bluuebunny/crossref_metadata_2025_split huggingface dataset:
HP (2–20) derived from the amino terminal region of Helicobacter pylori ribosomal protein L1 exerts its antifungal effects by damaging the plasma membranes of Candida albicans
Authors: Lee Dong Gun , Kim Pyoung Il , Park Yoonkyung , Jang Seung‐Hwan , Park Seong‐Cheol , Woo Eun‐Rhan , Hahm Kyung‐Soo 
Published: August 2002

AbstractThe fungicidal effects of the peptide HP (2–20), derived from the N‐terminal sequence of Helicobacter pylori ribosomal protein L1 (RPL1), have been investigated. HP (2–20) displays a strong fungicidal activity against various fungi, without haemolytic activity against human erythrocyte cells, and the fungicidal activity is inhibited by Ca2+ and Mg2+ ions. In order to investigate the fungicidal mechanism(s) of HP (2–20), the amount of intracellular trehalose was measured in C. albicans. It was found that the amounts of intracellular trehalose were decreased when HP (2–20) was used. The action of the peptide against fungal cell membranes was further examined by the potassium‐release test; HP (2–20) was found to increase the amount of K+ released from the cells. Furthermore, HP (2–20) caused significant morphological changes, as shown by scanning electron microscopy, and by testing the membrane disrupting activity using liposomes (phosphatidyl choline/cholesterol; 10 : 1, w/w). Our results suggest that HP (2–20) may exert its antifungal activity by disrupting the structure of cell membranes, via pore formation or direct interaction with the lipid bilayers. Copyright © 2002 European Peptide Society and John Wiley & Sons, Ltd.
Systematic optimization of a lead‐structure identities for a selective short peptide agonist for the human orphan receptor BRS‐3
Authors: Weber Dirk , Berger Claudia , Heinrich Timo , Eickelmann Peter , Antel Jochen , Kessler Horst 
Published: August 2002

AbstractThe orphan receptor, human bombesin receptor subtype 3 (BRS‐3) was assigned to the G‐protein coupled bombesin receptor family because of its high sequence homology with the neuromedin B receptor (NMB‐R) and gastrin‐releasing peptide receptor (GRP‐R). Since its pharmacology is still unknown, new highly potent and selective tool‐substances are needed, that may be able to elucidate its possible role in obesity and cancer.We have performed structure activity relationship studies on the high affinity peptide agonists [D‐Phe6,β‐Ala11,Phe13,Nle14]Bn(6–14) and [D‐Phe6,Phe13]Bn(6–13)propylamide, using their ability to mobilize intracellular calcium in BRS‐3 transfected CHOGα‐16 cells combined with receptor binding studies. It was demonstrated that for [D‐Phe6,β‐Ala11,Phe13,Nle14]Bn(6–14) the side chains of the residues Trp8 and Phe13, and to a smaller extent β‐Ala11, are the important amino acid side chains for receptor activation and binding, however for [D‐Phe6,Phe13]Bn(6–13) propylamide His12 seems to be more important than Phe13. C‐ and N‐terminal deletions and amino acid substitutions allowed further understanding. It was demonstrated that substitution of His12 by Tyr leads to a high selectivity towards GRP‐R. Using the acquired information, a small tetrapeptide library was designed with compounds presenting Trp and Phe at varying stereochemistry and distances, which led to the discovery of the lead‐structure H‐D‐Phe‐Gln‐D‐Trp‐Phe‐NH2. Systematic SAR revealed the important structural features of this peptide, C‐terminal optimization resulted in the highly active and selective BRS‐3 agonist H‐D‐Phe‐Gln‐D‐Trp‐1‐(2‐phenylethyl)amide. In summary, the size of the peptide was reduced from 8 or 9 amino acids to a tripeptide for BRS‐3. Copyright © 2002 European Peptide Society and John Wiley & Sons, Ltd.
Conformational analysis of the Gαs protein C‐terminal region
Authors: D'ursi Anna Maria , Albrizio Stefania , Greco Giovanni , Mazzeo Sonia , Mazzoni Maria R. , Novellino Ettore , Rovero Paolo 
Published: August 2002

