Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Crotonates”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 199 records · Page 11Linked to original sources
PubMed1994

[Experimental study of differentiation between tumor and inflammation using MR imaging: correlation between VX2 tumors and croton oil induced inflammation in the rabbit's femoral muscle].

We evaluated the various Magnetic Resonance (MR) sequences for differentiation between tumors and inflammation. Experimental models of rabbit's tumors (VX2) and inflammation induced by croton oil in the femoral muscle were used for this evaluation. Both types of lesions presented a high intensity area on T2-weighted and heavy T2-weighted images. An inflammatory lesion was revealed with iso-/low intensity area and tumors were defined as high signal lesions on Sinc saturation fat suppression T1-weighted, standard T1-weighted and fat suppression T1-weighted images by the 3 Point dixon method. T1, T2 values of tumor and inflammatory lesions were also measured. The T1 value of the tumors was 1186 +/- 58 msec (n = 5) and that of the inflammatory lesion was 1097 +/- 40 msec (n = 3). The T2 value of the tumors was 71 +/- 13 msec (n = 5) and that of the inflammatory lesions was 70 +/- 5.5 msec (n = 3). There were no significant differences between both the T1 and T2 values. Calculated relative proton density was 0.69 +/- 0.14 (n = 4) in the tumors, and 0.42 +/- 0.12 (n = 3) in the inflammatory lesions. A statistical difference (p < 0.05) was found in both value. These results suggest that a T2-weighted image is not useful for differentiation between tumors and inflammation, and a T1-weighted image might be useful for such differentiation. This phenomenon is related to the difference of the proton density.

Animals↗
PubMed1999

Antioestrogenic effect of trans-dehydrocrotonin, a nor-clerodane diterpene from Croton cajucara Benth. in rats.

This study examined trans-dehydrocrotonin (t-DCTN), a nor-clerodane diterpene isolated from the Brazilian medicinal plant Croton cajucara Benth., for a possible antioestrogenic activity using immature rats as a model system for bioassay of oestrogen, and for an antiimplantation effect in regularly cycling rats of proven fertility. In the antioestrogen test, t-DCTN (25 and 50 mg/kg) effectively prevented oestrogen-induced increases of uterine wet weights. In addition, the vaginal openings provoked by oestrogen were completely prevented by t-DCTN. However, blastocyst-implantation was only insignificantly affected in t-DCTN pretreated animals. These results suggest that t-DCTN may be an antioestrogen and warrants further studies with regard to its mechanism of action.

Animals↗
PubMed2000

Constituents of Croton menthodorus and their effects on electrically induced contractions of the guinea-pig isolated ileum.

The present study examines the effects of the extracts [petroleum ether, CHCl(3), CHCl(3)MeOH (9:1) and MeOH], partially purified fractions and pure compounds from Croton menthodorus on the electrically induced contractions of the isolated guinea-pig ileum (ECI). The results of the experiments indicate that CHCl(3)/MeOH (9:1) and MeOH extracts, tested at concentrations of 100, 50 and 25 microg/mL, dose-dependently reduced the guinea-pig ileum contractions, whereas petroleum ether and CHCl(3) extracts did not affect it. Furthermore, the partially purified fractions III-VI from the CHCl(3)/MeOH extract, each tested at concentrations of 100, 50 and 25 microg/mL also inhibited ECI. Finally, pure compound 1 (6 x 10(-6), 3 x 10(-6), 1 x 10(-6) M) isolated and purified from the most active fraction III significantly reduced, in a dose-dependent manner, the electrical contractions of the ileum. Compound 1 was identified by NMR and EI-MS data as the morphinandien-7-one, O-methylflavinantine.

Animals↗
PubMed1999

Investigation of genotoxic activity of trans-dehydrocrotonin, a clerodane diterpene from Croton cajucara.

The genotoxic action of three doses of trans-dehydrocrotonin (t-DCTN), an active ingredient obtained from the bark extracts of an Amazon native plant, Croton cajucara, were examined in Swiss mouse bone marrow cells in vivo, submitted to acute intraperitoneal treatment, by micronucleus (MN) and chromosomal aberration (CA) tests. The statistical tests (Anova and Tukey) made to compare the results obtained in each of the three doses of t-DCTN with the negative-control group showed that the frequencies of MN and mitotic index were equal to the negative-control and that the frequencies of CA were lower than that observed in the negative-control. Therefore, based on our results it can be said that t-DCTN is not genotoxic nor cytotoxic to mouse bone marrow cells, submitted to acute intraperitoneal treatment in vivo. Teratogenesis Carcinog. Mutagen. 19:377-384, 1999.

Animals↗
PubMed1994

Isolation of isoguanosine from Croton tiglium and its antitumor activity.

