Hepatoprotective activity of Trichopus zeylanicus extract against paracetamol-induced hepatic damage in rats.

Trichopus zeylanicus extract has been evaluated for its antihepatotoxic and choleretic activities in rats. The plant leaf suspension (1000 mg/kg; wet weight) as well as its methanol extract (100 mg/kg) showed a remarkable hepatoprotective activity against paracetamol-induced hepatotoxicity as judged from the serum marker enzymes, liver histology and levels of lipid peroxides in liver. The effect of the methanol extract was found to be concentration dependent. The water and hexane extracts were almost inactive. The methanol extract (100 mg/kg) also exhibited choleretic activity in anesthetized normal rats. In short, we report here for the first time the antihepatotoxic as well as choleretic properties of T. zeylanicus.

Human cutaneous leishmaniasis caused by Leishmania (Viannia) braziliensis in Santiago del Estero, Argentina: identification of parasites by monoclonal antibodies and isoenzymes

Estudos de diagnostico, caracterizacao parasitaria e identificacao foram conduzidos em pacientes humanos com lesoes cutaneas de leishmaniose na Provincia de Santiago del Estero, no norte da Argentina. Os procedimentos de diagnostico foram: biopsias de lesoes para utilizacao em esfregacos e inoculacao em hamster; aspiracao (com agulha) de ulceras, para cultura "in vitro". As tecnicas a IFAT-IgG e o teste intradermico de Montenegro. Oito cepas de parasitas foram isoladas, sendo estas obtidas de pacientes com lesoes ativas...

Effect of quassin on the metabolism of catecholamines in different life cycle stages of Culex quinquefasciatus.

Quassin, a mosquito larvicide isolated from Quassia amara, inhibits tyrosinase activity in the larvae of Culex quinquefasciatus. Since tyrosinase is directly involved in sclerotisation of the cuticle, it is suggested that quassin, as a larvicide, inhibits development of the cuticle. In presence of quassin phenylalanine, tyrosine and L-dopa levels were increased in larvae. In the larval stages, mosquitoes have a high concentration of phenylalanine and tyrosine with the level of the latter being very high just before pupation and then declines sharply. Monoamine oxidase (MAO), an enzyme directly involved in the metabolism of catecholamines, remained unaffected by quassin, in fact the level of adrenaline also remained unchanged in larvae during quassin poisoning. MAO showed high variation in its activity between synthetic and natural substrates. Tyramine is not a substrate for MAO. Tyrosinase activity was high in developing stages and negligibly low in adults and showed specificity to L-dopa. Phenylalanine and tyramine are unaffected by tyrosinase. Blood feeding did not influence the activity of both these enzymes.

Larvicidal efficacy of Quassin against Culex quinquefasciatus.

Crushed aqueous extracts of leaf, wood, bark and flowers of Quassia amara showed antilarval activity against C quinquefasciatus. Quassin has been identified to be the antilarval principle present in this plant and was effective against mosquito larvae at a concentration of 6 ppm. Quassin was present to the extent of 0.1 to 0.14 per cent (average 0.12%) on a dry weight basis in wood of Q. amara. This compound is an unsaturated lactone and it gave a positive response to the Legal test, characteristic of unsaturated lactones. Quassin lost its antilarval activity on treatment with strong alkalies. Quassin was over five times as active as carbaryl, a synthetic antilarval agent.