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At least 919 records · Page 51Linked to original sources
PubMed2002

Effects of S-petasin on corticosterone release in rats.

Petasites hybridus is used in Chinese herbal medicine. S-petasin is a bioactive compound isolated from leaves or roots of Petasites hybridus. S-petasin has been used to relieve gastrointestinal pain, lung disease, and spasms of the urogenital tract. However, the side effect of S-petasin on endocrine systems are still not clear. This study explored the effects of S-petasin on the release of corticosterone in vivo and in vitro. An intravenous injection of S-petasin (10 microg/kg) decreased both basal and adrenocorticotropin (ACTH)-induced plasma corticosterone concentration in male rats. In vitro, S-petasin (3 x 10(-6) - 10(-4) M) caused a significant reduction of basal and ACTH-stimulated release of corticosterone from the enzymatically dispersed rat zona fasciculata-reticularis (ZFR) cells in a dose-dependent manner. In order to study possible mechanisms, ZFR cells were incubated with S-petasin (10(-5) M) in the presence or absence of forskolin (adenylate cyclase activator, 10(-6) - 10(-4) M), 8-Br-cAMP (a cAMP analogue, 10(-6) 10(-4) M), 25-OH-cholesterol (pregnenolone biosynthesis precursor, 10(-5) M) combined with trilostane (a blocker of 3beta-hydroxysteriod dehydrogenase, 3beta-HSD, 10(-6) M) and deoxycorticosterone (corticosterone biosynthesis precursor, 10(-9) - 10(-6) M) at 37 degrees C for 1h. The concentration of pregnenolone and corticosterone in media were measured by radioimmunoassay. The stimulatory effects of corticosterone secretion induced by forskolin (10(-5) - 10(-4) M), 8-Br-cAMP (10(-5) - 10(-4) M) and deoxycorticosterone (10(-7) - 10(-6) M) were reduced by S-petasin at 10(-5) M. The stimulatory effects of pregnenolone secretion induced by 25-OH-cholesterol combined with or without trilostane was reduced by S-petasin at 10(-5) M. These results suggest that S-petasin inhibits the production of corticosterone from rat ZFR cells in part through decreasing the activities of adenylyl cyclase, P450scc and 11beta-hydroxylase.

8-Bromo Cyclic Adenosine Monophosphate↗
PubMed2003

In vivo and in vitro assessment of the androgenic potential of a pulp and paper mill effluent.

The androgenic potential of a New Zealand pulp and paper mill effluent was measured by applying a combination of in vitro and in vivo bioassays with mosquitofish (Gambusia affinis) and goldfish (Carassius auratus). The in vivo method assessed the rate of gonopodial development (masculinization) and alterations from normal reproductive behavior in adult female mosquitofish exposed for 21 d to untreated or secondary-treated pulp mill effluent. A second in vivo mosquitofish exposure tested the effect of glass-fiber (type C) filtration of secondary-treated effluent on rates of expression of the same endpoints. Extractable organics analyses of effluents and extracts thereof were conducted. Mosquitofish demonstrated significant masculinization on exposure to either treated or untreated effluent; the frequency of gonopodial development was reduced with effluent secondary-treatment. Male mating behavior was observed in the masculinized adult females. Glass-fiber (type F) filtration of the treated effluent eliminated the masculinizing effect, suggesting that the bioactive compounds were associated with the suspended solids. The in vitro method measured the binding of compounds within a treated thermomechanical/bleached kraft effluent extract to androgen receptors contained in goldfish testis cytosol. Exposure to extracts of either the particulate (glass-fiber filtered) or the dissolved organic fraction of the effluent produced significant binding (as indicated by the displacement of radiolabeled testosterone) to the androgen receptor in goldfish gonadal tissue. Thus, the dissolved organics extract of the treated effluent contained compounds androgenic to goldfish in vitro but not to mosquitofish in vivo. The combined in vitro and in vivo data suggest that the effluent in question could exert effects on the reproductive physiology of fishes through an androgenic mechanism. The androgenic compounds androstenedione and testosterone were not detected in the extracts used for the in vitro component of this study.

Androgens↗
PubMed1992

Regulation of glycoprotein IIb-IIIa receptor function studied with platelets permeabilized by the pore-forming complement proteins C5b-9.

