Efeito hipoglicemiante da farinha do fruto de maracujá-do-mato (Passiflora nitida Kunth) em ratos normais e diabéticos / Hypoglycemic effect of Passiflora nitida Kunth fruit flour on normal and diabetic rats

A região amazônica é detentora de uma vasta biodiversidade de frutos, porém pouco explorada quanto o seu potencial nutricional e econômico. Dentre estes frutos destaca-se o maracujá-do-mato (Passiflora nitida Kunth), espécie silvestre, de fruto comestível, com sabor exótico e de boa aceitabilidade para consumo. No presente estudo objetivou-se analisar as características nutricionais do mesocarpo do fruto da P. nitida e avaliar o potencial hipoglicemiante em ratos normais e diabéticos. A farinha do mesocarpo do fruto foi elaborada e analisada quanto a composição centesimal. A atividade hipoglicemiante foi avaliada por meio de dois modelos experimentais em ratos Wistar. O mesocarpo apresentou baixa concentração de macronutrientes e alto teor de umidade, cinzas e fibras. No experimento agudo, após 15 minutos da administração da sacarose, os níveis glicêmicos foram de 146±12 mg dL-1 no grupo controle e 112±2,5 mg dL-1, no grupo que recebeu 1g kg-1 de peso da farinha. No experimento crônico, após 21 dias, houve redução de 493 mg dL-1 para 302 mg dL-1 (38,7 %) e 195 mg dL-1 (60,4%) na glicemia nos grupos que foram tratados com 20 e 40% de ração enriquecida com a farinha, respectivamente, em relação ao grupo diabético não tratado. Em ambos os modelos experimentais, a farinha do mesocarpo mostrou-se eficaz na redução da glicemia. O fruto de P. nitida mostrou-se um produto natural em potencial para o controle da glicemia no diabetes.

The Amazon region has a vast biodiversity of fruits but is little explored as to its nutritional and economic potential. Among these fruits is "maracuja-do-mato" (Passiflora nitida Kunth), a wild species of edible fruit with exotic flavor and good acceptability for consumption. The aim of the present study was to analyze the nutritional characteristics of P. nitida fruit mesocarp and to evaluate its hypoglycemic potential in normal and diabetic rats. Flour from the fruit mesocarp was prepared and analyzed as to its centesimal composition. Hypoglycemic activity was assessed by means of two experimental models in Wistar rats. The mesocarp showed low concentration of macronutrients and high humidity, ash and fiber content. In the acute experiment, after 15 minutes of sucrose administration, glucose levels were 146 ± 12 mg dL-1 in the control group and 112 ± 2.5 mg dL-1 in the group receiving 1 g kg-1 flour weight. In the chronic experiment, after 21 days, glucose levels reduced from 493 mg dL-1 to 302 mg dL-1 (38.7%) and 195 mg dL-1 (60.4%) in the groups treated with 20 and 40% animal food enriched with the flour, respectively, in relation to the diabetic untreated group. In both experimental models, the mesocarp flour was effective in reducing blood glucose. P. nitida fruit seems to be a potential natural product in the glycemic control of diabetes.

Natural probes for cholinergic sites: L-bebeerine actions on the neuromuscular transmission, the nicotinic receptor/ionic channel complex, and contraction of skeletal muscles.

The mechanisms underlying the muscle relaxant activity of 1-bebeerine (BB), a tertiary alkaloid isolated from the roots of Chondrodendron platyphyllum, were examined in mammalian and amphibian skeletal muscles. Injections of BB (0.05-1 g/kg, i.p.) in rats caused a dose-related flaccid paralysis and respiratory arrest at high doses. In isolated rat diaphragm and toad sartorius muscles, BB depressed the indirectly elicited muscle twitches (IC50: 228 microM and 5.4 microM, respectively, at 22 degrees C) and blocked the nerve-elicited muscle action potential. The neuromuscular blockade was not reversed by neostigmine (10 microM). High concentrations of BB (170 and 340 microM) caused muscle contracture unrelated to the junctional blockade, and intensified by increasing the bath temperature. Analysis of the contraction properties showed that BB (40 and 80 microM) increased the twitch/tetanus ratio (46% and 125%) and prolonged the relaxation time; the falling phase of the directly elicited action potential in toad sartorius muscle fibers was slower probably by a decreased potassium conductance. BB (0.1-340 microM) reduced the binding of [125l]alpha--bungarotoxin to the junctional ACh receptor of the rat diaphragm (IC50: 47.7 microM, at 37 degrees C. At low concentrations BB (1.5-15 microM) induced either opening or blockade of the ACh receptor-ionic channel. The results showed that BB blocked noncompetitively the neuromuscular transmission through a mechanism that affects the ACh recognition site and the ionic channel properties. The alkaloid also produced muscle contracture and changed the contractile properties through its extra-junctional action at the calcium handling by the sarcoplasmic reticulum or the contractile machinery.

