHARMACOLOGY RELEVANCE: Cymbopogon schoenanthus (C. schoenanthus) and Helianthemum lippii (H. lippii) are Saharan species found in the South West of Algeria, in the region of Bechar. Both plants are used in traditional medicine to treat gastrointestinal disorders. OBJECTIVE: The aim of our study was to characterize the composition of the ethyl acetate (EtOAc) and n-Butanol (n-BuOH) extracts of C. schoenanthus and H. lippii, and to elucidate and compare their effect on the reactivity of the rat distal colon. MAIN METHODS: The plants were macerated in a hydroalcoholic solution. After concentration, the aqueous solutions of the residues were submitted to liquid-liquid extractions to obtain EtOAc and n-BuOH extracts. The phenolic and flavonoid content of the extracts was determined by high performance liquid chromatography coupled with mass spectrometry with a time of flight analyzer (HPLC-TOF/MS). The effect of the extracts was tested on the rat distal colon, namely on the basal tone and on KCl- and Ach-induced precontracted preparations. RESULTS: HPLC-TOF/MS identified 32 phenols and flavonoids in the extracts. The four extracts relaxed the rat distal colon, the effect being noticed on the basal tone and on the KCl- and Ach-induced precontractions. The EtOAc and the n-BuOH extracts of H. lippii decreased the basal tone of the rat distal colon more markedly than the correspondent extracts of C. schoenanthus. Moreover, the n-BuOH extract of C. schoenanthus decreased the basal tone more markedly than the EtOAc extract of this plant but there was no difference between extracts of H. lippii. The EtOAc extracts of both C. schoenanthus and H. lippii totally reverted both the KCl- and the Ach-induced precontraction of the rat distal colon. However, the n-BuOH extracts of the two plants reverted the Ach-precontracted colon but not the colon that has been precontracted with KCl. CONCLUSION: Extracts of H. lippii contain a higher level of phenols compared to the extracts of C. schoenanthus. All extracts of C. schoenanthus and H. lippii caused marked relaxation of the isolated rat distal colon, either when applied directly or when tested over KCl- and Ach-induced precontraction. These results give support to the use of C. shoenanthus and H. lippii in traditional medicine, namely for gastrointestinal diseases.

The contribution of beta-2 adrenergic, muscarinic and histamine (H1) receptors, calcium and potassium channels and cyclooxygenase pathway in the relaxant effect of Allium cepa L. on the tracheal smooth muscle.

ETHNOPHARMACOLOGICAL RELEVANCE: There are report regarding therapeutic effects for Allium cepa L. (A. cepa) in Iranian traditional medicine and the plant has showed anti-inflammatory, anti-allergic, anti-hyperglycemic, antioxidant, anti-cancer, anti-hypertension, anti-hypercholesterolemia and anti-asthmatic activities in previous studies. AIM OF THE STUDY: In this study, the contribution of ß2 adrenergic, muscarinic and histamine (H1) receptors, calcium and potassium channels, and cyclooxygenase pathway in the relaxant effect of A. cepa extract on tracheal smooth muscle (TSM) was assessed. MATERIALS AND METHODS: TSM was contracted by KCl (60 mM) or methacholine (10 µM) for 5 min and cumulative concentrations of A. cepa extract (2, 4, 8, 16, 32 and 64 mg/ml) were added to organ bath every 5 min. Theophylline (0.2, 0.4, 0.6 and 0.8 mM) as positive control, and saline (1 ml) as negative control were also examined in non-incubated tissues. The relaxant effect of A. cepa extract was examined on non-incubated and incubated TSM with propranolol, chlorpheniramine, diltiazem, atropine, glibenclamide and indomethacin. RESULTS: A. cepa showed concentration-dependent relaxant effects on non-incubated TSM contracted by KCl (60 mM) or methacholine (10 µM), (P < 0.01 to p < 0.001). There was no significant difference in the relaxant effects of A. cepa between non-incubated and incubated tissues with glibenclamide, atropine, chlorpheniramine and indomethacin. The plant extract showed significant lower relaxant effects in incubated TSM with propranolol and diltiazem compared to non-incubated tissues. EC50 values of A. cepa extract in incubated TSM with propranolol and diltiazem were significantly lower than non-incubated tissues (p < 0.001 and p < 0.05, respectively). The relaxant effects of different concentrations of the extract of A. cepa were not significantly different with those of theophylline. The concentrations of A. cepa extract and theophylline were significant correlated with their relaxant effects (p < 0.05 to p < 0.001). In incubated TSM with propranolol and diltiazem, concentration ratio minus one (CR-1) values was positive (2.65 ±â€¯0.63 and 1.28 ±â€¯0.43 respectively). CONCLUSION: The A. cepa extract showed relatively potent relaxant effect on TSM which was comparable to the effect of theophylline. The results showed that ß2-adrenergic stimulatory and/or calcium channel blockade are the possible mechanisms for the relaxant effects of the plant.

