摘要:

AbstractThe effects of aconitine, higenamine and coryneine derived from processed aconite, a Sino‐Japanese medicine on pulse rate were examined in unanaesthetized mice. The intraperitoneal (i.p.) administration of the water extract (3 mg/kg) of processed aconite produced a bradycardia, like bigeminy, within 15 min which was prolonged for 30 min. Aconitine (30 μg/kg, i.p.) produced a similar bradycardia. Higenamine induced tachycardia at doses of 30 and 100 μg/kg, i.p. The aconitine‐induced bradycardia was antagonized completely by higenamine (10 μg/kg, i.p.), isoproterenol (1 μg/kg. s.c.), or scopolamine (10 μg/kg. s.c.). The anti‐aconitine effect of higenamine was prevented by propranolol (1 mg/kg, i.p.). Centrally administered aconitine (1 and 3μg) also induced bradycardia. The aconitine (i.c.v.)‐induced bradycardia was prevented by centrally administered atropine (1 μg, i.c.v.). These results demonstrated that aconitine (i.p.)‐induced bradycardia is mainly due to a central muscarinic action. As higenamine has a peripheral β1‐adrenergic action, like isoproterenol, the inhibition by higenamine of aconitine‐induced bradycardia is due to phy

ISSN:0951-418X    

DOI:10.1002/ptr.2650080302

出版商:John Wiley&Sons, Ltd.    

年代:1994

数据来源: WILEY

摘要:

AbstractFourteen different extracts of nine vasoactive medicinal plants used in European and African phytotherapy and traditional medicine were pharmacologically tested for their possible calcium antagonistic mode of action. The criteria for the selection of plants were: use in traditional medicine in the treatment of cardiovascular diseases, ‘nonspecific’ spasmolytic activity (mode of action not known), natural compounds with structural similarities to already known ‘calcium‐antagonists’ or calcium‐antagonists that have been found in species of the same tribe. All plant extracts were investigated against contractions of aortic strips induced by K+‐depolarization. Extracts derived fromAmmi visnaga, Guajacum officinale, Olea europaea, Peucedanum ostruthiumandRuta graveolensshowed a clear activity, whileCryptolepis sanguinolenta, Leonurus cardiaca, Passiflora incarnataandSolidago giganteashowed no effect in this test. A comparison between K+‐ and norepinephrine‐induced contractions evaluated the selectivity of the inhibition, which is demonstrated by the isolation and identification strategy for the Ca++‐antagonistic principles ofOlea europaealeaves andPeucedanum

ISSN:0951-418X    

DOI:10.1002/ptr.2650080303

出版商:John Wiley&Sons, Ltd.    

年代:1994

数据来源: WILEY

摘要:

AbstractThe accidental transmission of Chagas' disease by donor blood is recognized as a serious problem in the Latin America. This paper describes the screening of natural products as possible new chemoprophylactic additives in blood banks. Ten plant‐derived alkaloids, three terpenes, three quinones and 14 crude plant extracts were tested against bloodstream forms ofTrypanosoma cruziY strainin vitroat 4°C at a concentration of 250 μg/mL, using gentian violet as the baseline drug. The bisbenzylisoquinoline alkaloids, cocsuline, daphnandrine, daphnoline, isochondodendrine, gyrocarpine, limacine and pheanthine and the naphthoquinone, plumbagin completely lysed the trypomastigote forms ofT. cruziat a concentration of 250 μg/mL, this activity was verified by the subculture of the treated medium during 4 months. The active alkaloids, pheanthine, daphnoline and limacine were evaluated for mutagenicity by the sister chromatid exchange assay (SCE) in peripheral lymphocytes. Daphnoline and pheanthine elicited no significant increase of the SCE up to 50 μg/mL, while limacine significantly increased the SCE values at a concentration of 25 μg/mL, and 50

ISSN:0951-418X    

DOI:10.1002/ptr.2650080304

出版商:John Wiley&Sons, Ltd.    

