Acetylcholine-induced Contractions Research Articles

Effects of the Polyherbal Wattana Formula on Food Intake, Intestinal Transit, and Ileum Contraction in Wistar Rats

The polyherbal Wattana formula (WNF) has been used in traditional practice for over 30 years to promote health and prevent age-related issues. However, no scientific evidence supports its efficacy, including its impact on the gastrointestinal system in older individuals. This study examined the effects of WNF on intestinal transit, body weight, and food intake in Wistar rats that received oral WNF at doses of 100, 300, or 1000 mg/kg for 14 days. Following treatment, the small intestine was isolated, and intestinal transit was assessed via charcoal meal travel distance. Compared to the vehicle, 1000 mg/kg WNF significantly reduced intestinal transit in the charcoal meal test and decreased body weight. Additionally, 600 µg/mL WNF extract impeded acetylcholine-induced ileum smooth muscle contraction ex vivo. WNF at all doses demonstrated no effects on food intake. Our findings suggest that WNF may have potential antidiarrheal effects and benefits in weight management and abdominal spasm reduction.

8-[(4-benzylpiperazin-1-yl)methyl]-3-(2-chlorophenyl)-7-hydroxy-chromen-4-one is an activator of contractile activity of intestinal smooth muscles with reversible M2 cholinomimetic properties

Background. Several pathologies (such as diabetes mellitus, Parkinson’s and Alzheimer’s diseases, multiple sclerosis, etc.) are accompanied by degeneration of cholinergic neurons, which are key regulators of the contractile function of the gastrointestinal tract walls, leading to atony and paresis. An effective strategy for normalizing the lack of contractile function of visceral SM is the use of drugs - selective agonists of muscarinic acetylcholine receptors (mAChRs) of the M2 subtype. The high similarity of the structure of the agonist-binding sites of different subtypes of mAChRs causes problems to develop selective ligands for these receptors. Nowadays, there is an urgent necessity to develop selective agonists of M2 subtype receptors as pharmacological tools for laboratory research and promising drugs. The aim of the present research was to investigate the effect of the 8-[(4-benzylpipe­razin-1-yl)methyl]-3-(2-chlorophenyl)-7-hydroxy-chromen-4-one (compound 1), which was in silico predicted to bind mAChRs, on the contractile activity of rat caecum circular smooth muscle. Materials and Methods. The research was carried out on rats. The contractile activity was studied tensometrically in the isometric mode on preparations of the circular smooth muscles of the caecum of Wistar rats. The kinetic properties of individual spontaneous contractions of SM preparations were determined in accordance with the method of multivariate mechanokinetic analysis with the calculation of mechanokinetic parameters for the phases of contraction and relaxation: time (τ0, τC and τR), force (Fmax, FC and FR), velocity (VC and VR) and impulse (Imax, IC and IR). The kinetic properties of acetylcholine-induced contractions were analyzed by calculating the normalized maximum velocities of the contraction (Vnc) and relaxation (Vnr) phases. Results. It was found that compound 1 caused an increase in the amplitude of acetylcholine-induced contractions; this effect was eliminated by preincubation of SM with the mAChRs M2 subtype inhibitor AF-DX 116. It was revealed that compound 1 (0.1–50 μM) also has the ability to significantly activate the functional activity of colonic SM in a dose-dependent manner, increasing the force and frequency of spontaneous contractions, as well as their mechanokinetic parameters. It was found that the presence of compound 1 (0.1 μM) in the solution washing the smooth muscle for a long time leads to a significant increase in the amplitude and frequency of spontaneous contractions, which tends to reach a stationary mode after 40 minutes of its action. The effect of compound 1 was stable for at least an hour of application to the caecum, and was reversible and significantly eliminated by washing the SM. Conclusions. Compound 1 stimulates the contractile activity of the cecal smooth muscle and exhibits M2 cholinergic properties.

Taxifolin Reduces Blood Pressure via Improvement of Vascular Function and Mitigating the Vascular Inflammatory Response in Spontaneously Hypertensive Rats.