AbstractThe C‐terminal domain of the heterotrimeric G protein α‐subunits plays a key role in selective activation of G proteins by their cognate receptors. Several C‐terminal fragments of Gαs (from 11 to 21 residues) were recently synthesized. The ability of these peptides to stimulate agonist binding was found to be related to their size. Gαs(380–394) is a 15‐mer peptide of intermediate length among those synthesized and tested that displays a biological activity surprisingly weak compared with that of the corresponding 21‐mer peptide, shown to be the most active. In the present investigation, Gαs(380–394) was subjected to a conformational NMR analysis in a fluorinated isotropic environment. An NMR structure, calculated on the basis of the data derived from conventional 1D and 2D homonuclear experiments, shows that the C‐terminal residues of Gαs(380–394) are involved in a helical arrangement whose length is comparable to that of the most active 21‐mer peptide. A comparative structural refinement of the NMR structures of Gαs(380–394) and Gαs(374–394)C379A was performed using molecular dynamics calculations. The results give structural elements to interpret the role played by both the backbone conformation and the side chain arrangement in determining the activity of the G protein C‐terminal fragments. The orientation of the side chains allows the peptides to assume contacts crucial for the G protein/receptor interaction. In the 15‐mer peptide the lack as well as the disorder of some N‐terminal residues could explain the low biological activity observed. Copyright © 2002 European Peptide Society and John Wiley & Sons, Ltd.
Antioxidant and non‐toxic properties of Piper betle leaf extract: in vitro and in vivo studies
Authors: Choudhary Dharamainder , Kale Raosaheb K. 
Published: August 2002

AbstractPiper betle leaves are used in folk medicine for the treatment of various disorders and is commonly chewed among Asians. The present study investigates the protective efficacy of P. betle leaf extract. The presence of the extract inhibited the radiation induced lipid peroxidation process effectively. This could be attributed to its ability to scavenge free radicals involved in initiation and propagation steps. Oral supplementation with extract (1, 5 and 10 mg/kg) was administered daily for 2 weeks to Swiss albino mice and the hepatic antioxidant status was analysed. The GSH content was enhanced and no appreciable change was found in the levels of oxidative damage in terms of lipid peroxidation. Also, the specific activity of SOD increased in a dose dependent manner. These factors indicate the elevation of antioxidant status in the animals. The effect on the glyoxalase system which is considered to be activated under stress conditions was also investigated. Our findings did not observe any significant change in gly I and gly II activities, implying a non‐stress condition after oral treatment of the extract. The present study indicates the antioxidant activity of P. betle leaf extract and its potential to elevate the antioxidant status. Copyright © 2002 John Wiley & Sons, Ltd.
Effect of Acanthopanax senticosus Harms on biogenic monoamine levels in the rat brain
Authors: Fujikawa Takahiko , Soya Hideaki , Hibasami Hiroshige , Kawashima Hitoshi , Takeda Hidekatsu , Nishibe Sansei , Nakashima Kunio 
Published: August 2002

AbstractThe extract of the stem bark of Acanthopanax senticosus Harms (ASH) is known to have healing and protective effects on stress‐induced disturbance of mental status. We have analysed whether a single or chronic (2 week) administration of ASH can affect concentrations of noradrenaline (NA), dopamine (DA) and their metabolites in the normal rat brain. A single p.o. administration of ASH elevated the NA and DA levels in the whole brain of rats in a dose‐dependent manner. A single or 2 week administration of ASH (500 mg/kg) showed a marked increase in the DA level only in the striatum. However, NA levels were increased by a single dose of ASH in a wide range of brain regions such as the cortex, hypothalamus, striatum, hippocampus, substantia nigra and pons. When administered for 2 weeks no increase in NA levels was seen in these brain regions, except for an increase in the frontal cortex and anterior hypothalamus. The present results suggest that ASH may act by regulating NA and DA levels in specific brain regions related to stress response and Parkinson's disease. Copyright © 2002 John Wiley & Sons, Ltd.
In vitro antioxidant activity of non‐cultivated vegetables of ethnic Albanians in southern Italy
Authors: Pieroni A. , Janiak V. , Dürr C. M. , Lüdeke S. , Trachsel E. , Heinrich M. 
Published: August 2002

