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At least 1,315 records · Page 73Linked to original sources
PubMed2000

Antagonistic effects of 3 sesquiterpene lactones from Atractylodes macrocephala Koidz on rat uterine contraction in vitro.

AIM: To study the effects of three sesquiterpene lactones: atractylenolide I (8,9-dehydroasterolide, B), 4,15-epoxy-8 beta-hydroxyasterolide (C), and atractylenolide III (8 beta-hydroasterolide, D) from Atractylodes macrocephala Koidz, on rat isolated uterus smooth muscle. METHODS: Rat isolated uteri bathed in De Jalon I solution were used; acetylcholine (ACh), CaCl2, and oxytocin (Oxy) were used to evoke the contraction of uterus. RESULTS: B, C, and D 28 or 56 mumol.L-1 inhibited the spontaneous movement of uterus, reducing their rest force, contractile force, and movement ability. B 28 or 56 mumol.L-1 also slowed down the frequency of uterus spontaneous contraction, but C or D did not. B, C, or D 28 and 56 mumol.L-1 inhibited the uterine spasm induced by Oxy and ACh. Likewise, Ver 0.28 mumol.L-1, B, C, and D 28 or 56 mumol.L-1 relieved the contraction mediated by CaCl2 in high-KCl solution, but B, C, or D had not marked influence on the maximal response of uterus to CaCl2. CONCLUSION: B, C, and D inhibit the movement of uterus smooth muscle, and the mechanism is related to the inhibition of cholinergic system as well as Ca2+ movement.

Acetylcholine↗
PubMed2001

Assessment of the cytotoxic and clastogenic activities of the sesquiterpene lactone lynchnopholide in mammalian cells in vitro and in vivo.

Lychnopholide (LNP), a sesquiterpene lactone with antitumor, trypanocidal, and antimicrobial activities, was isolated from Vanillosmopsis erythropappa. The present study was carried out to assess the cytotoxic and clastogenic potential of this new agent in human cultured lymphocytes and Swiss bone marrow cells before the agent was used in medicine. The mitotic index, chromosomal aberrations (CAs), sister chromatid exchanges (SCEs), and proliferation index were investigated. There was no alteration in the number of CAs and SCEs in the continuous in vitro treatment. However, the highest concentration (0.2 microg/ml) of LNP was cytotoxic. LNP (0.1, 0.2, and 0.4 microg/ml) induced a significant increase in CA frequency at the G2 phase in all treated cultures. Only the highest concentration (26.67 mg/kg) caused a significant increase in the total number of CAs in the in vivo investigation. On the basis of these results, LNP had a clastogenic effect on both test systems and a cytotoxic effect in vitro.

Adult↗
PubMed2000

Asymmetric synthesis of biologically useful 3,4-disubstitutedgamma- lactone (3,4-db).

3,4-Disubstituted gamma-lactones 9 and 10 were stereoselectively synthesized from 3,4-unsaturated aliphatic alcohol. The synthetic methods of homoallylic alcohol were discussed. Asymmetric dihydroxylation of the double bond was performed by Sharpless' method with (DHQD)2 PHAL or (DHQ)2 PHAL. The stereochemistry of the product was assigned. The (3R,4R)- and (3S,4S)-compounds were obtained with high enantiomeric excess.

Alcohols↗
PubMed2001

The sesquiterpene lactone dehydroleucodine reversibly inhibits Allium cepa L. root growth.

Here, we prove that dehydroleucodine, a sesquiterpene lactone, at low concentrations (25-100 microM) slowed down the Allium cepa L root growth by 22-70% respectively neither affecting cell viability nor cell size. Removal of the drug after 24 h incubation restored the normal growth rate of the roots. Higher concentrations (200 microM) of dehydroleucodine were deleterious for the roots. As cell size did not change, it is most likely that dehydroleucodine affected some event of cell division cycle making it longer. Thus, dehydroleucodine could be a useful tool to slow down cell proliferation.

Cell Size↗
PubMed2001

Relationship between lactone ring forms of HCPT and their antitumor activities.