The effect of a 10-day-long treatment with taxifolin (TAX, 20 mg/kg/day p.o.) was investigated on spontaneously hypertensive rats (SHRs) with a focus on the vascular functions of isolated femoral arteries and thoracic aortas. TAX reduced blood pressure in SHRs. In femoral arteries, TAX increased acetylcholine-induced relaxation, reduced the maximal NA-induced contraction, and reduced acetylcholine-induced endothelium-dependent contraction (EDC); however, TAX had no effect on the vascular reactivity of isolated thoracic aortas. In addition, TAX elevated the total nitric oxide synthase (NOS) activity and iNOS protein expression but reduced cyclooxygenase-2 (COX2) protein expression in the tissue of the abdominal aorta without changes in Nos2 and Ptgs2 gene expressions. TAX also increased the gene expression of the anti-inflammatory interleukin-10 (Il10). In addition, in vitro studies showed that TAX has both electron donor and H atom donor properties. However, TAX failed to reduce superoxide production in the tissue of the abdominal aorta after oral administration. In conclusion, our results show that a decrease in the blood pressure in TAX-treated SHRs might be attributed to improved endothelium-dependent relaxation and reduced endothelium-dependent contraction. In addition, the results suggest that the effect of TAX on blood pressure regulation also involves the attenuation of COX2-mediated pro-inflammation and elevation of anti-inflammatory pathways.

Specialized Pro-resolving Mediator Improves Vascular Relaxation via Formyl Peptide Receptor-2.

The resolution of inflammation is an active phenomenon important for switching off inflammatory processes once the harmful stimuli are removed and facilitate the return to homeostasis. Specialized pro-resolving mediators (SPMs), such as lipoxin A4, resolvin D1, and resolvin E1, derived from ω-3 or ω-6 polyunsaturated fatty acids, are crucial for the resolution of inflammation. We hypothesized that SPMs are decreased in hypertension which contributes to the acetylcholine-induced contraction in resistance arteries, which are well known to be mediated by leukotrienes and prostaglandins. Moreover, treatment with SPMs will decrease this contraction via formyl peptide receptor-2 (FPR-2) in resistance arteries from spontaneously hypertensive rats (SHR). We performed a comprehensive eicosanoid lipid panel analysis, and our data showed for the first time that precursors of SPMs are decreased in SHR, limiting the production of SPMs and resolution of inflammation in vivo. This phenomenon was associated with an increase in lipid peroxidation in resistance arteries. Although SPMs did not abolish acetylcholine-induced contraction, these lipid mediators improved endothelial function in arteries from SHR via FPR-2 activation at nanomolar concentrations. SPMs also buffered TNF-α-induced reactive oxygen species generation in endothelial cells from C57Bl/6 mice. We suggest that FPR-2 and SPMs could be revealed as a new target or therapeutic agent to improve vascular function in arteries from hypertensive rats.

An In Vitro and In Silico Characterization of Salvia sclarea L. Methanolic Extracts as Spasmolytic Agents.

The use of medicinal plant species and their products is widespread in the field of gastrointestinal and respiratory diseases. This study aimed to evaluate the traditional use of Salvia sclarea L., clary sage, finding the possible mechanisms of its spasmolytic and bronchodilator actions in in vitro conditions supported by molecular docking analysis, along with the antimicrobial effects. Four dry extracts were prepared from the aerial parts of S. sclarea, using absolute or 80% (v/v) methanol by the method of a single-stage maceration or an ultrasound-assisted extraction. Characterization of the bioactive compounds by high-performance liquid chromatography indicated the presence of significant amounts of polyphenolics, with rosmarinic acid as the prevalent one. The spontaneous ileal contractions were best inhibited by the extract prepared with 80% methanol and maceration. The same extract was superior in the carbachol- and KCl-induced tracheal smooth muscle contractions, being the strongest bronchodilator agent. The most powerful relaxation of KCl-induced ileal contractions was achieved with the extract made of absolute methanol by maceration, while the 80% methanolic extract made with the ultrasound method generated the best spasmolytic effects in the acetylcholine-induced ileal contractions. Docking analysis suggested that apigenin-7-O-glucoside and luteolin-7-O-glucoside exhibited the highest binding affinity to voltage-gated calcium channels. Gram (+) bacteria were more susceptible to the effects of the extracts, particularly Staphylococcus aureus, in contrast to Gram (-) bacteria and Candida albicans. This is the first study to point out the influence of S. sclarea methanolic extracts on the gastrointestinal and respiratory spasm reduction, paving the way for their potential place in complementary medicine.

Dimethyl Sulfoxide Enhances Acetylcholine-Induced Contractions in Rat Urinary Bladder Smooth Muscle by Inhibiting Acetylcholinesterase Activities.

