Estudo dos efeitos comportamentais, neuroquÃmicos e tÃxicos do Ãleo essencial de Zingiber officinale Roscoe / Study of the behavioral, neurochemical and toxic effects from the essential oil of Zingiber officinale Roscoe

AUTOR(ES)
DATA DE PUBLICAÇÃO

2004

RESUMO

Ginger (Zingiber officinale Roscoe) is a plant largely used around the world, not just as a spice, but also for its medicinal properties. The behavioral and neurochemical effects were studied in mice daily administered with the essential oil of Ginger (EOG 25, 50 e 100 mg/Kg, i.p. and p.o.). In the 7th day of treatment, it was assessed the elevated-plus maze (EPM), open field (OF) rota rod (RR), passive avoidance (PA) and oxotremorine-induce tremor tests, to evaluate the behavioral effects of the drug. In the 8th day of the protocol, mice that received EOG (100 mg/Kg, i.p.) were killed to study the neurochemical effects of EOG on hipoccampus and striatum. Toxic effects of EOG were studied in mice (that received a single administration of EOG 200, 400 e 800 mg/Kg, i.p.), and rats (with hepatic injury induced by CCl4, and treated with EOG 50, 100 e 200 mg/Kg, i.p. in a single administration). Results showed that OEG does not have anxiolytic effects on EPM test; in OF test, EOG (50 e 100 mg/Kg, i.p.) showed a sedative effect, decreasing the number of crossings, grooming and rearing in 37%, 28% and 75%, respectively, with OEG 100 mg/Kg. It was also observed a dose-dependent effect of the drug, which maximum effect observed with 100 mg/Kg (i.p.) of the drug. The oral administration of EOG also induced a sedative effect, occuring only in the group treated with the highest dose of the essential oil. In RR test, EOG did not induce any significant alteration on motor coordination of the animals. In PA test, EOG produced a cognitive impairment in animals treated with EOG100 mg/Kg, i.p. and p.o. Even 24h after the drug administration, the cognitive impairment was still evident. When associated with scopolamine, EOG (50 e 100 mg/Kg, i.p. and p.o.) potentiated the amnesic effect of scopolamine. The anticholinergic effect of EOG (100 mg/Kg, i.p.) was proved to reverse the tremors induced by oxotremorine in mice. EOG, in striatum decreased DA and increased the concentrations of DOPAC, NE and 5HT in 40%, 15%, 22% and 81%, respectively. In hippocampus, OEG decreased DA, DOPAC and increased 5HT in 75%, 64% e 81%, respectively. The decrease of DA in striatum justifies the sedative effect of the drug and the aterations observed on hipoccampus seem to contribute to the amnesic effect of EOG. The study of toxic effects of EOG showed that the drug is relatively safe and it does not have any toxic effects, according to the protocols established in the present work. The acute administration of the essential oil (200, 400 and 800 mg/Kg, i.p.) did not induce any other toxic effect besides sedation. The daily administration of EOG did not produce any toxic effect, besides the diarrhea, observed in animals that received EOG 50 and 100 mg/Kg, i.p. and p.o. EOG (200 mg/Kg, i.p.) was effective in reversing the hepatic injury induced by CCl4 in rats. The treatment with the essential oil (200 mg/Kg, i.p.) reduced in 35% and 23% the activity of the enzymes ALT and AST, respectively. EOG seems to exert its hepatoprotective action by decreasing lipid peroxidation generated by the hepatic metabolism of CCl4, wich produces extremely danous free radicals

ASSUNTO(S)

memÃria zingiber officinale roscoe pilocarpina zingiber officinale roscoe escopolamina antagonistas muscarÃnicos farmacologia memory pilocarpine antagonistas colinÃrgicos scopolamine oxotremorina oxotremorine comportamento

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