RESUMO
Medicinal and aromatic plants are biologically and economically valuable species because of their intrinsic value as plants, ability to produce secondary metabolites, possible use in the pharmaceutical and food industries, germplasm availability and applications in traditional medicine. In addition, they hold social and economic importance due to the ancestral knowledge they represent and because they are part of the livelihood of many families. Most of them are collected from the wild and are in serious danger of extinction. Through biotechnological tools it is possible to develop their germplasm and obtain new and improved varieties from wild material, while advocating the alternative of production by cultivation instead of extracting it from nature. The objective of this review is to provide an updated perspective on the traditional uses, conservation status and biotechnological advances in a group of 30 plant species native to the American continent.
Las plantas medicinales y aromaÌticas deben ser valoradas tanto por su valor intriÌnseco como tales, por su capacidad de producir metabolitos secundarios, su posible uso en las industrias farmaceÌutica y alimentaria y por sus aplicaciones en medicina tradicional. AdemaÌs, tienen importancia social y econoÌmica debido al conocimiento ancestral que representan y porque son parte del sustento de muchas familias. La mayoriÌa de estas especies son recolectadas de la naturaleza y estaÌn en grave peligro de extincioÌn. A traveÌs de herramientas biotecnoloÌgicas es posible desarrollar su germoplasma y obtener variedades nuevas y mejoradas a partir de material silvestre; esta estrategia propicia la alternativa de produccioÌn por cultivo en lugar de extraerla de la naturaleza. El objetivo de esta revisioÌn es proporcionar una perspectiva actualizada de los usos tradicionales, el estado de conservacioÌn y los avances biotecnoloÌgicos en un grupo de 30 especies de plantas nativas del continente americano.
Assuntos
Plantas Medicinais , Biotecnologia , Fitoterapia , Medicina Tradicional , Farmacognosia , América , Exploração de Recursos Naturais , Conservação dos Recursos NaturaisRESUMO
The tropane alkaloids scopolamine and hyoscyamine arestill extracted from plants that belong to several species of Solanaceae because their chemical syntesis is difficult and expensive. These anticholinergic agents are employed in medicine as antispasmodics, preoperative medication and for the treatment of motion sickness. In our laboratory, hairy roots of Brugmansia candida, a South American plant which both alkaloids, were obtained through transformation with Agrobacterium rhizogenes and cultured in vitro. To increase the productivity of the cultures, these were exposed to different elicitors: CaCl2, salicylic acid and autoclaved roots of B. candida. The effects on growth, alkaloid accumulation and release into the medium were evaluated. CaCl2 at 50.00 and 100.00 mM, increased the accumulation of scopolamine and hyoscyamine after 24 hours ( 30-60per cent), while after 48 hour levels of 50.00 mM decreased their accumulation ( 50per cent). No effect was observed on release of alkaloids into the medium. Salicylic acid, a compound involved in plant defense, at 0.01 and 1.00 mM increased accumulation of booth alkaloids (ranging from 30 to 170 per cent), particularly after 24 and 48 hours. There was also increase in the release of scopolamine and hyoscyamine into the medium. The homogenized roots had a positive effect on alkaloid accumulation in the roots throughout the experiment (ranging from 100 to 500 per cent). This was most noticeable for hyoscyamine, particulary after 24 and 72 hours of exposition. The results seen with homogenized roots are probably due to endogenous elicitors which are liberated in the subsequent steps of autoclaving and sonication.