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Digitalis purpurea L. is one of the two unique species of economic interest in the genus Digitalis. It is important because is one of the principal source of cardenolides, irreplaceable drugs in the treatment of heart failure. The present work was done with the objective to determinate the effect of inoculum density and gaseous atmosphere renovation in D. purpurea plants cultivated in Temporal Immersion Systems (TIS). To do this, several parameters like inoculums density (6, 12, 18 explants per TIS) and the use forced ventilation were studied. The highest biomass production was obtained when 12 explants were inoculated (104.03 gFW and 5.74 gDW). On the contrary, the lower inoculum density caused a negative effect in plant development and the biomass did not increase. On the other hand, the renovation of atmosphere mediated by forced ventilation induced a higher oxidative stress associated to an increase of digitoxin synthesis. Both factors are of great importance for biomass and secondary metabolites production in plants with pharmaceutical interest. [ABSTRACT FROM AUTHOR]

Genetic transformation is a tool of special interest for developing new biotechnological strategies for the production of bio-active compounds such as cardenolides, which are exclusively obtained from plants. To date, Digitalis plants are the main economically viable source of cardenolides for the pharmaceutical industry. This study describes the development of efficient plant regeneration and Agrobacterium-mediated genetic transformation protocols for Digitalis purpurea L. First, a plant regeneration procedure starting from leaf segments of in vitro-cultivated plants was established and the minimal inhibitory concentration of G-418 (geneticin) for callus induction was determined. Both leaf segments and callus tissue were sensitive to G-418 70 mg l. Afterwards, two Agrobacterium strains were used to test their T-DNA transfer ability on D. purpurea leaf tissues, EHA105 and C58C1Rif (pMP90), both harboring the binary vector pTJK136. Strain C58C1Rif (pMP90) yielded a higher number of transformed plants than EHA105. Successful transformation was confirmed by histochemical β-glucuronidase (GUS) assays of the putative transgenic tissues and PCR analyses using β- glucuronidase ( uidA)- and neomycin phosphotransferase II ( nptII)-specific primers. Southern blot hybridization confirmed the stable integration of the nptII gene in the transgenic plants. In total, 518 independent transgenic lines were regenerated with an average of 6.91 transgenic lines per initial leaf segment infected with A. tumefaciens strain C58C1Rif (pMP90). To date, only a few studies have been published on the genetic transformation of Digitalis species. The protocols for plant regeneration and genetic transformation described in this paper will contribute to functional studies for a better understanding of cardenolide biosynthetic pathways and the metabolic engineering of cardenolides to develop high-yielding improved genotypes. [ABSTRACT FROM AUTHOR]

The article presents a study on the phytochemical examination of the flowering plant Digitalis purpurea's seeds which resulted in the isolation of 15 cardenolide glycosides including three new compounds showing cytotoxicity against leukemia cells and human liver cancer cells. It mentions that the structure of glycosides was determined by nuclear magnetic resonance (NMR) spectroscopy. It reveals that the cytotoxic activity of cardenolide glycosides was reduced by addition of a hydroxy group.

The plants of the genus Digitalis are characterized by the production of cardenolides, drugs widely used worldwide in the treatment of heart failure. In previous research a transformation protocol was developed from leaf disc of Digitalis purpurea L., using geneticin as selection marker. However some escapes in the selection process were obtained. So it is necessary to develop a more efficient selection scheme using another selective agent. Therefore, the aim of the present research was to select the minimum lethal concentration of hygromycin B during callus induction and shoots multiplication of D. purpurea. For callus induction we studied five concentrations of hygromycine B (3, 6, 9, 12, 15 mg l-1) during 28 days. Besides, the effect in shoot multiplication of four concentrations of hygromycine B (25, 50, 75, 100 mg l-1) was studied during 30 days. The minimal lethal concentration for callus formation was 12 mg l-1. In the case of shoot multiplication, 100% mortality was showed at 75 mg l-1 strictly after 30 days. The proposed selection scheme is recommended for future work at genetic transformation in this species. [ABSTRACT FROM AUTHOR]