This paper describes the isolation of isoguanosine from Croton tiglium L. and its cytotoxic effect against several tumor cell lines in culture and newly reports that isoguanosine has an antitumor activity against implanted S-180 ascitic tumor mice. Isoguanosine is effective at the dose of 24 mg/kg/day x 5, with T/C value of 168%. Isoguanosine inhibits the growth of S-180 and Ehrlich solid tumor in mice at the optimal doses of 96 mg/kg/day x 12 and 48 mg/kg/day x 12, with 1-T/C values of 65% and 60%, respectively.

Adenosine↗
PubMed1990

Effects of chronic oral administration in mice of the gut-stimulating crystals of Croton penduliflorus seed oil.

Crystals from Croton penduliflorus seeds (CPC) were administered at weekly intervals in two doses (7 mg/kg and 21 mg/kg) by gastric intubation to mice over 12 weeks. CPC induced purgation in the treated mice, with the higher dose having a more profound effect. Mice treated with CPC developed skin lesions with swollen scrotums. There were significant changes in the PCV, Hb and plasma proteins of treated mice. Gangrene of the tail with subsequent sloughing was observed, particularly in the low dose group. Mice in the low dose group also experienced retarded growth. A significant clinical finding in the treated mice was abortion during late pregnancy and 100% fetal mortality. It was concluded that, apart from its purgative effect, CPC can cause toxic effects in chronic administration. Use in pregnant women should be discouraged.

Abortifacient Agents↗
PubMed1991

Effects of Croton zehntneri aqueous extracts on some cholinergic- and dopaminergic-related behaviours of laboratory rodents.

The effects of aqueous Croton zehntneri leaf and branch extracts, orally administered, on some dopaminergic- and cholinergic-related behaviours were studied in rats and mice. The leaf extract did not modify apomorphine-induced stereotypic behavior, haloperidol-induced catalepsy and active avoidance/escape responses. The branch extract reduced stereotypy but did not interfere with catalepsy and active avoidance behavior. Both extracts were capable of increasing the tremor induced by oxotremorine.

Animals↗
PubMed1995

Effects of essential oil of Croton zehntneri, and of anethole and estragole on skeletal muscles.

Extracts of the essential oil of Croton zehntneri (CzEO) yield a mixture of substances in which the major components are anethole and estragole. The action of CzEO and of pure anethole and estragole (at 0.05-1.0 mg/ml) were studied in muscle preparations of the toad and rat. All three oils blocked twitches evoked by nerve stimulation. In the rat diaphragm direct stimulation resulted in enhanced twitches (CzEO), partially depressed twitches (estragole) and anethole did not induce a significant change. The response of toad rectus to acetylcholine was reduced by all three oils. Caffeine contractions of the rectus abdominis and sartorius muscles were enhanced by all oils. This enhancement in the case of the sartorius was blocked by procaine. Lowering the temperature to 4 degrees C in the presence of CzEO, anethole or estragole provoked a contraction which could be blocked by procaine. CzEO, anethole or estragole alone sometimes caused contractions. The occurrence of this response was increased by elevation of calcium (to 22 mM). Other divalent cations and La3+ were also effective, in order: La3+ > Ca2+ > Mn2+ > Ba2+ > Mg2+ except in the case of anethole where the order of Ca2+ and Mn2+ are interchanged. CzEO- and estragole-induced contractions were blocked by procaine. The data suggest that CzEO, anethole and estragole may have two sites of action on muscle fibers: the post junctional membrane, by blocking neuromuscular transmission, and on the sarcoplasmic reticulum (SR), by increasing myoplasmic calcium.

Allylbenzene Derivatives↗
PubMed2000

Diterpenoids from the roots of Croton macrostachys.

Three novel diterpenoids have been isolated from the roots of Croton macrostachys. The structure and stereochemistry of the compounds have been unambiguously settled as neoclerodan-5,10-en-19,6beta;20,12-diolide, 3alpha, 19-dihydroxytrachylobane, and 3alpha,18,19-trihydroxytrachylobane from detailed spectroscopic evidence.

Diterpenes↗
PubMed2001

Cytotoxic labdane diterpenoids from Croton oblongifolius.

Three labdane diterpenoids, 2-acetoxy-3-hydroxy-labda-8(17),12(E)-14-triene, 3-acetoxy-2-hydroxy-labda-8(17),12(E)-14-triene, and 2,3-dihydroxy-labda-8(17),12(E),14-triene were isolated from stem bark of Croton oblongifolius. Their structures were established by spectroscopic data, and each was also tested for cytotoxicity against various human tumor cell lines. The latter compound showed non-specific, moderate, cytotoxicities against all the cell lines; whereas the first two compounds were less active.

Antineoplastic Agents, Phytogenic↗
PubMed2001

Labdane and pimarane diterpenes from Croton joufra.

From the chloroform extract of the leaves of Croton joufra, the diterpenes 2alpha,3alpha-dihydroxy-labda-8(17),12(13),14(15)-triene and 3beta-hydroxy-19-O-acetyl-pimara-8(9),15-dien-7-one, were isolated. Their structures were established by spectroscopic methods. One of the compounds showed weak lethality in the brine shrimp assay.

