bluuebunny/crossref_metadata_2025 huggingface dataset:
Highly sensitive assay of okadaic acid using protein phosphatase and paranitrophenyl phosphate
Authors: Simon Jean François , Vemoux Jean‐Paul
Published: October 2006

A colorimetric phosphatase‐inhibition bioassay was developed for the quantitative measurement of okadaic acid (OA) the main diarrhetic toxin responsible for diarrhetic shellfish poisoning. The assay used an artificial substrate, paranitrophenylphosphate, and a semi‐purified protein phosphatase PP2Ac containing extract prepared from rabbit muscle. Calibration dose‐inhibition curves were constructed using standard OA and they permitted easy determination of the enzyme concentration Et in their linear portion. In the range of linearity, the slope increased when Et decreased, thus giving a detecting limit of 0.04 pmol in the reaction mixture (1 ml). The lowest assayable concentration of OA was 4 ng/ml in aqueous solutions and 40 ng/ml (i.e., 100 ng of OA per g of mussel tissue) in crude methanol mussels extracts. The infra and interassay coefficients of variation in the measurement of OA for the toxin spiked aqueous samples averaged, respectively, 7.7% and 3.7%, and interexperiments coefficients of variation for the toxin spiked mussel extracts averaged 4.6%. The presence of OA was ascertained by a method in which one assay was performed at two or three different levels of enzyme concentration. The rapidity, accuracy, reproducibility, specificity, and simplicity of the procedure provides a simple way to assay okadaic acid in buffered or complex solutions. © 1994 wiley‐Liss, Inc.
Interactions between bacteria and harmful algae: A review
Authors: Doucette Gregory J.
Published: October 2006

The ways in which bacteria interact with eukaryotic, unicellular algae are extremely diverse. Such relationships vary widely according to a number of criteria, including spatial and temporal scales, the degree of specificity, and if the relationship can be characterized as beneficial or detrimental to any of the organisms involved. These criteria can be applied to our assessment of how microbes interact with those species involved in the formation of harmful algal blooms (HABs). The aim of this paper is to assess the current state of our knowledge of bacterial/HAB interactions as they pertain to the influence of bacteria on HAB population dynamics, the role of bacteria in the production of toxins normally attributed to the algae, and the suggestion that HABs may act as vectors for pathogenic bacteria. Given that viruses are now considered to play a potentially important role in structuring phytoplankton communities, the possible effects of viruses on the population dynamics of harmful algal species are also addressed. © 1995 Wiley‐Liss, Inc.
Ethanolic extraction, purification, and partial characterization of a fluorescent toxin from the coral reef crab, Lophozozymus pictor
Authors: Lau C. O. , Tan C. H. , Khoo H. E. , Li Q. T. , Yuen R.
Published: October 2006

A purification procedure for Lophozozymus pictor toxin (LPTX) following ethanolic extraction of whole crab homogenate is described. The ethanol‐extracted toxin (LPTX‐E) had higher yield and specific activity than the hot aqueous‐extracted one (LPTX‐H). It was found that LPTX‐E was fluorescent and cochromatographed with LPTX‐H on two‐dimensional thin‐layer chromatography. Although LPTX‐E, LPTX‐H, and palytoxin (P. caribaeorum, PTX) had similar migration and retention times when analysed on high performance capillary electrophoresis and gel permeation‐high performance liquid chromatography respectively, LPTX‐E and LPTX‐H were both fluorescent in contrast to PTX In addition, LPTX‐E had a different retention time compared with PTX when chromatographed on reversed phase high performance liquid chromatography in the solvent system 80% acetonitrile and 0.02 M Tris‐HCI, pH 7.2, at a 4:1 ratio, respectively, indicating some differences in their chemical structures. © 1995 Wiley‐Liss, Inc.
Fate in humans of dietary intake of cyanogenic glycosides from roots of sweet cassava consumed in Cuba
Authors: Hernández Teresa , Lundquist Per , Oliveira Lourdes , Cristià Rafael Perez , Rodriguez Elena , Rosling Hans
Published: October 2006

We studied if consumption of boiled fresh roots from sweet cassava varieties grown in Cuba resulted in exposure to cyanogenic glycosides and their final breakdown product, cyanide. When adult, nonsmoking subjects consumed 1‐4 kg cassava over 2 days, their urinary levels of the main cyanide metabolite, thiocyanate, only increased from a mean ± SEM of 12 ± 2 to 22 ± 2 μ.mol/l, indicating a negligible cyanide exposure. Their mean urinary linamarin, the main cyanogenic glucoside in cassava, increased from 2 ± 1 to 68 ± 16 μmol/l. In a second experiment 5 subjects consumed one meal of 0.5 kg boiled cassava that contained 105 μ‐mol linamarin and 8 μ.mol hydrogen cyanide (HCN). Quantitative urine collections prior to and after intake showed that 28% of linamarin was excreted during the following 24 hours, whereas a modest increase of urinary thiocyanate (SCN) only corresponded to the small amount of free HCN ingested. These results indicate that the dominant cyanogen in boiled cassava is glycosides that pass through the human body without causing cyanide exposure. It remains to be studied whether humans occasionally possess intestinal or tissue β‐glucosidases that can hydrolyse cyanogenic glycosides from cassava. © 1995 Wiley‐Liss, Inc.
Metabolism of the Fusarium mycotoxins zearalenone and deoxynivalenol by yeast strains of technological relevance
Authors: Böswald Christoph , Engelhardt Gabriele , Vogel Herbert , Wallnöfer Peter R.
Published: October 2006