AIM: To study the relationship between the lactone forms of 10-hydroxycamptothecin (HCPT) and their antitumor activities. METHODS: Antitumor activity of the two forms of HCPT was studied in vitro using seven cultured human and mouse tumor cell lines. Mice bearing sarcoma 180 and solid hepatoma were treated with HCPT (0.5, 1, and 2 mg/kg, ip) and tumor growth inhibition was assayed. HPLC method was employed to investigate the conversion of two forms of HCPT in different pH conditions and cultured tumor cells. RESULTS: It was found that both forms of HCPT (O-HCPT and C-HCPT) showed similar activities in vitro against a number of tumor cell lines at the same concentration; but C-HCPT was more effective (about two times) than O-HCPT in vivo. The difference between in vitro and in vivo results could be explained by the conversion of O-HCPT into C-HCPT in a certain condition, which was shown by the HPLC analysis of HCPT at different pH values and in cultured tumor cells. CONCLUSION: Both forms of HCPT were effective against tumor growth, but C-HCPT was more effective than O-HCPT, the latter could be converted into the former under certain conditions.

Animals↗
PubMed1996

Inhibition of smooth muscle cell calcium mobilization and aortic ring contraction by lactone vastatins.

OBJECTIVE: To determine the effects of vastatins on the contraction of rat aortic rings and to assess their effects on calcium mobilization using cultured smooth muscle cells from rat aorta. METHODS: Aortic rings from Sprague-Dawley rats were mounted on stainless steel wires to determine the generation of tension using force-displacement transducers. The tension (g) developed by angiotensin II (100 nmol/l) was measured under basal conditions and after 45 min incubation with 20 micromol/l simvastatin. The effect of 20 mol/l simvastatin, lovastatin, mevastatin and pravastatin on noradrenaline concentration-response curves and the angiotensin II-induced calcium mobilization was also evaluated. RESULTS: Addition of angiotensin II to aortic rings incubated in Krebs' Ringer bicarbonate medium produced tension generation (0.9 +/- 0.12 g = 100%). Treatment of aortic rings with simvastatin inhibited the angiotensin II-induced contraction 58 +/- 0.06%. To evaluate this effect further, dose-response curves with noradrenaline were measured in the presence and absence of 20 micromol/l simvastatin, lovastatin, mevastatin and pravastatin. The results indicate that simvastatin, lovastatin and mevastatin inhibited the contraction induced by noradrenaline (10 micromol/l) by about 50%. Pravastatin did not inhibit aortic ring contraction. Furthermore, the concentration required for 50% of the maximal contraction (EC50) by noradrenaline (6.2 +/- 0.1 nmol/l) was significantly increased by simvastatin, lovastatin, mevastatin and pravastatin. The inhibition of vascular contraction by vastatins appears to involve inhibition of 3-hydroxy-3-methylglutaryl (HMG)-CoA reductase activity because the inhibitory effect of simvastatin was reduced 50% by 10 mmol/l mevalonic acid. To determine whether the depression of vascular contraction by these agents was correlated with cell calcium changes, the angiotensin II-induced calcium mobilization was determined in Fura-2 loaded cells, before and after treatment with these inhibitors. Simvastatin, lovastatin and mevastatin significantly reduced the angiotensin II-induced calcium mobilization. The concentration that induced 50% inhibition was 3.3 micromol/l for simvastatin, 17.4 micromol/l for mevastatin and 21.7 micromol/l for lovastatin. No effect of pravastatin on calcium mobilization was observed. CONCLUSIONS: These findings suggest that lactone vastatins depress vascular contraction by reducing cytosolic calcium release in vascular smooth muscle cells. These agents also appear to exert competitive and non-competitive type antagonisms on noradrenaline action.

Angiogenesis Inhibitors↗
PubMed2002

[Synthesis of signaling N-acyl-homoserine-lactones participating in quorum sensing in rhizosphere and soil bacteria Pseudomonas and Xanthomonas].

Signaling molecules assigned to N-acyl-homoserine-lactones (AHL) serve as autoinducers for the genes controlling the quorum sensing regulatory system. In many gram-negative bacteria, AHL are the key factors responsible for density-dependent regulation of exoenzyme and secondary metabolite production; they also participate in interaction between bacteria and higher organisms. The soil and rhisosphere bacteria Pseudomonas and Xanthomonas from different geographical zones of Russia and the former USSR were analyzed for the presence of the AHL producers. Screening was conducted by using a test system based on the mutant strain Chromobacterium violaceum, which was unable to synthesize AHL but produced a pigment violacein in the presence of exogenous AHL. The AHL-like compounds proved to be formed by 9.7% of the studied bacteria. Various Pseudomonas species differed in the capacity to synthesize this compounds. In at least a half of the isolated P. aureofaciens and P. aeruginosa, an intense AHL production was observed, whereas the AHL-producers were far less frequent among the P. fluorescens, P. chlororaphis, P. lemonnieri, P. geniculata, and P. putida. None of the 41 Xanthomonas maltophilia strains examined synthesized AHL.

