Kirley M. Canuto

Amburoside A, a glucoside from Amburana cearensis, protects mesencephalic cells against 6-hydroxydopamine-induced neurotoxicity

This study evaluates the potential neuroprotective properties of amburoside A, a glucoside isolated from Amburana cearensis, on rat mesencephalic cell cultures exposure to the neurotoxin 6-hydroxydopamine (6-OHDA). The parameters determined were cell viability by the 3[4,5-dimethylthiazole-2-il]-2,5-diphenyltetrazolium bromide (MTT) method, nitric oxide (NO) and free radical formation by the measurement of nitrite concentration and thiobarbituric acid reacting substance (TBARS) formation as an indication of cellular lipid peroxidation. The results showed that AMB was less effective as a curative agent in the MTT assay, since its addition after 6-OHDA did not reverse the neurotoxins effect, except at the highest concentration (AMB, 100 microg/ml). Similarly, the higher nitrite levels observed after exposure of the cells to 6-OHDA were only partially reversed by AMB, at this highest concentration. However, when AMB (0.5, 1, 10 and 100 microg/ml) was added before the toxin, it appeared to protect neuronal cells against 6-OHDA toxicity in a concentration-dependent manner, as shown by MTT assay. AMB also prevented free radical formation indicated by the increased nitrite concentration induced by 6-OHDA. Cells exposed to 6-OHDA showed a 3.4 times increase in TBARS concentration as compared to controls, and this effect was inhibited from 24% up to 64% by AMB (0.1-100 microg/ml), indicative of a neuroprotective effect. In conclusion, we show that AMB, acting as an antioxidant compound, presents a significant neuroprotective effect, suggesting that this compound could provide benefits as a therapeutic agent in neurodegenerative disease such as Parkinsons.

Leaf essential oils of four Piper species from the State of Ceará - Northeast of Brazil

Os oleos essenciais obtidos por hidrodestilacao das folhas de quatro especies de Piper (P. arboreum, P. crassinervium, P. dilatatum and P. tuberculatum), coletadas no estado do Ceara, foram analisados por CG-EM. Os rendimentos dos oleos, calculados sobre o peso do material fresco, variaram entre 0,03 - 0,11% (p/p). Os oleos foram caracterizados pela presenca de mono- e sesquiterpenos, exceto o oleo de P. arboreum, no qual foram identificados apenas sesquiterpenos. b-Elemeno (0,58-3,03%), (E)-cariofileno (2,71-37,78%), germacreno D (3,43-11,81%), biciclogermacreno (2,83-25,07%) e d-cadineno (0,52-2,44%) foram detectados em todas as amostras analisadas. Os monoterpenos majoritarios identificados foram a-pineno (11,27%), b-pineno (20,01%), 1,8-cineol (10,81%) e linalol (28,61%) para P. crassinervium, e a-felandreno (22,53%) e D-3-careno (10,20%) para P. dilatatum. Biciclogermacreno (25,03 e 25,07%) para P. arboreum e P. dilatatum, (E)-nerolidol (11,12%) para P. arboreum, germacreno D (11,81%) para P. tuberculatum e (E)-cariofileno (10,26 e 37,78%) para P. dilatatum e P. tuberculatum, foram os principais sesquiterpenos. Este trabalho descreve, pela primeira vez, a composicao quimica dos oleos essenciais de P. crassinervium e P. tuberculatum.

A comparative chemical and pharmacological study of standardized extracts and vanillic acid from wild and cultivated Amburana cearensis A.C. Smith.

