RESUMO

Successive applications of insecticides to control Plutella xylostella L. (Lepidoptera: Plutellidae) have resulted in the emergence of resistant populations of this insect. A novel control measure for this target insect could be the use of botanical insecticides derived from plant tissues. Hence, we experimentally tested aqueous extracts of Alibertia edulis (Rich.), Alibertia intermedia (Mart.), and Alibertia sessilis (Vell.) K. Schum. found in the Brazilian savannah in order to investigate their potential to disrupt the life cycle of P. xylostella. Aqueous extracts of the leaves of A. intermedia and A. sessilis negatively affected the development of P. xylostella in all stages of the life cycle, prolonging the larval stage and causing mortality in the larval or pupal stages. Treatments with A. intermedia and A. sessilis extracts caused the lowest fecundity and the number of hatched larvae. The harmful effects of these aqueous extracts on the life cycle of P. xylostella may be attributable to the flavonoids and other phenolic compounds present in A. intermedia and A. sessilis. These aqueous botanical extracts are low in toxicity when compared to non-aqueous pesticides, and may emerge as an effective approach for control of populations of P. xylostella.

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Although Alibertia edulis (L.C. Rich.) A.C. Rich decoction is used in Brazilian folk medicine due to its possible antihypertensive effect, this species has never been critically investigated as a hypotensive drug. So, the aim of this study was to evaluate the possible hypotensive and antihypertensive effects of the oral administration of Alibertia edulis aqueous extract (AEAE) in normotensive and hypertensive rats, and evaluate its inter-relation with a possible diuretic activity. MATERIAL AND METHODS: Different doses of AEAE (20, 65 and 200mg/kg) were tested on the mean arterial pressure (MAP) of normotensive Wistar rats and after induction of renovascular hypertension (two-kidney, one-clip Goldblatt model). In addition, the diuretic effects of AEAE were compared with hydrochlorothiazide (HCTZ) in an acute and repeated-dose treatment for 7 days. Volume, sodium, potassium, chloride, calcium contents, pH and density were estimated in urine samples collected after 8 or 24h. Plasma sodium, potassium, total protein, urea, creatinine, AST and ALT concentrations were measured in samples collected at the end of the experimental period (seventh day). Finally, the antioxidant activity of the AEAE was assessed using the DPPH radical scavenging and ferric ions reducing power assay. RESULTS: The intraduodenal administration of the HCTZ and AEAE significantly reduced, in a dose-dependent manner, the MAP in both normotensive and hypertensive rats. Otherwise, the heart rate was not affected by any treatment. Acute and prolonged oral administration of AEAE (200mg/kg) and HCTZ caused a significant increase in volume and urinary concentrations of sodium, potassium and chloride. Moreover, urinary calcium concentration was significantly increased after administration of AEAE (200mg/kg). Finally, AEAE was able to present important in vitro antioxidant properties. CONCLUSION: The results obtained have shown that AEAE presents potent diuretic activity and significant hypotensive and antihypertensive effect. In addition, this study may confirm part of the pharmacological activity popularly attributed to this species and opens perspective for the future use in various renal and cardiovascular diseases.

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RESUMO

Neste trabalho objetivou-se avaliar a ecofisiologia da germinação de sementes de Alibertia edulis (Rich) A. Rich. ex DC. (marmelo) sob diferentes condições ambientais. Dois experimentos foram realizados no Laboratório de Nutrição e Metabolismo de Plantas da UFGD. O experimento I avaliou quatro temperaturas (15, 20, 25 e 30°C) e duas condições de iluminação (presença e ausência de luz) e o experimento II o efeito de soluções salinas de KCl , NaCl e CaCl2 nos potenciais osmóticos de 0,0 (controle); -0,4; -0,8; -1,2; -1,6; -2,0 MPa na germinação das sementes. As sementes apresentam fotoblástismo neutro e não germinam a 15°C. A 25°C foi observada maior porcentagem e índice de velocidade de germinação e comprimento de parte aérea de plântulas. As sementes são sensíveis salinidade causada por NaCl, KCl e CaCl2, que afetam negativamente a germinação das sementes e no crescimento das plântulas.

The target of this study was to evaluate seed ecophysiology germination of Alibertia edulis (Rich) A. Rich. ex DC. (quince) at different environmental condition. Two experiments were done at the Laboratory of Nutrition and Metabolism of Plant from UFGD (Universidade Federal da Grande Dourados). Experiment I evaluated 4 temperatures (15, 20, 25 e 30°C) and two light conditions (absence and presence of light); experiment II evaluated the salt effect of KC1, NaCl and CaCl2 at osmotic potencial of 0,0 (control); -0,4; -0,8; -1,2; -1,6; -2,0 MPa seed germination. The seeds are photoblastism neutral and do not germinate at 15 ° C. The 25 ° C showed a higher rate of speed and percentage of germination and shoot length of seedlings. The seeds are sensitive to salinity caused by NaCl, KCl and CaCl2, which negatively affect seed germination and seedling growth.

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RESUMO

The aim of this work was to develop a micropropagation protocol for Alibertia edulis, a medicinal Brazilian Cerrado plant. A. edulis seeds were sterilized and germinated in water-agar. Fifteen millimeter long explants from the seedlings cultivated for 50 days were used for the multiplication in three consecutive subcultures. The cytokinin benzyladenine (BA) alone or combined with indole-3-butyric acid (IBA) was added to » MS medium. The treatments containing combinations of the BA + IBA induced more shoot proliferation than the BA alone, with the optimum concentration of 0.5 mg.L-1 for both growth regulators. A. edulis shoots elongated easily and the presence of growth regulators did have a positive effect on the shoot elongation. Consecutive subcultures also had a positive effect on both sprouting and shoot elongation. Activated charcoal was essential for rooting, and all rooted plants were able to acclimatize.

Foi desenvolvido um protocolo de micropropagação para A. edulis, uma espécie arbórea frutífera e medicinal presente no Cerrado brasileiro. Sementes de A. edulis foram esterilizadas e germinadas em ágar-água. Explantes de 15 mm foram retirados das plântulas e cultivados por 50 dias em meio de multiplicação e três subculturas. A citocinina benzilalanina (BA), sozinha ou em combinação com ácido indol butírico (IBA) foram adicionados em no meio » MS. Os tratamentos contendo combinações de BA-IBA induziram uma maior proliferação de brotos que aqueles somente com BA, e a concentração ótima desses reguladores de crescimento foi de 0.5 mg.L-1 para cada. Os brotos de A. edulis facilmente se alongaram e a presença de reguladores de crescimento no meio de cultura teve efeito positivo sobre o alongamento. Da mesma forma, as consecutivas subculturas tiveram um efeito positivo tanto sobre a brotação quanto no alongamento. Carvão ativado foi essencial para o enraizamento dos ramos, e todas as plantas foram aclimatadas com sucesso.