Recent evidence suggests that the cytoplasmic domains of platelet glycoprotein (GP) IIb-IIIa are involved in the agonist-initiated transformation of this integrin into a receptor for fibrinogen. To identify intracellular reactions that regulate the receptor function of GP IIb-IIIa, membrane-impermeable agonists and antagonists were introduced into the platelet by permeabilizing the plasma membrane with the pore-forming complement proteins C5b-9. Platelet responses were then analyzed by flow cytometry. Non-lytic concentrations of C5b-9 caused permeabilization of the platelet plasma membrane, as determined by uptake of a water-soluble fluorescent tracer dye. The complement pores were large enough to permit the entry of fluorescein isothiocyanate (FITC)-labeled oligopeptides in a size-dependent manner. Under conditions of low external Ca2+, C5b-9 treatment per se did not activate GP IIb-IIIa, as measured by binding of the activation-dependent antibody FITC-PAC1. However, FITC-PAC1 binding to C5b-9-permeabilized platelets was stimulated by a thrombin receptor agonist acting at the cell surface and by guanosine 5'-O-(thiotriphosphate), a membrane-impermeable activator of G proteins. Permeabilization also permitted the entry of cyclic AMP and the peptide, RFARKGALRQKNV, a pseudo-substrate inhibitor of protein kinase C. Each of these inhibited agonist-induced FITC-PAC1 binding to permeabilized platelets but not to intact platelets. Agonist-induced GP IIb-IIIa activation in permeabilized platelets was also inhibited by tyrphostin-23, a protein tyrosine kinase inhibitor. Thus, C5b-9 can be used to permeabilize the plasma membrane to permit the selective entry of small peptides and other bioactive compounds into permeabilized platelets. Results obtained with these platelets indicate that GP IIb-IIIa receptor function is regulated by a network of signaling reactions involving G proteins, serine/threonine kinases, and tyrosine kinases.

Amino Acid Sequence↗
PubMed2003

[Studies on the chemical constituents of Cirsium japonicum DC].

AIM: In order to look for new bioactive compounds, investigation on the chemical constituents, especially on the typical polyacetylenes from the rhizomes of Cirsium japonicum DC. was carried out. METHODS: Chromatographic techniques including silica column chromatography and preparative silica thin-layer chromatography were used to separate and purify the constituents. Their structures were elucidated by physicochemical properties and spectral analyses including UV, IR, 1HNMR, 13CNMR, HMQC, HMBC and HREIMS. RESULTS: Twelve compounds were isolated from the rhizomes of Cirsium japonicum DC., and their structures were identified as cis-8, 9-epoxy-heptadeca-1-ene-11, 13-diyne-10-ol (1), ciryneol A (2), 8,9,10-triacetoxyheptadeca-1-ene-11,13-diyne (3), ciryneone F (4), cireneol G (5), ciryneol H (6), ciryneol C (7), p-coumaric acid (8), syringin (9), linarin (10), beta-sitosterol (11) and daucosterol (12). CONCLUSION: Compounds 4, 5 and 6 are new compounds, compound 3 is a new natural product and compound 8 was isolated from this plant for the first time.

Cirsium↗
PubMed2003

[Inhibition of magnesium lithospermate B on the c-Jun N-terminal kinase 3 mRNA expression in cardiomyocytes encountered ischemia/reperfusion injury].

AIM: To study the function of c-Jun N-terminal kinase 3 (JNK3) in the process of ischemic/reperfused heart injury and the mechanism underlying the protective action of magnesium lithospermate B (MTB), a bioactive compound isolated from Danshen. METHODS: By in situ hybridization, JNK3 mRNA was detected in the ventricular preparations of the Langendorff ischemic/reperfused rat heart. The inhibitory effect of MTB on the expression of JNK3 mRNA was also investigated. RESULTS: The purple and blue hybridization signals were located in the cytoplasm of the cardiomyocytes, which were weaker in the non-perfused hearts and stronger in the hearts encountered 30 min of ischemia and 30 min of reperfusion. Image analysis showed that the expression of JNK3 mRNA in the cardiomyocytes increased after 30 min of ischemia and 30 min of reperfusion, which showed significant difference compared with that in the cardiomyocytes of the non-perfused heart and the control heart (P < 0.05). Treatment with of 0.1, 1 and 10 mumol.L-1 MTB abolished the elevation of JNK3 mRNA expression in the ischemic/reperfused heart (P < 0.05). CONCLUSION: JNK3 may be another component in the signal transduction pathway of ischemia/reperfusion induced cardiomyocyte apoptosis. MTB may protect the heart from ischemia/reperfusion injury by reducing apoptosis through inhibition of the JNK3 activity.

