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ABSTRACT: Chronic myeloid leukemia (CML) is a potentially fatal stem-cell cancer. P-glycoprotein (P-gp/ABCB1) activity has been described as a relevant factor in the chemotherapeutic failure and correlated to a poor prognosis in these malignancies. In the present study, we investigated the mechanism of the antineoplastic activity of 3β-acetyl tormentic acid (3ATA), a triterpene isolated from C. lyratiloba, on Lucena-1, an MDR leukemia cell line, that overexpressed P-gp/ABCB1. Results showing that this triterpene induced DNA-fragmentation, activation of caspase-3 and cytochrome c release indicated that its activity is mediated by the activation of the intrinsic pathway of apoptosis. Interestingly, this triterpene did not interfere with P-gp/ABCB1 expression or activity, indicating that induction of death is not mediated by any effect on this protein. Moreover, the results show that none of the others triterpenes from C. lyratiloba were able to modulate the activity of P-gp/ABCB1. Together these results suggest 3ATA and the other triterpenes as a promising material for the development of anti-neoplastic drugs for leukemia and other tumors independent of P-gp/ABCB1 activity or expression.
Investigational New Drugs 02/2012; 30(1):105-13. · 3.36 Impact Factor
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ABSTRACT: Multidrug resistance (MDR) is considered the main cause of cancer chemotherapy failure and patient relapse. The active drug efflux mediated by transporter proteins of the ABC (ATP-binding cassette) family is the most investigated mechanism leading to MDR. With the aim of inhibiting this transport and circumventing MDR, a great amount of work has been dedicated to identifying pharmacological inhibitors of specific ABC transporters. We recently showed that 3β-acetyl tormentic acid (3ATA) had no effect on P-gp/ABCB1 activity. Herein, we show that 3ATA strongly inhibited the activity of MRP1/ABCC1. In the B16/F10 and Ma104 cell lines, this effect was either 20X higher or similar to that observed with MK571, respectively. Nevertheless, the low inhibitory effect of 3ATA on A549, a cell line that expresses MRP1-5, suggests that it may not inhibit other MRPs. The use of cells transfected with ABCC2, ABCC3 or ABCC4 showed that 3ATA was also able to modulate these transporters, though with an inhibition ratio lower than that observed for MRP1/ABCC1. These data point to 3ATA as a new ABCC inhibitor and call attention to its potential use as a tool to investigate the function of MRP/ABCC proteins or as a co-adjuvant in the treatment of MDR tumors.
International Journal of Molecular Sciences 01/2012; 13(6):6757-71. · 2.60 Impact Factor
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ABSTRACT: Dorstenia arifolia is a plant that has been used in the folk medicine to produce hypnotic, sedative and ansiolitic effects but the pharmacological properties have not yet been studied. In addition, the smoke of its rhizome is reputed to induce lethargic sensation.
The present study investigated possible activities of the methanol extract (ME) of Dorstenia arifolia rhizome on the central nervous system (CNS).
ME was tested for sedative, hypnotic and anticonsulsant effects using locomotor activity evaluation, pentobarbital-induced sleeping time and pentylenetetrazol (PTZ)-induced convulsion, respectively.
Intraperitoneal administration of ME (10 and 50mg/kg) significantly decreased locomotor activity from 205.2+/-25.6 movements/min (DMSO) to 112.1+/-18.4 (P<0.05) and 114.9+/-16.9 (P<0.05), respectively. Flumazenil (10 mg/kg), an antagonist of GABA(A) receptor, prevented the ME-induced sedation. Treatment with ME (50mg/kg) significantly increased the duration of pentobarbital-induced sleeping time from 41.0+/-2.3 to 57.9+/-2.9 min (P<0.05). The latencies to seizures after intraperitoneal injection of PTZ was recorded and compared between groups. ME promoted a significant protection of PTZ-induced seizures and mortality in a dose-dependent manner.
Our findings indicate that ME of Dorstenia arifolia rizhome has pronounced central effects, and that the sedative and anticonvulsant activities may be related to a facilitation of the GABAergic transmission.