Dimethyl sulfoxide (DMSO) has been used not only as an experimental solvent, but also as a therapeutic agent for interstitial cystitis. The therapeutic effects of DMSO on interstitial cystitis are presumed to involve anti-inflammatory and analgesic effects. However, the effects of DMSO on urinary bladder smooth muscle (UBSM) have not been fully investigated. Thus, in this study, we investigated the effects of DMSO on rat UBSM contractions, and these effects were compared with those of acetone, which has a structure in which the sulfur of DMSO is replaced with carbon. DMSO (0.5-5%) enhanced acetylcholine (ACh)-induced contractions, whereas acetone (3 and 5%) suppressed them. Additionally, DMSO (5%) suppressed carbachol-induced contractions. DMSO/acetone (0.5-5%) inhibited 80 mM KCl-induced contractions in a concentration-dependent manner; however, the inhibitory effects of DMSO were weaker than those of acetone. The enhancing/suppressing effects of DMSO and acetone were almost completely abolished by wash out. DMSO and acetone (0.5-5%) inhibited recombinant human acetylcholinesterase (rhAChE) activity in a concentration-dependent manner. At 0.5 and 1%, the inhibitory effects of DMSO on rhAChE activity were more potent than those of acetone. These findings suggest that DMSO can enhance ACh-induced UBSM contractions and promote urinary bladder motility by inhibiting acetylcholinesterase (AChE), although DMSO also inhibits Ca2+ influx-mediated UBSM contractions. In addition, the sulfur atom in DMSO might play an important role in its enhancing effect on ACh-induced contractions by inhibiting AChE, as acetone did not enhance these contractions.

Mechanisms of the White Sea cod Gadus morhua marisalbi (Gadidae) intestinal smooth muscle cholinergic contraction: the contribution of various subtypes of M-cholinergic receptors and Rho-kinase

The study of the functioning of various body systems in diff erent vertebrates is one of the key tasks of comparative physiology. Teleost fi sh are a large group of vertebrates, however, the mechanisms of functioning of their digestive tract have been studied little and mainly only for such a model object as Danio rerio. The aim of this work was to characterize the participation of various subtypes of M-cholinergic receptors and the enzyme Rho-kinase in the cholinergic contraction of the intestinal smooth muscles of the White Sea cod Gadus morhua marisalbi (Gadidae). A longitudinal strip was excised from the proximal cod intestine and placed in an apparatus for recording contractile responses in the isometric mode. Contractile responses to acetylcholine were ompletely blocked by atropine. Blockade of M3 cholinergic receptors with 4-DAMP resulted in a decrease in acetylcholine-induced contraction compared with the control response. Blockade of M1 receptors with pirenzepine led to a weakening of contraction, less pronounced than with blockade of M3 cholinergic receptors. Blockade of M2-cholinergic receptors with methoctramine did not affect the magnitude of the contractile response. Incubation of preparations with the Rho-kinase inhibitor fasudil was accompanied by a significant decrease in contractile responses compared with the control, as well as a faster decrease in the contraction force after reaching the “peak” of the reaction. Thus, acetylcholine causes contraction of cod intestinal smooth muscle by activating M3- and M1- but not M2-cholinergic receptors. The activity of the Rho-kinase enzyme contributes to the development and maintenance of cod intestinal smooth muscle contraction under the action of acetylcholine. The results obtained are of interest for comparative physiology, may be important for understanding the mechanisms of the damaging effect of environmental factors on the bony fish’ body, as well as for the use of fish as objects of preclinical studies of drugs.

The differences in the adrenergic receptors of proximal urethra between sexes.

The bladder and urethra work as a physiologically functional unit to facilitate continence in the storage and voiding phase. Sex differences have been found in the urethral contraction in response to α-adrenergic receptor activation. This study aimed to investigate the role of adrenergic receptors in the proximal urethra of male and female mice. Urinary bladder and proximal urethral smooth muscle (USM) samples from male and female C57BL/6 mice were isolated and mounted in an organ bath. Acetylcholine-induced contraction of the urinary bladder was compared in male and female mice. Phenylephrine and norepinephrine (NE) induced little contraction at a lower concentration, but a relaxing phase of female proximal USM was observed at a higher concentration. This contraction profile was inhibited by NG-nitro-L-arginine, lidocaine, and capsaicin. In addition, the NE-induced contraction was greater in the incubation of propranolol than that of L-NNA or lidocaine. These results suggested that the β-adrenoceptor may be the dominant receptor of female proximal USM, and the activity of calcitonin gene-related peptide sensory nerves and nitrergic nerves may pose an anti-contraction effect on the proximal urethra in female mice. β-adrenoceptor may be the dominant receptor of female proximal USM. The use of β-adrenergic receptor blocker agents might have the potential for the treatment of female voiding dysfunction.

