Sarcorucinine-D Inhibits Cholinesterases and Calcium Channels: Molecular Dynamics Simulation and In Vitro Mechanistic Investigations.

Acetylcholinesterase (AChE) inhibitors and calcium channel blockers are considered effective therapies for Alzheimer's disease. AChE plays an essential role in the nervous system by catalyzing the hydrolysis of the neurotransmitter acetylcholine. In this study, the inhibition of the enzyme AChE by Sarcorucinine-D, a pregnane type steroidal alkaloid, was investigated with experimental enzyme kinetics and molecular dynamics (MD) simulation techniques. Kinetics studies showed that Sarcorucinine-D inhibits two cholinesterases-AChE and butyrylcholinesterase (BChE)-noncompetitively, with Ki values of 103.3 and 4.66 µM, respectively. In silico ligand-protein docking and MD simulation studies conducted on AChE predicted that Sarcorucinine-D interacted via hydrophobic interactions and hydrogen bonds with the residues of the active-site gorge of AChE. Sarcorucinine-D was able to relax contractility concentration-dependently in the intestinal smooth muscles of jejunum obtained from rabbits. Not only was the spontaneous spasmogenicity inhibited, but it also suppressed K+-mediated spasmogenicity, indicating an effect via the inhibition of voltage-dependent Ca2+ channels. Sarcorucinine-D could be considered a potential lead molecule based on its properties as a noncompetitive AChE inhibitor and a Ca2+ channel blocker.

Trigonella foenum-graecum Methanolic Extract on Isolated Smooth Muscles and Acetylcholinesterase Enzyme: An In Vitro and Mechanistic In Silico Investigation.

Results: When tested on the baseline of isolated tissues, Tfg.Cr was devoid of any activity (stimulant or relaxant) till 10 mg/ml. This is an interesting finding, keeping in mind that the fenugreek seeds are used to alleviate constipation and diarrhoea. When Tfg.Cr was tried for any potential AChE inhibitory activity, it did show an inhibitory effect in increasing concentrations (47-380 µg/ml). This inhibitory effect was comparable to the effect produced by a standard AChE inhibitor physostigmine. One of the known fenugreek constituents, diosgenin, was also tested, and it also showed an AChE inhibitory effect in a concentration-dependent manner (11-190 µg/ml). Interaction between diosgenin and AChE was further investigated by molecular docking and molecular dynamics simulations for 100 ns, which showed that diosgenin interacted with the active-site gorge of AChE through hydrophobic, pi-pi stacking, and hydrogen bonds with various amino acids of the AChE enzyme. Conclusion: The results show that the fenugreek extract does not possess any GI stimulant or relaxant activity even though it is used traditionally in GI motility disorders. The extract and diosgenin could inhibit the AChE enzyme pointing towards their benefit to enhance the memory.

Spasmolytic Effect of Grewia asiatica Fruit Extract on Isolated Smooth Muscles is Mediated via Multiple Pathways.

BACKGROUND: Grewia asiatica Linn, or phalsa, is a commonly consumed fruit in Pakistan. The fruit is employed in the traditional medicine practice of Pakistan as a smooth muscle relaxant in different gastrointestinal (GI) and cardiovascular diseases. In this investigation, we show the antispasmodic and vasorelaxant actions of Grewia asiatica fruit extract. METHODS: A 70% methanolic crude extract of the plant material was prepared (Ga.Cr). Different isolated GI tissue preparations and endothelium-intact aortas from rats were utilized to observe the pharmacological actions of the extract. RESULTS: Ga.Cr, in increasing concentrations, inhibited the spontaneously contracting rabbit jejunum. In an effort to determine the mechanism of this relaxant action, contractions were induced in jejunum and ileum tissues with K+ (80 mM). Ga.Cr was able to only partially inhibit these induced contractions indicating that the mechanism might not be completely through a blockade of Ca2+ channels (CCB). When tested on low K+-(25 mM) sustained contractions, Ga.Cr cumulatively suppressed these contractions (0.1-10 mg/ml), indicating an opening of K+ channels (KCO) as the mechanism. Cromakalim, a standard KCO, was also more specific in blocking low K+-induced contractions. For the effect in aorta tissues, Ga.Cr suppressed the agonist-induced contractions from 0.3 mg/ml to 10 mg/ml. Upon challenge with L-NAME, a nitric oxide (NO) blocker, the extract response curve shifted right, indicating vasodilation was mediated via endothelial NO. CONCLUSION: This study shows that GI antispasmodic and vasodilator activities of Ga.Cr may be mediated via a KCO mechanism in the GI tract and through the release of NO from vascular endothelium.

