摘要:

AbstractThe cardiovascular activity of the aqueous (A) and 30% MeOH (B) fractions of an ethanol extract of the daffodil bulbs (Narcissus tazetta) was examined using invivoandin vitropreparations of normotensive rats and in the presence/absence of various blockers: α, β‐adrenergic, cholinergic, ganglionic, histaminergic, enzyme converson inhibitor, calcium channel. These fractions (A and B) produced similar dose‐dependent hypotensive responses in the anesthetized animals. The responses induced by fraction B might be mediated via adrenergic and cholinergic receptor activation. In isolated atrial preparations, fraction A increased the atrial rate (+ ve chronotropism) but not the atrial tension (inotropism). Fraction B, however, produced negative chronotropic but positive inotropic responses. Fraction B had no effect on the untreated tail vascular smooth muscle but increased the tension on AVP‐preconstricted helical strips. It is suggested that the daffodil bulb contains cardiovascular active substances, the sum total of the effects produced accounts for the hypotensive action. It is further shown that these substances are distinct from those of well‐documented antimitotic nar

ISSN:0951-418X    

DOI:10.1002/ptr.2650060502

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractThe highly irritant new Euphorbia factors N1and N2were isolated as a mixture from latex ofE. nematocyphaHand.‐Mazz., by a combination of counter current distribution and chromatographic methods. Spectroscopic and chemical analyses revealed their structures to be 3‐0‐(2,4,6,8‐tetradecatetraenoyl)ingenol (1) and 3‐0‐(2,4,6,8‐pentadecatetraenoyl)ingenol (2),

ISSN:0951-418X    

DOI:10.1002/ptr.2650060503

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractMethanol and water extracts of 30 Indonesian medicinal plants were tested for inhibitory activity on avian myeloblastosis virus (AMV)‐reverse transcriptase (RT). The most potent inhibition was shown by extracts ofLoranthus parasiticus(whole plant),Helicteres isora(fruit),Terminalia belerica(fruit peel),Strobilanthes crispus(leaves) andWoodfordia floribunda(flower and leaves). Two kinds of template‐primers, (rA)n‐(dT)12–18and (rC)n‐(dG)12–18were examined for polymerization reaction but the inhibitory activity was stronger in the (rC)n‐(dG)12–18directed reaction in most of the samples. These extracts showed no appreciable cytotoxicity at concentrations where over 90% of RT activit

ISSN:0951-418X    

DOI:10.1002/ptr.2650060504

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractCortical microsomes of human kidneys were used to study the effect of an extract ofDesmodium adscendenson the cytochrome P450‐dependent arachidonic acid (AA) metabolism. The phenolic compounds tyramine and hordenine, as well as triterpenoid saponins known to be present in the plant were also evaluated along with the extract, ann‐butanol fraction (nBF) of the crude plant extract. The extract and the compounds were pre‐incubated with the microsomal suspension before the addition of cofactors and radioactive AA. The products of the reactions and the unreacted AA were extracted, separtaed by HPLC and measured radiometrically. The total amount of radioactive AA converted, and the production of AA metabolites identified as epoxy‐eicosatrienoic acids, monohydroxy‐eicosatetraenoic acids, 19‐, 20‐ and di‐hydroxy derivatives of AA, were inhibited by nBF. The inhibition by nBF was shown to be dose‐dependent. A saponin, sapogenin and the phenolic compounds present inD. adscendensdid not inhibit this oxygenation of AA. The results indicate that this plant contains an as yet unidentified inhibitor for the third pathway

ISSN:0951-418X    

DOI:10.1002/ptr.2650060505

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractTen compounds with potential chemopreventive activity were studied to determine their effects on microsomal mixed‐function oxidase and epoxide hydratase activity. In these studies, the highest nontoxic concentration of each compound was incubated with 1 mg rat liver microsomal protein and either [H3]benzo[a]pyrene 4,5‐oxide or [H3]benzo[a]pyrene 7,8‐dihydrodiol. High performance liquid chromatographic analysis of the metabolites was used to determine the ratio of metabolites to unmetabolized parent compound and then compared with control samples. Three of the ten compounds affected epoxide hydratase activity. Capsaicin inhibited; whereas, catechin and esculetin enhanced EH activity. Seven of the compounds tested inhibited microsomal mixed‐function oxidase activity. In order of potency, these seven compounds were tannic acid, d‐limonene, capsaicin, ellagic acid, propyl gallate, esculetin and catechin. Since the mutagenic and/or carcinogenic action of many chemicals is dependent upon the metabolic activity of microsomal mixed‐function oxidase and epoxide hydrase, the modulation of this activity by these chemicals provides further evidence in support of their potential chemopreventive