The effect of thymol on acetylcholine-induced contractions of the rat ileum and uterus under ex vivo conditions.

Thyme (Thymus vulgaris L.) is a well-known medicinal plant, the aerial parts of which have long been used internally or externally as a traditional remedy for various diseases. Thyme essential oils have important pharmaceutical applications and are regularly used in the pharmaceutical, food and cosmetic industries. In folk medicine, thyme preparations are used to treat respiratory, digestive, cardiovascular and nervous disorders, as well as to relieve dysmenorrhea. Thymol, a major constituent of Thymus vulgaris essential oil, has been shown to affect skeletal and smooth muscle excitation and contraction. Therefore, the main objective of this study was to evaluate its effect on acetylcholine (ACh)-induced rat intestinal and uterine preparations. Isolated ileum and uterine horn preparations were placed in a 20-ml organ bath containing Tyrode or De Jalon solution and exposed to graded concentrations of ACh (0.036, 0.109, 0.36, 1.09, 3,6, 10.9, and 36μM) and either 0.02 or 0.2mM thymol. Additionally, the dose-response relationship of thymol impact on intestinal and uterine contraction was evaluated. Contraction changes were monitored using an isometric transducer. Thymol at the higher dose (0.2mM) significantly reduced ACh-induced intestinal and uterine contractions. Thus, this study provides new important data on competitive actions between thymol and ACh. In the dose-response study, the IC50 values were calculated as 5.26mM for the ileum and 5.35mM for the uterus. Our results demonstrated the efficacy of thymol in reducing ileal and uterine smooth muscle contractions, thus supporting the use of thyme in traditional medicine in the treatment of digestive disorders and painful menstrual cramps.

Effects of Extracts and Flavonoids from Drosera rotundifolia L. on Ciliary Beat Frequency and Murine Airway Smooth Muscle.

Extracts from Drosera rotundifolia are traditionally used to treat cough symptoms during a common cold. The present study aimed to investigate the impact of extracts from D. rotundifolia and active compounds on the respiratory tract. Tracheal slices of C57BL/6N mice were used ex vivo to examine effects on airway smooth muscle (ASM) and ciliary beat frequency (CBF). Phosphodiesterase (PDE) inhibition assays were carried out to test whether PDE1 or PDE4 are targeted by the active compounds. An ethanol–water extract, as well as an aqueous fraction of this extract, exerted antispasmodic properties against acetylcholine-induced contractions. In addition, contractions induced by 60 mM K+ were abrogated by the aqueous fraction. Effects on ASM could be attributed to the flavonoids quercetin, 2″-O-galloylhyperoside and hyperoside. Moreover, the Drosera extract and the aqueous fraction increased the CBF of murine tracheal slices. Quercetin and 2″-O-galloylhyperoside were identified as active compounds involved in the elevation of CBF. Both compounds inhibited PDE1A and PDE4D. The elevation of CBF was mimicked by the subtype-selective PDE inhibitor rolipram (PDE4) and by 8-methoxymethyl-IBMX. In summary, our study shows, for the first time, that a Drosera extract and its flavonoid compounds increase the CBF of murine airways while antispasmodic effects were transferred to ASM.

Anti-diarrhoeal effects of Garcinia kola (Heckel-Holl) seed methanolic extract and its fractions in animal models