A Hylarana latouchii Skin Secretion-Derived Novel Bombesin-Related Pentadecapeptide (Ranatensin-HLa) Evoke Myotropic Effects on the in vitro Rat Smooth Muscles.

Amphibians have developed successful defensive strategies for combating predators and invasive microorganisms encountered in their broad range of environments, which involve secretion of complex cocktails of noxious, toxic and diverse bioactive molecules from the skins. In recent years, amphibian skin secretions have been considered as an extraordinary warehouse for the discovery of therapeutic medicines. In this study, through bioactivity screening of the Hylarana latouchii skin secretion-derived fractions, a novel peptide belonging to ranatensin subfamily (ranatensin-HLa) was discovered, and structurally and pharmacologically-characterised. It consists of 15 amino acid residues, pGlu-NGDRAPQWAVGHFM-NH2, and its synthetic replicate was found to exhibit pharmacological activities on increasing the contraction of the in vitro rat bladder and uterus smooth muscles. Corresponding characteristic sigmoidal dose-response curves with EC50 values of 7.1 nM and 5.5 nM were produced, respectively, in bladder and uterus. Moreover, the precursor of ranatensin-HLa showed a high degree of similarity to those of bombesin-like peptides from Odorrana grahami and Odorrana schmackeri. Hylarana latouchii skin continues to serve as a storehouse with diverse lead compounds for the development of therapeutically effective medicines.

The Stimulatory Effects of Medicinal Plants on ß2-adrenoceptors of Tracheal Smooth Muscle.

Medicinal plants have been identified and used as primary sources in prevention and treatment of pulmonary diseases (mainly obstructive pulmonary diseases) from ancient times due to various pharmacological activities. In this review, the stimulatory effects of extracts, some fractions and constituents of medicinal plants on ß2-adrenoceptors which could be used as possible therapeutic agents in the future were reviewed. Various databases including; Medline, PubMed, ScienceDirect, Scopus, and Google Scholar were searched using stimulatory effect, ß2-adrenoceptors, possible mechanism, tracheal smooth muscle (TSM), medicinal plants and their constituents as keywords from 1985 to 2017. All studied plants including; Nigella sativa, Rosa damascena, Thymus vulgaris, Carum copticom, Carum carvi, Zataria multiflora, Crocus sativus, Cuminum cyminum, Liomnia acidissima, Portulaca oleraceae, Satureja hortensis, Ephedra sinica and Achillea millefolium showed relaxant effect on tracheal smooth muscle with a stimulatory effect on ß2-adrenoceptors mechanism. The studied plants and their constituents could be of therapeutic value in clinical practice as a bronchodilatory drug by ß2-adrenoceptors stimulatory mechanism for treatment of obstructive pulmonary diseases.

Anorectal manometry assessment of sphincter relaxation after local-regional anesthesia with posterior perineal block.

INTRODUCTION: Since the 1970s, in the USA, we witnessed a progressive increase of one-day surgical procedures. This attitude soon gained ground in Europe as well. In proctology, this kind of clinical approach has always been limited by the acute sensitivity of the anal- perineal area and by difficulties in attaining a complete sphincter relaxation with local anesthesia. Posterior perineal block seems to be associated with both a good pain control and an effective sphincter relaxation. MATERIAL AND METHODS: Between January 2017 and January 2018, we enrolled in our study 33 patients suffering from hemorrhoidal disease. They were all subjected to posterior perineal block. We measured anal resting pressure and squeeze pressure before and after anesthesia. Measurements where taken 5 minutes before and 15 minutes after the administration of local. RESULTS: We registered an average decrease of 39,2% of resting pressure and of 45,4% of squeeze pressure. CONCLUSIONS: We may state that perineal posterior block, while reducing striated muscle contractile activity, also causes a relevant reduction of anal basal tone. During surgical procedures done under regional anesthesia, we experienced a good sphincter relaxation, which was comparable, if not equal, to that induced by general anesthesia. In fact, 10 to 15 minutes after performing the block you could observe the elevation of the inferior margin of the exterior sphincter and the concomitant descent of the inferior margin of the internal sphincter (coaxial dislocation). KEY WORDS: Anorectal manometry, Anesthesia, Local-regional, Perineal block.

Functional mechanism of tracheal relaxation, antiasthmatic, and toxicological studies of 6-hydroxyflavone.

