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Aim of the study Coriander (Coriandrum sativum) is traditionally used for various gastrointestinal and cardiovascular disorders and this study was designed to rationalize its use in dyspepsia, abdominal colic, diarrhea, hypertension and as diuretic. Materials and methods Coriander crude extract (Cs.Cr) was evaluated through in vitro and in vivo techniques. Results Cs.Cr caused atropine sensitive stimulatory effect in isolated guinea-pig ileum (0.1–10 mg/ml). In rabbit jejunum preparations, Cs.Cr evoked a similar contractile response but in the presence of atropine, it exhibited relaxation against both spontaneous and high K+ (80 mM)-induced contractions as well as shifted the Ca2+ concentration–response curves to right, similar to that caused by verapamil. Cs.Cr (1–30 mg/ml) caused fall in arterial blood pressure of anesthetized animals, partially blocked by atropine. Cs.Cr produced vasodilatation against phenylephrine and K+ (80 mM)-induced contractions in rabbit aorta and cardio-depressant effect in guinea-pig atria. Cs.Cr produced diuresis in rats at 1–10 mg/kg. Bio-assay-directed fractionation revealed the separation of spasmogenic and spasmolytic components in the aqueous and organic fractions respectively. Conclusions These results indicate that coriander fruit exhibits gut stimulatory, inhibitory and hypotensive effects mediating possibly through cholinergic, Ca2+ antagonist and the combination of these mechanisms respectively. Diuretic activity adds value to its use in hypertension.

Ethnopharmacological relevance Cardamom ( Elettaria cardamomum ) is traditionally used in various gastrointestinal, cardiovascular and neuronal disorders. Aim of the study To rationalize cardamom use in constipation, colic, diarrhea, hypertension and as diuretic. Materials and methods Cardamom crude extract (Ec.Cr) was studied using in vitro and in vivo techniques. Results Ec.Cr caused atropine-sensitive stimulatory effect in isolated guinea-pig ileum at 3–10 mg/ml. In rabbit jejunum preparations, Ec.Cr relaxed spontaneous and K + (80 mM)-induced contractions as well as shifted Ca ++ curves to right, like verapamil. Ec.Cr (3–100 mg/kg) induced fall in the arterial blood pressure (BP) of anaesthetized rats, partially blocked in atropinized animals. In endothelium-intact rat aorta, Ec.Cr relaxed phenylephrine (1 μM)-induced contractions, partially antagonized by atropine and also inhibited K + (80 mM) contractions. In guinea-pig atria, Ec.Cr exhibited a cardio-depressant effect. Ec.Cr (1–10 mg/kg) produced diuresis in rats, accompanied by a saluretic effect. It enhanced pentobarbital-induced sleeping time in mice. Bio-assay directed fractionation revealed the separation of spasmogenic and spasmolytic components in the aqueous and organic fractions respectively. Conclusion These results indicate that cardamom exhibits gut excitatory and inhibitory effects mediated through cholinergic and Ca ++ antagonist mechanisms respectively and lowers BP via combination of both pathways. The diuretic and sedative effects may offer added value in its use in hypertension and epilepsy.

This study describes the antihypertensive, antispasmodic, bronchodilator and hepatoprotective activities of the aqueous-methanolic extract of Carum copticum Benth. seeds (CSE) to rationalize some of its traditional uses. CSE (3-100 mg/kg) caused a dose-dependent fall in arterial blood pressure in anaesthetized rats. In isolated rabbit aorta and jejunum preparations, CSE (0.1-3.0 mg/ml) caused an inhibitory effect on the K+-induced contractions. The calcium channel blocking (CCB) effect was confirmed when CSE shifted the Ca2+ dose-response curves (DRCs) to right similar to verapamil. In isolated guinea-pig tracheal preparations, it caused inhibition of carbachol and K+-induced bronchoconstriction at 0.1-1.0 mg/ml as well as shifted the dose-response curves (DRCs) of carbachol and histamine to the right with suppression of maximum response suggestive of non-specific bronchodilator effect mediated possibly through CCB. Pretreatment of rats with CSE (500 mg/kg orally for 2 days at 12 h intervals) prevented paracetamol (640 mg/kg) and CCl4 (150 ml/kg)-induced rise in serum alkaline phosphatase (ALP) and aminotransferases (AST and ALT). The same dose of CSE was able to prevent the CCl4-induced prolongation in pentobarbital-induced sleeping time in mice confirming its hepatoprotectivity. These results indicate the presence of calcium antagonist(s) in Carum copticum seeds and thus provides sound mechanistic basis for some of their folkloric uses.