年代:1994

数据来源: WILEY

摘要:

AbstractAn ethanolic extract ofCapparis cartilaginea(CC) at a dose of 1–10 mg/kg caused a dose‐dependent fall in blood pressure and heart rate in anaesthetized rats. These effects were not blocked by atropine (1 mg/kg) and pretreatment with CC did not alter the pressor response to norepinephrine, indicating that the cardiovascular effects of CC are independent of cholinergic or adrenergic receptor involvement. In spontaneously beating guinea‐pig atria, CC induced a concentration‐dependent (0.1–1 mg/mL) decrease in force and rate of atrial contractions. In rabbit thoracic aorta, CC caused inhibition of norepinephrine or K+‐induced contractions. In guinea‐pig ileum, CC (1 mg/mL) inhibited submaximal contractions induced by acetylcholine, histamine or 5‐HT. Spontaneous contractions of rat uterus were also abolished when CC was added to the tissue bath at similar concentrations. These results suggest that the direct relaxant action of CC on myocardium and blood vessels may be responsible for its hypotensive and bradycardiac effects observed in thein vivostudies. Moreover, CC exhibits general spasmolytic activity in different smooth musc

ISSN:0951-418X    

DOI:10.1002/ptr.2650080305

出版商:John Wiley&Sons, Ltd.    

年代:1994

数据来源: WILEY

摘要:

AbstractThein vitroactivities of 20Strychnosalkaloids have been determined against three species of protozoa and the active compounds were then assessed forin vitrocytotoxic activity using KB cells. 3′,4′‐dihydrosambarensine was the most active againstPlasmodium falciparum, and was relatively nontoxic to KB cells (cytotoxic/antiprotozoal ratio, 1474). Usambarensine displayed the most selectivity againstEntamoeba histolyticawhile 3′,4′‐dihydrousambarensine was the most selective compound againstGiardia intestinalisalthough the cytotoxic/antiprotozoal ratios (20.4 and 6.6 respectively) were less favourable tha

ISSN:0951-418X    

DOI:10.1002/ptr.2650080306

出版商:John Wiley&Sons, Ltd.    

年代:1994

数据来源: WILEY

摘要:

AbstractThe acute effects were compared of selected flavonoids on the pulmonary vascular circuit in two experimental models of pulmonary hypertension, produced by hypoxia and by prostaglandin F2α(PGF2α) in anaesthetized dogs. In all dogs, haemodynamic variables (pulmonary artery pressure, pulmonary artery wedge and aortic pressure, pulmonary vascular resistance, cardiac output) were recorded in the control state, during hypoxia or PGF2α‐induced pulmonary vasoconstriction, and after equimolar doses (5 mM/kg/i.v.) of luteolin, apiin and rhoifolin. The effects observed after flavonoid administration were compared with those of equimolar doses of nifedipine. The results obtained have shown that luteolin and apiin caused a decrease of hypoxic pulmonary vascular resistance to normoxic values and of the pulmonary arterial pressure while cardiac output remained unchanged. Rhoifolin produced no change in hypoxic pulmonary vasoconstriction, but decreased cardiac output and aortic pressure. The response of the pulmonary hypertension induced by PGF2αto flavonoids and nifedipine was nearly identical to that of hypoxia‐induced pulmonary hypertension. The mechanism of action of these flavonoids is di

ISSN:0951-418X    

DOI:10.1002/ptr.2650080307

出版商:John Wiley&Sons, Ltd.    

年代:1994

数据来源: WILEY

摘要:

AbstractEquisetum bogotense(Equisetaceae) andFuchsia magellanica(Onagraceae) were used by the Mapuche Amerindians as diuretics. Intravenous administration of hydroalcoholic extracts to rats elicited a hypotensive response of −29.0% ±4.5% and −24.2% ±0.5% respectively in the mean blood pressure of normotensive animals at a dose of 5 mg crude extract/kg body weight. The activity was found to be related with polar compounds. ForFuchsia, the active principles are related to tannins. A single oral dose of 500 mg/kg body weightEquisetumextract produced a significant increase (p<0.05) in the urine output in rats, while inFuchsiaa reduction in diuresis was observed. The diuretic effect of theEquisetumextract was weak compared with hydrochlorothiazide at 25 mg/kg body weight. The data presented support the use ofE. bogotensein Chilean traditional medicine. A micropropagation method forE. bogotensewas established by culturing shoot tips in Murashige‐Skoog medium with macro and micronutrients diluted 4‐fold and containing 0.1 mg/L thiamine, 100 mg/L myoinositol, 1.0 mg/L NAA and 0.1

