Munasib Khan

Ethnopharmacological evaluation of the anticonvulsant, sedative and antispasmodic activities of Lavandula stoechas L.

Lavandula stoechas L. (Lamiaceae) has been used for a long time in traditional medicine as an anticonvulsant and antispasmodic. The aqueous-methanolic extract of L. stoechas flowers (LS) was studied for its possible anticonvulsant and antispasmodic activities. When tested in mice, LS (600 mg/kg) significantly reduced the severity and increased the latency of convulsions induced by pentylene tetrazole (PTZ). LS likewise reduced PTZs lethality. LS up to a dose of 600 mg/kg was found devoid of any hypnotic effect in mice, however, animals were found to be dull, calm and relaxed. The sedative effect of the plant extract was confirmed, as it prolonged the pentobarbital sleeping time in mice similar to that of diazepam. In isolated rabbit jejunum preparations, LS caused a dose-dependent (0.1-1.0 mg/ml) relaxation of spontaneous contractions. LS also inhibited K(+)-induced contractions in a similar dose range, thereby suggesting calcium channel blockade. This effect was confirmed when pretreatment of the jejunum preparation with LS produced a dose-dependent shift of the Ca(2+) dose-response curve to the right, similar to the effect of verapamil, a standard calcium channel blocker. These data indicate that the plant extract exhibits anticonvulsant and antispasmodic activities. Its calcium channel blocking property may be mechanistically related to these activities. Its usefulness in folk medicine appears thus to be based on a sound mechanistic background.

Antispasmodic and bronchodilator activities of St John's wort are putatively mediated through dual inhibition of calcium influx and phosphodiesterase

The crude extract of aerial parts of St Johns wort (Hypericum perforatum) (Hp.Cr) and its fractions were studied in vitro for its possible spasmolytic and bronchodilator activities to rationalize some of its medicinal uses. In rabbit jejunum preparations, Hp.Cr caused a concentration‐dependent relaxation of both spontaneous and K+ (80 mm)‐induced contractions at a similar concentration range (0.1–1.0 mg/mL), similar to that produced by papaverine, whereas verapamil was relatively potent against K+‐induced contractions. Hp.Cr shifted the Ca2+ concentration–response curves (CRCs) to the right, similar to that caused by papaverine or verapamil and also caused leftward shift of isoprenaline‐induced inhibitory CRCs, similar to papaverine. In guinea‐pig tracheal preparations, Hp.Cr caused relaxation of carbachol and K+‐induced contractions at similar concentrations (0.01–0.3 mg/mL) and also shifted the isoprenaline‐induced inhibitory CRCs to the left, similar to that caused by papaverine. In rabbit aorta preparations at rest, Hp.Cr produced a moderate vasoconstriction, while exhibited vasodilator effect against phenylephrine and K+‐induced contractions. Papaverine and verapamil also produced similar non‐specific vasodilation, but were devoid of any vasoconstrictor effect. Hp.Cr caused suppression of atrial force of contractions at concentrations about 20 times higher than those that produced inhibitory effect in smooth muscle preparations, similar to papaverine. These results suggest that the spasmolytic effects of Hp.Cr are mediated through dual inhibition of calcium influx and phosphodiesterase (PDE)‐like mechanisms, which might explain the medicinal use of St Johns wort in the disorders of gastrointestinal and respiratory tracts. Furthermore, the presence of Ca2+ antagonist and PDE inhibitory‐like constituents might also be contributing to some extent in the well established use of plant in depression.

Gut and airways relaxant effects of Carum roxburghianum

ETHNOPHARMACOLOGICAL RELEVANCE Carum roxburghianum is traditionally used in hyperactive gastrointestinal and respiratory disorders. The present study was carried out to investigate the possible gut and airways relaxant potential of Carum roxburghianum to rationalize its folk uses. MATERIALS AND METHODS Crude extract of Carum roxburghianum (Cr.Cr) was studied in in vivo and in vitro techniques. RESULTS Cr.Cr exhibited protective effect against castor oil-induced diarrhea in mice at 100-1000 mg/kg. In rabbit jejunum preparations, Cr.Cr (0.03-3.0 mg/mL) caused relaxation of spontaneous and K(+) (80 mM)-induced contractions at similar concentrations, like papaverine. Pretreatment of tissues with Cr.Cr (0.1-1.0 mg/mL) shifted Ca(++) concentration-response curves (CRCs) to right, like verapamil. Cr.Cr (0.03 and 0.1 mg/mL) caused leftward shift of isoprenaline-induced inhibitory CRCs, similar to papaverine. In isolated guinea-pig ileum, Cr.Cr (0.01 and 0.03 mg/mL) produced rightward parallel shift of acetylcholine-curves, like atropine. Cr.Cr (1.0-30 mg/kg) caused suppression of carbachol (CCh, 100 μg/kg)-induced increase in inspiratory pressure of anaesthetized rats. In guinea-pig trachea, Cr.Cr (0.03-1.0 mg/mL) relaxed CCh and high K(+)-induced contractions, shifted isoprenaline-induced inhibitory CRCs to left at 0.1 and 0.3 mg/mL and CCh-curves parallel to right (0.01 and 0.03 mg/mL). Cr.Cr did not cause any mortality of mice up to 10 g/kg dose. CONCLUSION These results indicate that Carum roxburghianum possess combination of antidiarrheal, antispasmodic and bronchodilatory effects, which provides pharmacological basis to its traditional use in the disorders of gut and airways hyperactivity, like diarrhea, colic and asthma.

