Search results for "pharmacognosy"

Saponins from the Roots of Nylandtia spinosa

2007

From the roots of Nylandtia spinosa, four new triterpene saponins, 3- O-beta- d-glucopyranosylpresenegenin 28- O-beta- d-galactopyranosyl-(1-->4)-[alpha- l-arabinopyranosyl-(1-->3)]-beta- d-xylopyranosyl-(1-->4)-[beta- d-apiofuranosyl-(1-->3)]-alpha- l-rhamnopyranosyl-(1-->2)-beta- d-fucopyranosyl ester ( 1), 3- O-beta- d-glucopyranosylpresenegenin 28- O-beta- d-galactopyranosyl-(1-->4)-[alpha- l-arabinopyranosyl-(1-->3)]-beta- d-xylopyranosyl-(1-->4)-alpha- l-rhamnopyranosyl-(1-->2)-beta- d-fucopyranosyl ester ( 2), 3- O-beta- d-glucopyranosylpresenegenin 28- O-beta- d-apiofuranosyl-(1-->4)-[beta- d-galactopyranosyl-(1-->2)]-beta- d-xylopyranosyl-(1-->4)-alpha- l-rhamnopyranosyl-(1-->2)-be…

Pharmacological properties of the methanol extract from Mentha suaveolens Ehrh.

2002

The present study analyses the pharmacological activity in in vivo and in vitro models of the methanol extract obtained from the leaves and steams of Menta suaveolens Ehrh. This extract lacked toxicity, but exhibited a central nervous system depressant action; an analgesic effect in models of chemical and mechanical stimulation suggesting the induction of a peripheral analgesic response. The extract also exhibited an antiinflammatory action inhibiting the rat paw oedema induced by carrageenin. Moreover, the in vitro studies showed a significant diminution in the contractile effects induced by histamine, serotonin and acetylcholine.

COX-2 and sPLA2 inhibitory activity of aqueous extract and polyphenols of Rhizophora mangle (red mangrove)

2006

The aqueous extract of Rhizophora mangle bark and its polyphenolic fractions showed remarkable in vitro antiinflammatory activity in a preliminary study. The low molecular weight fraction exhibited cyclooxygenase-2 inhibitory activity while the total aqueous extract and the low molecular weight fraction showed secretory phospholipase A(2) inhibitory activity.

Medicinal plants and antimicrobial activity.

2005

In the present paper, we analyze the past, present and future of medicinal plants, both as potential antimicrobial crude drugs as well as a source for natural compounds that act as new anti-infection agents. In the past few decades, the search for new anti-infection agents has occupied many research groups in the field of ethnopharmacology. When we reviewed the number of articles published on the antimicrobial activity of medicinal plants in PubMed during the period between 1966 and 1994, we found 115; however, in the following decade between 1995 and 2004, this number more than doubled to 307. In the studies themselves one finds a wide range of criteria. Many focus on determining the antim…

Flavonoids fromAlphitonia neocaledonica

1995

In vitro studies of methanol and dichloromethanol extracts ofJuniperus oxycedrus L.

1997

The present study evaluated the effect of methanol and dichloromethanol extracts obtained from the leaves and stems of Juniperus oxycedrus against neurotransmitter-induced contraction in different isolated tissues of rats and guinea-pigs. Diverse concentrations of these extracts inhibit the concentration curve response to histamine, serotonin and acetylcholine. These results contribute to explaining the use of this plant in folk medicine. © 1997 John Wiley & Sons, Ltd.

Cardiovascular effects of the methanol and dichloromethanol extracts fromTeucrium flavum L.

1998

The effects on arterial blood pressure and heart rate of the methanol and dichloromethanol extracts from Teucrium flavumL. were analysed in urethane anaesthetized rats. Mean arterial blood pressure was significantly reduced by the i.v. administration of both extracts to normotensive rats. The methanol extract also induced a decrease in the heart rate, while the dichloromethanol extract lacked any effect on this parameter. © 1998 John Wiley & Sons, Ltd.

A review of the pharmacology and toxicology ofAstragalus

1997

Some Astragalus species are used as forage for livestock and wild animals. Many species are used in folk medicine for their hepatoprotective, antioxidative, immunostimulant, and antiviral properties, whereas others are toxic, and in many cases the toxic principles can pass to humans through milk and meat. Three groups of chemicals have been described as pharmacologically active principles: polysaccharides, saponins and phenolics. In addition, three kinds of toxic principles have been reported: indolizidine alkaloids, aliphatic nitro compounds and selenium. © 1997 John Wiley & Sons, Ltd.

Investigation of the Alkaloid Content of Rauwolfia serpentina Roots from Regenerated Plants.

1991

The indole alkaloid content of RAUWOLFIA SERPENTINA roots from regenerated plants (from stem-and root-callus) was compared with the parental stock. Although the total alkaloid content seems to be slightly higher in the roots from regenerated plants, HPLC-analysis of individual alkaloids indicated that the contents of the alkaloids ajmaline ( 1), serpentine ( 2), and reserpine ( 3) are lower than in the roots of the parental stock. The glucoalkaloid raucaffricine ( 4) was identified as a constituent of all samples, thus providing the first evidence for its occurrence in roots of RAUWOLFIA SERPENTINA.

Isolation and identification of the antibacterial compounds from Helichrysum stoechas.

1991

Fractionation of the dicholoromethane extract of the aerial parts of Helichrysum stoechas yielded seven isolates (1-7), which exhibited varying antimicrobial activity against Gram-positive bacteria. Pure compounds 1-3 have been previously reported in the same species and 4 and 5 were identified as italipyrone and plicatipyrone, previously isolated from H. italicum and H. plicatum. The two other isolates are helipyrone (6) and homoarenol (7) mixed with related substances. Compound 6c (4,4'-dihydroxy-5,6,5',6'-tetramethyl-3,3'-methylen-di-pyr-2-one) and 6b helipyrone with one methyl substitution, have not been previously reported in other species.