The Fusarium mycotoxin zearalenone (ZEA), added at a level of 2 μ/ml, was reduced stereoselectively by cultures of Candida tropicalis, Torulaspora delbrückii, Zygosaccharomyces rouxii, and 7 Saccharomyces strains to both α‐ and β‐zearalenol. In contrast, only a‐zearalenol was produced from ZEA by Pichia fermentans and several yeast strains of the genera Candida, Hansenula, Brettanomyces, Schizosaccharomyces, and Saccharomycopsis. No glucose conjugates of ZEA (zearalenone‐4‐β‐D‐glucopyranoside) were detected. The trichothecene mycotoxin deoxynivalenol (DON) was not metabolized by any of the yeast strains that were used for analysis. © 1995 Wiley‐Liss, Inc.
Maitotoxin increases voltage independent chloride and sodium currents in GH4C1 rat pituitary cells
Authors: Young Roger C. , McLaren Matthew , Ramsdell John S.
Published: October 2006

Maitotoxin (MTX) is a 3,424 dalton polyether marine toxin that causes influx of calcium through type L voltage‐dependent calcium channels (L‐VDCC) in GH4C1 rat pituitary cells, presumably as the result of membrane depolarization. In this study we have investigated the ionic conductances responsible for MTX‐induced depolarization under voltage clamp conditions using the perforated and ruptured patch methods. MTX‐induced steady‐state voltage independent currents of nearly 400 pS/pF within seconds of addition to the bath. Ion substitution experiments demonstrated these currents are consistent with the conductance of sodium and chloride, but not calcium, ions. MTX induction of the voltage‐independent chloride conductance in GH4C1 cells occurred concurrently without modification of L‐VDCC currents. Pretreatment with nimodipine eliminated voltage activation of L‐VDCC, and reduced by two thirds the voltage independent current. Analysis as a function of time of MTX exposure revealed that the first 60 sec of MTX‐induced currents were not affected by nimodipine pretreatment, but subsequent additional currents were prevented. This indicates that the initial currents induced by MTX occur independently of L‐VDCC mediated calcium entry, but full activation of these currents by MTX likely requires the involvement L‐VDCC. Taken together this work identifies a voltage‐independent sodium/chloride conductance as an initial action of MTX, one that may promote the sequence of ionic events leading to activation of L‐VDCC and massive calcium entry. © 1995 Wiley‐Liss, Inc.
The impact of clustering in physician and pharmacy services on the accuracy of pharmaceutical exposure risk estimates
Authors: Burkhart Greg A. , Hammerstrom Thomas
Published: October 2006

Record‐linkage databases have been used to evaluate the safety of approved drugs. Outcome and exposure data collected in these databases are contingent upon temporal contacts between patients and their physicians and pharmacists. We examined the theoretical effect of temporal clustering in physician and pharmacy services on pharmaceutical risk estimates by generating computer modeled datasets of the dates of provider services. Incidence density ratios were estimated for each dataset by comparing the incidence of the hypothetical outcome during exposure to that during no exposure. The presence of clustering in provider services, the risk associated with exposure, the length of the risk period, the number of refills and the underlying physician visit rates were varied by dataset. Biased estimates of the incidence density ratio were obtained in datasets with clustering. The magnitude of bias decreased with increasing length of the risk period, increasing number of refills and increasing physician visit rate. A sample of an HMO record‐linkage database showed evidence of clustering in physician visits at the patient level when the transaction dates for all physician visits were tested for clustering. Researchers using record‐linkage databases or data derived from patient interactions with providers to study the acute risk of pharmaceutical exposures, should consider the possibility of biased risk estimates for outcomes that cluster with other outcomes and exposure.
Drug‐induced acute pancreatitis
Authors: Bergholm U. , Langman M. , Rawllins M. , Gaist D. , Andersen M. , Edwards I. R. , Wiholm B.‐E.
Published: October 2006

The incidence of acute pancreatitis appears to have increased in the USA, Denmark and in the United Kingdom and one suggested explanatory factor is a simultaneously increased use of certain drugs.

This report surveys the available information on the association between drugs and acute pancreatitis in the literature and in spontaneous reporting systems in Denmark, Sweden and in the United Kingdom, supplemented with information from the WHO data base.

Apart from one case‐control study which provided evidence for an association between diuretic use and acute pancreatitis, the information in the literature is based on single case reports. About 15 drugs are frequently reported both in literature, and in spontaneous reporting systems, to be associated with pancreatitis and can be regarded as adverse reaction signals. The validity of such data is often low and does not provide information on relative or absolute risks, if any, for a drug adverse reaction association.

To elucidate the possible role of drugs in etiology of acute pancreatitis, further formal epidemiologic studies are needed.
Synthesis and MALDI‐TOF analysis of dendritic‐linear block copolymers of lactides: Influence of architecture on stereocomplexation
Authors: Richez Alexandre , Belleney Joel , Bouteiller Laurent , Pensec Sandrine
Published: October 2006

Formation of a stereocomplex from polylactide copolymers can be tuned by changing the size and the chain topology of the second block in the copolymer. In particular, the use of a dendritic instead of linear architecture is expected to destabilize the cocrystallisation of polylactide blocks. With this idea in mind, dendritic‐linear block copolymers were synthesized by ring‐opening polymerization (ROP) of lactides using benzyl alcohol dendrons of generation 1–3 as macroinitiators and stannous octoate as catalyst. Polymers with controlled and narrow molar mass distribution were obtained. The MALDI‐TOF mass spectra of these dendritic‐linear block copolymers show well‐resolved signals. Remarkably, 10% or less of odd‐membered polymers are present, indicating that ester‐exchange reactions which occur classically parallel to the polymerization process, were in these conditions, very limited. Thermal analysis of polyenantiomers of generation 1–3 and the corresponding blends were examined. The blend of a pair of enantiomeric dendritic‐linear block copolymers exhibit a higher melting temperature than each copolymer, characteristic for the formation of a stereocomplex. Melting temperatures are strongly dependent on the dendron generation. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 6782–6789, 2006
In situ electron spin resonance study of styrene grafting of electron irradiated fluoropolymer films for fuel cell membranes
Authors: Mitov Svetlin , Hübner Gerold , Brack Hans‐Peter , Scherer Günther G. , Roduner Emil
Published: October 2006