The use of Euphorbia hirta L. (Euphorbiaceae) in diarrhea and constipation involves calcium antagonism and cholinergic mechanisms.

BACKGROUND: Euphorbia hirta (Linn) family Euphorbiaceae has been used in indigenous system of medicine for the treatment of gastrointestinal disorders. This study was designed to determine the pharmacological basis for the medicinal use of E. hirta in diarrhea and constipation. METHODS: The aqueous-methanol extract of whole herb of E. hirta (EH.Cr) and its petroleum ether (Pet.EH), chloroform (CHCl3.EH), ethyl acetate (Et.Ac.EH) and aqueous (Aq.EH) fractions were tested in the in-vivo experiments using Balb/c mice, while the in-vitro studies were performed on isolated jejunum and ileum preparations of locally bred rabbit and Sprague Dawley rats, respectively, using PowerLab data system. RESULTS: Qualitative phytochemical analysis showed the presence of alkaloids, saponins, flavonoids, tannins, phenols, cardiac glycosides, while HPLC of EH.Cr showed quercetin in high proportion. In mice, EH.Cr at the dose of 500 and 1000 mg/kg showed 41 and 70% protection from castor oil-induced diarrhea, respectively, similar to the effect of quercetin and loperamide, while at lower doses (50 and 100 mg/kg), it caused an increase in the fecal output. In loperamide-induced constipated mice, EH.Cr also displayed laxative effect with respective values of 28.6 and 35.3% at 50 and 100 mg/kg. In rabbit jejunum, EH.Cr showed atropine-sensitive inhibitory effect in a concentration-dependent manner, while quercetin and nifedipine exhibited atropine-insensitive effects. Fractions of E. hirta also produced atropine-sensitive inhibitory effects except Pet.EH and CHCl3.EH. On high (80 mM) and low (20 mM) K+ - induced contractions, the crude extract and fractions exhibited a concentration-dependent non-specific inhibition of both spasmogens and displaced concentration-response curves of Ca++ to the right with suppression of the maximum effect similar to the effect quercetin and nifedipine. Fractions showed wide distribution of spasmolytic and Ca++ antagonist like effects. In rat ileum, EH.Cr and its fractions exhibited atropine-sensitive gut stimulant effects except Pet.EH. CONCLUSION: The crude extract of E. hirta possesses antidiarrheal effect possibly mediated through Ca++ antagonist like gut inhibitory constituents, while its laxative effect was mediated primarily through muscarinic receptor agonist like gut stimulant constituents. Thus, these findings provide an evidence to the folkloric use of E. hirta in diarrhea and constipation.

Mentha: A genus rich in vital nutra-pharmaceuticals-A review.

The genus Mentha comprises several aromatic species, which are cultivated world-over due to their distinct aroma and commercial value. In addition to traditional food flavoring uses, Mentha are well recognized for their folk medicinal uses, especially to treat cold, fever, and digestive and cardiovascular disorders. A number of biological activities such as antioxidant, antimicrobial, biopesticidal, antitumor, anticancer, antiviral, antiallergic, antiinflammatory, antihypertensive, and urease inhibitory activity have been ascribed to Mentha. The traditional pharmacological attributes of Mentha herbs can be linked to the occurrence of bioactive phytochemicals such as terpenoids, alcohols, rosmarinic acid, and antioxidant phenolics among others. A rich source of bioactives, different species of Mentha, can be explored as a promising candidate for the development of nutra-pharmaceuticals. This review covers the nutritional, phytochemical, and traditional medicinal aspects and multiple biological activities of some commonly available species of Mentha so as to explore their potential applications for nutra-pharmaceutical and cosmo-nutraceutical industry. Detailed chemical profile and pharmaceutical attributes of various Mentha essential oils are also covered. Moreover, based on computational analysis, quantitative chemical component-antioxidant activity relationship model is reviewed to predict and correlate structure-activity relationship of potential bioactives in selected Mentha essential oils leading to discovery and developmenmt of novel natural drugs.