Cardenolides are secondary metabolites produced by plants of the genus Digitalis. These are widely used in treatments of congestive heart failure. Failed attempts to obtain suitable cardenolide levels from in vitro culture of Digitalis plants have pointed genetic transformation as a promising strategy to obtain highly productive plants. Transformation systems have been already developed for Digitalis minor and Digitalis lanata to achieve this aim, whereas related investigations have been done in other species of the same genus. Selection of candidate genes for transformation depends on the analysis of the cardenolide biosynthesis pathway. The latter is partially established, from phytosterol oxidative degradation to progesterone reduction. Many authors point this reaction as the first specific key step of the pathway. However, the recent discovery of two genes encoding this enzyme activity in Digitalis purpurea, with different expression patterns, calls this statement into question. Pathway flexibility and possible connections with other hormone-related processes imply an additional challenge in this regard. Therefore, functional studies of these genes and their signaling pathways are required to improve design Digitalis transformation strategies, maximizing cardenolide productivity as well as minimizing hazardous side effects on transformed plants viability. [ABSTRACT FROM AUTHOR]

The cardiac glycoside, digitoxin, from Digitalis purpurea L (Scrophulariaceae), a cardiac glycosidal (cardenolide) extract from Calotropis procera (Ait) R Br (Asclepiadaceae), azadirachtin and neem oil from Azadirachta indica A Juss (Meliaceae) were tested for their effects against larvae and adult stages of the camel tick, Hyalomma dromedarii Koch (Acari: Ixodidae). The contact LC[sub50] values of the first three materials against adults were 4.08, 9.63 and >40.7 µg cm][sup-2], respectively, whereas the dipping LC[sub50] values of the four materials were 409.9, 1096, > 5000 and > 5000 mg litre[sup-1], respectively. Contact and dipping LC[sub50] values of the extract and azadirachtin against larvae were 6.16, >20.3 μg cm[sub-2] and 587.7 and >2500mg litre[sup-1], respectively. Azadirachtin had no effects on egg production or feeding of adults up to 5000mg litre[sup-1]; however at 2500mg litre[sup-1], it caused significant reduction in feeding activity of larve, prolonged the period for moulting to nymphal stage, and caused 60% reduction in moultability. Results of the two cardiac glycoside materials are comparable with those of several commercial acaricides. The risks and benefits associated with the use of cardiac glycosides are considered. [ABSTRACT FROM AUTHOR]

Diabetes mellitus is a risk factor for congestive heart failure. Diabetics with congestive heart failure should have good glycemic control, treatment of hypertension and dyslipidemia, and treatment with diuretics, angiotensin-converting enzyme inhibitors, and β blockers as well as digoxin, if the left ventricular ejection fraction is abnormal. Patients with chronic obstructive pulmonary disease may have left ventricular failure because of a coexistent cardiac disorder or right ventricular failure from pulmonary hypertension. An acute respiratory tract infection may precipitate right ventricular failure and should be treated. Alveolar hypoxia should be corrected by improving alveolar ventilation through relieving airflow obstruction with bronchodilators and by increasing inspired oxygen concentration. Loop diuretics should be used cautiously. Beta blockers may be given to patients with chronic obstructive pulmonary disease and left ventricular failure if bronchospasm is not present. Angiotensin-converting enzyme inhibitors should be used to treat left ventricular failure. Digitalis should not be used in patients with right ventricular failure due to chronic obstructive pulmonary disease. Nonsteroidal anti-inflammatory drugs are contraindicated in patients with congestive heart failure. There are controversial data about the negative interaction between aspirin and angiotensin-converting enzyme inhibitors in patients with congestive heart failure. Patients with arthritis and congestive heart failure needing large doses of aspirin for pain relief may be treated instead with acetaminophen, tramadol, or Percocet if necessary for chronic severe pain. [ABSTRACT FROM AUTHOR]

Progesterone 5β-reductase, which catalyzes the reduction of progesterone to 5β-pregnane-3,20-dione, was purified 770-fold to homogeneity from the cytosolic fraction of shoot cultures of Digitalis purpurea. This purification involved DEAE-Sephacel, affinity chromatography (Blue-Sepharose CL-6B and adenosine 2′,5′-bisphosphate-Sepharose 4B) and elution from a gel matrix after non-dissociating PAGE. The molecular mass determined by SDS/PAGE was 43 kDa and the molecular mass determined by gel-filtration chromatography on calibrated Sephadex G-200 was 280 kDa, thus indicating that the native protein is a polymer consisting of several subunits. The purified enzyme had a Km value of 6 μM for NADPH and 34 μM for progesterone. The enzyme had a strong substrate specificity for progesterone. The relative rates for other steroids such as testosterone, cortisone and cortisol were much lower. The trypsin digestion of the purified progesterone 5β-reductase resulted in 100 peptide fragments. The largest fragment after trypsin digestion and sequence analysis consisted of 13 amino acids. [ABSTRACT FROM AUTHOR]