Three different electron beam irradiated fluoropolymers (ETFE, FEP, and PVDF) as well as their grafting reactions with styrene in different diluents were investigated by means of electron spin resonance (ESR). Depending on the atmosphere during irradiation, ESR spectra of peroxy and alkyl radicals were observed. Radical decay as a function of time and temperature was investigated in the presence and absence of solvent. Grafting levels and number of monomer units per chain were calculated for both types of radicals. Irradiation atmosphere, grafting temperature, and added solvent affect the morphology of the fluoropolymers, in particular the crystalline versus amorphous fractions and their swelling. They thus influence the rate at which the initial radicals at the polymer backbone are reached during the grafting process. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 3323–3336, 2006
Antileishmanial activity of harmaline and other tryptamine derivatives
Authors: Evans A. Tudor , Croft Simon L.
Published: October 2006

Tryptamine derivatives harmaline and α‐ethyltryptamine were found to possess a novel antiparasitic action against human pathogen Leishmania mexicana amazonensis both in vitro and in vivo. In vitro, harmaline was the most potent compound tested, with an ED50 of 99μ, whilst α‐ethyltryptamine (ED50 149 μ) had the best therapeutic index (2). In vivo, α‐ethyltryptamine was most effective when given orally (ED50 47 mg/kg), but was also effective when given topically. We suggest that further investigation of traditional plant drugs containing derivatives of β‐carbolines and alkyltryptamines would provide a number of novel antiparasitic drugs.
Enhancement of adipose differentiation of mouse 3T3‐L1 fibroblasts by ginsenosides
Authors: Sekiya Keizo , Okuda Hiromichi , Hotta Yasuo , Arichi Shigeru
Published: October 2006

Some ginsenosides, extracted and purified from the roots of Panax ginseng C. A. Meyer, stimulated adipose differentiation of mouse 3T3‐L1 fibroblasts. Ginsenoside Rb1 induced adipose differentiation of 3T3‐L1 cells in a culture medium supplemented with 20% fetal calf serum, but not in one with 10% fetal calf serum. Furthermore, ginsenoside Rb1 enhanced adipose differentiation induced by insulin or dexamethasone plus 1‐methyl‐3‐isobutylxanthine (DEX‐MIX). Other ginsenosides such as ginsenoside Rd and Rh2 also enhanced DEX‐MIX‐induced adipose differentiation, but ginsenosides Re, Rg1 and Ro had no effect. These results suggest that there is a clear structure‐activity relationship to the 20(S)‐protopanaxadiol aglycone group only in stimulation of adipose differentiation.
Pharmacological analysis of the inhibitory effect of jatrophone, a diterpene isolated from Jatropha elliptica, on smooth and cardiac muscles
Authors: Calixto João B. , Sant'Ana Antonio E. G.
Published: October 2006

The present work was conducted to analyse the effect of the diterpene jatrophone on drug and electrically evoked contractions of cardiac and smooth muscle preparations. Pre‐incubation of the isolated rat uterus with jatrophone (1–100 μM), for 20 min caused a decrease in the maximal contractions and a rightward displacement of the dose‐response curves to acetylcholine, bradykinin, and oxytocin. In the isolated longitudinal muscle from guinea‐pig ileum, jatrophone (1.6–12.8 μM) produced a concentration‐dependent inhibitory effect of acetylcholine, bradykinin and histamine‐induced contractions. In this tissue, jatrophone was about 5 to 8‐fold more potent in inhibiting acetylcholine and bradykinin than in uterine muscle. In strips of guinea‐pig ileum, guinea‐pig urinary bladder, rat left atrium electrically stimulated, and dog ureter contractions, jatrophone (1–100 μM) caused a concentration‐dependent inhibitory effect. In preparations electrically stimulated, jatrophone was about 2.5 to 23‐fold less potent compared to those values obtained against agonist‐induced contractions in the guinea‐pig ileum. These results demonstrate that jatrophone exerts direct inhibitory effect on cardiac and smooth muscle preparations and show that its inhibitory potency may vary according to the tissue and/or stimulus employed to induce muscle contractions.
Pharmacological Investigation on Sodium Salt and Acetyl Derivative of Anacardic Acid
Authors: Bhattacharya Salil K. , Mukhopadhyay Meeta , Rao Patchala J. R. Mohan , Bagchi Anjana , Ray Anil B.
Published: October 2006

Sodium salts of anacardic acid (SA) and O‐acetyl anacardic acid (AA) were subjected to pharmacological screening primarily on paradigms known to be affected by prostaglandin (PG) synthesis inhibitors. Results were compared with those elicited by known cyclo‐oxygenase inhibitors. SA and AA had little discernible effect on general behaviour and showed overt signs of central stimulation in unusually large doses. SA augmented spontaneous motor activity in mice and attenuated hexobarbitone hypnosis in rats. It augmented the convulsant action of pentylene‐tetrazol and inhibited the anticonvulsant effect of phenobarbitone against maximal electroshock‐induced seizures in rats. SA inhibited catalepsy induced by morphine and haloperidol in rats, and antagonized bradykinin‐induced catalepsy when administered intracerebroventricularly (i.c.v.) in rats. Both exhibited significant anti‐inflammatory activity against carrageenin‐induced acute inflammation in rats. This anti‐inflammatory effect was also in evidence when SA was administered i.c.v. SA and AA had no per se effect on rectal temperature in rats but significantly attenuated the hyperthermia induced by i.c.v. bradykinin or i.p. carrageenin. In all these parameters the effects of SA or AA were comparable to those elicited by diclofenac, aspirin or acetaminophen. However, unlike aspirin and diclofenac, which showed significant antinociceptive activity against phenylquinone‐induced writhing technique, SA was additionally effective against radiant heat and thermic stimulation‐induced nocisponsive technique. Both SA and AA appeared to be fairly safe drugs as assessed by acute toxicity studies. Like the cyclo‐oxygenase inhibitor, diclofenac, SA significantly reduced rat brain PGE2 and PGF2α concentrations, as assessed by a radioimmunoassay technique. Pharmacological and biochemical studies indicate that anacardic acid functions as a PG synthesis inhibitor, with the added advantage of having a central analgesic property.
The cellular actions of the avermectins
Authors: Wann Kenneth T.
Published: October 2006