ISSN:0951-418X    

DOI:10.1002/ptr.2650080308

出版商:John Wiley&Sons, Ltd.    

年代:1994

数据来源: WILEY

摘要:

AbstractIntravenous administration of a hydro‐methanolic extract ofArtemisia scoparia(3–30 mg/kg) produced hypotensive and bradycardiac effects. These effects remained unaltered in atropine treated animals and the presence of the extract did not modify the vasoconstrictor response of norepinephrine, indicating that cardiovascular effects of the plant extract are not mediated through activation of muscarinic receptors or adrenoceptor blockade. In thein vitrostudies, it suppressed the spontaneous movements of rabbit jejunum in a concentration‐dependent (0.1‐1 mg/mL) manner. The plant extract inhibited K+‐induced tonic contraction in a manner similar to that of verapamil. Exposure of tissue to Ca++‐free Kreb's solution abolished the spontaneous movements which were restored on addition of Ca++. In tissue pretreated with plant extract or verapamil, addition of Ca++(50 μM) failed to restore spontaneous contractions. These data indicate thatArtemisia scopariacntains Ca++channel blocker‐like constituent(s) which may explain the hypotensive effect observedin vivoand the traditional use of the plant as

ISSN:0951-418X    

DOI:10.1002/ptr.2650080309

出版商:John Wiley&Sons, Ltd.    

年代:1994

数据来源: WILEY

摘要:

AbstractThe essential oils from threeXylopiaspecies (X. frutescens, X. pynaertii, X. sericea), Annonaceae, have been examined by GC and GC/MS, and screened for bacteriostatic and fungistatic activities. The main components of each oil have been identified. The major constituents ofX. frutescensstem bark oil were α‐cubebene (25.2%) and δ‐cadinol (27.4%). The root ofX. pynaertiiwas rich in elemol (27.1%), while the stem bark oil contained δ‐cadinene (10.3%), γ‐muurolene (10.1%) and cubenol (12.6%). The major components ofX. sericearoot bark oil werep‐cymene (22.8%) and α‐gurjunene (13.8%). These oils exhibited moderate bacteriostatic and fungis

ISSN:0951-418X    

DOI:10.1002/ptr.2650080310

出版商:John Wiley&Sons, Ltd.    

年代:1994

数据来源: WILEY

摘要:

AbstractThe efficacy of Wen‐Pi‐Tang and each of its crude drug extracts on the proliferation of mouse mesangial cells was determined in terms of [3H]thymidine uptake. When Wen‐Pi‐Tang was added to the medium of mesangial cell cultures, it suppressed the proliferation of mesangial cells markedly. Similar to the effects of Wen‐Pi‐Tang, Rhei Rhizoma, its main ingredient, exerted an inhibitory effect on mesangial cell proliferation at a relatively low concentration. Ginseng Radix and Aconiti Tuber were also an effective crude drug. As for Zingiberis Rhizoma, an inhibitory activity at relatively high concentration was noted. However, the proliferation of mesangial cells in the presence of Glycyrrhizae Radix showed no particular alteration. As is clear from the results of the present study, Rhei Rhizoma, Ginseng Radix, Aconiti Tuber and Zingiberis Rhizoma alone each exert an inhibitory effect. The inhibition of mesangial cell proliferation by Wen‐Pi‐Tang can thus be explained by the action of th

ISSN:0951-418X    

DOI:10.1002/ptr.2650080311

出版商:John Wiley&Sons, Ltd.    

年代:1994

数据来源: WILEY