Abietanes↗
PubMed2001

Three clerodane diterpenoids from Croton eluteria Bennett.

Three furanoid clerodanes have been isolated from the stem bark of Croton eluteria Bennett. Their structures have been established by spectroscopic methods. The compounds were named cascarillin B (7alpha-acetoxy-3,4,15,16-diepoxy-12-oxo-cleroda-13(16),14-dien-20-al), cascarillin C (7alpha-acetoxy-15,16,12,20-diepoxy-20-hydroxy-cleroda-3,4,13(16),14-triene) and cascarillin D (7alpha-acetoxy-3,4,15,16-diepoxy-cleroda-13(16),14-dien-20-al).

Diterpenes↗
PubMed2000

Anti-HIV-1 phorbol esters from the seeds of Croton tiglium.

Five phorbol diesters, together with three known ones, were isolated from a MeOH extract of the seeds of Croton tiglium, and their structures were determined by spectroscopic methods and selective hydrolysis of acyl groups. These compounds were assessed for their abilities to inhibit an HIV-induced cytopathic effect (CPE) on MT-4 cells and to activate protein kinase C (PKC) associated with tumor-promoting action. 12-O-Acetylphorbol-13-decanoate and 12-O-decanoylphorbol-13-(2-methylbutyrate) effectively inhibited the cytopathic effect of HIV-1 [complete inhibitory concentration (IC100) values of 7.6 ng/ml and 7.81 microg/ml, and minimum cytotoxic concentration (CC0) value of 62.5 and 31.3 microg/ml, respectively]; however, 12-O-acetylphorbol-13-decanoate showed no activation of PKC at concentrations of 10 and 100 ng/ml. 12-O-Tetradecanoylphorbol-13-acetate (TPA) was found to be not only the most potent inhibitor of HIV-1-induced CPE (IC100 value of 0.48 ng/ml), but also the most potent activator of PKC (100% activation at 10 ng/ml).

Animals↗
PubMedDate not supplied

Purification and characterization of a toxin inhibiting protein synthesis from Croton mongue, a Madagascar Euphorbiaceae.

Monguine, a thermostable toxic protein was extracted from the seeds of Croton mongue (Euphorbiaceae) and purified by ion-exchange chromatography on DEAE-cellulose and gel filtration on Sephadex G-25 and G-15. Polyacrylamide gel electrophoresis of purified monguine in the presence of sodium dodecyl sulfate and after treatment with 2-mercaptoethanol showed one band corresponding to a molecular weight of 9000. The same molecular weight was determined by analytical centrifugation. Amino acid analysis revealed a high content in both aspartic and glutamic acids (or the corresponding amides). The LD50 (24 h) is 12 mg/kg of mouse body weight. Monguine inhibits protein synthesis in hepatoma tissue culture cells and globin synthesis in a rabbit reticulocyte lysate.

Amino Acids↗
PubMed2002

Investigations on the antinociceptive activity of crude extracts from Croton cajucara leaves in mice.

The crude leaf extracts of Croton cajucara Benth. were studied for their antinociceptive property in chemical and thermal models of nociception in mice. All the tested extracts (hexanic, chloroformic and methanolic), at oral doses of 100 and 200 mg/kg demonstrated significant inhibition of acetic acid-induced writhing and the second phase response of formalin, but did not manifest a significant effect in hot-plate test.

Acetic Acid↗
PubMed2001

Antihypertensive and vasorelaxant effects of aqueous extract from Croton schiedeanus Schlecht in rats.

Antihypertensive and vasorelaxant effects of treatment with the aqueous extract of Croton schiedeanus Schlecht (AECS) were investigated in anaesthetized spontaneously hypertensive rats (SHR). Intravenous bolus injections of AECS (5-100 mg/kg) elicited dose-dependent decreases in mean arterial pressure (MAP) and heart rate (HR). Additionally, AECS (10(-6)-3x10(-3)g/ml) completely relaxed the contractions induced by high K(+) concentrations in intact rat aortic rings in a concentration-dependent manner.

Animals↗
PubMed1997

Chemical composition and antimicrobial activity of Croton urucurana Baillon (Euphorbiaceae).

In the methanolic extract of Croton urucurana Baillon (Euphorbiaceae) a number of known compounds, such as acetyl aleuritolic acid, stigmasterol, beta-sitosterol, campesterol, beta-sitosterol-O-glucoside, sonderianin, catechin and gallocatechin were isolated and identified by MS and NMR spectroscopy, HRGC and data from literature. The antibacterial activity of the aqueous-EtOH extract, some fractions of the methanolic extract and some of the isolated compounds, were tested against Staphylococcus aureus and Salmonella typhimurium. Acetyl aleuritolic acid exhibits the best minimum inhibitory concentration (MIC) against both Staphylococcus aureus and Salmonella typhimurium.

Anti-Bacterial Agents↗