AbstractA total of 27 extracts from non‐cultivated and weedy vegetables traditionally consumed by ethnic Albanians (Arbëreshë) in the Vulture area (southern Italy) were tested for their free radical scavenging activity (FRSA) in the DPPH (1,1‐diphenyl‐2‐picrylhydrazil radical) screening assay, for their in vitro non‐enzymatic inhibition of bovine brain lipid peroxidation and for their inhibition of xanthine oxidase (XO). In both antioxidant assays strong activity was shown for Leopoldia comosa (bulbs, syn.: Muscari comosum) and Centaurea calcitrapa (young whorls). In the lipid peroxidation assay, extracts from leaves of Origanum heracleoticum, Urtica dioica and Tordylium apulum showed a remarkable inhibitory activity (>50%), too. In the case of Leopoldia comosa and Origanum heracleoticum this activity was comparable to quercetin (at a concentration of 50 μM) and Rhodiola rosea extract. Extracts from non‐cultivated Cichorium intybus, Chondrilla juncea and Stellaria media showed strong in vitro inhibition of xanthine oxidase, with an activity higher than that of a reference extract from Ledum groenlandicum. These findings suggest that weedy vegetables may be useful antioxidants of interest in the prevention of ageing related diseases, CNS disorders and as potential sources of phytomedicines against hyperuricaemia and gout. Copyright © 2002 John Wiley & Sons, Ltd.
Estrogenic activity of Nigella damascena extracts, evaluated using a recombinant yeast screen
Authors: Agradi E. , Fico G. , Cillo F. , Francisci C. , Tomè F. 
Published: August 2002

AbstractWe used the yeast estrogen screen (YES) containing a human estrogen receptor to evaluate the estrogenic activity of extracts obtained from Nigella damascena seeds. Alcohol extracts obtained by direct extraction of seeds showed a low estrogenic activity, while the alcohol extract obtained after extraction with solvents of increasing polarity showed a strong estrogenic activity. This suggests the presence in Nigella of polar components whose activity can be clearly demonstrated after previous elimination of interacting apolar components that may mask the activity of more polar components. The response of both alcohol fractions follow a bell‐shaped curve indicating a concentration‐dependent relationship. Copyright © 2002 John Wiley & Sons, Ltd.
Bioactivity studies on β‐sitosterol and its glucoside
Authors: Villaseñor Irene M. , Angelada Jennifer , Canlas Arlyn P. , Echegoyen Deborah 
Published: August 2002

Abstractβ‐Sitosterol and β‐sitosteryl‐β‐D‐glucoside were isolated as analgesic constituents from the leaves of Mentha cordifolia Opiz. The acetic acid‐induced writhing test showed that β‐sitosterol and β‐sitosteryl‐β‐D‐glucoside decreased the number of squirms induced by acetic acid by 70.0% and 73.0%, respectively, at a dose of 100 mg / kg mouse. Statistical analysis using the Kruskall Wallis one‐way analysis of variance by ranks showed that these isolates approximate the analgesic activity of mefenamic acid at a 0.001 level of significance. The hot plate method confirmed their analgesic activities, as β‐sitosterol and β‐sitosteryl‐β‐D‐glucoside exhibited a 300% and 157% increase in pain tolerance, respectively, while mefenamic acid, a known analgesic, showed a 171% increase. Neither isolate exhibited antiinflammatory activity using the carrageenan‐induced mouse paw oedema assay.β‐Sitosterol also exhibited anthelminthic and antimutagenic activities. In vitro tests using live Ascaris suum as test animals showed that the behaviour of worms treated with β‐sitosterol approximated that of the positive controls, Combantrin and Antiox. An in vivo micronucleus test showed that β‐sitosterol inhibited the mutagenicity of tetracycline by 65.3% at a dose of 0.5 mg /kg mouse. At the same dose, it did not exhibit chromosome‐breaking activity. Copyright © 2002 John Wiley & Sons, Ltd.
Inhibitory effects of Korean medicinal plants and camelliatannin H from Camellia japonica on human immunodeficiency virus type 1 protease
Authors: Park Jong Cheol , Hur Jong Moon , Park Ju Gwon , Hatano Tsutomu , Yoshida Takashi , Miyashiro Hirotsugu , Min Byung Sun , Hattori Masao 
Published: August 2002