Ivermectin is a synthetic derivative of the naturally occurring fermentation products, the avermectins. It was introduced as an antiparasitic drug in 1981, is now widely used in many countries, and as a drug has attracted considerable attention. In veterinary medicine its broad spectrum of activity has proved invaluable. In clinical trials in man its action seems to surpass that of currently available alternatives. The putative mode of action of the avermectins (AVMs) is unique, and this action has prompted within the industry a rethink of current strategies and a search for new drugs with equal activity. As tools the AVMs are also sufficiently refined to permit detailed probing of the properties of the GABA receptor channels of both mammalian and non‐mammalian systems. Consequently our knowledge of such systems has been enhanced by the judicious use of these probes. In this review the principal cellular actions of the AVMs are discussed. These actions provide insight into the possible mechanisms underlying the potent biological activity displayed by these agents.
Activation of immunoresponder cells by the protein fraction from aged garlic extract
Authors: Hirao Yuzo , Sumioka Isao , Nakagami Satoru , Yamamoto Michiko , Hatono Syunzo , Yoshida Susumu , Fuwa Tohru , Nakagawa Shizutoshi
Published: October 2006

F‐4, a protein fraction isolated from aged garlic extract strongly stimulates mice peritoneal macrophages in terms of glucose utilization and exhibits cytostatic activity in vitro. F‐4 also has a mitogenic activity on spleen cells. In vivo, F‐4 induced the stimulation of carbon clearance activity in mice. No obvious activities were observed in the low molecular fraction of aged garlic in these tests, but weak effects were found in the fructan fraction (F‐3).
Structural role of an unsaturated lactone in acute toxicity of rubratoxin B isolated from Penicillium rubrum
Authors: Feng Y. P. , Wong S. M. , Evans M. A.
Published: October 2006

Rubratoxin B is a substituted higher homolog of byssochlamic acid in which the ethyl group is replaced by a six‐membered ring containing an unsaturated lactone. Hydrogenation of the unsaturated lactone greatly reduces the acute toxixity of the compound. The acute median lethal doses of rubratoxin B and hydrogenated rubratoxin in male mice were 5.6 and 31 mg/kg, respectively. Pretreatment with phenobarbital (60 rag/kg × 4 days) or with SKF 525A (40 mg/kg) failed to significantly alter the toxicity of either compound. Histopathological examination of mice treated with rubratoxin B (3.5 mg/kg) revealed areas of hepatic zonal necrosis and marked necrosis of kidney tubules. No necrosis was observed in mice treated with hydrogenated rubratoxin (20 mg/kg). Hepatic microsomal mixed function oxidase activity was significantly reduced in mice pretreated with rubratoxin B (0.5 mg/kg × 4 days), while pretreatment with hydrogenated rubratoxin (2.5 mg/kg × 4 days) failed to depress microsomal activity. Our studies document the requirement of an alpha, beta unsaturated lactone ring for rubratoxin B toxicity. Based on the results from these studies the mechanism for rubratoxin B induced toxicity is postulated to be due to its electrophilic properties and subsequent alkylating activity.
Effects of chalcones isolated from licorice roots on leukotriene biosynthesis in human polymorphonuclear neutrophls
Authors: Kimura Yoshiyuki , Okuda Hiromichi , Okuda Takuo , Arichi Shigeru
Published: October 2006

The effects of chalcones and flavanones isolated from Sinkiang Licorice (Glycyrrhiza inflata Bat.) on leukotriene B4(LTB4) and C4(LTC4) formation in human polymorphonuclear neutrophils (PMNs) were investigated. Licochalcone A (2‐methoxy‐4,4′‐dihydroxy‐5‐α,α‐dimethyl‐allylchalcone) and licochalcone B (2‐methoxy‐3,4,4′‐trihydroxychalcone), at concentrations of 10−3 to 10−6 M, inhibited calcium ionophore A 23187 (A 23187)‐induced LTB4 and LTC4 formation in human PMNs. The concentration of licochalcones A required for 50% inhibition (LC50) of LTB4 and LTC4 formation was 4.6 × 10−7 and 4.2×10−6 M, respectively, using 2 μM A 23187. The IC50 values of licochalcone B for LTB4 and LTC4 formation were also 1.2 × 10−6 and 2.0×10−6 M, respectively. In addition, licochalcones A and B significantly increased cyclic AMP level in human PMNs at concentrations of 10−4 to 10−3 M. Licochalcones A and B were found to reduce the elevation of the cytosolic free calcium concentration induced by calcium ionomycine, dose‐dependently, in the presence of 1 mM Ca2+ or 1 mM EGTA.
Mechanisms of hypoglycemic activity of panaxans A and B, glycans of Panax ginseng roots: Effects on plasma level, secretion, sensitivity and binding of insulin in mice
Authors: Suzuki Yutaka , Hikino Hiroshi
Published: October 2006

