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PubMed2001

Blood glucose- and triglyceride-lowering effect of trans-dehydrocrotonin, a diterpene from Croton cajucara Benth., in rats.

AIM: The objective of this study was to assess in rats the antidiabetic effects (i.e. reduction of hyperglycaemia and hypertriglyceridaemia) of trans-dehydrocrotonin (t-DCTN), a bioactive diterpene isolated from the popular medicinal plant Croton cajucara. METHODS: Hyperglycaemia was induced by intraperitoneal injection of streptozotocin (STZ) and hypertriglyceridaemia by oral administration of ethanol in rats. The blood glucose levels were measured by the glucose oxidase method using commercially available enzyme kits. RESULTS: Treating rats with t-DCTN (50 mg/kg) significantly reduced STZ-induced increases in blood glucose levels as well as ethanol-induced increases in blood triglycerides. CONCLUSION: The results suggest that t-DCTN has an antidiabetic potential that warrants further research on its mechanism and clinical significance.

Animals↗
PubMed2001

Effect of trans-dehydrocrotonin, a 19-nor-clerodane diterpene from Croton cajucara on experimental hypertriglyceridaemia and hypercholesterolaemia induced by Triton WR 1339 (tyloxapol) in mice.

The effect of trans-dehydrocrotonin (t-DCTN) from Croton cajucara Benth. was investigated in mice on Triton WR 1339 (tyloxapol)-induced hypercholesterolaemia and hypertriglyceridaemia. Mice treated with single application of tyloxapol (400 mg/kg, i.p.) demonstrated significantly increased blood levels of total cholesterol and triglycerides at 24 h and 48 h after its injection, compared to normal controls. These increases were found to be markedly suppressed in animals treated orally with 25 and 50 mg/kg t-DCTN or 100 mg/kg gemfibrozil, an established antihypercholesterolaemic drug. These results suggest that t-DCTN may be a suitable candidate for combating pathologies associated with hyperlipaemia.

Animals↗
PubMed2001

Antigenotoxicity of trans-dehydrocrotonin, a clerodane diterpene from Croton cajucara.

The antigenotoxic action of three doses of trans-dehydrocrotonin (t-DCTN), the active ingredient obtained from the bark extract of Croton cajucara, a plant native to the Amazon, was determined in Swiss mice in vivo. Mice were submitted to acute intraperitoneal and gavage treatments, then their bone marrow cells were subsequently analyzed by micronucleus (MN) and chromosome aberration (CA) assays. Comparisons were performed between the three doses of t-DCTN and the negative-control group. Statistical analysis indicated that doses of 50 and 75 % of the LD(50), via intraperitoneal treatment or gavage injection, were antimutagenic with regard to cyclophosphamide. However, the dose of 25 % of the LD(50) was only antimutagenic when administered by gavage. Based on these observations, it can be suggested that gavage is the most effective method of administering t-DCTN. In addition, t-DCTN showed no cytotoxic effects in the bone marrow cells regardless of the route of exposure.

Animals↗
PubMed2002

Croblongifolin, a new anticancer clerodane from Croton oblongifolius.

A new furoclerodane, croblongifolin, together with one known clerodane, crovatin and one known labdane, nidorellol, were isolated from the stem bark of Croton oblongifolius. Structures were established based on spectroscopic and X-ray analysis. Croblongifolin showed a significant cytotoxicity against various human tumor cell lines including HEP-G2, SW620, CHAGO, KATO3 and BT474.

Antineoplastic Agents, Phytogenic↗
PubMed2002

ent-trachyloban-3beta-ol, a new cytotoxic diterpene from Croton zambesicus.

The dichloromethane extract of leaves of Croton zambesicus (Euphorbiaceae) showing in vitro cytotoxicity against human cervix carcinoma cells was investigated in order to identify its active compounds. A bio-guided fractionation by HSCCC followed by MPLC led us to isolate a trachylobane diterpene, ent-trachyloban-3beta-ol, with cytotoxic properties (IC50 on HeLa cells = 7.3 microg/ml). This is the first report on the cytotoxicity of a trachylobane diterpene.

Antineoplastic Agents↗
PubMed2003

Cytotoxic effect of the diterpene lactone dehydrocrotonin from Croton cajucara on human promyelocytic leukemia cells.