Animals↗
PubMedDate not supplied

Bioactive actinomycetes from Krishna River sediments of Andhra Pradesh.

Sediment samples from Krishna River at Nagayalanka of Andhra Pradesh, India were investigated as a source of actinomycetes to screen for the production of novel bioactive compounds. During our investigation on fresh water actinomycetes from 5 different river sediment samples, a total of 80 actinomycetes were isolated. Out of these 80 isolates, 30 isolates which showed distinct macromorphological characteristics were selected. The antimicrobial and enzymatic activities were studied for all the 30 isolates. The preliminary study for antimicrobial activity by cross streak method indicated that 16 isolates (53.3%) have excellent antagonistic properties. All these 16 isolates were subjected to detailed submerged fermentation studies. It was observed that 12 isolates (40.0%) exhibited antibacterial activity, 9 isolates (30.0%) showed antifungal activity while 5 isolates (16.6%) showed both antibacterial and antifungal activities. All the 30 isolates were also subjected for the determination of enzymatic activities 25 isolates (83.3%) exhibited amylolytic activity while 27 isolates (90.0%) showed proteolytic activity. Among these isolates, six promising isolates were selected for detailed morphological, cultural, physiological and biochemical studies. It was established that these isolates belong to the Streptomyces genus by virtue of their cell wall composition pattern and were identified as strains of different Streptomyces species like S. rochei, S. alanosinicus, S. erumpens, S. griseoplanus, S. gancidicus and S. nigrogriseolus.

Actinobacteria↗
PubMed2004

Isolation and partial structural evaluation of a cardiotoxic factor from Indian common murrel (Channa striatus L.) skin extract.

It was earlier reported from this laboratory that, Channa striatus, L a common edible fish, whose skin extract (CSSE) was pharmacologicaclly potent and contains several bioactive compounds. In the present communication a cardiotoxic factor was isolated and purified by thin layer chromatography followed by silica gel and neutral alumina column chromatography. Spectroscopic studies (UV, IR, 1H and 13C NMR, FAB-MS) indicated that the lethal cardiotoxic factor (CSS-CTF II) was an aromatic alkaloid compound with -NH, > C = C < and -OH functional groups. The molecular weight was found to be 413 dalton. LD50 of CSS-CTF II was found to be 42.5 mg/kg (i.v) in Swiss albino male mice. Pharmacological studies showed that CSS-CTF II possesses hypotensive and cardiotoxic activities and produced death through apnoea in experimental animals but had no effect on nerve muscle preparations. The haematological and biochemical data also indicated the toxic nature of CSS-CTF II, through significant fall in haemoglobin, total RBC, WBC, platelet count and increased cardiac marker enzyme CPK and CPK-MB value in experimental animals. The present investigation thus established the toxic nature of CSS-CTF II isolated from edible fish C. striatus skin extract. Further work is needed to identify CSS-CTF II's mechanism of action and its antagonism for therapeutic purpose.

Animals↗
PubMed2003

Stereoselective oxidation of aliphatic diols and reduction of hydroxy-ketones with galactitol dehydrogenase from Rhodobacter sphaeroides D.

From the Rhodobacter sphaeroides mutant D a galactitol dehydrogenase (GDH) was isolated and characterized in an earlier investigation (1). The enzyme expressed activity with a wide spread substrate spectrum, like sugars, sugar alcohols, secondary alcohols or the corresponding ketones and it can be used for the production of the rare sugar L-tagatose by regioselective oxidation of galactitol (2). This study focuses on the preparation of optically pure aliphatic diols by oxidation of one enantiomer or stereospecific reduction of keto-alcohols and diketones. The oxidation of 1,2-propanediol, 1,2-butanediol, 1,2-pentanediol and 1,2-hexanediol occurred highly specific with the S-enantiomer leaving the R-enantiomer of the diols in the reaction vessel. Also (S)-1,2,6-hexanetriol was oxidized by GDH to 1,6-dihydroxy-2-hexanone. The Km values of these reactions decreased with increasing length of the carbon chain. Reduction of hydroxyacetone or 1-hydroxy-2-butanone resulted in an excess of 93% (S)-1,2-propanediol and more than 98% of (S)-1,2-butanediol, respectively. The diketone 2,3-hexanedione was only reduced to (2R,3S)-2,3-hexanediol, one of the possible four configurations. The wide substrate spectrum on one hand and the selectivity in the reaction on the other hand make GDH a very interesting enzyme for the production of optically pure building blocks in the chemical synthesis of bioactive compounds.