This study investigated the In vitro spasmolytic and In vivo anti-diarrhoeal effects of Garcinia kola seed extract/fractions. Extraction was done by maceration in 70% methanol, serially partitioned in ethyl acetate and n-hexane. Qualitative phytochemical screening was carried out on the crude extract/fractions. The In vitro spasmolytic effect of the extract and fractions at different concentrations (0.5×103, 0.2×103,0.1×103, 0.6×102 mg/ml) were investigated against spontaneous and acetylcholine-induced contractions in isolated rabbit jejunum as well as histamine-induced contractions using isolated guinea pig ileum. The In vivo anti-diarrhoeal effect of the extract was evaluated using three diarrhoeal models: castor oil-induced diarrhoea, charcoal meal gastrointestinal transit time and castor oil-induced enteropooling. In each model, 25 mice were randomly divided into five groups of 5 mice each. Group I served as the untreated control, while group II was a positive control. Groups III-V were administered 125, 250 and 500 mg/kg of the crude methanol extract, respectively. The crude extract, ethyl acetate and aqueous fractions at 0.5×103 mg/ml respectively exhibited 14.4%, 12.9% and 12.2% spasmolytic activities against acetylcholine-induced rabbit jejunum contractions. Histamine-induced guinea pig ileum contractions were inhibited by crude extract (6.2%), ethyl acetate (6.2%), aqueous fraction (7.2%) at 0.6×102 mg/ml. For castor oil-induced diarrhoea, the crude extract at 500 mg/kg produced a significant (p < 0.05) decrease in the diarrhoeal index and faecal weight with a percentage inhibition of 70.4% compared with controls. Similarly, the crude extract (500 mg/kg) significantly (p < 0.05) decreased the charcoal meal gastrointestinal transit time with a percentage inhibition of 33.9% and elicited significant (p < 0.05) intraluminal fluid reduction (9.1%) in castor oil-induced enter pooling test when compared with the untreated group. In conclusion, the anti-motility and anti-secretory activities of the crude extract were attributed to the phytochemical constituents present.

In-Vitro Evaluation of Some Traditional Medicinal Plants on Calcium Oxalate Urolithiasis

The prevalence of urolithiasis in Middle East countries is predominantly high. Traditional medicinal plants play a role in the prevention and management of urolithiasis. The effect of Petroselinum crispum, rind of Citrus sinensis L., rind of Citrus limon L., Ammi visnaga (L.) LAM., Tamarindus indica L., Nigella sativa L., Cymbopogon proximus Hochst. ex A. Rich., Hibiscus sabdariffa L., Hordeum vulgare L., and Cymbopogon schoenanthus (L.) Spreng. on calcium oxalate crystallization was investigated in-vitro. The antispasmodic activity on acetylcholine-induced contraction in rat ileum was also screened ex-vivo. A significant reduction in the mean diagonal of calcium oxalate crystals was observed for P. crispum, C. proximus, N. sativa, and C. limon (4.41 mm, 4.71, 5.44, and 5.67 mm, respectively) compared to the negative control (12.19 mm). H. sabdariffa exhibited antinucleation effect however, P. crispum showed a marked inhibition of calcium oxalate aggregation at 10 mg/mL after 60 min compared to the negative control. A remarkable ex-vivo antispasmodic activity was observed for C. proximus, C. schoenanthus, and A. visnaga extracts. Our results provide scientific evidence for the traditional use of the studied plant-derived products as potential therapies for calcium oxalate urolithiasis.

Modulation of carbachol-induced Ca2+ oscillations in airway smooth muscle cells by PGE2

PGE2 is a potent bronchodilator, but the mechanisms underlying this effect have not been fully elucidated. Acetylcholine-induced contractions of airway smooth muscle (ASM) are associated with the generation of repetitive Ca2+ oscillations in airway smooth muscle cells (ASMC) and the force of contraction is positively correlated with the frequency of the underlying Ca2+ oscillations. The purpose of the present study was to examine if carbachol-evoked Ca2+ oscillations in isolated ASMC were inhibited by PGE2.Isolated murine ASMC loaded with fluo4-AM were imaged with a Nipkow spinning disk confocal microscope. Cells responded to application of CCh (1 μM) by generating an initial Ca2+ transient followed by a series of Ca2+ oscillations. This activity was abolished by PGE2 (300 nM) and the EP2R agonist (R)-butaprost (3 μM) and the inhibitory effects of PGE2 were reversed by application of the EP2R antagonist PF-04418948 (100 nM). Activation of adenylate cyclase using forskolin (1 μM) mimicked the effects of PGE2. The PKA activator, 6-MB-cAMP (300 μM) reduced the frequency of CCh-induced Ca2+ oscillations by 33% and the PKA inhibitor Rp-8-CPT-cAMPs partially reversed the inhibitory effects of PGE2. The EPAC activator 007-AM (10 μM) reduced the frequency of the oscillations by 60% and joint application of 007-AM and 6-MB-cAMP reduced oscillation frequency by ∼85%. CCh-induced Ca2+ oscillations were inhibited by 2-APB and tetracaine, but caffeine-evoked Ca2+ transients were resistant to PGE2.These data suggest that PGE2 inhibits CCh-induced Ca2+ oscillations in murine ASMC via stimulation of EP2Rs and a mechanism involving activation of PKA and EPAC.