Homoserine↗
PubMed2000

Rapid analysis of terpene lactones in extract of Ginkgo biloba L. by high performance liquid chromatography.

A new rapid analytical method was developed for the quantification of terpene lactones (bilobalide(BB) and ginkgolide A, B, C, J) in extract of Ginkgo biloba L. (EGb) using a liquid-liquid solvent extraction procedure followed by high performance liquid chromatography. EGb was dissolved in 30% ethanol and extracted with ether. After evaporation, the residue was then determined by HPLC on a C18 column with methanol-water-orthophosphoric acid (25:75:0.1, V/V) as eluent and refractive index (RI) detection. Results showed that the excellent sample clean-up procedure is more simple and specific, and saves more time (less than 20 min) than any other methods that have been reported, and also leads to high recoveries (> 99.0%) and low RSDs (< 2.0%). The reproducible method is regarded to be very useful for evaluating the quality of extract of Ginkgo biloba L.

Chromatography, High Pressure Liquid↗
PubMed1992

[Effects of calcium channel blocker verapamil on hippocampal kindled seizures induced by coriaria lactone in rabbits].

Eighteen fully kindled rabbits, whose epilepsy had been produced by intrahippocampal (i.h.) injections of 2 microliters of diluted solution containing 0.32 or 0.55 micrograms of coriaria lactone (CL), were separated into three groups. One of them was used as the control group. For seizure, all animals were given CL (0.6-1 micrograms/2 microliter i.h.). Ten minutes later, the verapamil (VR) group of six rabbits was treated with VR (1.5 or 2 mg/kg i.m. 2.5 or 5 micrograms/2 microliters i.h.); the normal saline (NS) group (six rabbits) received 0.8 ml/kg (i.m., in the same volume as that of the VR 2 mg/kg injection) or 2 microliters (i.h.) of NS; the control group of six received neither VR nor NS. The experiments were made once every eight days. Hippocampal EEGs of all animals were recorded by telemetric method and their behavior after injection was observed continuously in 4-7 hours. The results of the experiment indicated that the i.h. administration of 2.5 or 5 micrograms/2 microliters of VR is effective on hippocampal kindled seizures induced by CL in rabbits, but the curative effects of the i.m. administration of 1.5 or 2 mg/kg of VR were less notable than those of the i.h. administration.

Animals↗
PubMed1992

[Observation of paired-pulse depression in CA1 region of hippocampal slices from coriaria lactone-kindled rats].

Paired-pulse depression (PPD) technique was used to investigate the potency of recurrent synaptic inhibition mediated by GABA in area CA1 of 54 hippocampal slices from coriaria lactone (CL)-kindled and control rats. When paired stimuli were sent to the axon of CA1 pyramidal cell and Schaffer collaterals, the effect of population spike PPD lasted about 40-60ms; no significant change was observed on PPD potency between kindled and control groups (P = 0.06, 2-way ANOVA). The results indicate that the GABA-ergic synaptic inhibition seemed not to play a key role in the maintenance of the chemical kindling induced by CL.

Animals↗
PubMed1992

[Ultrastructural observation of SC1001-sodium on brain neurons kindled seizures by coriaria lactone in rabbits].

The ultrastructural changes of hippocampus and cerebral cortex neurons were derived from the rabbits kindled by coriaria lactone and from the kindled rabbits after treatment with SC1001 Na. The results of experiment showed that the hippocampus and cerebral cortex neurons in the kindled group had some degenerative changes, such as the swelling mitochondria, dilated rough endoplasmic reticulum and Golgi complexes when the injuries of neurons were not serious, but the seriously injured neurons were subjected to rupture of the cell membrane and solution of most organella, with only a small amount of degenerative organella. In the group treated with SC1001 Na, the ultrastructure of brain neurons demonstrated a tendency of recreation to normal which showed that SC1001 Na had cured many of the degenerative brain cells. This suggested that active treatment is very important for the epileptic patients.

Animals↗
PubMed2003

[Effect of coriaria lactone on the ATP-sensitive potassium channels in pyrimidal neurons of rats].

OBJECTIVE: To acquire knowledge about the effect of Coriaria lactone (CL) on ATP-sensitive potassium channels (KATP) in cultured pyrimidal neurons of rats and the role of KATP in epileptogenesis. METHODS: Experiments were conducted by the use of cell culture technique and single channel patch clamp technique. RESULTS: The reversion potential of neuron KATP was nearly 0 mV under the condition of the same high K+ level in both bath solution and pole solution. The channel could be blocked by TEA, and the channel current could be induced by 30 mumol/L DNP but inhibited by 0.5 mol/L ATP. The conductance of KATP channel current was 78.23 +/- 12.04 pS, and this KATP channel could be remarkably activated by CL and specifically blocked by Glibenclamide. CONCLUSION: The activation of neuron KATP may play a role of decreasing the action potential and thus protecting the neurons from the seizure induced by CL.