AbstractTo identify substances with anti‐human immunodeficiency virus (HIV) activity in traditional medicines, 101 extracts of Korean medicinal plants were screened for their inhibitory effects on HIV type 1 protease (PR). The enzyme activity was determined by HPLC. Of the extracts tested, strong inhibitory effects were observed in the acetone extracts of the pericarp and leaves of Camellia japonica, the water extract of the leaves of Sageretia theezans and the methanol extract of the aerial part of Sophora flavescens. Camelliatannin H from the pericarp of C. japonica, showed a potent inhibitory activity on HIV‐1 PR with IC50 of 0.9 μM. Copyright © 2002 John Wiley & Sons, Ltd.
In vitro activity of Triclisia patens and some bisbenzylisoquinoline alkaloids against eishmania donovani and Trypanosoma brucei brucei
Authors: Camacho Maria del Rayo , Phillipson J. David , Croft Simon L. , Rock Peter , Marshall Sarah J. , Schiff Paul L. 
Published: August 2002

AbstractIn the search for antiprotozoal compounds from natural sources, Triclisia patens displayed activity against L. donovani promastigotes (IC50 = 1.5 μg/mL) and T. b. brucei blood stream trypomastigote forms (IC50 = 31.25 μg/mL). In addition, a total of 20 bisbenzylisoquinoline alkaloids were screened for antileishmanial and antitrypanosomal activity in vitro. Fangchinoline (IC50 = 0.39 μM) was found to be as active as the standard pentamidine against Leishmania donovani promastigotes. Phaeanthine was three‐fold more active (IC50 = 2.41 μM; 1.5 μg/mL) than the standard drug Pentostam against L. donovani amastigotes, but at this concentration was toxic to murine macrophages. In contrast, cocsoline (IC50 = 12.3 μM; 6.76 μg/mL) was as active as Pentostam, and was not toxic to macrophages at this concentration. Thalisopidine showed the strongest activity (IC50 = 1.14 μM) against Trypanosoma brucei brucei blood stream form trypomastigotes, but was less active than pentamidine. Copyright © 2002 John Wiley & Sons, Ltd.
Scavenger activity of Allium psekemense B. Fedtsch
Authors: Štajner D. , Milić‐DeMarino M. , Čanadanović‐Bruner J. , Popović M. 
Published: August 2002

AbstractIn the present study the antioxidative properties of the bulbs, leaves and stalks of Allium psekemense B. Fedtsch were investigated. The activities of antioxidant enzymes (superoxide dismutase, catalase, peroxidase, glutathione peroxidase), quantities of malonyldialdehyde, superoxide and hydroxyl radicals and reduced glutathione and also the content of total flavonoids, chlorophylls a and b, carotenoids, vitamin C and soluble proteins were determined. The results indicate that extracts from all plant organs exhibited antioxidant activity. The highest antioxidant activity was observed in the leaves. Furthermore, the ESR signal of DMPO‐OH radical adducts in the presence of the leaf phosphate buffer (pH 7) extract was reduced by 54.3%. Copyright © 2002 John Wiley & Sons, Ltd.
Effect of  Ginkgo biloba extract on β‐adrenergic receptors in different rat brain regions
Authors: Hadjiivanova Ch. I. , Petkov V. V. 
Published: August 2002

