Estudo farmacológico e toxicológico de Alpinia speciosa Schum

Abstract

Alpinia speciosa Schum or nutans is a plant of the Zángiberaceae family. It is known popularly as "colony" (colônia) , an indigenous plant of the tropical Asia and natura- lized in some parts of the tropical America and adapted in Brazil. The plant is used in many parts of the north and northeast Brazil to control hypertension and as diuretic, besides being used to control many other diseases. We nave made a pharmacological evaluation of its effects on some experimental models. We have also determined its composition of Na' and K' found in the alcoholic extract and tea. The values observed were 51.0 mEq for Na', and 132 mEq for K in the extract, and 0,0 mEq of Na' and 26 mEçj for K' in the tea. A -phytochemical analisis of the leaves demonstra- •a ted the presence of catecquic tanins, phenols and alkaloids basides some essences. When iniected by intra peritoneal route the nidro- alcoholic extract, in dose range of 100 to 1400 mg/kg, or 2500-18000 mg/kg oral route in mice produced: writting, psy- chomotor excitation, hypokinesis and pruritus. By using thevof Tainter and MILLER we found a LD-q by ip route of 0,760 ± 0,126 g/kg and 10,0 i 2,5 g/kg by oral administration for the hydroa1c~ncLic extract. A subacute toxicity was made by injecting 1/4 of the LDcn for 30 days and the results show an increase in transaminases and lactate dehydrogenases, whereas other parameters such as glucose, blood urea and creatinine were considered normais. A histopathological analysis of some organs (Li- ver, spleen, gut, lung and heart) showed no alterations. A hemogram made with peripheral blood demostrated only elevated lymphocites counting. The animais treated with the extract showed a 50% loss of body weight. The drug promoted also a prolongation of the sleeping time. The hydroalcoholic extract induced in the rat a dose dependent fali in blood pressure in doses of 10 to 30 mg/kg. We found that cholinergic or adrenergic blockers were unable to block this effect. A similar effect on blood pressure was shown in dog. In the isolated atria the extract induced a reduc tion of the frequency and the inotropic responses, but both the extract and the tea had no effect on the diuresis of the rat.