Previously, we described tracheal rat rings relaxation by several flavonoids, being 6-hydroxyflavone (6-HOF) the most active derivative of the series. Thus, its mechanism of action was determined in an ex vivo tracheal rat ring bioassay. The anti-asthmatic effect was assayed in in vivo OVAlbumin (OVA)-sensitized guinea pigs. Finally, the toxicological profile of 6-HOF was studied based on Organization of Economic Cooperation and Development guidelines with modifications. 6-HOF-induced relaxation appears to be related with receptor-operated calcium channel and voltage-operated calcium channel blockade as the main mechanism of action, and also through the production of relaxant second messengers NO and cGMP. Molecular docking supports that 6-HOF acts as calcium channel blocker and by activation of nitric oxide synthase. In addition, the in vivo anti-asthmatic experiments demonstrate the dose-dependent significant anti-allergic effect of 6-HOF induced by OVA, with best activity at 50 /kg. Finally, toxicological studies determined a LD50 > 2,000 mg/kg and, after 28 day of treatment with 6-HOF (50 mg/kg) by intragastric route, mice did not exhibit evidence of any significant toxicity. In conclusion, experiments showed that 6-HOF exerts significant relaxant activity through calcium channel blockade, and possibly, by NO/cGMP-system stimulation on rat trachea, which interferes with the contraction mechanism of smooth muscle cells in the airways. In addition, the flavonoid shows potential anti-asthmatic properties in an anti-allergic pathway. Furthermore, because the pharmacological and safety evidence, we propose this flavonoid as lead for the development of a novel therapeutic agent for the treatment of asthma and related respiratory diseases.

Myorelaxant Activity of essential oil from Origanum majorana L. on rat and rabbit.

ETHNOPHARMACOLOGICAL RELEVANCE: Origanum majorana L. (Lamiaceae) was usually used in Moroccan folk medicine to treat infantile colic and abdominal discomfort. MATERIALS AND METHODS: The essential oil from the aerial part of the dry Origanum majorana L. (EOOM) was obtained through hydro distillation and analyzed by gas chromatography/mass spectrometry (GC/MS). The effect of EOOM on muscle relaxation was measured on rabbit and rat intestinal smooth muscle mounted in an isotonic transducer. RESULTS: 1) The main compounds obtained from the aqueous extract of this plant were alpha Terpineol, L-terpinen-4-ol and Beta.-Linalool. 2) EOOM inhibited in a concentration-dependent manner spontaneous contraction of rabbit jejunum, with an IC50 = 64.08 ±â€¯2.42 µg/mL. 3) In rat intestine, EOOM induced the relaxation of the tissue in concentration-dependent manner with an IC50 = 39.70 ±â€¯2.29 µg/mL when the tissue was pre-contracted with CCh 10-6 M, and 48.70 ±â€¯2.26 µg/mL when the tissue was pre-contracted with 25 mM KCl. 4) The relaxation effect induced by EOOM was more important than that obtained in the presence of atropine, hexamethonium, Nifedipine, L-NAME and Blue of methylene. CONCLUSION: the present result indicates that essential oil of Origanum majorana L. exhibit an effect on intestinal relaxation in vitro. This effect further validates the traditional use of Origanum majorana L. to treat infantile colic and abdominal discomfort.

Airway smooth muscle relaxant activity of Cordia dodecandra A. DC. mainly by cAMP increase and calcium channel blockade.

ETHNOPHARMACOLOGICAL RELEVANCE: The fight against chronic respiratory diseases needs the exploration of new active compounds with properties that contribute to diminish the symptoms or resolve the disease alongside current therapy. MATERIALS AND METHODS: Eight extracts obtained from the bark and leaves of a Mayan medicinal plant used to treat asthma, Cordia dodecandra A. DC., were investigated for their relaxant effect on rat isolated tracheal rings pre-contracted with carbachol [1 µM]. The underlying functional mode of action of the most effective extract was assessed and the chromatographic fingerprints of more active extracts were analyzed. RESULTS: The dichloromethane bark extract (DECd-b) was the most effective and potent (Emax= 87.57 ±â€¯1.32 %; EC50 = 392.7 ±â€¯5.18 µg/mL). DECd-b relaxant effect was maximized in presence of isoproterenol (ß-adrenergic agonist, [10 µM]) and theophylline (phosphodiesterase unspecific inhibitor, [10 µM]). DECd-b also showed efficient relaxation of KCl [80 mM]-induced contraction and inhibition of CaCl2-induced contraction. Pre-incubation with propranolol (non-selective ß-adrenergic antagonist, [10 µM]), SQ22536 (adenylyl cyclase inhibitor; [100 µM]), ODQ (guanylyl cyclase inhibitor; [10 µM]), l-NAME (nitric oxide synthase inhibitor; [10 µM]), indomethacin (a cyclooxygenase unspecific inhibitor; [10 µM]), glibenclamide (ATP-sensitive potassium channel blocker; [10 µM]) and 2-aminopyridine (voltage-gated potassium channel blocker [100 µM]) did not modify the DECd-b relaxant-effect curve. The chromatographic analysis of DECd-b suggests the cordiaquinones presence with double conjugated bounds such as menaquinone. CONCLUSIONS: Results suggest that DECd-b induces relaxation mainly by cAMP increase and Ca2+ channel blockade. The chromatographic profiles and UV spectrum of DECd-b and HECd-l suggest the presence of molecules with structure of meroterpenoid naphthoquinones. This work report scientific evidence of C. dodecandra medicinal specie, which contributes to the pharmacological and phytochemical background of C. dodecandra providing an added value to the traditional use of this specie.