AbstractThe effect of oral administration of Ginkgo biloba extract at a dose of 90 mg/kg for 7 consecutive days on rat brain β‐adrenergic receptors in the frontal cortex, hippocampus, striatum and hypothalamus was studied. Ginkgo biloba treatment induced a significant decrease in the density (Bmax) of β‐adrenoreceptors in the frontal cortex and hippocampus. It has been suggested that modulation of the β‐adrenergic system is implicated in the favourable effects of Ginkgo biloba extracts on learning and memory. Copyright © 2002 John Wiley & Sons, Ltd.
Jasmine absolute (Jasminum grandiflora L.) and its mode of action on guinea‐pig ileum in vitro
Authors: Lis‐Balchin M. , Hart S. , Wan Hang Lo B. 
Published: August 2002

AbstractJasmine (Jasminum grandiflorum L.) is used in aromatherapy as a holistic treatment for apathy, hysteria, uterine disorders and childbirth, muscle relaxation and coughs. Its stimulant nature, on inhalation, has been shown both in animals and man. Jasmine has a spasmolytic activity on guinea‐pig ileum and rat uterus in vitro. The mechanism of action of the spasmolytic activity, studied in vitro using a guinea‐pig ileum smooth muscle preparation, was postsynaptic and not atropine‐like. The spasmolytic effect of jasmine absolute was most likely to be mediated through cAMP, and not through cGMP. The mode of action in vitro resembled that of geranium, lavender and peppermint oils. The contradictory effect in vitro and in vivo is probably due to the solely physiological effects of jasmine absolute in vitro (producing a relaxation) compared with that in vivo, where it has a strong psychological input, producing a stimulant effect in man and enhanced movement in animals. Copyright © 2002 John Wiley & Sons, Ltd.
In vitro anti‐hepatoma activity of fifteen natural medicines from Canada
Authors: Lin Liang‐Tzung , Liu Li‐Teh , Chiang Lien‐Chai , Lin Chun‐Ching 
Published: August 2002

AbstractFifteen crude drugs, Stellaria media Cyrill. (Caryophyllaceae), Calendula officinalis L. (Compositae), Achillea millefolium L. (Compositae), Verbascum thapsus L. (Scrophulariaceae), Plantago major L. (Plantaginaceae), Borago officinalis L. (Boraginaceae), Satureja hortensis L. (Labiatae), Coptis groenlandica Salisb. (Ranunculaceae), Cassia angustifolia Vahl. (Leguminosae), Origanum majorana L. (Labiatae), Centella asiatica L. (Umbelliferae), Caulophyllum thalictroides Mich. (Berberidaceae), Picea rubens Sargent. (Pinaceae), Rhamnus purshiana D.C. (Rhamnaceae) and Hibiscus sabdariffa L. (Malvaceae), which have been used as folk medicine in Canada, were evaluated for their anti‐hepatoma activity on five human liver‐cancer cell lines, i.e. HepG2/C3A, SK‐HEP‐1, HA22T/VGH, Hep3B and PLC/PRF/5. The samples were examined by in vitro evaluation for their cytotoxicity. The results showed that the effects of crude drugs on hepatitis B virus genome‐containing cell lines were different from those against non hepatitis B virus genome‐containing cell lines. C. groenlandica was observed to be the most effective against the growth of all five cell lines and its chemotherapeutic values will be of interest for further studies. Copyright © 2002 John Wiley & Sons, Ltd.
Aloe arborescens extract inhibits TPA‐induced ear oedema, putrescine increase and tumour promotion in mouse skin
Authors: Shimpo Kan , Ida Chikako , Chihara Takeshi , Beppu Hidehiko , Kaneko Takaaki , Kuzuya Hiroshi 
Published: August 2002