Adenosine Triphosphate↗
PubMed2004

[Effect of coriaria lactone on the activation of Ca(2+)-activated K+ channel in hippocampal pyrimidal neurons of rats].

OBJECTIVE: This research sought to disclose the regulatory effect of Coriaria lactone (CL) on the Ca(2+)-activated K+ channel in hippocampal pyrimidal neurons of Wistar rats in epileptogenesis. METHODS: Cell-attached and inside-out methods of patch clamp technique were used to record the activity of single channel. The sample data were stored in a computer and analyzed by the application of Pclamp softwares. RESULTS: 1. By means of inside-out method, the KCa channels (120.34 +/- 25.12) pS on the membrane of hippocampal pyrimidal neurons showed a distinct dependence on calcium concentration (n = 6) and on voltage (n = 17), and the channels could be blocked by TEA. 2. With the use of cell-attached method, the KCa channels could be activated by CL apparently (n = 25, P < 0.01). 3. In the conditions where the neuronal membranous voltage was kept at 20 mV and the [Ca2+]i at 10(-8) mol/L in bath solution, the CL at concentrations from 0 microliter/ml to 1.0 microliter/ml could make the open state probability of KCa to increase from 0.025 to 0.553 (P < 0.01), the mean opening time (ms) to prolong from 1.875 +/- 0.412 to 6.829 +/- 0.136, and the mean closing time (ms) to decrease from 179.342 +/- 13.831 to 6.412 +/- 1.383 (n = 25, P < 0.01). CONCLUSION: The membranous KCa activation induced by CL may play an important negative feedback regulating role in the mechanism of epileptogenesis.

Animals↗
PubMed2004

[Anti-aging action of the total lactones of ginkgo on aging mice].

AIM: To investigate the effects of total lactones of ginkgo on aging by using D-galactose induced aging mice and natural aging mice. METHODS: By using D-galactose induced aging mice, to detect the LF content in heart and liver, the Hyp content in liver, the MAO, GSH-Px activities and the NO content in cerebrum. The apoptosis of cerebral cell was determined by terminal deoxy-nucleotidyl transforase-mediated dUTP-digoxigenin nick end-labeling (Tunel) in natural aging mice. RESULTS: TLG was shown to increase the GSH-Px activities, reduce the NO content and decrease the MAO activity in cerebrum. Meanwhile, TLG was found to reduce the LF content in liver and heart and raise the Hyp content in liver. TLG was shown to inhibit apoptosis of cerebral cell and decrease the number of apoptotic cells in the brain. CONCLUSION: TLG possesses effect on antiaging via attenuating lipid peroxidation and NO and apoptosis of cerebral cells.

Aging↗
PubMed2004

[Determination of GA, GB and GC in total lactone of ginkgo (TLG) raw material].

OBJECTIVE: To determine the different lactone content of 10 batches of TLG raw material. METHODS: RP-HPLC-ELSD were used to determine ginkgolide A, B, C(GA, GB, GC). RESULTS: Content of GA, GB and GC were different but TLG very high (all > 90%). CONCLUSION: The quality of TLG could be affected by habitat, season and the preparation method.

Chromatography, High Pressure Liquid↗
PubMed2006

[Expression of Merlin in cortex of temporal lobe and in hippocampal CA1 region of the Kindling Model of Epilepsy induced by corciaria lactone in rats].

OBJECTIVE: To explore the relationship between merlin and hippocampal sclerosis of temporal epilepsy. METHODS: The kindling model of epilepsy induced by corciaria lactone (CL) in rats was used. The expression of merlin in neuron of cortex of temporal lobe and hippocampal CA1 region was observed using immunohistochemistry method. Comparison of the amount of neuron with expression of merlin in the two locations was made between the kindled group, non-kindled group and control group. RESULTS: The expression of merlin in neuron of cortex of temporal lobe and hippocampal CA1 region of the kindled group was higher than the expression of the other two groups (P < 0.05), and there was no significant difference between the expression in the non-kindled group and that in the control group (P > 0.05). The expression of merlin in glial cell of the same region of all groups was seldom seen. CONCLUSION: The super-expression of merlin in neuron of cortex of temporal lobe and hippocampal CA1 region of the kindled rats may be involved in the process of neuronal apoptosis and hippocampal sclerosis.

Animals↗