Journal of ethnopharmacology 03/2010; 130(1):9-12. · 2.32 Impact Factor
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ABSTRACT: In Brazilian folk medicine, extracts from Piper species are used to reduce blood pressure. Previously, we demonstrated the vasodilatory activity of crude extracts from leaves of Piper truncatum explaining their possible use in the treatment of hypertension in traditional medicine. In the present study, we investigated the effects of eudesmin, a lignan isolated from hexane extract of leaves from Piper truncatum, on the contractility of rat aortas and the possible mechanisms involved in its vascular action. Eudesmin induced an intense concentration-dependent relaxation of aortic rings precontracted with phenylephrine. The concentration of eudesmin necessary to reduce phenylephrine-induced aortic contraction by 50% (IC(50)) was 10.69+/-0.67 microg/ml. Eudesmin-induced vasodilation required an intact endothelium since vascular relaxation was inhibited by mechanic removal of endothelium, and by pretreatment with nitric oxide synthase inhibitor and soluble guanylate cyclase inhibitor. Relaxation induced by eudesmin was also impaired in the presence of indomethacin and diphenhydramine, a cyclooxygenase inhibitor and an antagonist of type 1 histamine receptor (H(1)), respectively. IC(50) was increased to 18.1+/-1.8 and 18.1+/-2.6 microg/ml (P<0.05; n=6) after exposure to indomethacin and diphenhydramine, respectively. Atropine (muscarinic receptor antagonist), propranolol (beta-adrenoceptor antagonist) and glibenclamide (ATP-sensitive K(+) channel blocker) did not alter the effect of eudesmin. These results indicate that eudesmin-induced vascular relaxation in rat aorta is mediated by release of nitric oxide and prostanoid through the involvement of histamine receptor present in the endothelial cells.
European journal of pharmacology 02/2009; 606(1-3):150-4. · 2.59 Impact Factor
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ABSTRACT: Schinus is a genus of the Anacardiaceae family and contains Schinus terebinthifolius, the Brazilian pepper tree that is widely used in folk medicine. We investigate the anti-allergic activity of the ethyl acetate fraction of S. terebinthifolius Raddi (ST fraction). HPLC analysis reveled that gallic acid, methyl gallate and 1,2,3,4,6-pentagalloylglucose are the major aromatic components of the fraction. Oral pre-treatment with the ST fraction (100 mg/kg) significantly inhibited paw edema induced by compound 48/80 (100 ng/paw) and to a lesser extent, the allergic paw edema (OVA, 3 microg/paw). The ST fraction (100 and 200 mg/kg) also inhibited the edema induced by histamine (100 microg/paw), preventing mast cell degranulation and, consequently, histamine release in Wistar rat peritoneal mast cells induced by C 48/80 (5 microg/mL). This histamine inhibition was also observed after mast cell pre-treatment with both methyl gallate and 1,2,3,4,6-pentagalloylglucose (100 microg/mL), the isolated compounds from the ethyl acetate fraction. Pre-treatment with the ST fraction (100 mg/kg) significantly inhibited total leukocyte and eosinophil accumulation in pleural cavities 24 h after the intrathoracic injection of OVA (12.5 microg/cavity). This effect was related to the inhibition of CCL11/eotaxin and CCL5/RANTES in pleural lavage fluid. Pre-treatment with this fraction (100 mg/kg) failed to reduce the cell influx that was observed after LPS-injection into pleural cavity (250 ng/cavity). These findings demonstrate the anti-allergic effect of the ST fraction, which includes the inhibition of edema formation and histamine release caused by mast cell degranulation and eosinophil influx into the pleural cavity probably reflected by the decreased levels of chemokines in recovered pleural lavage fluid.