Olive (Olea europea) is used in traditional medicine as a remedy for hypertension. The aqueous-methanolic crude extract of O. europea fruit (OeF.Cr) was studied in anaesthetized rats and its possible mechanism was elucidated using isolated cardiovascular preparations. Intravenous administration of OeF.Cr produced a dose-dependent (30-100 mg/kg) fall in arterial blood pressure in normotensive anaesthetized rats. This effect remained unaltered in atropinized animals. In the in vitro studies OeF.Cr (0.1-3.0 mg/ml) inhibited spontaneously beating guinea-pig atria. Moreover, it relaxed K+ and/or phenylephrine-induced contractions of rabbit aortic preparations over a dose range of 0.1-3.0 mg/ml, suggesting calcium channel blockade (CCB). The CCB effect was confirmed when pretreatment of the vascular preparations with OeF.Cr produced a dose-dependent rightward shift of the Ca2+ dose-response curves, similar to verapamil. These results suggest that the blood pressure lowering effect of olive is mediated through CCB, justifying its use in hypertension.

Berberis orhob, otrvs Bien. ex Aitch. (B.o.) has been reported to have antihypertensive effect in different experimental models. The aim of present study was to evaluate the possible antihypertensive mechanism. Aqueous methanolic extract of B.o. roots and its various fractions namely (ethyl acetate, n-butanol or aqueous) in different concentrations (10 ng/mL, 100 ng/mL, I pg/mL, 10 pg/mL, 100 pg/mL ) were evaluated in isolated perfused rabbit heart to assess their effect on force of contraction, HR and perfusion pressure. The crude extract of B.o. and its fractions exhibited a significant decrease in heart rate, contractility and perfusion pressure of isolated rabbit heart, however, butanolic fraction produced more prominent effect and was selected for further study. The effects of butanol fraction were not blocked by atropine (10' M) in isolated perfused heart. However, butanol fraction significantly blocked the effects of adrenaline (10' M). It is therefore conceivable that cardiac depressant activity of B.o. butanol fraction might be due to the presence of certain 3-blocking agents which might be responsible for antihypertensive effect However, further experiments are required to isolate the active compound(s) and elucidate exact mechanism of action.

Traditionally Thymus linearis Benth. have been used for treatment of various diseases including hypertension. The present study was conducted to evaluate the hypotensive and antihypertensive effect of aqueous methanolic extract of aerial parts of Thymus linearis Benth. in normotensive and hypertensive rats. Acute and subchronic studies were also conducted. The aqueous methanolic extract produced a significant decrease in SBP, DBP, MBP and heart rate of both normotensive and hypertensive rats. LDv, of the extract was found to be 3000 mg/kg. The extract also exhibited a reduction in serum ALT, AST, ALP, cholesterol, triglycerides and LDL levels, while a significant increase in HDL level was observed. It is conceivable therefore, that Thymus linearis Benth. contains certain active compound(s) that are possibly responsible for the observed antihypertensive activity. Moreover, these findings further authenticate the traditional use of this plant in folklore medicine.

In order to rationalize the traditional uses of Asphodelus tenuifolius in cardiovascular complaints, aqueous-ethanol extract of the plant was investigated for hypotensive and diuretic activities using in vivo and in vitro models. Intravenous administration of the extract in anesthetized rats produced 14.5 (95% CI; 13.3–15.6), 24.5 (95% CI; 21.3-27.9) and 35.3% (95% CI; 32.0–42.5) fall in mean arterial blood pressure at the doses of 3, 10 and 30 mg/kg, respectively. The extract increased the urine volume and electrolytes excretion significantly at the doses of 300 and 500 mg/kg in rats. In rabbit’s isolated aorta preparations, the extract, like verapamil, relaxed K+ (80 mM)-induced contractions more potently than phenylephrine (1 µM)–induced contractions, indicating Ca2+ antagonistic activity. The extract produced dose-dependent stimulant followed by depressant effects in spontaneously contracting rabbit’s paired atria preparations. The results suggest that the extract of A. tenuifolius has hypotensive and diuretic effects in animals.

Prunes are dried fruits of several species of Prunus, including that of Prunus domestica Linn (Rosaceae) and are used for the treatment of hypertension in traditional systems of medicine in India and Pakistan. We investigated the blood pressure lowering, angiotensin converting enzyme (ACE) inhibitory and diuretic activities of the aqueous-methanolic crude extract of dried fruits of P. domestica (Pd.Cr.) in rats. Intravenous administration of the Pd Cr decreased mean arterial blood pressure, systolic blood pressure (SBP) and diastolic blood pressure (DBP) of the ketamine-diazepam anesthetized normotensive rats dose-dependently, at the dose range of 1 to 30 mg/kg. In vitro, the extract was fond to have serum ACE inhibitory activity, with IC50value of 1.102 mg/ml. The extract did not increase urine output in rats. The study concludes that the crude extract of prunes has hypotensive and ACE inhibitory activities, which provides scientific justification for its traditional uses as cardioprotective and antihypertensive remedy. Key words: Prunes, Prunus domestica, hypotensive, angiotensin converting enzyme (ACE) inhibition, diuretic.