The objectives of this work were to carry out a comparative chemical study and to evaluate the antinociceptive and anti-inflammatory activities of ethanol extracts (EtOHE) and vanilic acid (VA) from cultivated and wild Amburana cearensis A.C. Smith (Fabaceae), an endangered species used in Northeast Brazil for the treatment of asthma. The HPLC analysis of EtOHE, showed that coumarin (CM) and VA were the major constituents from the cultivated plant, while in the extract from the wild plant the major constituents were amburoside A (AMB) and CM. Pharmacological tests were performed with male Swiss mice or male Wistar rats acutely administered with 100-400mg/kg, p.o. of EtOHEs or 12.5-50mg/kg, p.o. of VA. EtOHEs from A. cearensis with 4, 7 or 9 months of cultivation significantly inhibited, from 32 to 64%, both phases of the formalin test in mice. Similar results were observed with the EtOHE from the wild species. VA significantly reduced both phases of the formalin test. This effect was partially reversed by naloxone. EtOHE from cultivated or wild A. cearensis inhibited the carrageenan (Cg)-induced mice paw edema. Furthermore, VA inhibited the paw edema and the leukocyte migration in rat peritoneal cavity induced by Cg. On the other hand, it did not inhibit the edema and the increase of vascular permeability induced by dextran in the rat paw. All together, these results indicate that the EtOHE from cultivated A. cearensis exhibit similar chemical and pharmacological profiles, as related to the wild plant. VA is, at least partially, responsible for these pharmacological effects. Its antinociceptive effect occurs by a mechanism partly dependent upon the opioid system, while the anti-inflammatory action was manifested in inflammatory processes dependent on polymorphonuclear cells and are probably related to the VA inhibition of cytokines as observed by others.

Antiproliferative effects of several compounds isolated from Amburana cearensis A. C. Smith.

Abstract Amburana cearensis a common tree found in Northeastern Brazil is widely used in folk medicine. The present work evaluated the cytotoxicity of kaempferol, isokaempferide, amburoside A and protocatechuic acid isolated from the ethanol extract of the trunk bark of A. cearensis. The compounds were tested for their cytotoxicity on the sea urchin egg development, hemolysis assay and 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide assay using tumor cell lines. Isokaempferide and kaempferol, but not amburoside A and protocatechuic acid, inhibited the sea urchin egg development as well as tumor cell lines, but in this assay isokaempferide was more potent than kaempferol. Protocatechuic acid was the only compound able to induce hemolysis of mouse erythrocytes, suggesting that the cytotoxicity of kaempferol and isokaempeferide was not related to membrane damage.

Effects of Amburoside A and Isokaempferide, Polyphenols from Amburana cearensis, on Rodent Inflammatory Processes and Myeloperoxidase Activity in Human Neutrophils

The present study evaluated the anti-inflammatory activity of amburoside A (a phenol glucoside) and isokaempferide (a flavonol) isolated from the trunk bark of Amburana cearensis, a medicinal plant used in northeast Brazil for the treatment of asthma. Animals (male Wistar rats or Swiss mice) pre-treated with amburoside A (25 and 50 mg/kg) or isokaempferide (12.5, 25 and 50 mg/kg), orally or intraperitoneally, showed a significant inhibition of the paw oedema induced by carrageenan (1%), prostaglandin E(2) (30 nmol/paw), histamine (200 microg/paw) or serotonin (200 microg/paw). Histological and morphometric evaluations of the rat paw oedema induced by carrageenan showed that amburoside A and isokaempferide also inhibited the accumulation of inflammatory cells. Amburoside A reduced significantly the paw oedema and the increase in vascular permeability induced by dextran, as related to the control group. Similar results were observed with the isokaempferide pre-treatment. Furthermore, amburoside A or isokaempferide inhibited both leucocyte and neutrophil migrations, in mouse peritoneal cavity, after the carrageenan injection. The polyphenols were not cytotoxic and blocked N-formyl-methyl-leucyl-phenylalanine-induced myeloperoxidase release and activity in human neutrophils. In addition, amburoside A and isokaempferide at 50 and 100 microg/ml concentrations reduced significantly the lipopolysaccharide-mediated increase in tumour necrosis factor-alpha (TNF-alpha) levels. These results provide, for the first time, evidence to support the anti-inflammatory activity of amburoside A and isokaempferide that seems to be related to an inhibition of inflammatory mediators, such as TNF-alpha, as well as histamine, serotonin and prostaglandin E(2), besides leucocyte infiltration in a dose- or concentration-dependent manner. These anti-inflammatory effects can be explained, at least in part, by the ability of these compounds to reduce neutrophil degranulation, myeloperoxidase activity, mediators as well as TNF-alpha secretion.