Evaluation of prokinetic and laxative effects of Hippophae rhamnoides in rodents.

Hippophae rhamnoides (Family; Elaeagnaceae) fruit extract was investigated for prokinetic and gut excitatory effects to rationalize its therapeutic utility in gastrointestinal complaints like delayed gastric emptying and constipation. The fruit extract of Hippophae rhamnoides (Hr.Cr) prepared in hydro-methanol (30:70) was verified for flavonoids, tannins, coumarins and terpenes as plant constituents. In mice, Hr.Cr administration caused an increased in faecal production and charcoal meal transport (50-300mg/kg, per-oral.), similar to activity pattern of carbamylcholine (1 mg/kg). Laxative and prokinetic effects of Hr.Cr were found partially atropine-sensitive. On challenge with isolated intestinal tissues, Hr.Cr charged a dose-dependent spasmogenic effect on jejunum (0.01-1mg/mL) preparations of rabbit and in ileal tissues (guinea-pig) at the dose range of 0.03 to 3mg/mL, following predominant relaxing impact at increased concentrations. Unlike carbamylcholine, stimulant effect of Hr.Cr was partly antagonized in atropine incubated tissues. These data attest the laxative, prokinetic and gut excitatory activities of Hippophae rhamnoides probably mediated through partial activation of muscarinic receptors. Further in agreement of the current findings with earlier reports on gastric emptying effects of Hippophae rhamnoides seed oil, this is the first study of its kind providing insight into mechanism to the laxative potential of Hippophae rhamnoides fruit, thus rationalizing its medicinal use in constipation.

Pharmacological basis for the medicinal use of Alcea rosea in airways disorders and chemical characterization of its fixed oils through GC-MS.

Alcea rosea L. also known as Althea rosea belongs to the Malvaceae family. This medicinal herb, traditionally used to treat several conditions including airway disorders like asthma and chronic bronchitis. This study evaluated the bronchodilatory effects and possible mechanism of A. rosea on guinea-pig tracheal tissues. Moreover lipophilic profiling of A. rosea has been carried out by using Gas-Chromatography-Mass-Spectrometry. A total of 19 compounds have been identified from the plant, n-hexane fraction. These compounds have been further confirmed from their Van den Dool and Kratz (I) Indices. Major class of metabolite identified from the plant includes fatty acid, saturated and unsaturated fatty acid esters. Hydrocarbons have also been detected from the n-hexane fraction. These fatty acid esters have not been reported previously by GC-MS and were identified first time from the flowers of Alcea rosea. In-vitro experiments were performed on guinea-pig tracheal tissues, mounted in Kreb's solution at 37°C and bubbled with carbogen. In isolated guinea-pig trachea, A. rosea inhibited carbamylcholine and K+ (80 mM)-induced contractions, potentiated isoprenaline concentration-response curves (CRCs) and suppressed Ca2+ CRCs. These results suggest that A. rosea cause bronchodilation through dual inhibition of phosphodiesterase enzyme and Ca2+ influx, which substantiate its potential in airways disorders.

Pharmacological Evaluation of Gut Modulatory and Bronchodilator Activities of Achyranthes aspera Linn.