International Immunopharmacology 08/2008; 8(11):1552-60. · 2.38 Impact Factor
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ABSTRACT: Buxales (sensu Dahlgren 1980) is an order formed by two families: Buxaceae and Daphniphyllaceae. Among the families of Rosiflorae, (or Rosanae), the positioning of Buxaceae and Daphniphyllaceae show great controversy according to the modern botanists. In order to verify the validity of 1980-Dahlgren's positioning of Buxales (with Buxaceae and Daphniphyllaceae) into the superorder Rosiflorae, a detailed study of micromolecular composition of the Rosiflorae families have been made. The triterpene alkaloids were found to be the prevailing class of secondary metabolites (91%) in Buxales. Triterpenes, steroids and flavonoids can also be found together with very low amount of iridoids. It is important to note that it has not been recorded any reference on the hydrolisable tannin production by these two famylies. However tannins are the characteristic natural products produced by Rosiflorae species, so this kind of compounds have been considered the truly chemotaxonomic markers for the superorder. Excluding Buxales, the superorder Rosiflorae, shows a poor tendency for alkaloid production: only 10 from 40 families present such kind of metabolism even so in a very timid way of expression. In conclusion buxales as stipulated by Dahlgren is characterized by an expressive production of squalene-derived alkalois, feeble presence of flavonoids and terpenoids and lack of references about tannin production. On the other hand, the other Rosiflorae families are characterized by the huge production of tannins. Thus these chemical features indicate scarce affinities among these two plant groups.
Nordic Journal of Botany 06/2008; 19(5):541 - 546. · 0.55 Impact Factor
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ABSTRACT: The cytotoxicity of four triterpenoids, euscaphic acid (1), tormentic acid (2), 2alpha-acetyl tormentic acid (3), and 3beta-acetyl tormentic acid (4), isolated from the roots of Cecropia lyratiloba (Moraceae) by countercurrent chromatography, was evaluated in vitro in sensitive and multidrug resistant leukemia cell lines. A structure/activity relationship analysis of the compounds was performed. Acetylation of compound 2 at C2 increased its activity by a factor of 2 while acetylation at C3 had a smaller effect. Compound 1 induces death by activation of caspase-3, dependent apoptotic pathway. Furthermore, the four triterpenoids were also active toward a multidrug resistant (MDR) leukemia cell line, overexpressing glycoprotein-P (P-gp). These results reveal the potential of the terpenoids as source for the development of new anti-neoplastic and anti-MDR drugs.
Bioorganic & Medicinal Chemistry 01/2008; 15(23):7355-60. · 2.92 Impact Factor
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ABSTRACT: Volatile and semi-volatile components of maté (Ilex paraguariensis St. Hil.) were analysed by headspace solid-phase microextraction (HS-SPME) coupled to gas chromatography and mass spectrometry. Five SPME fibres coated separately with 100 microm poly(dimethylsiloxane) (PDMS), 65 microm PDMS-divinylbenzene (DVB), 70 microm carbowax (CW)-DVB, 85 microm carboxen (CAR)-PMDS or 50/30 microm DVB-CAR, were tested. Seventy compounds were identified in the sample headspace, including propanal, (E)-2-pentenal, hexanal, (E)-2-hexenal, 6-methyl-5-hepten-2-one, (E,Z)-2,4-heptadienal, (E,E)-2,4-heptadienal, (E,Z)-3,5-octadien-2-one, beta-cyclocitral, 3-ethyl 4-methyl-(1H)-pyrrole-2,5-dione, alpha-ionone, geranylacetone, beta-ionone, dihydroactinidiolide and caffeine. Extraction parameters such as temperature, time and sample mass were studied and optimized. The best conditions for trapping volatile and semi-volatile compounds were obtained using a DVB-CAR fibre at 80 degrees C for 60 min with a sample mass starting from 100 mg in a vial of 4 mL.
Phytochemical Analysis 12/2007; 18(6):469-74. · 2.63 Impact Factor
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ABSTRACT: Rheedia longifolia Planch et Triana belongs to the Clusiaceae family. This plant is widely distributed in Brazil, but its chemical and pharmacological properties have not yet been studied. We report here that leaves aqueous extract of R. longifolia (LAE) shows analgesic and anti-inflammatory effects. Oral or intraperitoneal administration of this extract dose-dependently inhibited the abdominal constrictions induced by acetic acid in mice. The analgesic effect and the duration of action were similar to those observed with sodium diclofenac, a classical non-steroidal analgesic. In addition to the effect seen in the abdominal constriction model, LAE was also able to inhibit the hyperalgesia induced by lipopolysaccharide from gram-negative bacteria (LPS) in rats. We also found that R. longifolia LAE inhibited an inflammatory reaction induced by LPS in the pleural cavity of mice. Acute toxicity was evaluated in mice treated with the extract for seven days with 50 mg/kg/day. Neither death, nor alterations in weight, blood leukocyte counts or hematocrit were noted. Our results suggest that aqueous extract from R. longifolia leaves has analgesic and anti-inflammatory activity with minimal toxicity and are therefore endowed with a potential for pharmacological control of pain and inflammation.