TRPC5 is essential in endothelium-dependent contraction of aorta from diet-induced obese mice

The role of the Ca2+-permeable ion channel TRPC5 in regulating vasocontraction in obesity is poorly understood. Here, we investigated whether TRPC5 contributes to vascular dysfunction in obesity by promoting endothelium-dependent contraction via activation of cytosolic phospholipase A2 (cPLA2) in the aortic endothelial cells of obese mice. Acetylcholine-induced endothelium-dependent relaxation and contraction in the aorta were measured using wire myography. PLA2 activity was measured by the fluorogenic PLA2 substrate Bis-BODIPY™ FL C11-PC. The intracellular Ca2+ level in response to acetylcholine was measured by Fluo-4 fluorescence. Endothelium-derived contracting factors were assessed by enzyme immunoassay. Diet-induced obesity (DIO) attenuated endothelium-dependent vasodilation, enhanced endothelium-dependent contraction (EDC), and increased the expression of TRPC5 in the mouse aorta. Activation of TRPC5 promoted EDC in the wild-type mouse aorta, whereas pharmacological inhibition and genetic knockout of TRPC5 decreased EDC in the DIO mouse aorta. Moreover, cPLA2 phosphorylation and activity were higher in aortic endothelial cells from DIO mice, and this was attenuated by inhibition and knockout of TRPC5. Cyclooxygenase 2 (COX-2) expression was increased in DIO mouse endothelium and was decreased by a TRPC5 inhibitor and knockout of TRPC5. Release of prostaglandins F2α (PGF2α) and E2 (PGE2) was involved in TRPC5-regulated EDC in DIO mice. This study demonstrated that TRPC5 contributes to endothelial and vascular dysfunction and is involved in EDC through activation of cPLA2 and enhanced COX-2-PGF2α/PGE2 levels in DIO mice.

Linalyl acetate restores colon contractility and blood pressure in repeatedly stressed-ulcerative colitis rats.

BackgroundUlcerative colitis (UC) is related to stress, but few studies have evaluated the influence of stress on factors affecting colon contractility in rats with UC. Also, there have been no studies investigating beneficial effects of linalyl acetate (LA), the major component of lavender essential oil, in repeatedly stressed-ulcerative colitis rats. Therefore, we investigated the differences in factors affecting colon contractility of UC rats with or without repeated restraint stress (RRS) and the effects of LA on these parameters in repeatedly stressed-UC rats.MethodsRats were assigned to following groups: control, RRS, UC, RRS+UC, and RRS+UC treated with LA or sulfasalazine. To induce UC, rats were administered 2% dextran sodium sulfate (DSS) water on days 1–5, followed by tap water on days 6–15 and DSS water on days 16–20. RRS was induced by immobilizing rats for 2 hr/day on days 1–20. LA or sulfasalazine were daily administered on days 16–20.ResultsDisease activity index (DAI) was markedly increased in RRS+UC. Serum interleukin-6 levels and acetylcholine-induced colon contraction were higher in RRS+UC than in control, RRS and UC. Colon nitrite levels also significantly increased in RRS+UC compared to the control and RRS. Blood pressure (BP) was higher in RRS+UC than in the control and UC. Both LA and sulfasalazine was effective in decreasing DAI, colon nitrite levels, acetylcholine-induced colon contraction in RRS+UC. Sulfasalazine significantly reduced serum IL-6 levels in RRS+UC with decreasing tendency in RRS+UC treated by LA. Only LA significantly reduced BP in RRS+UC.ConclusionsOur findings emphasize the importance of stress management in UC patients. Also, LA may be beneficially used in repeatedly stressed-UC patients with high BP.