Panaxan A did not affect plasma insulin levels and insulin sensitivity, whereas Panaxan B elevated the plasma insulin level and enhanced insulin sensitivity in vivo. When mice were treated with panaxan B, insulin secretion from pancreatic islets was potentiated, while direct addition of panaxan B to pancreatic islets from normal mice showed no enhancement of insulin secretion in vitro. Hypoglycemic activity of panaxan B was not inhibited by indomethacin. Panaxans A and B showed hypoglycemic activity in spontaneously diabetic mice. Insulin binding to isolated adipocytes obtained from panaxan B‐treated mice was significantly increased, while direct addition of panaxan B to isolated adipocytes from normal mice elicited no increase of insulin binding. It is concluded that a part of the hypoglycemic activity of panaxan B is due to increase of the plasma insulin level and enhancement of insulin sensitivity, while that of panaxan A is attributable to other mechanisms.
Toxicity studies on six plants used in the traditional Arab system of medicine
Authors: Shah A. H. , Qureshi S. , Tariq M. , Ageel A. M.
Published: October 2006

Toxicity studies were done on six plants used in the traditional Arab system of medicine, namely: Aloe vera, Ammi majus, Areca catachu, Citrullus colocynthis, Cuminum cyminum and Zizyphus spina‐christi. During acute toxicity tests, observations were made for 24 h while the animals were treated for 3 months in chronic treatment. External morphological changes, visceral toxicity, haematological changes, and spermatogenic dysfunction, besides effects on average body weight and vital organ weight, were recorded. In the acute toxicity test, C. colocynthis showed a dose dependent toxic effect. On chronic treatment, per cent lethality was found to be significant in A. catachu, A. vera and C. colocynthis treated groups where haematological changes were also observed. The spermatogenic dysfunction was significant in A. vera and C. colocynthis treated animals. C. cyminum and Z. spina‐christi on the other hand, reduced sperm abnormalities.
Antimicrobial activity of selected plants employed in the Spanish mediterranean area. Part II
Authors: Recio M. C. , Rios J. L. , Villar A.
Published: October 2006

The antimicrobial properties of 59 plants used in folk medicine to treat general infectious diseases were studied. The in vitro antimicrobial activity of chloroform and methanol plant extracts were assayed using the agar‐streak method and 38 of them showed activity against some of the microorganisms tested. Bioautography established the probable active compounds. Inhibition bands were identified as containing terpenoids and polyphenolic compounds.
Capsaicin pretreatment protects free radical induced rat lung damage on exposure to gaseous chemical lung irritants
Authors: De Amit Krishna , Ghosh Jagat Jiban
Published: October 2006

Pretreatment with capsaicin tends to normalize pulmonary lipid peroxidation changes induced by exposure to sulfur dioxide, formalin or nitrogen dioxide gases. This protective effect of capsaicin pretreatment appears to be due to the stabilization of the rat lung membrane lipid system.
Cytotoxic action of alpha‐methylene lactones towards HeLa cells in culture
Authors: Chagonda L. , Lockey P. M. , Marples B. A. , Salt W. G. , Traynor J. R.
Published: October 2006

Possible targets to account for the qtotoxic activity of the a‐methylene containing sesquiterpenes elephantopin and vernoleph, and an a‐methylene‐lactone steroidal derivative, 3‐methoxy‐16‐methylene‐17‐oxo‐17a‐Dhomoestra‐1,3,5,(10)‐triene, have been studied. The compounds reduced surface and intracellular thiol levels in HeLa S3 ceb, caused an inhibition of Na+/K+‐ATPase and an inhibition of the incorporation of [3H]thymidine into macromolecules. In addition, the steroidal compound, but not the sesquiterpene elephantopin, released lysosomal enzymes and caused marked changes in the structural integrity of the cells. Observed effects of α‐methylene lactones on cellular respiration and [3H]thymidine uptake were not a consequence of alkylation. The results support the concept of the cell membrane and in particular Na+/K+‐ATPase as a target for sesquiterpene lactone alkylation.
Anti‐inflammatory and related actions of Syzygium cuminii seed extract
Authors: Chaudhuri A. K. Nag , Pal Siddhartha , Gomes A. , Bhattacharya Siddhartha
Published: October 2006

The chloroform fraction of Syzygium cuminii seeds was found to cause significant inhibition of carrageenin, kaolin and other mediator‐induced oedema. The extract inhibited exudation of protein, leakage of dye in peritoneal inflammation and migration of leucocytes. The extract also caused inhibition of grannloma formation, experimental arthritis and also turpentine‐induced joint oedema. Significant anti‐pyretic action of the extract was also observed against yeast‐induced pyrexia. These observations established the anti‐inflammatory effect of S. cuminii seed extract in exudative, proliferative and chronic stages of inflammation along with an anti‐pyretic action.
Comparative studies on the involvement of histamine and substance P in the inflammatory response of capsaicin in rat paw
Authors: de Krishna Amit , Ghosh Jagat Jiban
Published: October 2006

Direct administration of capsaicin (isolated from Capsicum frutescens) in the rat paw caused a dose‐related inflammatory response, which reached a maximum peak within 10 min and remained steady for 180 min after injection. Pretreatment with histamine H1 receptor antagonist and substance P antagonist produced significant inhibition to this capsaicin‐induced paw oedema. Results indicate the involvement of histamine in the early phase and both histamine and substance P in the later phase of capsaicin‐induced inflammation in the rat paw.
The effect of plant growth regulators and nutrient conditions on growth and alkaloid production in multiple shoot cultures of Rauwolfia serpentina
Authors: Roja G. , Benjamin B. D. , Heble M. R. , Patankar A. V. , Sipahimalani A. T.
Published: October 2006

