ContribuiÃÃo para a validaÃÃo do uso medicinal de amburana cearensis (cumaru): estudos farmacolÃgicos com o isocampferÃdio e o amburosÃdio

• Autor(a) principal: Luzia Kalyne Almeida Moreira Leal
• Data de Publicação: 2006
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UFC
• Texto Completo: http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=104
• topic: Amburana cearensis; IsocampferÃdio; AmburosÃdio A; Atividades AntiinflamatÃria; Antioxidante; Relaxante muscular; Amburana cearensis; Isokaempferide; Amburoside A; Antiinflammatory; Antioxidan; Muscle relaxant activities; FARMACOLOGIA

Amburana cearensis is a medicinal plant from Northeast Brazil popularly known as âcumaruâ. Its stem bark has an odor characteristic of the presence of coumarin, being used in alternative medicine for the treatment of bronchitis and asthma. The present study investigated the toxicity, as well as the anti-inflammatory, antioxidant and smooth muscle relaxant activities of isokaempferide (IKPF, 3-metylflavonol) and amburoside A (AMB, phenolic glucoside), bioactive constituents of the plant. The intraperitoneal administration (ip) of IKPF or AMB, in single doses (50-200 mg/kg), showed low toxicity in mice. In primary hepatocyte cultures, only IKPF (100 ug/ml) reduced significantly the cellular viability, as assessed by the MTT test. ICPF and AMB (12.5- 50 mg/kg, ip) presented anti-inflammatory activities, observed initially by inhibitions of the carrageenan (Cg), prostraglandin E2 (PGE2), dextran (Dx), histamine or serotonin-induced paw edemas. Besides, IKPF and AMB (12.5 â 50 mg/kg) produced 39 and 50% reductions, respectively, of neutrophil migration as assessed by histopathological/morphometric analyses of the Cg-induced paw edema. The increase of vascular permeability induced by Dx in mice was also significantly inhibited by IKPF or AMB. Mice pretreatments (oral or ip) with IKPF or AMB (25 and 50 mg/kg) reduced peritoneal Cg or fMLP-induced leucocytes and neutrophil migrations. Also, IKPF and AMB partially prevented fMlP-induced neutrophil degranulation in human blood, as determined by the decrease in 66 and 52% of activities of the enzymes myeloperoxidase and elastase, respectively. The two compounds were not cytotoxic for neutrophil, as assessed by the MTT test. AMB showed hepatoprotective and antioxidant actions in the model of CCl4-induced liver toxicity in rats, as determined by the liver enzymes activity (AST and ALT), catalase, lipoperoxidation (TBARS assay), reduced glutathione, and histological analysis. In the isolated guinea pig trachea, IKPF (10-1000 Âg/ml) and AMB (10- 3000 Âg/ml) produced a concentration-dependent relaxation of the muscle precontracted by carbacol or KCl. The epithelium removal improved IKPF-induced relaxation, but did not alter the AMB effect. IKPF-induced relaxation was inhibited in 41% by L-NAME; 31 and 50% by ODQ (3 and 33 uM); 31% by propranolol and 37% by capsaicin. In the trachea pre-contracted by KCl (40 mM), the pre-incubation with glibenclamide or iberiotoxin, inhibited the IKPF-induced relaxation by 39% and 38%, respectively. On the other hand, 4-aminopyridine did not significantly influence the effect of IKPF. However, in the muscle pre-contracted with 120mM KCl the relaxant effect of IKPF was significantly reduced and not affected by glibenclamide. In conclusion, results showed that IKPF and AMB present anti-inflammatory, muscular relaxant and/or antioxidant activities, justifying the traditional use of Amburana cearensis in the treatment of respiratory tract diseases that present inflammation, oxidative stress, and bronchoconstriction as pathophysiological characteristics.