Relaxant effect of bioactive component compatibility of San-ao decoction on In vitro guinea pig airway smooth muscle: A dose-response relationship study

Background: Component compatibility is important to the modernization of traditional Chinese medicine. Studies have shown that San-ao decoction (SAD) can treat respiratory diseases by relaxing airway smooth muscle (ASM) and reducing airway hyper-responsiveness. However, whether its bioactive components and compatibility also present with similar relaxant effects remains unknown. This study aims to explore the potential relaxant property, dose-response relationship, and underlying mechanisms of the bioactive component compatibility in SAD. Methods: Network pharmacology was primarily used to identify the bioactive components of SAD and uncover its underlying mechanisms. ASM tension force measuring technique was utilized to verify the relaxant and dose-response effects on in vitro guinea pig ASM. Results: We postulated pseudoephedrine hydrochloride (PH), amygdalin (AM), and diammonium glycyrrhizate (DG) to be the bioactive components of SAD, which could effectively relax ASM in a dose-dependent manner on both acetylcholine-induced and spontaneous contraction. Both PH and AM could lead to DG dose–response curve shift. The regression equation of these three bioactive components was Y = −2.048 × X1 + 0.411 × X2 + 14.052 × X3 (X1, X2, X3 representing PH, AM, and DG, respectively). The underlying mechanisms of these components might be associated with the regulation of smooth muscle contraction. Conclusions: PH, AM, and DG are the bioactive components of SAD, which can relax ASM in a dose–response manner and exert a synergistic effect. Clinically, compatibility of these three bioactive components may serve as a new complementary and alternative treatment for respiratory diseases.

Investigation of the effect of trazodone on spontaneous and acetylcholine-induced bladder detrusor smooth muscle contractions

Objective: The management of psychiatric patients is often complicated by medical comorbidities, complex pharmacological regimens, and side effects secondary to these regimens. In the current study, it was aimed to investigate the effects and mechanism of action of trazodone on rat bladder smooth muscle contractility in vitro. Method: Sixteen adult male Wistar albino rats were euthanized by the cervical dislocation method following ether anesthesia. Two muscle strips of 2 × 10 mm in size were prepared vertically from the bladder by opening a longitudinal incision from the neck of the bladder in the direction of the apex. The strips were tied properly and hung in the organ bath. All contraction amplitudes and frequencies were recorded. After a 45-min adaptation period, contractions were induced by applying 105 M acetylcholine (ACh) to all spontaneously contracting bladder strips. After 20 min, doses of trazodone (109 M vs 103 M) were given cumulatively. The resulting effects were recorded. Results: The groups were compared within themselves: a significant difference was found between the initial tensions in the group with ACh-induced contractions and the tensions after the administration of trazodone at 109, 108, 107, 106, 105, 104, and 103 M doses (p < 0.0001). In the group with spontaneous contractions, a significant difference was found between the initial tensions and the tensions after the administration of trazodone at 109, 108, 105, and 104 M doses (p < 0.0001). Conclusion: Results showed that trazodone had a significant inhibitory effect on bladder smooth muscle contractions in vitro, especially at concentrations of 104 and 103 M.

Antidiarrheal and Antioxidant Activities of the Aerial Parts of Caralluma dalzielii N. E. Brown

Pharmacognosy Research,2022,14,1,82-88.DOI:10.5530/pres.14.1.12Published:December 2021Type:Original ArticleAuthors:Chinenye J. Ugwah-Oguejiofor, Halilu E. Mshelia, Junaidu Bello, Isah Inuwa, and Abdullahi Sulaiman Author(s) affiliations:Chinenye J. Ugwah- Oguejiofor1,*, Halilu E. Mshelia2,3, Junaidu Bello1, Isah Inuwa1, Abdullahi Sulaiman1 1Department of Pharmacology and Toxicology, Faculty of Pharmaceutical Sciences Usmanu Danfodiyo University Sokoto, Sokoto, NIGERIA. 2Department of Faculty of Pharmacy, Cyprus International University, Nicosia, Mersin 10, TURKEY. 3Department of Pharmacognosy and Ethnopharmacy, Faculty of Pharmaceutical Sciences, Usmanu Danfodiyo University, P.M.B. 2346 Sokoto, NIGERIA. Abstract:Background: Caralluma dalzielii N.E. Brown is commonly referred to as “Karan massalanci” in the Northwest Nigeria where it is used in treating several ailments including pain, diarrhea and stomach issues. Objectives: This study was aimed to investigate the antidiarrheal and antioxidant activities of aqueous aerial parts extract of Caralluma dalzielii. Materials and Methods: The aqueous aerial parts extract of Caralluma dalzielii (CDE) (100, 200 and 400 mg/kg) was evaluated for antidiarrheal properties against gastrointestinal motility, castor oil-induced and prostaglandin-E2 (PGE2) enteropooling models in Wistar rats. Its antioxidant properties were studied by determining the total phenolic content (TPC) using Folin-Ciocalteu reagent, its free radical scavenging activity using 1, 1-Diphenyl-2-Picrylhydrazyl (DPPH) and its ferric reducing antioxidant power (FRAP) assays using potassium ferrocyanide ferric chloride methods. Ascorbic acid was used as the reference. Spasmolytic effect was studied in isolated rabbit jejunum preparations in an organ bath experiment using acetylcholine (ACh). Results: CDE significantly (p<0.05) reduced gastrointestinal transit of charcoal meal and the total number of diarrheal feces in the animals. The total phenolic content was determined to be 36.67±3.33 mg GAE/g. IC50 value of 63.44 mg/mL was calculated in DPPH assay. The FRAP value was found to increase as the concentration of the extract increased. CDE inhibited acetylcholine-induced contraction of the rabbit jejunum in a concentration dependent manner with complete inhibition at 20.48 mg/mL of the extract. Conclusion: The extract of Caralluma dalzielii possesses antidiarrheal activities which may be related to its antimotility, antioxidant and antispasmodic properties. Keywords:Antioxidant, Antispasmodic, Caralluma dalzielii, Gastrointestinal motility, Rabbit jejunum.View:PDF (543.04 KB) Full Text