An Ethnobotanical Survey on Fuel Wood and Timber plant Species of Kaghan Valley, Khyber pakhtoonkhwa Province, Pakistan

A survey was conducted to explore the fuel wood species and timber producing species of Kaghan valleys, Pakistan. Consumption pattern and impact on the forest resources were also taken into consideration. A questionnaire was used as a survey instrument to obtain desired data. For this study, 10 villages were randomly selected. In each village, 10 persons that were randomly selected were interviewed. Only one person was interviewed from a household. A total of 100 respondents were interviewed. The studies revealed that, 75 plant species belonging to 41 families were utilized as fuel wood and 41 species belonging to 25 families were utilized as timber. Three tree species; Quercus incana, Cedrus deodara and Taxus wallichiana was found endangered. There is a dire need to conserve these species. Key words : Ethnobotany, fuel wood, timber species, Kaghan valleys, Khyber Pakhtoon Khwa Province, Pakistan.

Antispasmodic, bronchodilator and blood pressure lowering properties of Hypericum oblongifolium – possible mechanism of action

The crude extract of Hypericum oblongifolium (Ho.Cr), which tested positive for flavonoids, saponins and tannins caused concentration‐dependent (0.1–1.0 mg/mL) relaxation of spontaneous and high K+ (80 mM)‐induced contractions in isolated rabbit jejunum preparations, suggesting a Ca++ antagonistic effect, which was confirmed when pretreatment of the tissue with Ho.Cr produced a rightward shift in the Ca++ concentration‐response curves, like that caused by verapamil. Ho.Cr relaxed carbachol (1 μM) and high K+‐induced contractions in guinea pig tracheal preparations. It caused a dose‐dependent (3–100 mg/kg) fall in arterial blood pressure of rats under anesthesia. In isolated guinea pig atria, Ho.Cr caused inhibition of both atrial force and rate of spontaneous contractions. When tested in rabbit aortic rings, Ho.Cr exhibited a vasodilator effect against phenylephrine (1 μM) and high K+‐induced contractions. These results indicate that Ho.Cr possesses gastrointestinal, respiratory and cardiovascular inhibitory effects, mediated via a Ca++ antagonist mechanism. Copyright

Laxative effect of Ispaghula: Physical or chemical effect?

Seed husk of Plantago ovata (ispaghula) is a popular laxative used to regulate bowel movements. It is generally believed that its laxative effect is mediated through its fibre and/or hydrophilic mucilloid contents. We demonstrate in this communication that it also contains active chemicals causing a laxative effect. An aqueous–methanol extract of ispaghula at a dose range of 1–10 mg/mL caused a dose‐dependent stimulatory effect in guinea‐pig ileum. Pretreatment of tissue with atropine (1 μM) completely blocked the contractile effect of a supra‐maximal dose of acetylcholine (10 μM) similar to that of the lower doses of ispaghula (1–4 mg/mL), however, the effect of the larger doses (6 and 10 mg/mL) was blocked partially. These results indicate that the stimulatory effect of ispaghula at lower doses is mediated through an ACh‐like mechanism and the effect of high doses was mediated partially through unknown mechanism(s).

Insight into the bronchodilator activity of Vitex negundo

Abstract Context: Vitex negundo Linn. (Verbenaceae) is traditionally used in hyperactive respiratory disorders. Objective: This study explored the mechanisms underlying the effectiveness of Vitex negundo in hyperactive respiratory disorders. Materials and methods: Crude extract of V. negundo leaves was obtained. For in vivo bronchodilatory activity in anesthetized rats, different doses (1, 3, 10, 30, and 50 mg/kg) of the crude extract of V. negundo (Vn.Cr) were tested. The underlying mechanisms were studied in isolated guinea pig tracheal strips, suspended in organ baths at 37 °C. Results: Intravenous doses of the crude extract of Vn.Cr showed dose-dependent bronchodilatory effect (9–50%) against carbachol (CCh; 100 µg/kg)-induced bronchoconstriction, similar to aminophylline. In isolated guinea-pig tracheal strips, Vn.Crrelaxed CCh (1 µM) and high K+ pre-contractions with respective EC50 values of 0.72 (0.48–1.10; n = 5) and 3.38 mg/mL (1.84–6.21; n = 4), similar to papaverine. Diltiazem also relaxed both contractions with more potency against high K+ pre-contraction (p < 0.05). Pre-incubation of the tracheal strips with Vn.Cr potentiated the isoprenaline inhibitory concentration response curves (CRCs), similar to papaverine. Discussion: The inhibitory effect against CCh and high K+ suggests involvement of phosphodiesterase (PDE) inhibitory pathway(s), in addition to an inhibitory effect on Ca++ entry. This finding was further strengthened when pre-treatment of the tracheal strips potentiated the isoprenaline CRCs. Conclusion: Results suggest Vn.Cr possesses a combination of papaverine-like PDE inhibitor and diltiazem-like Ca++ entry blocking constituents, which partly explain its bronchodilatory effect, thus validating its medicinal importance in asthma.