Dihydroxydihydrobenzopyrenes↗
PubMedDate not supplied

Efficacy of garbanzo and soybean flour in suppression of aberrant crypt foci in the colons of CF-1 mice.

BACKGROUND: Epidemiological studies have reported a low incidence of colon cancer in countries with high legume consumption. Moreover, experimental studies have found that legumes, such as soybeans and pinto beans, have anticancer properties. While garbanzo beans are a rich source of various phytochemicals, they have not been well studied. In the present study, the azoxymethane (AOM)-induced aberrant crypt foci (ACF) in CF-1 mice was utilized as a model to assess and compare the effects of garbanzo flour to that of soy flour. MATERIALS AND METHODS: Twenty, 5-week-old CF-1 mice were divided into four groups of 5 animals each: 10% garbanzo, 10% soy, 10% mixed (soy and garbanzo flours), and control (rodent chow). Animals received subcutaneous injections of AOM (10-mg/kg B. W.) once a week for two weeks to induce ACF. At week ten, the animals were sacrificed and the colons were scored. RESULTS: There was a 64% (p <0.001) suppression of ACF for animals fed the garbanzo flour, versus an inhibition of 58 and 55% (p<0.001) for the soy and mixed flour groups, respectively. DISCUSSION: These results demonstrate that garbanzo beans possess bioactive compounds capable of inhibiting the formation of pre-cancerous lesions in mice and suggest that, like soybeans, their consumption contributes to a reduction in colon cancer incidence.

Animals↗
PubMed2004

[Nuts, cardio and cerebrovascular risks. A Spanish perspective].

Nuts have been included in human diets for ages. They are very appreciated and used as a central component of sweets and desserts. However, during the last decades, scientific interest in those foods has increased enormously as many epidemiologic studies show protective effects of nut consumption on coronary heart disease in different population groups. To date, many clinical trials have analyzed the positive effects of nuts consumption (almond, walnut, pistachio, Macadamia nut, and pecan) on the lipid profile, decreasing total and low density lipoproteins (LDL) cholesterol. However, whether these effects are only due to their fatty acid composition or to any other bioactive compounds, such as tocopherols, phytosterols and phytoestrogens, it is still unknown. This paper, aims to review comparative composition aspects of nuts, such as the positive effects on body weight, lipoprotein metabolism, and protection against cardiovascular and cerebrovascular diseases. The inclusion of 25 g/day of nuts, mainly raw, into a prudent diet seems to be recommended. Further investigations, as actual information is still scarce, in order to dilucidate the relationship between nuts consumption and vascular diseases are proposed.

Body Weight↗
PubMed2005

[Acute dyspnoea following transfusion of plasma-containing blood products].

A 35-year-old male patient who was given chemotherapy because of chronic myeloid leukaemia became dyspnoeic after transfusion of thrombocytes; initially, no explanation could be found for this dyspnoea. He went home before all diagnostic procedures were evaluated. Chest X-ray revealed bilateral pulmonary oedema, which could be due to transfusion-related acute lung injury (TRALI), especially since there were no indications for a cardiac aetiology. The patient was sent to the nearest hospital where he was treated with diuretics and observed for 24 hours. There were no complications. The pathogenesis of TRALI has been attributed to an interaction between anti-granulocyte antibodies and granulocytes. In addition, bioactive compounds produced during the storage of blood products have been implicated. It is important to recognize TRALI as the cause of dyspnoea when cardiac or pulmonary causes are excluded. The overall prognosis is good when treatment is started in time. The management of TRALI is supportive, with mechanical ventilation when necessary. After excluding donors with proven anti-granulocyte antibodies from further donation, there is no increased risk for recurrent episodes after future transfusion of plasma-containing blood products.

Acute Disease↗
PubMed2004

[Free radical scavenger and lipid peroxidation inhibiting effects of medicinal plants used in phytotherapy].

