Digitalis purpurea.  洋 地 黄 叶 Yáng dì huáng yè      
PART USED: Dry leaf
TOXICITY:  Highly toxic
INDICATIONS
1. Heart tonic.[1]
References
Inner Path can not take any responsibility for any adverse effects from the use of plants. Always seek advice from a professional before using a plant medicinally.
Constituents.
Research.
Digitalis glycosides incrase the force of contaction of the heart without increasing the oxygen consumption, and slow the heart rate when auricular fibrillation is present.[1] Digitalis leaf, even in the standardized form is rarely used, due to their potency and different onset of action. It is preferable to use the isolated glycosides and only under close medical supervision.[1] Digoxin is the glycoside of choice since it is the least cumulative and most rapidly excreted; it is very widely prescribed and very valuable therapeutically.[1]
Due to their cumulative effect the glycosides can easily exhibit toxic symptoms; these include nausea, vomiting and anorexia.[1]
References
[1] Potter's New Cyclopaedia of Botanical Drugs and Preparations  R.C. Wren Revised by Elizabeth M. Williamson and Fred J Evans. First published in Great Britain in 1988 and reprinted in 1989 and 1994 by the C. W. Daniel Company Limited. 1 Church Path, Saffron Walden Essex. Published 1988 Printed and bound by Biddles, Guildford ISBN 085207 1973.

Anti-tumour activity of Digitalis purpurea L. subsp. heywoodii.
López-Lázaro M1, Palma De La Peña N, Pastor N, Martín-Cordero C, Navarro E, Cortés F, Ayuso MJ, Toro MV.
Abstract
Recent research has shown the anticancer effects of digitalis compounds suggesting their possible use in medical oncology. Four extracts obtained from the leaves of Digitalis purpurea subsp. heywoodii have been assessed for cytotoxic activity against three human cancer cell lines, using the SRB assay. All of them showed high cytotoxicity, producing IC50 values in the 0.78 - 15 microg/mL range with the methanolic extract being the most active, in non toxic concentrations. Steroid glycosides (gitoxigenin derivatives) were detected in this methanolic extract. Gitoxigenin and gitoxin were evaluated in the SRB assay using the three human cancer cell lines, showing IC50 values in the 0.13 - 2.8 microM range, with the renal adenocarcinoma cancer cell line (TK-10) being the most sensitive one. Morphological apoptosis evaluation of the methanolic extract and both compounds on the TK-10 cell line showed that their cytotoxicity was mediated by an apoptotic effect. Finally, possible mechanisms involved in apoptosis induction by digitalis compounds are discussed.
PMID: 14531018 DOI: 10.1055/s-2003-42789 Planta Med. 2003 Aug;69(8):701-4. ncbi.nlm.nih.gov

Phenylethanoid glycosides from Digitalis purpurea and Penstemon linarioides with PKCalpha-inhibitory activity.
Zhou BN, Bahler BD, Hofmann GA, Mattern MR, Johnson RK, Kingston DG.
Abstract
In a continuation of our search for potential tumor inhibitors from plants, it was found that the CH2Cl2-MeOH (1:1) extracts from Digitalis purpurea and Penstemon linarioides both showed PKCalpha-inhibitory bioactivity. Bioassay-directed fractionation of the extract from D. purpurea yielded the new, weakly active phenylethanoid glycoside 2-(3-hydroxy-4-methoxy-phenyl)-ethyl-O-(alpha-L-rhamnosyl)-(1-->3) -O- (alpha-L-rhamnosyl)-(1-->6)-4-O-E-feruloyl-beta-D-glucopy ran oside (1) together with the four known compounds calceolarioside A (2), calceolarioside B (3), forsythiaside (4), and plantainoside D (5). The extract from P. linarioides yielded the three known glycosides leucosceptoside A (6), acteoside (7), and poliumoside (8), together with the iridoid plantarenaloside (9). All of the isolated compounds, except compound 9, showed inhibitory activity against PKCalpha with IC50 values (in microM) of 125 (1), 0.6 (2), 4.6 (3), 1.9 (4), 14.8 (5), 19.0 (6), 9.3 (7), and 24.4 (8).
PMID: 9834166 DOI: 10.1021/np980147s J Nat Prod. 1998 Nov;61(11):1410-2. ncbi.nlm.nih.gov