Protective Effects of Amburoside A, a Phenol Glucoside from Amburana cearensis, against CCl4-Induced Hepatotoxicity in Rats

The aim of this study was to investigate the possible beneficial effects of amburoside A, AMB [4-(O-beta- D-glycopyranosyl)benzyl protocatechoate], against carbon tetrachloride (CCl (4)) toxicity in rats. AMB is a phenol glucoside from the Brazilian medicinal plant Amburana cearensis, popularly used for the treatment of respiratory tract affections. Acute AMB (25 and 50 mg/kg, I. P. or P. O.) treatments of CCl (4)-intoxicated rats significantly inhibited the increase in serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels, as compared to the group treated with CCl (4) only. Histological studies showed less centrolobular necrosis and inflammatory cell infiltrates in the liver of animals treated with AMB plus CCl (4), when compared to the group treated with CCl (4) alone. In hepatic tissues, AMB at both doses inhibited CCl (4)-induced thiobarbituric acid-reactive substances (TBARS) formation, indicating a blockade of CCl (4)-induced lipid peroxidation. AMB also reversed the decrement in glutathione contents of hepatic tissues in CCl (4)-intoxicated rats. Furthermore, it restored catalase activity to normal values, which was significantly increased after CCl (4) treatment. Our results indicate that CCl (4)-induced oxidative damage in hepatic tissues is reversed by AMB treatment. The protective effect of AMB is probably due to the phenolic nature of this glucoside.

Estudo fitoquímico de espécimens cultivados de cumaru (Amburana cearensis A. C. Smith)

Due to the threat of extinction of Amburana cearensis, a tree of medicinal importance for the Northeastern Brazil, a phytochemical analysis was performed with specimens obtained by seed germination. Ten compounds were isolated and identified by spectroscopic methods and comparison with literature data. p-Hydroxybenzoic acid, ayapin, (E/Z)-melilotosides are being reported for the first time for the genus, besides coumarin, isokaempferide, vanillic acid, protocatechuic acid, amburosides A and B which have already been found in the trunk bark. Based on physical and NMR spectroscopy evidences the structures of several melilotosides already described in the literature have been suggested to be revised.

Amburosides C-H and 6-O-protocatechuoyl coumarin from Amburana cearensis

Seis novos amburosideos (1-6) e o novo protocatecuato de 6-cumarila (7) foram isolados das sementes e cascas do caule de Amburana cearensis, juntamente com cumarina, 6-hidroxicumarina, isocampferideo, formononetina, acido vanilico, amburosideo A e acido (E)-o-cumarico. As estruturas quimicas dos novos compostos foram elucidadas com base na analise espectral de RMN (COSY, HSQC, HMBC e NOESY) e EM.

Amburanins A and B from Amburana cearensis: daphnodorin-type biflavonoids that modulate human neutrophil degranulation

). At concentration higher than 25 µg mL -1 , both compounds suppressed nearly 92% of the neutrophil degranulation and 53% of myeloperoxidase activity, thus indicating that they are potential anti-inflammatory lead compounds.

Phytochemistry, Pharmacology and Agronomy of Medicinal Plants: Amburana cearensis, an Interdisciplinary Study

Plants are an important source of biologically active substances, therefore they have been used for medicinal purposes, since ancient times. Plant materials are used as home remedies, in over-the-counter drug products, dietary supplements and as raw material for obtention of phytochemicals. The use of medicinal plants is usually based on traditional knowledge, from which their therapeutic properties are oftenly ratified in pharmacological studies.