Natural probes for cholinergic sites: L-bebeerine actions on the neuromuscular transmission, the nicotinic receptor/ionic channel complex, and contraction of skeletal muscles.

The mechanisms underlying the muscle relaxant activity of 1-bebeerine (BB), a tertiary alkaloid isolated from the roots of Chondrodendron platyphyllum, were examined in mammalian and amphibian skeletal muscles. Injections of BB (0.05-1 g/kg, i.p.) in rats caused a dose-related flaccid paralysis and respiratory arrest at high doses. In isolated rat diaphragm and toad sartorius muscles, BB depressed the indirectly elicited muscle twitches (IC50: 228 microM and 5.4 microM, respectively, at 22 degrees C) and blocked the nerve-elicited muscle action potential. The neuromuscular blockade was not reversed by neostigmine (10 microM). High concentrations of BB (170 and 340 microM) caused muscle contracture unrelated to the junctional blockade, and intensified by increasing the bath temperature. Analysis of the contraction properties showed that BB (40 and 80 microM) increased the twitch/tetanus ratio (46

and 125

) and prolonged the relaxation time; the falling phase of the directly elicited action potential in toad sartorius muscle fibers was slower probably by a decreased potassium conductance. BB (0.1-340 microM) reduced the binding of [125l]alpha--bungarotoxin to the junctional ACh receptor of the rat diaphragm (IC50: 47.7 microM, at 37 degrees C. At low concentrations BB (1.5-15 microM) induced either opening or blockade of the ACh receptor-ionic channel. The results showed that BB blocked noncompetitively the neuromuscular transmission through a mechanism that affects the ACh recognition site and the ionic channel properties. The alkaloid also produced muscle contracture and changed the contractile properties through its extra-junctional action at the calcium handling by the sarcoplasmic reticulum or the contractile machinery.

Anemophilus fungi in the western Brazilian Amazon basin.

The prevalence of anemophilus fungi was studied in three small towns located at the Brazilian border with Colombia and Venezuela (a hot and humid zone) during the month of July. On a single collection carried out in different spots, colonies were cultivated which could be attributed to eighteen different species of anemophilus fungi with predominance of Mucor (64%), Candida (55%), Rhodotorula (38%) and Penicillum (38%). The alternaria species, a very potent airbone allergen, was found only in one of the three collection spots with high prevalence of respiratory tract allergies.

[Prevalence of superficial mycoses in the adult population of the Brazil-Colombia frontier]. / Prevalência de micoses superficiais na população adulta da fronteira Brasil-Colômbia.

A microbiological study was performed in the adult population of tier Brazil-Colombia, a very damp place with warm weather. It was observed a higher prevalence of P. versicolor (41.5%) and candidiasis (28.09%), followed by P. hortai and E. floccosum. The T. Tonsurans was the principal agent of the trichophitics of the hair. It's a higher prevalence of superficial mycosis was observed in the male.

Prevalencia de micoses superficiais em escolares de localidades da regiao amazonica ocidental(fronteira Brasil-Colombia). / Occurrence of superficial mycosis in students of the westrn amazon region (frontier Brazil-Colombia

Realizaram-se estudos micologicos em escolares nos vilarejos da fronteira Brasil-Colombia em julho de 1978, dentro da floresta amazonica. Observaram-se prevalencia da pityriasis versicolor em escolares de Ypiranga e Vila Bittencourt e de Piedra Negra em escolares de Cucui, seguidas da tinea capitis por Trichophyton tonsurans. Analisou-se a predominancia das micoses superficiais no sexo feminino