Epidemiological and clinical studies have proved the beneficial effect of bioactive compounds of vegetables and medicinal plants used in phytotherapy on prevention of several diseases. Beyond the well-known natural antioxidants, such as vitamins, other natural substances can function as antioxidants. In 1992 the Saas Fee Declaration was published by leader nutritionist and biochemists underlining the importance of prevention in health maintenance based on scientific studies with natural compounds. According to the declaration the antioxidants are the main active and beneficial components. Authors joining with the spirit of Saas Fee Declaration have worked out a complex examination system to study the antioxidant, free radical scavenging and inhibitory effects on lipid peroxidation of isolated components, natural plant extracts and herbal preparations. The members of the system are the followings: hydrogendonating ability, reducing power, chelating activity, free radical scavenging activities measured by chemiluminescence techniques, electron paramagnetic resonance / spin trapping studies, inhibition of lipid peroxidation induced in rat brain / liver microsomes, consequencies and treatment of experimental hyperlipidemia, morphological and histological studies. Only one measurement cannot give enough information about the antioxidant properties of the products. Complex in vitro examination of a novel antioxidant can draw pictures of correlation between the chemical structure and antioxidant effect, the mechanism of its favourable effect and its presumable role in prevention of lipid peroxidation. With the use of these results planning and execution of in vivo examinations should be more precise, practical and essential.

Antioxidants↗
PubMedDate not supplied

Phytoestrogens and the risk of breast cancer: a review of the literature.

BACKGROUND: Over the last decade, interest in the physiological role of bioactive compounds in plants has increased dramatically. Of particular interest in relation to human health are the class of compounds known as the phytoestrogens, which embody several groups of nonsteroidal estrogens that are widely distributed within the plant kingdom, including isoflavones and lignans. Epidemiological studies suggest that diets rich in phytoestrogens, particularly soy and unrefined grain products, may be associated with low risk of breast cancer. This review presents the studies published so far exploring a link between dietary phytoestrogens and breast cancer risk. METHODS: A Medline search was conducted using the key words below. Further articles were obtained by cross-matching references of relevant articles. Twenty-one case-control and 15 prospective studies were identified since 1978. One meta-analysis and several review articles also were noted. RESULTS: Results from previous studies were analyzed and comparisons were made between each type of study. Controversy exists regarding this subject, and we found conflicting evidence in recent literature regarding this hypothesis. CONCLUSION: There is no clear evidence that phytoestrogen intake influences the risk of developing breast cancer.

Breast Neoplasms↗
PubMedDate not supplied

[Separation of vitamins by non-conventional techniques. Facilitated pertraction of vitamin C].

Pertraction (permeation through liquid membranes) is one of the new techniques applied for separation and advanced purification of bioactive compounds. The study on the facilitated pertraction of vitamin C with Amberlite LA-2 underlined the significant influences of the pH-gradient between the aqueous phases, carrier concentration and mixing intensity. Thus, for reaching the maximum efficiency of vitamin C pertraction, the pH-value of the initial aqueous phase below 2, the pH-value of the final aqueous solution greater than 11 and the Amberlite LA-2 concentration in solvent layer over 80 g/l are required.

Amines↗
PubMed2006

[Isolation and identification of hetisine-type alkaloids from Aconitum coreanum by high speed countercurrent chromatography].

AIM: To search for more bioactive compounds from the roots of Aconitum coreanum (Lèvl.) Rapaics. METHODS: High speed countercurrent chromatography was successfully applied to the separation of alkaloids from Aconitum coreanum. The structures were elucidated by their physicochemical properties and spectroscopic analysis. RESULTS: Two-phase solvent system composed of CHCl3-CH3OH-0.2 mol x L(-1) HCl (10:3:3, volume ratio) was used in this experiment, eight alkaloids were obtained from the roots of Aconitum coreanum, which were identified as: 2alpha-propionyl-11alpha,13beta-diacetyl-14-hydroxyhetisine (I), Guanfu base P (II), Guanfu base G (III), Guanfu base F (IV), Guanfu base Z (V), Guanfu base O (VI), Guanfu base A (VII), Guanfu base B (VIII). CONCLUSION: Compound I is a new alkaloid, named Guanfu base R.

Aconitum↗
PubMed2006

Poly-L-lactic acid: an overview.

In August 2004, the US Food and Drug Administration approved a poly-L-lactic acid (PLLA)-based injectable medical device for restoration and/or correction of the signs of facial fat loss (lipoatrophy) in people with human immunodeficiency virus. As a result, the properties of the PLLA microparticles have received considerable interest from the medical community. Polylactides have a long-standing history of safe use in medical applications, such as pins, plates, screws, intra-bone and soft-tissue implants, and as vectors for sustained release of bioactive compounds. The L-isomer of polylactic acid is a biodegradable, biocompatible, biologically inert, synthetic polymer. Putatively, PLLA microparticles initiate neocollagenesis as a result of a normal foreign-body reaction to their presence. The build-up of collagen over time creates volume at the site of injection, while the PLLA microparticles are metabolized to carbon dioxide and water and expelled through the respiratory system.

Absorbable Implants↗