Effect of methanol extract of Anacardium occidentale stem bark on agonist-induced contraction in rat uterine muscle

Anacardium occidentale (Ao) is widely used in ethnomedicine and the effect on contractility of the gut and heart muscles of laboratory rodents have been established however, its effect on the contractility of uterine muscle has been rarely researched. The present study investigated the effect of stem bark methanolic extract of Anacardium occidentale (AoME) on Isolated Rat Uterus Strips (IRUS). The Anacardium occidentale methanol extract (AoME) was obtained by solvent extraction. The IRUS were suspended in a bath containing 15 ml of De Jalon's solution through a silk connected to a force transducer. A tension of 1.0 g was applied. The strips were allowed to equilibrate for a period of 60–90 min before the commencement of the experiment. The extract (0.025- 0.3mg/ml) added cumulatively did not modify the normal tonus in most of the IRUS used except in one where it feebly contracted it. However, the contractile responses induced by acetylcholine (10-9 -10-5 M) and oxytocin (10-9 -10-5 M) on the IRUS were almost completely blocked by pre-incubated AoME at a concentration of 0.2 mg/ml. Stem bark methanol extract of Anacardium occidentale shifted the log concentration curve of both agonists to the right. The present results report the antagonistic effects of stem bark methanol extract of Anacardium occidentale on oxytocin and acetylcholine-induced contraction in rat uterus strips.&#x0D; Keywords: Anacardium occidentale, Oxytocin, Acetylcholine, Uterus, Smooth muscle

Psidium guajava leaf extract improves gastrointestinal functions in rats and rabbits: an implication for ulcer and diarrhoea management

Purpose Psidium guajava L. (Family, Myrtaceae) is reportedly used in ethnomedicine for the treatment of diarrhoea, inflammation, and gastroenteritis. Objective This study evaluated the gastrointestinal function of Psidium guajava leaf extract (PGLE) in rats and rabbits. Materials and methods Crude ethanolic PGLE was subjected to phytochemical and toxicity tests (acute and sub-acute). Standard analytical procedures were employed to evaluate the in vivo gastrointestinal motility, and gastroprotective effect of PGLE against aspirin-induced ulcers. Results In the phytochemical analysis, phenols were the highest (48.32 mg) followed by flavonoids (32.74 mg) and least in tannins (7.31 mg). The acute toxicity of PGLE was >6000 mg/kg. Administration of PGLE decreased significantly (p < 0.05) the body weight, while the liver biomarkers were not significantly altered (p > 0.05) when compared to the control. PGLE significantly increased extractible mucus weight and lowered gastric acid secretion in rats (p < 0.05). PGLE decreased significantly (p < 0.05) ulcer scores and indexes, and increased percentage ulcer inhibition in a dose-dependent manner compared to the negative and omeprazole-treated groups. PGLE dose-dependently inhibited basal amplitudes of contractions, and significantly inhibited acetylcholine-induced contractions, terminating them completely at higher doses. Conclusion PGLE may be a good anti-ulcer and anti-diarrhoeal agent, raising the prospect of novel drug development for such applications.