Multiple shoot cultures of Rauwolfia serpentina were established from axillary meristems of the field grown plants on Murashige and Skoog's medium supplemented with benzyladenine (BA) (1.0 ppm) and naphthalene acetic acid (NAA) (0.1 ppm). Growth hormones influenced the morphogenetic events of the shoot cultures such as root initiation in indoleacetic acid (IAA) combinations, stunted shoot formation in 2, 4‐dichlorophenoxyacetic acid (2, 4–D) and slender shoot formation in kinetin (Kn) + NAA combinations. The morphogenetic responses were associated with marginal changes in alkaloid production. The cultures produced high levels of alkaloids including ajmaline (0.15%) ajmalidine and 3–epi‐α‐yohimbine in Zenk's production medium. The alkaloid concentrations in the cultures were comparable to the alkaloids in the roots of the intact plant. The shoot cultures showed stability of growth and alkaloid production characteristics over a period of five years.
Attenuation of the increase in blood pressure and vascular reactivity by chronic oral administration of soft‐shelled turtle powder in spontaneously hypertensive rats
Authors: Feng Hong , Matsuki Norio , Saito Hiroshi
Published: October 2006

The effects of chronic oral administration of cryomilled powder of the soft‐shelled turtle (SST powder) on blood pressure, serum catecholamine contents and vascular reactivity of spontaneously hypertensive rats (SHR) and normotensive Wistar Kyoto rats (WKY) were studied. The SST powder was administered orally 20–500 mg/kg/day for 9 weeks. The treatment slowly but significantly reduced the blood pressure increase in SHR. However, the SST powder did not affect the blood pressure in WKY. Heart rate and wet heart weight were not affected by the SST powder treatment. Serum content of catecholamine and aldosterone and the plasma renin activity were also unaffected by the chronic administration of the SST powder. The increase in vascular resistance of isolated mesenteric vascular beds from SHR was significantly reduced by the chronic treatment of SST powder. Vascular reactivity to norepinephrine was also smaller in the SST powder‐treated group. The treatment did not affect vascular resistance or reactivity in WKY. These results suggest that chronic oral administration of the SST powder reduces the development of hypertension by decreasing the peripheral vascular resistance and reactivity. The SST powder may be useful for the treatment of hypertension.
Natural products and the development of selective antiprotozoal drugs
Authors: Wright Colin W. , Phillipson J. David
Published: October 2006

New drugs are urgently required for the treatment of amoebiasis, leishmaniasis, malaria and trypanosomiasis. In this review the potential of natural plant products as a source of antiprotozoal drugs is discussed with respect to biochemical differences between protozoa and hosts. Some of the ways in which pathogenic protozoa differ biochemically from their human hosts are described, and the modes of action of some antiprotozoal drugs which exploit these differences are mentioned. A selection of natural products of plant origin (alkaloids, terpenes, quinones and miscellaneous compounds) is illustrated with emphasis on their modes of action and potential for the development of selective antiprotozoal agents.
Effect of the aqueous extract and saponin fraction from the flowers of Verbascum thapsiforme on protein biosynthesis in a rat liver ribosomal system
Authors: Paszkiewicz‐Gadek Anna , Grochowska Krystyna , Gałasiński Władysław
Published: October 2006

The effect of fractions isolated from the aqueous extract of Verbascum flowers on protein biosynthesis was studied. A strong inhibitory effect of the aqueous extract on protein biosynthesis was demonstrated in isolated rat liver ribosomes. The saponin fraction was shown to be responsible for this activity and it was compared to commercial glycyrrhizic acid and its aglycon as the standard drungs. It was found that these compounds strongly inhibited the incorporation of [14C]leucine into proteins in vitro and that the target site for inhibition was the ribosome fraction from rat liver cells.
Coagulation of milk as an index of astringency of the bark extract of Bridelia ferruginea benth and lime juice for the formulation of a traditional gargle ‘Ogun Efu’
Authors: Orafidiya Lara O. , Lamikanra A. , Adediji Jokotade A.
Published: October 2006

The extent of the coagulation of milk by the ethanolic extract of bark of Bridelia ferruginea and lime juice has been used to determine the effective concentrations of these two major astringent ingredients of a traditionally prepared herbal gargle ‘Ogun Efu’. Optimal concentrations of the bark extract and lime juice, respectively, were required to give maximum coagulate heights. Combinations of the bark extract with lime juice resulted in a synergistic effect on the coagulate heights obtained. The concentrations of Bridelia bark extract and lime juice (when combined) that gave the highest coagulate height were used as the basis for the laboratory formulation of the gargle. The coagulate heights obtained with the laboratory formulated products, compared with those obtained with the traditionally prepared products, indicate that the milk coagulation test method for the determination of the effective concentrations of the two ingredients is dependable.
Oral hypoglycemic effect of Salacia reticulata in the streptozotocin induced diabetic rat
Authors: Serasinghe Soma , Serasinghe Palitha , Yamazaki Hiromi , Nishiguchi Keiko , Hombhanje Francis , Nakanishi Suehiro , Sawa Kazuko , Hattori Masao , Namba Tsuneo
Published: October 2006

The oral hypoglycemic activity of Salacia reticulata extract was evaluated in streptozotocin induced diabetic rats. The diabetic rats were orally administered an aqueous extract of Salacia reticulata and the plasma glucose concentration was determined at regular intervals following administration. The drug was effective as a hypoglycemic agent at all the doses tested (0.5 g/kg, 1.0 g/kg and 5.0 g/kg). The maximum percentage decrease in plasma glucose was observed between 1–5h following administration of the drug.
Activity of Ku Shen compounds against Staphylococcus aureus and Streptococcus mutans
Authors: Yamaki Masae , Kashihara Mikiko , Takagi Shuzo
Published: October 2006

Ten compounds were isolated from the Chinese crude drug, Ku Shen (Sophora flavescens Aiton). Seven compounds showed antimicrobial activity against Staphylococcus aureus and Streptococcus mutans. The activity principles were identified as kurarinone, sophoraflavanone G, iso‐kurarinone, kuraridine, kushenol C, D and nor‐anhydroicaritin.
Pharmacological studies on terpenoids from marine sponges: Analgesic and muscle relaxant effects
Authors: de Pasquale R. , Circosta C. , Occhiuto F. , de Rosa S. , de Stefano S.
Published: October 2006