Achyranthes aspera L. is traditionally used to relieve constipation, diarrhea, and asthma. Its crude extract (Aa.Cr) was evaluated through in vivo and ex vivo experiments to rationalize these medicinal uses of A. aspera and to provide their scientific basis. Aa.Cr, at 3 and 10 mg/kg, increased fecal output, similar to castor oil, whereas at 30, 100, 300, and 700 mg/kg, it protected against castor oil-induced diarrhea in mice when administered orally. Aa.Cr caused spasmogenic effect on rabbit jejunum and guinea pig ileum preparations, which was partially inhibited by atropine while completely blocked by cyproheptadine preincubation. Aa.Cr also relaxed high K+ (80 mM)-induced contraction in rabbit jejunum. Aa.Cr inhibited CCh (100 µg/kg)-induced bronchospasm in rats, similar to aminophylline. Like dicyclomine, Aa.Cr relaxed high K+ and CCh (1 µM)-induced contractions in guinea pig trachea and caused rightwards parallel shift of CCh concentration-response curves at the lower concentrations followed by non-parallel shift at the higher concentrations. On activity-directed fractionation, spasmogenic and spasmolytic activities of Aa.Cr were concentrated in aqueous and organic fraction, respectively. This study suggests the presence of dose-specific laxative and antidiarrheal effects in A. aspera, possibly mediated through cyproheptadine-sensitive receptors and dual cholinergic and calcium channel blockade, respectively. The latter combination is also a suggested mechanism underlying its bronchodilator effect. Copyright © 2017 John Wiley & Sons, Ltd.

Studies on antihyperlipidemic and endothelium modulatory activities of polyherbal formulation (POL4) and its ingredients in high fat diet-fed rats.

A compound herbal formulation (POL4) is used traditionally in interior parts (Distt. Badin) of Sindh, Pakistan, for the treatment of metabolic disorders like diabetes and hyperlipidemia. This study is aimed to determine the effectiveness of POL4 and its ingredients in hyperlipidemia and associated endothelial dysfunction and hypertension. POL4 is composed of equal proportion of Nigella sativa, Cichorium intybus, Trigonella foenum graecum and Gymnema sylvestre mixed in powdered form. Chronic (6 to 7 weeks) administration of POL4 and its ingredients mixed in diet caused a notable attenuation in total cholesterol, low density lipoprotein cholesterol, triglycerides, atherogenic index, C-reactive protein and glucose, while it has increased high density lipoprotein levels. POL4 intervention markedly (p<0.01) reduced systolic blood pressure in rats to 127±1.92 vs. 145.4±1.07 mm of Hg using tail-cuff method and significantly (p<0.05) improved endothelium-dependent relaxation (75±2.88 vs. 82.75±1.22%) to acetylcholine in isolated aortae of rats in treatment groups using force transducer and PowerLab system. Similar activities were assessed on the part of ingredients of POL4. These findings indicate that POL4 and its ingredients possess antihyperlipidemic, endothelium-dependent modulatory and antihypertensive activities, thus providing an evidence to the vernacular use of POL4 in hyperlipidemia and hypertension.

Pharmacological basis for the medicinal use of polyherbal formulation and its ingredients in cardiovascular disorders using rodents.

BACKGROUND: A compound herbal formulation (POL4) has been used in the indigenous system of medicine to treat cardiometabolic disorders like diabetes and associated hypertension. POL4 and most of its constituents have not been studied widely for its therapeutic use in hypertension. This study is aimed to determine the efficacy and possible insight into mechanism(s) for the medicinal use of POL4 and its ingredients in hypertension. METHODS: The aqueous methanolic extracts of POL4 (POL4.Cr) and its components [Cichorium intybus (Ci.Cr), Gymnema sylvestre (Gs.Cr), Nigella sativa (Ns.Cr) and Trigonella foenum graecum (Tfg.Cr)] were tested for blood pressure lowering activity in anaesthetized Sprague-Dawley rats. To assess the vasomodulatory effect, isolated tissue experiments were performed on rat aortic strips using isometric force transducer coupled with PowerLab data acquisition system. RESULTS: Administration of POL4 to rats caused a dose-dependent (1-100 mg/kg) fall in mean arterial pressure (MAP) with maximum effect of 85.33 ± 1.76% at 100 mg/kg, similar to the effect of verapamil. All ingredients of POL4 also decreased blood pressure with varying efficacy in following order Ns.Cr ≅ Ci.Cr > Tfg.Cr > Gs.Cr. In rat aortic preparations, POL4 and its ingredients inhibited K+ (80 mM)-induced contractions, Ci.Cr was the most potent followed by Ns.Cr > Tfg.Cr > Gs.Cr ≅ POL4. Against phenylephrine (P.E) contractions, Ci.Cr and Tfg.Cr exhibited complete relaxation, while POL4.Cr, Gs.Cr and Ns.Cr showed vasomodulatory effect. The Ca++ antagonist activity was confirmed when POL4 and its ingredients shifted Ca++ concentrations-response curves to the right in a manner similar to that of verapamil. On baseline of rat aorta, the parent formulation and its ingredients (except Tfg.Cr) exhibited partially phentolamine (1 µM)-sensitive vasoconstriction. CONCLUSION: These data show that POL4 and its constituents possess blood pressure lowering activity mediated through inhibition of Ca++ influx via membranous Ca++ channels and receptor (α-adrenergic) operated pathways. Thus, this study provides a rationale to the medicinal use of POL4 and its constituents in hypertension.

