RESUMO
We sought to compare the abilities of the specialist Lepidoptera Pyrrhopyge thericles (Hesperiidae) and the generalist Periphoba arcaei (Saturniidae) to assimilate three highly cytotoxic compounds from their larval host plant, Vismia baccifera (Clusiaceae) and to determine whether either insect discriminated in its assimilation of the compounds that are structurally similar but of variable cytotoxicity. Vismione B (1), deacetylvismione A (2), and deacetylvismione H (3) are cytotoxic compounds isolated from V. baccifera. Compound 1 was found in the 2nd and 3rd instars of P. arcaei, but not in the mature larvae or the pupae. Pyrrhopyge thericles assimilated trace quantities of compound 1 and deacetylvismione A (2), which were both found in the 3rd and 4th instars. In extracts of V. baccifera, compound 2 is present at levels approximately 6-fold greater than compound 1, indicating that the generalist P. arcaei is capable of selectively sequestering cytotoxic compounds from its host plant. Compounds 1 and 2 show comparable cytotoxicities in three different cancer cell lines, suggesting that properties other than cytotoxicity are responsible for the selective sequestration of 1 by P. arcaei. This study represents the first time that sequestration of this class of compounds has been recorded in the Lepidoptera.
Assuntos
Antracenos/metabolismo , Citotoxinas/metabolismo , Interações Hospedeiro-Parasita , Lepidópteros/fisiologia , Magnoliopsida/parasitologia , Animais , Antracenos/análise , Antracenos/isolamento & purificação , Citotoxinas/análise , Citotoxinas/isolamento & purificação , Larva/fisiologia , Magnoliopsida/química , Magnoliopsida/fisiologiaRESUMO
Traditional food systems offer a key link between the social and economic resilience of smallholder farmers and pastoralists and the sustainable food and nutrition security of global populations. This paper addresses issues related to socio-cultural diversity and the continuing complex engagement of traditional and modern communities with the plants and animals that sustain them. In light of some of the unhealthful consequences of the 'nutrition transition' to globalized modern diets, the authors define and propose a process for a more successful food system transition that balances agro-biodiversity and processed commodities to support diet diversity, health and social equity alongside sustainable economic growth. We review empirical research in support of practice and policy changes in agriculture, economic development and health domains as well as cross-sectoral and community-based innovation. High-value food crops within domestic and global value chains can be an entry point for smallholders' participation as contributors and beneficiaries of development, while sustainable small farms, as purveyors of environmental and public health services, diversify global options for long-term adaptation in the face of environmental uncertainty.
Assuntos
Agricultura/métodos , Biodiversidade , Cultura , Fenômenos Ecológicos e Ambientais , Indústria Alimentícia/tendências , Alimentos , Agricultura/tendências , Brasil , Conservação dos Recursos Naturais , Produtos Agrícolas , Diversidade Cultural , Dieta , Saúde , Humanos , Marketing , Plantas Comestíveis/crescimento & desenvolvimento , Formulação de PolíticasRESUMO
An ecology- and bioassay-guided search employed to discover compounds with activity against tropical parasitic diseases and cancer from the opisthobranch mollusk, Dolabrifera dolabrifera, led to the discovery of antileishmanial properties in the known compound, 5alpha,8alpha-epidioxycholest-6-en-3beta-ol (1). Compound 1 was identified through nuclear magnetic resonance spectroscopy (1H, 13C) and mass spectrometry. The compound was concentrated in the digestive gland of D. dolabrifera, but was not detected in other body parts, fecal matter or mucus. Compound 1 showed an IC50 of 4.9 microM towards the amastigote form of Leishmania donovani compared with an IC50 of 281 microM towards the control Vero cell line, a 57.3-fold difference, and demonstrated no measurable activity against Plasmodium falciparum, Trypanosoma cruzi, and the breast cancer cell line, MCF-7.
Assuntos
Antiprotozoários/isolamento & purificação , Descoberta de Drogas , Ergosterol/análogos & derivados , Leishmania donovani/efeitos dos fármacos , Moluscos/química , Animais , Antiprotozoários/farmacologia , Bioensaio , Ergosterol/isolamento & purificação , Ergosterol/farmacologiaRESUMO
An agricultural project in Highland Ecuador provided a model context to better understand the nutrition of rural women. The adequacy of women's nutrition and the strength of associations with age and socioeconomic status were studied in 104 rural households over four rounds (two seasons) during the 1995-1996 agricultural year using a cross-sectional with repeated-measures design. Women were at high risk for micronutrient deficiencies (calcium, iron, riboflavin, and vitamin B12) due to low intakes of animal products. Two distinct constructs representing socioeconomic status were identified: modern lifestyle and farming wealth. In multivariate models, farming wealth was associated with quality of women's diet (animal protein adjusted for energy, p = 0.01). Diet quality, in turn, was positively associated with anthropometric status (p = 0.02). Women over the age of 50 weighed approximately 3.7 kg less than younger women and consumed less energy (300 kcal) and micronutrients (p < 0.05). Age was positively associated with respiratory morbidity (p = 0.01). These findings, while directly relevant to a specific context, suggest the need for cross-cultural studies to identify the extent of, and factors contributing to, the risk of nutritional inadequacy in postreproductive women in developing countries.