Memórias do Instituto Oswaldo Cruz 03/2007; 102(1):91-6. · 2.15 Impact Factor
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ABSTRACT: 1. Brazilian forests show high diversity of medicinal plants and several are used in folk medicine for the treatment of hypertension and asthma. The aim of the present study was to investigate the effects of a methanol extract (ME) of Cecropia lyratiloba and its flavonoid fraction (FF) on the contractility of cardiac, vascular and tracheal smooth muscles. 2. Twitches of rat papillary muscles were obtained with electrical stimulation and were recorded before and after exposure to increasing concentrations of ME and FF. 3. Cardiac depression was induced by FF. At 500 microg/mL FF, the amplitude of twitches was reduced to 56.7 +/- 5.1% of control values (P < 0.05). 4. The contractile response to a single concentration of adrenaline (10 micromol/L) was measured before and after exposure to ME and FF in rat aorta rings with intact endothelium. Both ME and FF inhibited adrenaline-induced contractions of the aorta in a concentration-dependent manner. Adrenaline-induced contractions were reduced to 46.4 +/- 9.9 and 34.2 +/- 6.9% (P < 0.05) of control in the presence of 500 microg/mL ME and FF, respectively. 5. The flavonoids isolated from FF, namely isoorientin and a mixture of orientin and isovitexin, were also tested in the aorta. These flavonoid do not seem to be responsible for the vasorelaxant effects of ME and FF. 6. No changes were observed in acetylcholine-precontracted trachea when exposed to ME or FF. 7. Endothelium-dependent vasodilation induced by FF is likely to be mediated by the release of nitric oxide because vascular relaxation was abolished in the presence of N(omega)-nitro-L-arginine methyl ester, an inhibitor of nitric oxide synthase. 8. In conclusion, vascular relaxation induced by ME and FF could explain the traditional use of the extract of C. lyratiloba for treatment of arterial hypertension.
Clinical and Experimental Pharmacology and Physiology 01/2006; 33(1-2):109-13. · 1.85 Impact Factor
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Journal of Liquid Chromatography & Related Technologies 01/2006; 29(2):229-234. · 0.71 Impact Factor
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ABSTRACT: Nidularium procerum LINDMAN, a common bromeliaceae from the Brazilian flora, remains poorly studied regarding its chemical and pharmacological properties. We have recently published that N. procerum has potent analgesic and anti-inflammatory activities. In the present work, we have investigated potential mechanisms involved in the anti-inflammatory effects of N. procerum aqueous extract on lipopolysaccharide (LPS)-, platelet activating factor (PAF)- or formyl-methionyl-leucyl-phenylalanine (fMLP)-induced pleurisy models of inflammation. We found that the aqueous extract of N. procerum leaves (leaf aqueous extract; LAE) inhibits the neutrophil migration, production of inflammatory cytokines interleukin-1 and -6 (IL-1 and IL-6) and the generation of prostaglandin E2 (PGE2) in LPS-induced pleural inflammation in mice. Such inhibitory effect of N. procerum on PGE2 generation was tightly correlated to the inhibition of formation of new cytoplasmic lipid bodies within recruited leukocytes. N. procerum also blocked the in vivo neutrophil influx induced by injection of PAF or fMLP into the mouse pleural cavity and directly inhibited PAF-induced neutrophil chemotaxis in vitro. The data obtained in this study indicate that N. procerum LAE exerts its anti-inflammatory effects by interfering with the capacity of the host to respond to injury at different levels. Among the different functions affected by N. procerum LAE, lipid body formation, PGE2 and cytokine production and neutrophil chemotaxis are readily evidenced in relevant surrogate models. The N. procerum bioactive profile makes it an attractive candidate for future development as a drug or phytomedicine.