ISSN:0951-418X    

DOI:10.1002/ptr.2650060506

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractThe methanolic fraction of the root extract ofMikania cordatawas found to possess an inhibitory effect on carrageenin and other mediator—induced oedema; there was a significant inhibition of protein exudation, an increase in peritoneal capillary permeability and leucocyte migration in inflammatory conditions. The extract significantly inhibited both cotton pellet and carrageenin—induced granuloma formation, was effective in experimentally induced arthritic conditions and turpentine—induced joint oedema. The extract also possessed inhibitory effects on sodium urate‐induced experimental gout. A significant reduction of pyrexia was also found to occur when rats were treated with the extract. Thus it may be concluded that the methanolic fraction ofM. cordataroot extract possessed significant antiinflammatory effects in exudative, proliferative and chronic phases of inflammation and demonstrated an antipyretic a

ISSN:0951-418X    

DOI:10.1002/ptr.2650060507

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractTwo diterpenes fromJuniperus excelsa, obtained by bioautography‐guided isolation technique, were found to possess significant antibacterial activity in a two‐fold serial dilution assay. (+)‐Ferruginol (abieta‐8,11,13‐triene‐12‐ol) (1) and (−)‐sandaracopimeric acid (isopimara‐8(14), 15‐diene‐18‐oic acid) (2) exhibited significant activity againstBacillus subtilis, Staphylococcus aureusandStreptococcus durans, while their corresponding 3β‐hydroxy derivatives [(hinokiol (3) and 3β‐hydroxysandaracopimeric acid (4), also isolated fromJ. excelsa)] were found to be inactive. (+)‐Ferruginol, in addition, demonstrated strong activity againstMycobacterium smegmatis, M. intracellulare, M. xenopi and M. cheloni.The minimum inhibitory concentrations were determined for all compounds isolated from the active bioautographic zones, and were compared to those of the standard antibiotics chloramp

ISSN:0951-418X    

DOI:10.1002/ptr.2650060508

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractMethanol, hexane, aqueous and petroleum ether extracts of the whole plantPolygonum equisetiformedid not show any activity against ten bacterial and four fungal species. The butanol crude extract and all the pooled groups of this exhibited variable patterns of antimicrobial activity. Quercetin (a flavonol) has been isolated and identified as the major constituent. The antifungal and antibacterial activity of quercetin was compared with the antibacterial drugs gentamycin, streptomycin and ampicillin and the antifungal drug miconazole nitrate. The antifungal activity of quercetin was limited toCandida tropicalisand it had a narrow antibacterial spectrum of activity. However, its activities againstEnterobacter aerogenesandEscherichia coliwere low grade compared with ampicillin, stretomycin and gentamycin. Quercetin‐3‐O‐rhamnoside, quercetin‐3‐O‐glucuronide, quercetin‐3‐O‐arabinoside and isorhamnetin were also isolated in very low yield. They have not been reported previousl

ISSN:0951-418X    

DOI:10.1002/ptr.2650060509

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractSolasodine (C27H42O2N), a nitrogen analogue of diosgenin reduced serum cholesterol and LDL cholesterol by 73.3% and 73.5% and prevented atherogenesis (Atherogenic index‐control: 1.99; athero‐ group: 3.12; solasodine treatment 2.12–2.32). The cholesterol/phospholipid ratio was decreased by 42.02% while the HDL ratio was raised significantly. Solasodine treatment prevented the accumulation of cholesterol in the liver and aorta and regressed plaque size in the thoracic and abdominal aorta. Faecal excretion of cholesterol and phospholipids was significantly (p>0.001) increased suggesting that modulation of absorption was aff

ISSN:0951-418X    

DOI:10.1002/ptr.2650060510

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractTwenty‐one plant species were selected to provide samples for a pilot test of the newly established in‐house antiviral screening programme at The University of Mississippi. These species were selected on the basis of folkloric use or the present of lignans in the plant family to increase the likelihood of positive results. The percentage (19%) of species showing antiviral activity against either Rhino virus 1A or Herpes Simplex virus 1 was within the percentage range of plants with antiviral activity found in other screenings for which a similar basis for collection was used. The plant extracts were also screened for antimicrobial activity and for toxicity to brine shrimp. Results of the screenings for all biological activities were correlated with the basis for collection. The best correlation between basis for collection and biological activity was seen for species from plant families containing lignans that were collected based on folkloric use for colds and anti‐Rhino viral act

ISSN:0951-418X    

DOI:10.1002/ptr.2650060511

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY