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PubMed1983

Fractionation of a whey growth factor for Streptococcus agalactiae into two active components containing proteins.

Previously three factors (F-1, F-2, F-3) that stimulated in vitro growth of Streptococcus agalactiae were separated from wheys of milk and colostrum by chromatographic procedures. Now F-1 was separated further into two active components, F-1a and F-1b, when rechromatographed on an anion exchange resin with distilled water as eluent. The stimulatory activity was associated with two protein peaks whereas a third protein peak that was eluted in those fractions containing lactose was not stimulatory. Most of the stimulatory activity (76 to 80%) and protein (90 to 93%) were retained by a filter with retention of greater than 1,000 MW. Two stimulatory factors were confirmed by separation of F-1 fractions by step-gradient elution on a column of octadecylsilica; one protein peak was found for each of the three solvents. Samples with protein eluted with .1 N formic acid and formic acid: methanol (1:1) had stimulatory activity, whereas the sample with protein eluted with 100% methanol was inactive. Results were similar when F-1 fractions were applied to Sep-Pak (muBondapack C18) cartridges and eluted with water, 50% methanol, and 100% methanol. Proteins in the Sep-Pak eluates with stimulatory activity (water and 50% methanol) were heterogeneous and different when separated by high-voltage paper electrophoresis. Proteose-peptone preparations with added lactose were chromatographed on columns of anion exchange resin, with distilled water as eluent, and produced two peaks of protein with elution volumes comparable to peaks 1 and 3. Lactose appeared to be a major factor in eluting the second protein peak.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed2002

[Importance of biologically active components and plants in the prevention of complications of diabetes mellitus].

Diabetes complications, especially late (chronic) ones, are the main reasons of invalidity and early mortality. The most threatening diabetes complications are vascular and metabolic complications (diabetic neuropathy, angiopathy, cataract, glaucoma, optic neuropathy, retinopathy, diabetic nephropathy). Good diabetes control is very important, because in early stages these changes are reversible. In order to decrease the number of diabetes complications and to postpone their development, the use of biologic active components and plants is recommended. The most important biologic active substances for this purpose are vitamins and minerals, proteins, polysaccharides, lectins, saponins and flavonoids. According the scientific data, the mostly used plants are: Ginkgo biloba, Allium sativum, Silybum marianum, Panax Ginseng, Carica papaya, Vaccinium myrtillus, Phaseolus vulgaris. Some of them are proposed for treatment of symptoms related to venous and lymphatic vessel insufficiency, for the prophylaxis and treatment of liver damage caused by metabolic toxins, in chronic degenerative liver conditions, for the therapy of digestive disorders, to increase in the unspecific way the resistance of the organism to various environmental influences, and to stabilize membranes through antioxidant and radical scavenging actions.

Antioxidants↗
PubMed1983

Reconstitution of intercalator-induced DNA scission by an active component from nuclear extracts.

Treatment with intercalating agents causes formation of protein-associated DNA breaks in mammalian cells in culture and in the nuclei isolated from these cells. We found that this effect, when induced by the intercalator m-AMSA, required a component which could be dissociated from nuclei by 0.3 M NaCl. The effect was restored by combining the extracted nuclei with the nuclear extract. The active component of the extract eluted in gel filtration at a point corresponding to a molecular weight of 800 000. During its reaction with DNA, DNA-protein links and DNA breaks appeared in approximately equal frequencies. In this respect the reaction stimulated by m-AMSA resembled the reaction of a topoisomerase with DNA. However, intercalator-stimulated formation of protein-associated DNA breaks differed from the activity of the nuclear topoisomerase I in that there was a different optimum salt concentration and a different apparent molecular weight.

Aminoacridines↗
PubMed2001

Modified phosphatidylethanolamine as the active component of oxidized low density lipoprotein promoting platelet prothrombinase activity.

We analyzed the influence of the atherogenic oxidized low density lipoproteins (LDL) on the activity of the platelet prothrombinase complex, a major contributor to overall thrombin formation in vivo. Platelet dependent thrombin generation was found to be strongly stimulated by in vitro oxidized LDL. The enhancement was additive to that observed with the platelet agonist thrombin. Oxidized LDL increased the platelet binding of annexin-V, suggesting that the augmented surface exposure of aminophospholipids promoted the prothrombinase activity. All of the stimulatory activity of the oxidized LDL could be recovered in the microemulsions prepared from the lipid portion of the modified particles. Phospholipid vesicles were prepared containing the total lipids of the oxidized LDL but lacking specifically in one lipid component. Following the selective removal of the ethanolamine phospholipids (PE) from the LDL lipids, the platelet-dependent thrombin formation was markedly reduced. Vesicles enriched with the isolated PE fraction alone enhanced the thrombin generation. Analyses with autoxidized phospholipids indicated that oxidation products of unsaturated diacyl-PE were mainly responsible for the increased prothrombinase activity. Oxidized LDL and its PE fraction lost their stimulatory activity after treatment with NaCNBH(3), a chemical reductant of Schiff base adducts. Phospholipid vesicles supplemented with synthetic aldehyde-PE adducts largely reproduced the stimulation of the thrombin generation. We conclude that the oxidized LDL particles elicit a pronounced prothrombotic response by increasing the activity of the platelet prothrombinase complex. Specific oxidative modifications of the LDL-associated ethanolamine phospholipids are mainly responsible for this stimulation.

Blood Platelets↗
PubMed1994

Pseudorabies virus growth factor can be resolved into two active components.

Pseudorabies virus (PRV) growth factor (PRGF) which induces a transformed phenotype in normal MK-2 cells and represses the transformed phenotype of Hela cells was partially purified and resolved into two components (M(r) < 300 and < 180). Each of the PRGF components retained the transforming activity of the original factor in MK-2 cells but lost its transformation-repressing activity in Hela cells. The latter activity of PRGF could be reconstituted by simultaneous application of its two components. Two monoclonal antibodies against gII glycoprotein of PRV were able to neutralize both PRGF activities, thus supporting the previously suggested hypothesis that the PRV gene for glycoprotein gII might be involved in PRGF synthesis.

Animals↗
PubMed1999

Functional diversities of two activity components of circadian rhythm in genetical splitting mice (CS strain).

CS mice, an inbred strain, showed two distinctive characteristics in the circadian rhythm of locomotor activity: (1) large variation in the freerunning period, and (2) spontaneous rhythm splitting under continuous darkness. In the splitting rhythm there was a positive correlation between the freerunning period of the evening component and the activity time of the morning component. The phase-shifting effect of a 15-min light pulse was examined on the two activity components of the splitting rhythm. There were significant differences in the amount of light-induced phase response between the two components. A light pulse during the late subjective night induced a phase advance shift only in the morning component, while a light pulse during the early subjective night induced a phase delay shift only in the evening component. These results indicate functional diversities of the two activity components in the circadian locomotor rhythm of CS mice, and suggest that the circadian system in CS mice consists of two mutually coupled oscillators which have different circadian periods and different responsiveness to light. The CS mouse is a useful model to explore a genetic background of oscillator coupling in the circadian system of nocturnal rodents.

Animals↗
PubMed1994

Pharmacologically active components from a Peruvian medicinal plant, huira-huira (Culcitium canescens H. & B.).

The methanol extract of Huira-Huira (Culcitium canescens) showed analgesic effects in acetic acid-induced writhing and tail pressure tests, and it also produced potent prolongation of hypnosis induced by pentobarbital. The latter activity was used as an isolation-guide to determine the active components which were identified as dehydrocacalohastine, cacalohastine and cacalonol.

Analgesics↗
PubMed1999

Bacterial endotoxin is an active component of cigarette smoke.

BACKGROUND: Chronic bronchitis in cigarette smokers shares many clinical and histologic features with environmental lung diseases attributed to bacterial endotoxin (lipopolysaccharide [LPS]) inhalation. Experimental LPS inhalation mimics many of the acute effects of cigarette smoke in the lower airway. Therefore, we reasoned that LPS may be a biologically active component of cigarette smoke. DESIGN: The Limulus amebocyte lysate (LAL) assay was used to measure LPS in the tobacco and filter tip components of unsmoked 1R4F experimental cigarettes and commercially available "light" cigarettes, as well as in mainstream (MS) and sidestream (SS) smoke particles generated with an automated smoking machine and collected on ventilator mainflow filters. SETTING AND PARTICIPANTS: Blood LPS activity and plasma cytokine concentrations were measured in groups of healthy smokers and nonsmokers who reported to the walk-in clinic at the Baltimore VA Medical Center for unrelated complaints. MEASUREMENTS: Blood LPS levels were measured by LAL assay and plasma levels of tumor necrosis factor-alpha (TNF-alpha), interleukin 6 (IL-6), soluble TNF receptors I and II (sTNFR I and sTNFR II) were measured by enzyme-linked immunosorbent assay. RESULTS: Bioactive LPS was detected in both the tobacco portion (1R4F, 17.8+/-1.0 microg/cigarette; light, 26.8+/-7.3 microg/cigarette [mean+/-SE]) and filter tips (1R4F, 0.67+/-0.55 microg/cigarette; light, 0.70+/-0.39 microg/cigarette) of cigarettes. Bioactive LPS was also detected in both MS (1R4F, 120+/-64 ng/cigarette; light: 45.3+/-16 ng/cigarette) and SS smoke (1R4F, 18+/-1.5 ng/cigarette; light: 75+/-49 ng/cigarette). Although systemic absorption of inhaled LPS may occur, we failed to detect any differences between nonsmokers and smokers in median blood LPS levels (median values, 66.75 and 72.1 pg/mL, respectively; p = 0.55) or plasma concentrations of TNF-alpha (0 vs 0 pg/mL, respectively; p = 0.71), sTNFR I(1,469 vs 1,576 pg/mL, respectively), sTNFR II (2,011 vs 3,110 pg/mL, respectively), or IL-6 (8.8 vs 0 pg/mL, respectively; p = 0.20). CONCLUSIONS: Smoking one pack of cigarettes per day delivers a dose of respirable LPS that is comparable to the levels of LPS associated with adverse health effects in cotton textile workers. Thus, we suggest that the bioactive LPS in cigarette smoke may contribute to the pathogenesis of chronic bronchitis that develops in susceptible cigarette smokers.

Bronchitis↗
PubMed1987

Porphyrin derivatives having physical and chemical characteristics similar to those of the active components of hematoporphyrin derivative and with very strong photosensitizing effects.

The tumour-localizing fraction of hematoporphyrin derivative (Hpd) is thought to possess an essentially diporphyrin ether structure or, alternatively, a diporphyrin ester structure, the properties of which facilitate its retention in malignant cells and its biological activity on irradiation. To elucidate this problem further, we have synthesized the dimethyl, diethyl, dipropyl, di-n-butyl and di-iso-butyl ethers of hematoporphyrin. These ethers show chromatographic properties very similar to those of the active components of Hpd. Furthermore, they are much better photosensitizers in a cellular system than are crude Hpd or Photofrin II, and, like the components of Hpd, they are taken up and retained by cells according to their degree of non-polarity.

Carcinoma in Situ↗
PubMed2002

Reactive nitrogen species modulate the effects of rhein, an active component of senna laxatives, on human epithelium in vitro.

BACKGROUND: Senna laxatives are used worldwide. However, their misuse can lead to chronic mucosal inflammation with the accumulation of pigment-laden leukocytes and may cause colon cells to undergo apoptosis. This study explores the mechanisms by which rhein, an active component of senna, acts on a human intestinal cell line to induce ion secretion, apoptosis, and indirect chemotaxis of polymorphonuclear leukocytes. METHODS: Human colonic adenocarcinoma (CaCo-2) monolayer cells, in the presence or in the absence of rhein, were used to monitor the production of reactive nitrogen species using the Griess reaction. Modified Ussing chambers were used to study electrolyte secretion. The capacity to recruit human polymorphonuclear leukocytes was evaluated using masked well chemotaxis chambers. Rhein-induced apoptosis was investigated by counting apoptotic nuclei stained with Hoechst 33258 dye. RESULTS: Rhein caused a dose-dependent increase in short-circuit current that was abolished in chloride-free bathing buffer or by preincubating with 100 micromol/L NG-nitro-L-arginine (L-NAME) methyl ester. The concentration that maximally stimulated intestinal secretion, 50 micromol/L rhein, induced nitrate production. Supernatants obtained from CaCo-2 cultures after incubation with 50 micromol/L rhein stimulated a time-dependent polymorphonuclear leukocytes chemotaxis that was significantly decreased with 100 micromol/L L-NAME, whereas rhein per se was not active. Neutralizing antibodies anti-interleukin-8 (IL-8) and anti-ENA78 also inhibited chemotaxis. Overnight rhein incubation produced an increased number of apoptotic cells in the culture supernatant that was significantly decreased by preincubation with 100 micromol/L L-NAME. Light-degraded rhein had no effects on CaCo-2 monolayers. CONCLUSIONS: The integrity of rhein is crucial to generating nitric oxide, which mediates, with different time courses, ion secretion, chemotaxis, and apoptosis of human-derived cells.