Diterpenes exhibit potent antineoplastic properties against human and murine carcinoma cell lines. trans-Dehydrocrotonin from Croton cajucara, a Brazilian medicinal plant, is a nor-diterpene with antiulcerogenic activity. In this work, we examined the effect of trans-dehydrocrotonin (t-DCTN) on the vitality of HL60 cells by assessing the MTT reduction, protein content and phosphatase activity of these cells. Protein quantification indicated that t-DCTN reduced the number of cells with an IC50 of 500 microM; mitochondrial function (MTT reduction), was also inhibited (IC50 = 300 microM), when the cells were treated for 24 h. In contrast, when the cells were treated with this lactone in the initial plating and cultured for 96 h, t-DCTN was more toxic for all parameters analyzed: MTT and phosphatase activity (IC50 = 180 microM) and protein content (IC50 = 150 microM). The flavonoid utilized as positive control myricetin and the following IC50 values were obtained after 24 h of treatment: 300 and 192 microM for protein content and MTT reduction, respectively. According to the chemical characteristics of both compounds, the cytotoxic effect of t-DCTN could be explained through two mechanisms: adduct formation with DNA and proteins and/or oxidative stress induction.

Antineoplastic Agents, Phytogenic↗
PubMed2003

Cytotoxic activity of natural labdanes and their semi-synthetic modified derivatives from Croton oblongifolius.

Labda-7,12( E),14-triene-17-oic acid, previously isolated from Croton oblongifolius, and its derivatives were investigated for cytotoxicity against five human tumor cell lines. Six of these compounds, labda-7,12( E),14-triene-17-al, 17-hydroxylabda-7,12( E),14-triene, 17-acetoxylabda-7,12( E),14-triene, 15-hydroxylabda-7,13( E)-diene-17,12-olide, labda-7,13( E)-diene-17,12-olide, and 12,17-dihydroxylabda-7,13( E)-diene showed non-specific, moderate, cytotoxicity against all cell lines, whereas the other compounds were inactive.

Antineoplastic Agents, Phytogenic↗
PubMed2003

Myorelaxant effects of the essential oil of Croton nepetaefolius on the contractile activity of the guinea-pig tracheal smooth muscle.

The effects of the essential oil of Croton nepetaefolius (EOCN) on isolated guinea-pig trachea were investigated. EOCN decreased the preparation's basal tone (EC (50) = 4.3 microg/mL) with a maximal effect similar to that of aminophylline. EOCN fully relaxed preparations pre-contracted with 60 mM K+ (IC (50) = 113.0 microg/mL). EOCN did not alter the E (m) of smooth muscle cells in 5 and 80 mM K+. EOCN, at 300 and 600 microg/mL, reduced the contraction induced by ovalbumin (10 microg/mL) from 227.2 to 82.5 and 35.5 % of the 60 mM K+-induced contraction, respectively. EOCN blocked the submaximal contractions induced by histamine, carbachol and 60 mM K+ with a similar potency (IC (50) values = 123.9, 102.5 and 128.8 microg/mL, respectively). In conclusion, EOCN exerts respiratory smooth muscle antispasmodic activity by a mechanism that is probably myogenic and not specific for neurotransmitters and autacoids.

Animals↗
PubMed2004

New halimane diterpenoids from Croton oblongifolius.

Three new halimane-type diterpenoids, crotohalimaneic acid ( 1), crotohalimoneic acid ( 2) and 12-benzoyloxycrotohalimaneic acid ( 3), were isolated from the stem bark of Croton oblongifolius Roxb. Their structures were established on the basis of spectroscopic and X-ray analysis. Compounds 1 and 2 showed non-specific strong cytotoxicity against a panel of human tumor cell lines; whereas 3 was inactive.

Antineoplastic Agents, Phytogenic↗
PubMed2005

Diterpenes isolated from Croton zambesicus inhibit KCl-induced contraction.

A mixture of two new diterpenes was isolated from a dichloromethane extract of Croton zambesicus: ent-18-hydroxytrachyloban-3beta-ol (1) and ent-18-hydroxyisopimara-7,15-diene-3beta-ol (2). The two compounds crystallised together and were separated after derivatisation of the pimarane derivative with osmium tetroxide. The structure of 1 was elucidated by 1D- and 2D-NMR analysis and by X-ray diffraction of a crystal containing both compounds while 2 was only identified by crystallographic data. As this plant is widely used in African folk medicine against hypertension, we have analysed the vasorelaxant activity of the isolated molecules. The mixture of the two compounds inhibited the KCl-induced contraction of male Wistar rat aorta (IC (50) = 1 microg/mL), while the purified trachylobane (compound 1) and the hydroxylated pimarane showed a lower activity than the mixture.