Antispasmodic, bronchodilator, vasorelaxant and cardiosuppressant effects of Buxus papillosa.

BACKGROUND: The present research was carried out to investigate pharmacological properties of Buxus papillosa C.K. Schneid. (Buxaceae). METHODS: Buxus papillosa extracts of leaves (BpL), stem (BpS), roots (BpR) and BpL fractions: hexane (BpL-H), aqueous (BpL-A) also plant constituent, cyclomicrobuxine effect were studied in jejunum, atria, aorta and tracheal preparations from rabbit and guine-peg. RESULTS: Ca++ antagonistic effect of BpS, BpR, BpL-H, BpL-A and cyclomicrobuxine were conclusively suggested, when spontaneous contractions of rabbit jejunal preparation was relaxed along with subsequent relaxation of potassium chloride (80 mM) induced contractions. Ca++ antagonistic effect was further confirmed, when a prominent right shift like that of verapamil was observed in Ca++ concentration-response curves, drawn in a tissue pretreated with BpL (0.3-1.0 mg/mL). In rabbit tracheal tissues BpL, BpS, BpR, BpL-H and BpL-A produced a prominent relaxation in contractions induced by potassium chloride (80 mM) and carbachol (1 µm). When tested in rabbit aortic rings, BpL, BpS, BpR, BpL-H and BpL-A showed concentration-dependent (0.1-3.0 mg/mL) vasorelaxant effect against phenylephrine (1 µM) and high K+-induced contractions. In isolated guinea-pig right atria, BpL, BpS, BpR, BpL-H and BpL-A suppressed atrial force of spontaneous contractions, with BpL-A being most potent. CONCLUSIONS: Our results reveal that Buxus papillosa possesses gut, airways and cardiovascular inhibitory actions.

Flaxseed extract exhibits mucosal protective effect in acetic acid induced colitis in mice by modulating cytokines, antioxidant and antiinflammatory mechanisms.

New treatments for inflammatory bowel disease are of interest due to high rate of remission failure. Natural products have been effective in IBD therapeutics as they have multiple constituents. The aim of the present study was to evaluate the effect of Flaxseed extract (Fs.Cr) on ulcerative colitis and identify the possible mechanisms involved. Colitis was induced by intrarectal administration of 6% AA in BALB/c mice. Colonic mucosal damage was assessed after 24h by calculating disease activity index (DAI), macroscopic and histological damage scores, biochemical measurement of myeloperoxidase (MPO), malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT), and total glutathione activities. Since cytokines are involved in exacerbating inflammatory cascade with emerging role of innate immune cytokines in IBD therapeutics, we hence assessed the effect on the levels of TNF-α, IFN-γ and IL-17, at 6, 12 and 24h by ELISA. Fs.Cr ameliorated the severity of AA colitis as evident by improved DAI, macroscopic damage and the histopathological scores along with restoration of goblet cells. Fs.Cr decreased MDA and MPO activities and enhanced antioxidant activity compared to the AA group. Finally, Fs.Cr in doses (300 and 500mg/kg) decreased TNF-α and IFN-γ levels at all time points with simultaneous increase in IL-17 levels at 24h as compared to the AA group. These results suggest that Fs.Cr ameliorates the severity of AA colitis by reducing goblet cell depletion, scavenging oxygen-derived free radicals, reduce neutrophil infiltration that may be attributed due to decreasing IFN-γ and TNF-α and increasing IL-17 levels.