Anthraquinones↗
PubMed2000

Evaluation of major active components in St. John's Wort dietary supplements by high-performance liquid chromatography with photodiode array detection and electrospray mass spectrometric confirmation.

A RP-HPLC method with photodiode array detection and LC-electrospray ionization (ESI) MS confirmation was established for the determination of major active components in St. John's Wort dietary supplement capsules. The samples alternatively were extracted with ethanol-acetone (2:3) using a 55 degrees C water-bath shaker or an ambient temperature ultrasonic bath. Extracts were separated by RP-C18 chromatography using a 95-min water-methanol-acetonitrile-trifluoroacetic acid gradient. The major components were identified by photodiode array detection and then confirmed by LC-ESI-MS. The quantification of components was performed using an internal standard (luteolin). This method may serve as a valuable tool for the quality evaluation of St. John's Wort dietary supplement products.

Calibration↗
PubMed1992

Supercritical fluid extraction of active components in a drug formulation.

Sulfamethoxazole and trimethoprim have been extracted from a drug formulation, Septra Infusion, with pure supercritical carbon dioxide. Both direct extraction of the aqueous-based matrix and indirect extraction of the formulation immobilized onto Celite were studied. Exhaustive analytical extraction was achieved when active components were less than 1.0 mg. A number of co-extractants were found, but each was blind to the HPLC/UV assay.

Drug Combinations↗
PubMed2002

Rapidly and slowly activating components of delayed rectifier K(+) current in guinea-pig sino-atrial node pacemaker cells.

The components and properties of the delayed rectifier K(+) current (I(K)) in isolated guinea-pig sino-atrial (SA) node pacemaker cells were investigated using the whole-cell configuration of the patch-clamp technique. An envelope of tails test was conducted by applying depolarizing pulses from a holding potential of -50 mV to +30 mV for various durations ranging from 40 to 2000 ms. The ratio of the tail current amplitude elicited upon return to the holding potential to the magnitude of the time-dependent outward current activated during depolarizing steps was dependent on the pulse duration, while after exposure to the selective I(Kr) inhibitor E-4031 (5 microM) this current ratio became practically constant irrespective of the pulse duration. These observations are consistent with the presence of the E-4031-sensitive, rapidly activating and E-4031-resistant, slowly activating components of I(K) (I(Kr) and I(Ks), respectively) in guinea-pig SA node cells. The activation range for I(Kr), defined as the E-4031-sensitive current (half-maximal activation voltage (V(1/2)) of -26.2 mV) was much more negative than that for I(Ks), defined as the E-4031-resistant current (V(1/2) of +17.2 mV). I(Kr) exhibited a marked inward rectification at potentials positive to -50 mV, whereas I(Ks) showed only a slight rectification. In the current-clamp experiments, bath application of E-4031 (0.5 and 5 microM) initially slowed the repolarization at potentials negative to approximately -30 mV and produced a significant depolarization of the maximum diastolic potential, followed by the arrest of electrical activity, thus indicating that the late phase of the repolarization leading to the maximum diastolic potential at around -60 mV in spontaneous action potentials is primarily produced by I(Kr) in guinea-pig SA node cells. External application of the selective I(Ks) inhibitor 293B (30 microM) also delayed the repolarization process at potentials negative to about -20 mV and induced moderate depolarization of the maximum diastolic potential leading to the arrest of the spontaneous activity. These results provide evidence to suggest that both I(Kr) and I(Ks) are present and play crucial roles in the spontaneous electrical activity of guinea-pig SA node pacemaker cells.

Animals↗
PubMed1979

Antibacterial active components in human urine after administration of penicillins.