Some terpenoids extracted from marine sponge: triacetylated desidein (from Disidea pallescens), 2‐tetraprenyl benzoquinol and 4‐hydroxy‐3‐tetraprenylbenzoic acid (from Ircinia muscarum), 2‐polyprenyl benzoquinols (from Ircinia spinosula), avarol (from Disidea avara) and furospongin‐1 (from Spongia officinalis) were tested by multidimensional Irwin screening and with some tests for analgesic and muscle relaxant activity. The three prenylhydroquinols derivatives and avarol show a good analgesic activity and low toxicity.
Inhibitory effect of rehmaionoside B, a constituent of rehmaniae radix, on isolated bladder and urethral smooth muscle of mice
Authors: Nakase Kiyokazu , Kimura Ikuko , Kimura Masayasu , Kitagawa Isao
Published: October 2006

We have investigated the effects of rehmaionoside B and other constituents of Rehmaniae radix on bladder and urethral smooth muscle strips of mice. Of the five constituents investigated, rehmaionoside B (1 mg/mL) most effectively inhibited the contraction induced by noradrenaline (10 μg/mL) in urethral smooth muscle. These constituents, especially rehmaionoside B, not only inhibited the spontaneous contraction but slightly relaxed the normal tone of the bladder smooth muscle. The relaxation induced by rehmaionoside B (0.1 mg/mL) corresponded to 26.4% of the isoproterenol (1 μg/mL) response. Rehmaionoside B also inhibited the PGF2α‐induced spontaneous contraction of the bladder. The treatment with rehmaionoside B significantly inhibited arachidonic acid‐induced contraction of the bladder. This response was similar to that induced by indomethacin. Rehmaionoside B inhibited both urethral and bladder smooth muscles, which may affect micturition. The effect of rehmaionoside B on the bladder was an indomethacin‐like action.
Pharmacological investigations of sticky viscome extract (Cleome viscosa L.) in rats, mice and guinea‐pigs
Authors: Singh P. D. A. , West M. E.
Published: October 2006

The aqueous extract of seeds of Cleome viscosa L. has been studied for its pharmacological activities. It was found to be nontoxic when dosed orally and intraperitoneally to rats and mice. The extract showed significant analgesic activity in mice and local anaesthetic activity in guinea‐pigs. It potentiated the barbiturate sleeping time in rats and had a mild laxative effect, increasing the passage of soft faeces. It failed to protect against convulsions induced by picrotoxin in rats. The results are discussed in terms of the alleged uses of the plant in folklore medicine.
Reduction of agonist‐induced contractions of guinea‐pig isolated ileum by flavonoids
Authors: Capasso A. , Pinto A. , Mascolo N. , Autore G. , Capasso F.
Published: October 2006

The effect of 13 flavonoids on the contraction of guinea‐pig isolated ileum induced by prostaglandin E2 (PGE2) and leukotriene D4 (LTD4) have been investigated. Apigenin, quercetin and kaempferol at a concentration of 10 μM significantly (p<0.001) reduced the contraction to either agonist. Crysin and flavone antagonized only PGE2 (p<0.01). The other flavonoids were inactive. The blocking effect of apigenin, quercetin and kaempferol against PGE2 was also concentration‐ and time‐dependent, and was augmented by the calcium channel blocker verapamil or by lowering the extracellular calcium to 25%, consistent with a calcium‐mediated mechanism of protection which these flavonoids, at the same concentration, also showed against barium chloride (BaCl2)‐ or acetylcholine (ACh)‐induced contraction (p<0.05–0.001).
Teratogenic effects of Plectranthus fruticosus essential oil in mice
Authors: Pages N. , Fournier G. , Chamorro G. , Salazar M.
Published: October 2006

The teratogenic potential of Plectranthus fruticosus essential oil was evaluated in Swiss‐OF1 mice injected subcutaneously. They received daily 0, 15, 45 or 135 mg/kg body weight on days 6 to 15 of gestation. A slight maternal toxicity, as evidenced by reduced weight gain and some physical alterations, was observed among treated groups compared with controls. Animals were killed and subjected to uterine examination on day 17 of pregnancy. Plectranthus fruticosus essential oil induced both embryo‐ and feto‐toxicity in the three treated groups, as manifested by a statistically significant increase in the numbers of resorbed and malformed fetuses. The observed malformations were predominantly related to the eyes (anophthalmia).
Influence of Padma 28 on the spontaneous bactericidal activity of blood serum in children suffering from recurrent infections of the respiratory tract
Authors: Jankowski S. , Jankowski A. , Zielinska S. , Walczuk M. , Brzosko W. J.
Published: October 2006

The effect of Padma 28 on spontaneous bactericidal activity (SBA) of blood serum was tested in 19 children suffering from recurrent infections of the respiratory tract (RIRT). SBA was tested against three bacterial strains; Salmonella typhimurium 568, and Escherichia coli strains 044 and 055. A considerable increase (bactericidal index <2) of SBA was noted in 12 children (63.1%). In four children (21%) the increase of SBA was less pronounced (bactericidal index > 2). In three children (15.7%) no effect of Padma 28 on SBA of the serum was observed.
Tissue cultures of Artemisia annua: Organogenesis and artemisinin production
Authors: Fulzele D. P. , Sipahimalani A. T. , Heble M. R.
Published: October 2006