Cardiovascular effects of Juniperus excelsa are mediated through multiple pathways.

Juniperus excelsa Bieb. is used in folk medicine for lowering blood pressure (BP). Its BP-lowering effect, endothelium-dependent and endothelium-independent vasodilator effects, and cardio-modulatory effect are reported here. The crude extract of J. excelsa (Je.Cr) which tested positive for the presence of anthraquinone, flavonoids, saponins, sterols, terpenes, and tannins induced a dose-dependent (10–300 mg/kg) fall in the arterial BP of anesthetized rats. In isolated rabbit aorta, Je.Cr (0.01–5.0 mg/mL) inhibited high K+ (80 mM)- and phenylephrine (1 μM)-induced contractions, like that caused by verapamil and papaverine. In endothelium-intact rat aortic preparations, Nω-nitro-l-arginine methyl ester hydrochloride-sensitive vasodilator activity was noted from Je.Cr, which also relaxed the endothelium-denuded aorta tissues. In guinea pig atria, Je.Cr initially caused mild cardiac stimulation, followed by inhibition, like that exhibited by papaverine. Je.Cr prolonged the R–R interval in electrocardiogram of rats under anesthesia. These results reveal that cardiovascular effects of J. excelsa are mediated possibly through a combination of Ca++ antagonism, nitric oxide-modulating mechanism, and phosphodiesterase inhibitory mechanism, which explain its medicinal use in hypertension.

Pharmacological Basis for Medicinal Use of Lens culinaris in Gastrointestinal and Respiratory Disorders

Crude extract of Lens culinaris (Lc.Cr), which tested positive for presence of anthraquinones, flavonoids, saponins, sterol, tannins, and terpenes exhibited protective effect against castor oil‐induced diarrhea in mice at 100–1000 mg/kg. In rabbit jejunum preparations, Lc.Cr caused relaxation of spontaneous contractions at 0.03–5.0 mg/mL. Lc.Cr inhibited carbachol (CCh, 1 μM) and K+ (80 mM)‐induced contractions in a pattern similar to dicyclomine, but different from verapamil and atropine. Lc.Cr shifted the Ca++ concentration‐response curves to the right, like dicyclomine and verapamil. Pretreatment of tissues with Lc.Cr (0.03–0.1 mg/mL) caused leftward shift of isoprenaline‐induced inhibitory CRCs, similar to papaverine. In guinea‐pig ileum, Lc.Cr produced rightward parallel shift of CCh curves, followed by non‐parallel shift at higher concentration with suppression of maximum response, similar to dicyclomine, but different from verapamil and atropine. Lc.Cr (3.0–30 mg/kg) caused suppression of carbachol (CCh, 100 µg/kg)‐induced increase in inspiratory pressure of anesthetized rats. In guinea‐pig trachea, Lc.Cr relaxed CCh and high K+‐induced contractions, shifted CCh curves to right and potentiated isoprenaline response. These results suggest that L. culinaris possesses antidiarrheal, antispasmodic, and bronchodilator activities mediated possibly through a combination of Ca++ antagonist, anticholinergic, and phosphodiesterase inhibitory effects, and this study provides sound mechanistic background to its medicinal use in disorders of gut and airways hyperactivity, like diarrhea and asthma. Copyright

Nature cures nature: Hypericum perforatum attenuates physical withdrawal signs in opium dependent rats

Abstract Context: Hypericum perforatum Linn. (Hypericaceae) (St. John’s wort) attenuates opium withdrawal signs. Aim: To explore the therapeutic potential of Hypericum perforatum in the management of opium-induced withdrawal syndrome. Materials and methods: The effect of the Hypericum perforatum hydro-ethanol extract was investigated for potential to reverse naloxone (0.25 mg/kg)-induced opium withdrawal physical signs. Rats received opium extract (80–650 mg/kg) twice daily for 8 days along with Hypericum perforatum (20 mg/kg, orally) twice daily in chronic treatment and the same single dose 1 h before induction of withdrawal syndrome in the acute treated group. Results: Hypericum perforatum reduced stereotype jumps and wet dog shake number in the chronic treatment compared to the saline control group (F(2, 24) = 3.968, p < 0. 05) and (F(2, 24) = 3.689, p < 0.05), respectively. The plant extract in the acutely treated group reduced diarrhea (F(2, 24) = 4.850, p < 0. 05 vs. saline). It decreased rectal temperature by chronic treatment at 30 min (F(2, 24) = 4.88, p < 0.05), 60 min (F(2, 240 = 5.364, p < 0.01) and 120 min (F(2, 24) = 4.907, p < 0.05). Discussion and conclusion: This study reveals that the extract of Hypericum perforatum attenuates some physical signs of opium withdrawal syndrome possibly through direct or indirect interaction with opioid receptors. Further study is needed to clarify its mechanism.