Animals↗
PubMed2002

Effect of essential oil obtained from Croton cajucara Benth. on gastric ulcer healing and protective factors of the gastric mucosa.

The bark of Croton cajucara Benth. (Euphorbiaceae) is used widely in Amazonian folk medicine for the treatment of a wide range of gastrointestinal symptoms. Infusions of C. cajucara bark contain dehydrocrotonin (DHC), the furan diterpene, and an essential oil, a rich mixture of sesquiterpenes. Although the antiulcerogenic activity of the essential oil has been studied in different gastric ulcer models in mice and rats, its mechanism remains unclear. In this work, we examined the ability of this essential oil to increase PGE2 release from mucus cells, as well as its effects on the amount of gastric mucus and on the healing of acetic acid-induced gastric ulcers. The essential oil (100 mg/kg body wt., p.o), significantly increased PGE2 production by glandular cells (by 102% as compared to control) and the amount of Alcian blue binding to the gastric mucus. In chronic gastric ulcers, a single daily oral dose of essential oil (100 mg/kg body wt.) for 14 consecutive days accelerated ulcer healing to an extent similar to that seen with an equal dose of cimetidine. Thus, the protective and healing actions of the essential oil from C. cajucara bark on gastric lesions resulted mainly from an increase in PGE2 release and gastric mucus formation which would protect the gastric mucosa.

Animals↗
PubMed2003

Evaluation of the mutagenic, antimutagenic and antiproliferative potential of Croton lechleri (Muell. Arg.) latex.

Sangre de Drago is a red viscous latex extracted from Croton lechleri (Euphorbiaceae) cortex, renowned in South American popular medicine for its wound-healing properties. The in vitro antiproliferative effects were determined on the human myelogenous leukemia K562 cells line (IC50 = 2.5 +/- 0.3 microg ml(-1)). The mutagenic and antimutagenic activity of C. lechleri sap was examined by means of the Ames/Salmonella test. No mutagenic activity was found on the Salmonella typhimurium strains T98 and T100, either with or without S9 activation. On the other hand, the sap showed an inhibitory effect against the mutagenic activity of the indirectly acting mutagen 2-Aminoanthracene in presence of S9 and a moderate protective activity against directly acting mutagens Sodium Azide and 2-Nitrofluorene. Therefore we suggest that C. lechleri sap interacts with the enzymes of the S9 mix, thereby inhibiting the transformation of 2-Aminoantracene into its active forms.

Anthracenes↗
PubMed2006

The gastroprotective effect of the essential oil of Croton cajucara is different in normal rats than in malnourished rats.

It has been shown previously that malnourished rats are resistant to acute gastric lesions but not to subchronic gastric ulceration. It also has been demonstrated that the essential oil obtained from the bark of Croton cajucara (Sacaca) has antiulcer properties. In the present study, the ability of this essential oil to prevent the formation of gastric ulcers in rats fed a diet with 17% protein (normoproteic rats) or 6% protein (malnourished rats) was investigated. At a dose of 100 mg/kg body weight, orally, the essential oil significantly reduced the gastric injury caused by indomethacin (25% after 2 h and 70% after 4 h) only in normoproteic rats. In the pylorus ligature model, the essential oil increased the pH and gastric volume, but decreased the total acid concentration in both groups when compared to the respective control group. The essential oil significantly increased prostaglandin E2 production in glandular cells by 50% compared to the controls in both groups of rats. In addition, the amount of gastric mucus was two-fold higher in malnourished rats than in normoproteic rats. The present results show that the enhanced protective effect of essential oil in malnourished rats involved an increase in prostaglandin E2 production and mucus secretion, which are both factors that protect the gastric mucosa against damage. In agreement with this, malnourished rats always had a lower number of acute gastric ulcers.

Animals↗
PubMed2003

Alkaloids from Croton flavens L. and their affinities to GABA-receptors.

Phytochemical investigation of several plants of Croton flavens L. from Barbados has led to the isolation of the tetrahydroprotoberberine alkaloids scoulerine and coreximine, as well as the morphinanedienones salutaridine and its racemic form salutarine, sebiferine, norsinoacutine and flavinantine. In a screening for 3H-GABA displacing activity coreximine showed the highest affinity to the GABA(A) receptor.