Seeds of Artemisia annua obtained from different locations Europe(P1), Michigan USA (P2), Washington USA (P3), Hoechst India (P4) and Lucknow (P5) were germinated and grown in an experimental field station. The plants were harvested during the early flowering stage and analysed for artemisinin and arteannuin‐B. Plants from Europe produced the highest level of artemisinin (6.50 mg% fresh weight (F.‐W.)) and those from Lucknow produced the highest level of arteannuin‐B (21.42 mg% F.W.). Callus initiation and growth was achieved on Murashige and Skoog's medium supplemented with BA (1 ppm) + NAA (1 ppm) from the five plant types. The European variety gave multiple shoots in BA (0.1 ppm) + IAA (1 ppm) medium and root formation in NAA (1 ppm) + Kn (0.1 ppm) medium. Artemisinin and atreannuin‐B were detected in cultures of the European variety with complete differentiation (0.95 mg% F.W. and 6.57 mg% F.W. respectively).
Musclide‐A1: A novel Ca2+‐dependent protein kinase activator derived from musk and its cardiotonic potentiating action in guinea‐pig cardiac muscles
Authors: Kimura Masayasu , Kimura Ikuko , Uwano Teruko , Isoi Yukiko , Kadota Shigetoshi , Kikuchi Tohru
Published: October 2006

Musclide‐A1 (6‐methyl‐2, 5‐heptanediol 5‐(hydrogen sulfate)) was isolated from musk, a dried secretion from the preputial follicle of musk deer, Moschus moschiferus Linn. Musclide (100 μg/mL), a water‐soluble extract, and musclide‐A1 (30 μg/mL) potentiated β‐adrenergic cardiotonic action in guinea‐pig papillary muscles. Musclide‐A1 at 130 μM or 1,2‐dioctanoylglycerol at 200 μM potentiated the positive inotropic action induced by the maximal concentration of isoproterenol (258 nM). The potentiation was suppressed by 3 nM staurosporine or 1 μM H‐7, an inhibitor of Ca2+‐dependent protein kinase. Musclide‐A1 at 4 and 8 μM activated protein kinase C and other Ca2+‐dependent protein kinase in ventricular muscles of guinea‐pig. The activation of Ca2+‐dependent protein kinase was completely suppressed by 3 nM saturosporine. The activity of musclide‐A1 (4 μM) was comparable to that of 1,2‐dioctanoylglycerol (4 μM, the optimum concentration to stimulate protein kinase C), and were inhibited completely by 30 nM staurosporine. These results indicate that one mechanism of cardiotonic potentiation induced by musk, may be in part due to the activation of protein kinase C and other Ca2+‐dependent protein kinases.
Choleretic action of andrographolide obtained from Andrographis paniculata in rats
Authors: Tripathi G. S. , Tripathi Y. B.
Published: October 2006

Andrographolide, a diterpene, isolated from Andrographis paniculata exhibited a strong choleratic action when administered intraperitoneally (i.p.) to albino rats. This substance induced an increase in bile flow together with a change in the physical properties of the bile secretion.
Improvement of carbon tetrachloride‐induced liver injury by oral administration of soft‐shelled turtle powder in the rat
Authors: Feng Hong , Yasuhara Mikiko , Shimoto Yoshimasa , Matsuki Norio , Saito Hiroshi , Shiga Junji
Published: October 2006

The effects of orally administered soft‐shelled turtle powder on experimental liver injury induced by carbon tetrachloride were studied. Activities of transaminases and lactate dehydrogenase, content of albumin in serum, total protein, triglyceride and hydroxyproline in liver and histopathological assessment were used as indices of liver injury. Daily oral administration of 100 and 500 mg/kg soft‐shelled turtle powder for 6 weeks did not prevent the acute injury induced by a subsequent single injection of carbon tetrachloride. However, administration of soft‐shelled turtle powder for 6 weeks during chronic treatment with carbon tetrachloride significantly and dose‐dependently ameliorated the liver injury. The increases in glutamic‐pyruvic transaminase, glutamic‐oxaloacetic transaminase and lactate dehydrogenase in serum were attenuated, and there was a noticeable improvement of serum album and liver total protein content in rats treated with the powder. In addition, histopathological observation demonstrated a decrease in fatty degeneration in the liver of rats treated with the powder. None of the indices of liver injury was significantly affected by 6‐week oral administration of soft‐shelled turtle powder in non‐carbon tetrachloride‐treated rats. The results suggest that repeated administrations of soft‐shelled turtle powder have a therapeutic effect on chronic liver injury, by improving liver function and protein synthesis.
In vitro immunostimulating polysaccharide fractions from roots of Glycyrrhiza uralensis fish. et DC
Authors: Zhao J.‐F. , Kiyohara H. , Sun X.‐B. , Matsumoto T. , Cyong J.‐C. , Yamada H. , Takemoto N. , Kawamura H.
Published: October 2006

The water soluble anticomplementary, mitogenic and immune complex (IC) clearance enhancing crude polysaccharide fraction, prepared from the roots of Glycyrrhiza uralensis Fisch. et DC., was fractionated into five polysaccharide fractions by the addition of cetyltrimethylammonium bromide. A strongly acidic polysaccharide fraction (GR‐2), which has the most potent immunostimulating fraction, contained about 60% galacturonic acid with arabinose, galactose and glucose as the major neutral sugars, and a small quantity of protein. Pronase digestion did not alter the anticomplementary and mitogenic activities, however, endo‐α‐(1→4)‐polygalacturonase digestion reduced both activities. The IC clearance activity of GR‐2 was slightly decreased by pronase digestion but not by endo‐polygalacturonase digestion. GR‐2 was further purified by ion exchange chromatography and gave GR‐2IIa, GR‐2IIb and GR‐2IIc. GR‐2IIa and IIb are mainly composed of rhamnose, arabinose, galactose and galacturonic acid and showed only moderate anticomplementary activity. GR‐2IIc consisted of rhamnose, fucose, arabinose, mannose, glucose, galactose, glucuronic acid and galacturonic acid as the component sugars with a small quantity of protein. GR‐2IIc had the most potent anticomplementary, mitogenic and IC clearance activities. From these results it may be concluded that anticomplementary and mitogenic activities are caused by polysaccharides containing a polygalacturonan moiety.