AbstractThe ethyl acetate extract of the acetone‐soluble Aloe arborescens fraction was found to inhibit 12‐O‐tetradecanoylphorbol‐13‐acetate (TPA)‐induced ear oedema, putrescine increase and tumour promotion in mouse skin. Chromatographic analyses of this extract revealed that phenolic compounds such as aloenin, barbaloin and isobarbaloin could be useful as cancer chemopreventive agents against tumour promotion. Copyright © 2002 John Wiley & Sons, Ltd.
Antimycobacterial physalins from Physalis angulata L. (Solanaceae)
Authors: Januário A. H. , Filho E. Rodrigues , Pietro R. C. L. R. , Kashima S. , Sato D. N. , França S. C. 
Published: August 2002

AbstractCrude extracts and fractions from aerial parts of Physalis angulata have been bioassayed for antimycobacterial activity. Fraction A1‐29‐12 containing physalins B, F and D exhibited a minimum inhibitory concentration value (MIC) against Mycobacterium tuberculosis H37Rv strain of 32 μg/mL. Purified physalin B and physalin D were also tested showing MIC values against Mycobacterium tuberculosis H37Rv strain of >128 μg/mL and 32 μg/mL respectively, suggesting that physalin D plays a relevant role in the antimycobacterial activity displayed. Structural elucidation of both physalins D and B was based on detailed 13C and 1H NMR spectral analysis with the aid of 2D‐correlation spectroscopy (1H‐1H, COSY, HSQC and HMBC). The assignment of the 13C chemical shift for physalin D is reported here for the first time. Copyright © 2002 John Wiley & Sons, Ltd.
Extract of Yi Zhi Fang improves learning and memory behaviours of mice and its possible mechanisms
Authors: Shan Shao‐jie , Xu Qiu‐ping , Shoyama Yukihiro 
Published: August 2002

AbstractThe effects of Yi Zhi Fang extract (YZF) on learning and memory performances were investigated in mice using passive avoidance tasks. Oral administration of YZF improved learning and memory disorders induced by chemicals in both normal and senile mice.The acetylcholine (Ach) concentration, the muscarinic Ach receptors (M‐R) and the monoamine oxidase B (MAO‐B) activities were analysed by a radioimmunoassay, a radioligand receptor binding assay and UV spectrophotometry, respectively, using senile decapitated mice. The oral administration of YZF to the senile mice increased the M‐R concentration, while the concentration of Ach and the activity of MAO‐B decreased in senile mice brains. From these results it is evident that YZF promotes the function of the central cholinergic system and inhibits the activity of MAO‐B in mice brains resulting in an enhancement of learning and memory. Copyright © 2002 John Wiley & Sons, Ltd.
Evaluation of the antimicrobial potential of medicinal plants from the Ivory Coast
Authors: Atindehou K. Kamanzi , Koné M. , Terreaux C. , Traore D. , Hostettmann K. , Dosso M. 
Published: August 2002

AbstractA total of 148 crude ethanol extracts from 115 plant species were tested in vitro against Gram‐negative strains (Escherichia coli, Pseudomonas aeruginosa) and the Gram‐positive Staphylococcus aureus and Enterococcus faecalis. Moreover, they were submitted to antifungal assays against Candida albicans and Cladosporium cucumerinum, a human and a plant pathogenic microorganism, respectively, known to be good indicators of antifungal activity. No activity was detected against the Gram‐negative bacteria, while 14.8% and 10.8% of the extracts showed Gram‐positive bactericidal or bacteriostatic effects on S. aureus and E. faecalis, respectively. An antifungal activity was observed with 15 extracts (10.1%). Two species were particularly active against the fungi: Dioscorea minutiflora and Erythrina vogelii. The young tubers of D. minutiflora contain metabolites with a specific effect on fungi and were not active against the bacteria. On the other hand, E. vogelii was highly effective against the Gram‐positive bacteria and the fungi. Copyright © 2002 John Wiley & Sons, Ltd.