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.

The Prokinetic, Laxative, and Antidiarrheal Effects of Morus nigra: Possible Muscarinic, Ca(2+) Channel Blocking, and Antimuscarinic Mechanisms.

Morus nigra Linn. (black mulberry) is used in gastrointestinal ailments. This study demonstrates gut modulatory properties of M. nigra. The prokinetic, laxative, and antidiarrheal activities of M. nigra were assessed in mice, while isolated rabbit jejunum and guinea-pig ileum were used to explore insight into mechanism(s). At 30 and 70 mg/kg, the crude extract of M. nigra (Mn.Cr) exhibited atropine-sensitive prokinetic and laxative effects, similar to carbachol (CCh). While at higher doses (100, 300, and 500 mg/kg), Mn.Cr offered protection against castor oil-induced diarrhea. In rabbit jejunum, Mn.Cr and its chloroform fraction inhibited CCh-induced contractions more potently compared with high K(+) (80 mm). Conversely, petroleum fraction was more potent against high-K(+) -induced contractions. At 0.01 mg/mL, Mn.Cr caused a parallel shift in acetylcholine concentration-response curves (CRCs) followed by a non-parallel shift at 0.03 mg/mL, similar to dicyclomine. At further tested concentrations, Mn.Cr (0.1 and 0.3 mg/mL) and petroleum fraction suppressed Ca(2+) CRCs, similar to verapamil. In guinea-pig ileum, Mn.Cr, its aqueous and ethyl acetate fractions exhibited atropine-sensitive gut stimulant activity along with additional uncharacterized excitatory response in the aqueous fraction only. These results suggest that black mulberry possesses prokinetic, laxative, and antidiarrheal effects, putatively mediated through cholinomimetic, antimuscarinic, and Ca(2+) antagonist mechanisms, respectively. Copyright © 2016 John Wiley & Sons, Ltd.

Dual Inhibition of Ca(+2) Influx and Phosphodiesterase Enzyme Provides Scientific Base for the Medicinal Use of Chrozophora prostrata Dalz. in Respiratory Disorders.

The crude ethanolic extract of Chrozophora prostrata (Cp.Cr) was tested using in vivo and ex vivo assays for its possible bronchodilatory effects in order to validate its medicinal use in respiratory disorders, like asthma and cough. Cp.Cr exhibited dose-dependent inhibition of carbachol (CCh)-induced bronchospasm in anesthetized rats, similar to aminophylline. When tested on guinea-pig tracheal preparations, Cp.Cr caused relaxation of both CCh (1 µM) and high K(+) (80 mM)-induced contractions with comparable potencies, similar to papaverine, a dual inhibitor of phosphodiesterse (PDE) and Ca(+2) influx. Pre-treatment of the tracheal tissues with Cp.Cr resulted in potentiation of the inhibitory effect of isoprenaline on CCh-induced contractions, like that caused by papaverine indicative of PDE inhibitory activity, which was confirmed when Cp.Cr concentration dependently (1 and 3 mg/mL) increased intracellular cAMP levels of the tracheal preparations, like papaverine. Cp.Cr shifted concentrationresponse curves of Ca(+2) constructed in guinea-pig tracheal preparation towards right with suppression of the maximum response, similar to both verapamil and papaverine. These data indicate bronchodilator activity of Chrozophora prostrata mediated possibly through dual inhibition of PDE and Ca(+2) influx, thus, showing therapeutic potential in asthma with effect enhancing and side-effect neutralizing potential Copyright © 2016 John Wiley & Sons, Ltd.

Antispasmodic and antidiarrheal activities of rhizomes of Polygonatum verticillatum maneuvered predominately through activation of K⁺ channels: Components identification through TLC.