Four-hourly urine from volunteers and patients who had received penicillins orally or intravenously was investigated by means of thin layer chromatography and bioautography. Antibacterially active metabolites were not detected with only two of 12 penicillins, namely amoxicillin and mezlocillin. In the case of the other penicillins the metabolites possessed variable antibacterial activity as could be demonstrated using different test microorganisms. After administration of carbenicillin esters three antibacterially active spots were detected, one of which corresponded to penicillin G; the other two were active against Pseudomonas aeruginosa. The bioautogram after treatment with azlocillin showed two components which were active against Bacillus subtilis, Staphylococcus aureus and Escherichia coli; only the rapid moving component was active against P. aeruginosa, however. The formation and chemical nature of these additional active components is still to a large extent not understood. It is quite possible, however, that they affect the bio-availability of an antibiotic.

Administration, Oral↗
PubMed1999

Effects of glycyrrhizin, an active component of licorice roots, on Candida albicans infection in thermally injured mice.

Due to the generation of burn-associated CD8+ CD11b+ TCR gamma/delta+ type 2 T cells (burn-associated type 2 T cells), the susceptibility of thermally injured mice to infection with C. albicans has been shown to be increased by up to 50-fold when compared with normal mice. Glycyrrhizin (GR), an active component of licorice roots, reduced the susceptibility of thermally injured mice to C. albicans infection to levels observed in normal mice. Thermally injured mice inoculated with CD4+ T cells from GR-treated mice were also resistant to C. albicans infection. The following demonstrated that susceptibility to fungal infection was similar in thermally injured mice and normal mice inoculated with T6S cells (a clone of burn-associated type 2 T cells). This susceptibility of T6S mice (normal mice inoculated with T6S cells) was reversible by (i) administration of GR, (ii) inoculation of CD4+ T cells from GR-treated mice, and (iii) injection of a mixture of MoAbs targeted against type 2 cytokines (IL-4 and IL-10). After stimulation with anti-CD3 MoAb, splenic T cells from thermally injured and T6S mice, treated with GR or inoculated with CD4+ T cells from GR-treated mice, did not have type 2 cytokines in culture supernatants. They were present in splenic T cell cultures from thermally injured and T6S mice that were treated with saline or inoculated with naive T cells. These results suggest that GR, by inducing CD4+ T cells which suppress type 2 cytokines produced by burn-associated type 2 T cells, improves the resistance of thermally injured mice to C. albicans. An anti-type 2 T cell action of the CD4+ T cells derived from GR-treated mice was previously described.

Amphotericin B↗
PubMed1996

(Z,E)-alpha-farnesene--an electroantennogram-active component of Maladera matrida volatiles.

It has previously been shown in field-trapping experiments and laboratory olfactometer bioassays that virgin females of Maladera matrida Argaman (Coleoptera, Scarabaeidae) and their volatiles, both in the presence of food (cut peanut leaves), are efficient attractants for M. matrida males and females. In this study GC-EAD experiments using male antennae and GC-MS experiments revealed that (Z,E)-alpha-farnesene is an active component of M. matrida female volatiles. The identification and quantitive electrophysiological responses (EAG) of synthetic (Z,E)-alpha-farnesene were obtained with male and female antennae. It was also shown that (Z,E)-alpha-farnesene is not a component of the plant volatiles that serve as synergistic components of the mixture of attractants or of the source of food for M. matrida.

Animals↗
PubMed2001

Free radical scavenging active components from Cedrus deodara.

An activity-directed fractionation and purification process was used to identify the antioxidant components of Cedrus deodara. Dried heartwood powder of C. deodara was first defatted with petroleum ether and then extracted with chloroform. The chloroform extract showed strong antioxidant activity on 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical. This fraction was then subjected to separation and purification using silica gel column chromatography. Three compounds with potent antioxidant activity were isolated in significant yields and identified by spectroscopic methods ((1)H NMR, (13)C NMR, IR, and MS). They were identified as (-)-matairesinol, (-)-nortrachelogenin, and a dibenzylbutyrolactollignan (4,4',9-trihydroxy-3,3'-dimethoxy-9,9'-epoxylignan). This is the first report of the occurrence of these compounds in C. deodara.

Antioxidants↗