Muscarinic receptors, nitric oxide formation and cyclooxygenase pathway involved in tracheal smooth muscle relaxant effect of hydro-ethanolic extract of Lavandula angustifolia flowers.

BACKGROUND: Lavandula angustifolia (L. angustifolia) Mill. (Common name Lavender) is used in traditional and folk medicines for the treatment of various diseases including respiratory disorders worldwide. The relaxant effect of the plant on the smooth muscle of some tissues was shown previously. The present study has investigated the role of different receptors and pathways in the relaxant effect of L. angustifolia on tracheal smooth muscle. METHODS: Cumulative concentrations of the hydro-ethanolic extract of L. angustifolia flowers (0.5, 1, 2 and 4 mg/ml) were added on pre-contracted tracheal smooth muscle by methacholine (10 µM) or KCl (60 mM) on non-preincubated or preincubated tissues with atropine, chlorpheniramine, propranolol, diltiazem, glibenclamide, indomethacin, ω-nitro-L-arginine methyl ester (L-NAME) and papaverine. The results compared with of theophylline (0.2, 0.4, 0.6 and 0.8 mM) as positive control and saline (1 ml) as negative control. RESULTS: The extract showed concentration-dependent relaxant effects in non-preincubated tracheal smooth muscle contracted by KCl and methacholine (p < 0.05 to p < 0.001). The relaxant effect ofL. angustifolia was not significantly different between non-preincubated and preincubated tissues with chlorpheniramine, propranolol, diltiazem, glibenclamide, and papaverine. However, two higher concentrations of L. angustifolia in preincubated tissues with L-NAME (p < 0.01), indomethacin (p < 0.05 to p < 0.001) and atropine (p < 0.05) showed significantly lower relaxant effects than non-preincubated tissues. The EC50 values of L. angustifolia in tissues preincubated with indomethacin was significantly higher than non-preincubated trachea (p < 0.05). The effects of three first concentrations of the extract on KCl and methacholine-induced muscle contraction were significantly lower than those of theophylline (p < 0.05 to p < 0.001). CONCLUSIONS: These results indicated a relatively potent relaxant effect ofL. angustifolia that was lower than the effect of theophylline. The possible mechanisms of relaxant effect of this plant on tracheal smooth muscle are muscarinic receptors blockade, inhibition of cyclooxygenase pathways and/or involvement of nitric oxide production. Its clinical applications should be investigated in further studies.

Analysis of the main constituents of Changshu tablet and its spasmolysis effect against contraction induced by acetylcholine in the rat-isolated intestinal smooth muscle.

The Changshu tablet (CST), one kind of Chinese patent medicine with astringent to the intestine and relieving diarrhea, was made by the root of Rose odorata Sweet var. gigantean (Coll.et Hemsl.) Rehd.et Wils. Although CST has a long history of clinical application, but the research of its chemical composition is less. So the objective of this study was to investigate the main constituents and preliminarily research its effect of the contraction of isolated intestine in vitro. The contents of total polyphenols (126.23mg/g) and total triterpenoids (132.75mg/g) in CST were determined by ultraviolet spectrophotometry. Procyanidin B3, epigallo catechin, catechin, epicatechin, (-)-fisetinidol-(4α, 8)-(-)-catechin, (4α, 8)-(-)-fisetinidol-(-)-epicatechins and (+)-guibourtinidol-(4ß, 8)-epicatechin were identified and determined by high performance liquid chromatography and their contents were distributed from 0.04mg/g to 1.46 mg/g. CST showed significant inhibitory effect against acetylcholine-induced contraction on the rat-isolated intestinal smooth muscle with a dose-dependent manner from 0.06 to 0.6mg/mL. The maxim inhibition rates of CST on duodenum, jejunum, ileum and colon were 65.70±3.47%, 79.74±1.27%, 58.90±1.87% and 45.75±2.21% respectively. These results indicated that CST has a spasmolytic role in gastrointestinal motility which was probably mediated through inhibition of muscarinic receptors. All these findings promote the improvement of the quality control standard of CST and provide pharmacological foundation for clinical application of CST in gastrointestinal tract.