Polygonatum verticillatum has traditionally been used for various purposes. The present study was aimed to validate the antispasmodic and antidiarrheal properties of crude methanolic extract of rhizomes of P. verticillatum (PR). Isolated rabbit jejunum preparations were suspended in tissue baths to measure the isotonic responses using Power Lab data acquisition system for the antispasmodic activity of PR, while the antidiarrheal activity was conducted in vivo in mice. PR caused complete relaxation of the spontaneous contractions of isolated rabbit jejunum preparations in a dose-dependent mode. A complete inhibition was observed against low potassium (K(+); 25 mM)-induced contractions, while the plant extract partially inhibited the high K(+)(80 mM)-induced contractions. From a mechanistic point of view, the spasmolytic effect of PR against low K(+)was antagonized by glibenclamide similar to the effect of cromakalim, thus showing the presence of constituents in PR mediating spasmolytic activity predominantly through the activation of adenosine triphosphate-sensitive K(+)channels. When tested against castor oil-induced diarrhea in mice, oral administration of the plant extract manifested marked antidiarrheal activity at the doses of 500 and 1000 mg/kg similar to loperamide. This study provided a pharmacological basis for the medicinal use of PR in abdominal colic and diarrhea.

Phytochemical and biological evaluation of Buddleja polystachya growing in Saudi Arabia.

Several Buddleja species were the target of phytochemical and biological studies; however, nothing was reported concerning the chemistry of Buddleja polystachya Fresen. growing in Saudi Arabia. Sixteen constituents were isolated from the aerial parts of B. polystachya using various chromatographic techniques and were identified by the help of different spectral techniques including 1D, 2D NMR and mass spectrometry. Moreover, the different fractions were evaluated for their anti-inflammatory and hypoglycemic activities. The isobenzofuranone derivative (4-hydroxy-7-methylisobenzofuranone) (4), has been isolated for the first time from this natural source, B. polystachya, along with fifteen known compounds namely; phenolic fatty acid ester, 1'(4-hydroxyphenyl) ethanol ester of docosanoic (1), uvaol (2), sakuranetin (3), kumatakenin (5), cirsimaritin (6), 5-hydroxy-3,7,4'-trimethoxyflavone (7), oleanolic acid (8), herbacetin 3,7,8-trimethyl ether (9), ursolic acid (10), verbascoside (11), linarin (12), luteolin 7-O-ß-D-glucoside (13), luteolin 7-(6"-caffeoyl)-O-ß-D-glucopyranoside (14), luteolin (15), and 6-O-α-L-(4''-O-trans-cinnamoyl) rhamnopyranosylcatalpol (16). Regarding the biological activities investigated, the ethyl acetate fraction showed the most significant anti-inflammatory activity, followed by the n-butanol and the aqueous fractions. As for the petroleum ether and dichloromethane fractions, their anti-inflammatory effects were moderate. The highest hypoglycemic activity was possessed by the ethyl acetate fraction, followed by the dichloromethane fraction and the n-butanol fraction showed the weakest activity.

Studies on Bronchodilator Activity of Salvia officinalis (Sage): Possible Involvement of K+ Channel Activation and Phosphodiesterase Inhibition.

The aqueous methanolic extract of the aerial parts of Salvia officinalis (So.Cr) was studied to provide possible underlying mechanism(s) for its medicinal use in asthma using the in vivo bronchodilatory assay and isolated tracheal preparations. S. officinalis (1-10 mg/kg) dose-dependently inhibited carbachol (CCh)-induced bronchospasm in anesthetized rats with three-fold greater potency than the positive control, aminophylline. In tracheal preparations, So.Cr inhibited the low K+ (25 mM)-induced contractions. Pretreatment of the tissues with 4-aminopyridine reversed the inhibitory effect of the plant extract against low K+ , whereas glibenclamide did not show any effect, thus showing the involvement of voltage-sensitive K+ channels. When tested against the CCh-induced pre-contractions for the involvement of any additional mechanism, interestingly, the extract showed a dose-dependent (0.03-0.1 mg/mL) inhibitory effect and shifted the inhibitory concentration response curves of isoprenaline to the left, thus showing phosphodiesterase enzyme inhibitory-like action, similar to that of papaverine. These results indicate that the crude extract of S. officinalis possesses bronchodilatory activity mediated predominantly via activation of voltage-dependent K+ channels and inhibition of phosphodiesterase enzyme; thus, this study provides sound pharmacological basis for its medicinal use in hyperactive airways disorders such as asthma and cough. Copyright © 2015 John Wiley & Sons, Ltd.

