ABSTRACT
Resumen La Digitalis purpúrea ha sido utilizada por sus propiedades terapéuticas desde la antigüedad hasta nuestros días. Su difundido uso, tanto como la diversidad de indicaciones que tuvo, permitió que también se conociese desde antaño los riesgos a la salud para quien recibiese una dosis excesiva. La toxicología actual conoce y maneja perfectamente la intoxicación digitálica, sin embargo, muchas historias relacionadas con su uso son poco conocidas. Se presentan algunas de estas historias, muchas de ellas relacionadas con el mundo del arte.
Abstract Digitalis purpurea has been used because of its therapeutic properties since ancient times up to our days. Its wide- spread use as well as the variety of indications that it covered allowed to know the risks for health in case of overdose. Present toxicology is aware and knows perfectly well how to treat digitalic poisoning. However, many stories about digitalis are little known. Here, we show you some of them, specially the ones related with arts.
Subject(s)
Digitalis/adverse effects , Digitalis/toxicity , Medicine in the Arts , Plant Poisoning , Plants, Medicinal/adverse effects , Art , Digitalis/drug effectsABSTRACT
Long periods of high temperature or transitory increased temperature, a widespread agricultural problem, may lead to a drastic reduction in economic yield, affecting plant growth and development in many areas of the world. Heat stress causes many anatomical and physiological changes in plants. Its unfavorable effects can be alleviated by thermotolerance induced by exogenous application of plant growth regulators and osmoprotectants or by gradual application of temperature stress. Digitalis trojana Ivanina is an important medicinal plant species well known mainly for its cardenolides. The production of cardenolides via traditional agriculture is commercially inadequate. In this study, elicitation strategies were employed for improving crop thermotolerance and accumulation of cardenolides. For these purposes, the effects of salicylic acid (SA) and/or high temperature treatments in inducing cardenolide accumulation and thermotolerance were tested in callus cultures of D. trojana. Considerable increases in the production of cardenolides (up to 472.28 µg.g(-1) dry weight, dw) and induction of thermotolerance capacity were observed when callus cultures were exposed to high temperature for 2 h after pretreating with SA. High temperature treatments (2 h and 4 h) caused a marked reduction in superoxide dismutase (SOD; EC 1.15.1.1) and catalase (CAT; EC 1.11.1.6) activities, while SA pretreatment increased their activities. High temperature and/or SA appeared to increase the levels of proline, total phenolic, and flavonoid content. Elevated phenolic accumulation could be associated with increased stress protection. These results indicated that SA treatments induced synthesis of antioxidants and cardenolides, which may play a significant role in resistance to high temperature stress.
Subject(s)
Cardenolides/metabolism , Digitalis/physiology , Salicylic Acid/pharmacology , Stress, Physiological/drug effects , Temperature , Thermotolerance/drug effects , Catalase/metabolism , Digitalis/drug effects , Digitalis/enzymology , Flavonoids/metabolism , Phenols/metabolism , Proline/metabolism , Superoxide Dismutase/metabolismABSTRACT
The effect of hydrogen peroxide (H2O2) on callus cultures of four Digitalis species (Digitalis lamarckii, Digitalis trojana, Digitalis davisiana and Digitalis cariensis) increased catalase (CAT), superoxide dismutase (SOD), total phenolic, proline activity and cardiotonic glycoside production. Callus derived from hypocotyl explants was cultured on Murashige and Skoog medium supplemented with 0.25 mg L(-1) indole-3-acetic acid (IAA) and 0.5 mg L(-1) thidiazuron (TDZ). After a month of culture, callus was transferred to MS medium containing 10 mM H2O2 and then incubated for 6 h. The amount of five cardenolides (Lanatoside C, Digitoxin, Digoxigenin, Gitoxigenin and Digoxin) as well as CAT, SOD, total phenolic, proline activity from Digitalis species were compared. No digoxin was detected in all treatments and control groups. The total cardenolides estimated were in the order of D. lamarckii (586.65 µg g(-1) dw), D. davisiana (506.79 µg g(-1) dw), D. cariensis (376.60 µg g(-1) dw) and D. trojana (282.39 µg g(-1) dw). It was clear that H2O2 pre-treatment resulted in an increase in enzymatic and nonenzymatic antioxidants. However, a significant negative relationship between cardenolides production and overall activities of CAT, SOD, total phenolic and proline was evident. The described protocol here will be useful for the development of new strategies for a large-scale production of cardenolides.
Subject(s)
Antioxidants/metabolism , Digitalis/metabolism , Glycosides/metabolism , Hydrogen Peroxide/pharmacology , Catalase/metabolism , Digitalis/drug effects , Indoleacetic Acids/pharmacologyABSTRACT
The use of herbs as cures for human ailments is as old as modern man, but has now been replaced by synthetic drugs. However, the mixture of bioactive substances found in many traditional herbal remedies has similarities with modern combination therapies, like those developed by Sir John Crofton in Edinburgh for the treatment of tuberculosis. It is suggested that, in the development of these therapies, it might be possible to learn from the drug 'cocktails' found in plants.