Biological & Pharmaceutical Bulletin 07/2005; 28(6):1010-5. · 1.66 Impact Factor
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ABSTRACT: One of the major goals in chemotherapy is to circumvent anti-apoptotic strategies developed by tumor cells. In a previous paper, we showed that pomolic acid (PA) is able to kill the leukemia cell line K562 and its MDR derivative, Lucena 1. Here, we demonstrated that PA-induced apoptosis of HL-60 cells is dependent on the activation of caspases-3 and -9 and dissipation of the mitochondrial transmembrane potential (Deltapsim). Disruption of Deltapsim precedes caspase activation and is not inhibited by zVAD-fmk indicating mitochondria as the main target of PA. Our data pointed to the potential use of PA to overcome apoptosis resistance.
Cancer Letters 03/2005; 219(1):49-55. · 4.24 Impact Factor
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ABSTRACT: Several plants from the Brazilian Tropical Forest are used in folk medicine for treatment of hypertension and asthma. In this study, we investigated the effects of hexanic extracts of leaves (HLE) and stems (HSE) from Piper truncatum on the contractility of cardiac, vascular and tracheal smooth muscles. Twitches of cardiac muscles obtained with electrical stimulation were recorded before and after exposure to increasing concentrations of hexanic extracts. HLE and HSE respectively reduced significantly the amplitude of twitches to 57.05 +/- 11.63 and 61.58 +/- 5.70% of control in the presence of 100 microg mL(-1). Contractile response to a single concentration of adrenaline (epinephrine) was measured before and after exposure of rat aorta rings to HLE and HSE. Both extracts inhibited aorta contraction in a concentration-dependent manner. The concentration of 50% inhibitory effect (IC50) was 32.3 +/- 13.8 and 47.0 +/- 23.8 microg mL(-1) for HLE and HSE, respectively, in aorta with intact endothelium. HLE and HSE also reduced the acetylcholine-precontracted trachea in a concentration-dependent manner with maximal effect observed at 250 and 350 microg mL(-1), respectively. Vasodilatation and trachea relaxation induced by HLE and HSE could explain the use of Piper extracts to reduce blood pressure and bronchospasm.
Journal of Pharmacy and Pharmacology 12/2004; 56(11):1457-62. · 2.17 Impact Factor
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ABSTRACT: Plumbagin is a naturally occurring naphthoquinone isolated from roots of Plumbago scandens. The plant was collected at the Campus of Fundação Oswaldo Cruz, Rio de Janeiro, Brazil. P. scandens is used as a traditional medicine for the treatment of several diseases. The antimicrobial activity of plumbagin was evaluated using the macrodilution method. The compound exhibited relatively specific activity against bacteria and yeast. The minimum inhibitory concentration test showed the growth inhibiton of Staphylococcus aureus at a concentration of 1.56 g/ml and of Candida albicans at a concentration of 0.78 g/ml. These results suggest the naphthoquinone plumbagin as a promising antimicrobial agent.
Memórias do Instituto Oswaldo Cruz 11/2003; 98(7):959-61. · 2.15 Impact Factor
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ABSTRACT: Plants are known as important source in the search for new anti-cancer agents. Cytotoxicity-guided fractionation of leaves and fruits from Licania tomentosa Bench and leaves from Chrysobalanus icaco L. resulted in the isolation of betulinic, oleanolic and pomolic acids. These triterpenoids inhibited the growth and induced apoptosis of K562, an erythroleukemia cell line. Most importantly, they also inhibited the proliferation of Lucena 1, a vincristine-resistant derivative of K562 that displays several multidrug resistance (MDR) characteristics. Taken together, our findings emphasize the anti-tumor activity of these triterpenes on leukemia cell lines and call attention to their potential as anti MDR agents.
Cancer Letters 03/2003; 190(2):165-9. · 4.24 Impact Factor
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ABSTRACT: Centrifugal liquid-liquid partition chromatography presents significant advantages for the separation and purification of plant metabolites owing to the short operational time of the process and the elimination of possible irreversible adsorption of compounds. The crude chloroform extract from roots of Plumbago auriculata was analysed by countercurrent chromatography using hexane:ethyl acetate:methanol:water (40:10:10:2, v/v) as solvent system. The isolation of the naphthoquinones plumbagin and epi-isoshinanolone, the steroids sitosterol and 3-O-glucosylsitosterol, plumbagic and palmitic acids was easily achieved. Naphthoquinones are typical components of Plumbago species and they show interesting biological activities.
Phytochemical Analysis 16(4):278-81. · 2.63 Impact Factor