Natural Products Useful in Respiratory Disorders: Focus on Side-Effect Neutralizing Combinations.

This review summarizes literature related to medicinal plants reputed in traditional medical systems for treatment of asthma and coughs. The plants that are pharmacologically investigated for their effectiveness in such conditions, along with respective experimental protocol details, are also discussed. Some of plant origin compounds, which are considered useful as antitussive and antiasthmatic agents, are described as well. Chrysoeriol, a constituent of Aspalathus linearis (Fabaceae) was observed to be selective for relaxant effect in airways (through K+ channel activation), compared with other smooth muscles. We reported that Hypericum perforatum (Hyperieaceae), Andropogon muricatus (Poaceae), Juniper excelsa (Coniferae) and Nepeta cataria (Lamiaceae) exhibit bronchodilatory action, mediated through combination of Ca++ antagonist and phospohodiesrase inhibitory mechanisms, which scientifically explains their medicinal use in asthma. Hyocyamus niger (Solanaceae), Artemisia vulgaris (Compositae), Fumaria parviflora (Fumariaceae) and Terminalia bellerica (Combretaceae) caused bronchodilation via dual blockade of muscarinic receptors and Ca++ influx. Acorus calamus (Araceae), Carum roxburghianum (Apiaceae), Lens culinaris (Fabaceae) and Lepidium sativum (Cruciferae) mediate bronchodilatation through multiple pathways: anticholinergic and inhibition of Ca++ channels and PDE enzyme(s). In conclusion, this review presents an analysis of different novel combinations of pharmacological activities in medicinal plants with side effect-neutralizing/synergistic potential, setting new trends in the therapeutic options for hyperactive respiratory disorders such as asthma and cough. Copyright © 2015 John Wiley & Sons, Ltd.

Antidiarrheal and Antispasmodic Activities of Buddleja polystachya are Mediated Through Dual Inhibition of Ca(++) Influx and Phosphodiesterase Enzyme.

This study describes the antidiarrheal and antispasmodic activities of the hydro-alcoholic extract of Buddleja polystachya (Bp.Cr) with possible mode of action explored along with activity-directed fractionation. Bp.Cr and its aqueous (Bp.Aq) and organic fractions, petroleum ether (Bp.Pet), dichloromethane (Bp.DCM), ethylacetate (Bp.EtAc) and butanol (Bp.But), were tested using the in-vivo and in-vitro assays. The crude extract (100-300 mg/kg) showed 20 and 60% protection of castor oil-induced diarrhea in mice. In isolated rabbit jejunum, Bp.Cr like papaverine inhibited spontaneous and high K(+) (80 mM)-induced contractions equi-potently. In guinea-pig ileum, Bp.Cr showed a moderate spasmogenic effect. The activity-directed fractionation revealed that the spasmolytic activity was concentrated in the organic fractions and spasmogenic component in the aqueous fraction. Amongst the organic fractions, BP.DCM and Bp.Pet inhibited spontaneous and high K(+) -induced contractions equi-potently, while Bp.But, like verapamil was more potent against high K(+) . The crude extract and its organic fractions caused rightward shift in the Ca(++) -concentration response curves (CRCs), similar to verapamil, and all except Bp.But potentiated the isoprenaline-inhibitory CRCs to the left, similar to papaverine. The results of this study indicate that the crude extract of B. polystachya possesses antidiarrheal and antispasmodic activities, mediated possibly through dual inhibition of Ca(++) influx and phospodiesterase enzyme.