Alkaloids↗
PubMed2004

Three new glutarimide alkaloids from Croton cuneatus.

Analysis of the dichloromethane extract of the aerial parts of Croton cuneatus led to the isolation of the new glutarimide alkaloids: julocrotol (1), isojulocrotol (2), and julocrotone (3) along with the known compounds julocrotonine (4), lichexanthone (5) and selin-11-en-4alpha-ol (6). The structures of the new compounds were established by spectral methods. The in vitro cytotoxic activity of Compounds 1-6 was evaluated against six human tumor cells lines.

Alkaloids↗
PubMed2003

Review of sangre de drago (Croton lechleri)--a South American tree sap in the treatment of diarrhea, inflammation, insect bites, viral infections, and wounds: traditional uses to clinical research.

OBJECTIVE: The objective of this review is to provide an overview of the pharmacologic evidence that may or may not support clinical and ethnomedical uses of the sap of sangre de drago (dragon's blood; Croton lechleri Müll. Arg.). Data sources used were BIOSIS, EMBASE, PubMed, TOXLIT, International Pharmaceutical Abstracts, manual searches, papers on file from peer-reviewed journals, textbooks available at Armana Research, Inc., and researchers in the field of South American botanical medicine. CONCLUSIONS: The results of in vitro and in vivo studies largely support the majority of ethnomedical uses of sangre de drago including the treatment of diarrhea, wounds, tumors, stomach ulcers, herpes infection, the itching, pain and swelling of insect bites, and other conditions. Clinical studies of sangre de drago products have reported positive results in the treatment of traveler's and watery diarrhea and the symptoms of insect bites. Because the sap has shown low toxicity and preparations used in clinical studies were well tolerated, further clinical and pharmacologic studies are anticipated. Acknowledgment of the diversity in the chemical makeup of the sap from one geographic area to another and the recent characterization of alkaloid chemotypes of sangre de drago will require that materials developed for clinical use are standardized.

Animals↗
PubMed1985

Mouse skin melanoma induced in two stage chemical carcinogenesis with 7,12-dimethylbenz[a]anthracene and croton oil.

Mouse skin melanomas were induced in two stage skin carcinogenesis with 7,12-dimethylbenz[a]anthracene as initiator and croton oil as promoter. After approximately 25 weeks of promotion, small black macules of the skin were observed in C57BL, CDF1 and BDF1 mice, and progressively grew with time. Macules less than 2 mm in diameter were localized mostly in the lower portion of the dermis and, histologically, these lesions were consistent with the diagnosis of melanocytoma and were composed of polygonal to round cells loaded with large numbers of melanin granules. The cells were closely packed forming well-demarcated cell-nests with occasional columnar arrangement. In the macules over 2 mm in diameter, the cells were closely packed to form irregularly bordered cell-nests, showing invasive growth into the surrounding tissues. The lesions were diagnosed as malignant melanomas. The incidence of benign and/or malignant melanoma differed among strains: 80% in BDF1, 70% in CDF1, 30% in C57BL/6 and 0% in DBA/2 mice. One example of tumor induced in a CDF1 mouse was transplantable to homologous CDF1 mice.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1987

Comparative efficacy of clindamycin, erythromycin and spiramycin against Staphylococcus aureus in the rat croton oil pouch model.

Spiramycin, a macrolide antibiotic, has inferior in-vitro activity to erythromycin, but superior tissue penetration. Recent publications have suggested that the in-vivo activity of spiramycin should be re-assessed. The efficacy of clindamycin, erythromycin and spiramycin was compared against Staphylococcus aureus infections in the rat croton oil pouch model. The concentration of spiramycin in the pouch fluid was lower than the concentration of clindamycin or erythromycin after single or multiple intraperitoneal injections. In contrast, the concentration of spiramycin in the pouch wall (73.3 +/- 14.5 micrograms/g) was markedly higher than that of erythromycin (less than 7.5 micrograms/g). Multiple doses of spiramycin had no significant effect upon bacterial growth in the pouch, whereas clindamycin and erythromycin had a significant bactericidal effect. The results suggest that spiramycin is bound to tissues, diffuses poorly into tissue fluid and may therefore be ineffective against infections in large collections of tissue fluid.

Animals↗