- Âzadbakht, M. and Ghasemi Dehkordi, N., 2001. Identification of cardiac glycosides of Iranian Digitalis species by HPLC. The Journal of Mazandaran Univercity of Medical Sciences, 11: 25-31.
- Dattner, A,M., 2003. From medical herbalism to phytotherapy in dermatology: back to the future. Dermatologic Therapy, 16: 106–113.
- Ernst, M., de Pádua, R.M., Herl, V., Müller-Uri, F. and Kreis, W., 2010. Expression of 3β- HSD und P5βR, genes encoding for Δ5-3β-hydroxisteroid dehydrogenase (3β-HSD) and progesterone 5β-reductase (P5βR) in leaves and cell cultures of Digitalis lanata Ehrh. Planta Medicalogy, 76: 923-927
- Finsterbusch, A., Lindemann, P., Grimm, R., Eckerskorn, C. and Luckner, M., 1999. Delta(5)-3beta-hydroxysteroid dehydrogenase from Digitalis lanata Ehrh. - a multifunctional enzyme in steroid metabolism? . Planta, 209(4): 478-86.
- Fong, H., 2002. Integration of herbal medicine into modern medical practices: issues and prospect. Integrative Cancer Therapies, 3: 287-293.
- Fordyce, J.A. and Malcolm, S.B., 2000. Specialist weevil, Rhyssomatus lineaticollis, does not spatially avoid cardenolide defenses of common milkweed by ovipositing into pith tissue. Journal of Chemical Ecology, 26(12): 2857-2874.
- Fraire-Velázquez, S., Rodríguez-Guerra, R. and Sánchez-Calderón, L., 2011. Abiotic and biotic stress response crosstalk in plants. 3–26. In: Shanker, A.K. and Venkateswarlu, B., (Eds). Abiotic stress response in plants- physiological, biochemical and genetic perspectives. In Tech, Rijeka, 358p.
- Fujii, Y., Ikeda,Y. and Yamazaki, M., 1994. High-performance liquid chromatography determination of lanatosides in Digitalis lutea and Digitalis ambigua leaves. Journal Liquid Chromatogram, 17: 4451-4461.
- Heinrich, M., Barnes, J., Gibbons, S. and Williamson, E.M., 2004. Fundamentals of Pharmacognosy and Phytotherapy. Edinburgh, 336pp.
- Herl, V., Frankenstein, J., Meitinger, N., Müller-Ur,i F. and Kreis, W., 2007. ∆5-3β- hydroxysteroid dehydrogenase (3β-HSD) from Digitalis lanata. Heterologous expression and characterization of the recombinant enzyme. Planta Medicalogy, 73: 704-710.
- Hoelz, H., Kreis, W., Haug, B., and Reinhard, E., 1992. Storage of cardiac glycosides in vacuoles of Digitalis lanata mesophyll cells. Phytochemistry, 31: 1167-71.
- Huseini, H., Larijani, B., Radjabipour, B. and Mohsin, R., 2006. The Efficacy of Silybum marianum (L.) Gaertn. (Silymarin) in the Treatment of Type II Diabetes: A Randomized, Double-blind, Placebo-controlled, Clinical Trial. Phytotherapy Research, 20: 1036–1039.
- Kreis, W., Hensel, A. and Stuhlemmer, U., 1998. Cardenolide Biosynthesis in Foxglove. Planta Medicalogy, 64: 491-99.
- Kreis, W., 2007. Δ5-3β-hydroxysteroid dehydrogenase (3β-HSD) from Digitalis lanata. Heterologous expression and characterisation of the recombinant enzyme. Planta Medicalogy, 73: 704-710.
- Lin, C.C.,Yang, C.C., Phua, D.H., Deng, J.F. and Lu, L.H., 2010. An outbreak of foxglove leaf poisoning. Journal of the Chinese Medical Association, 73:97–100.
- Lopez-Lazaro, M., Palma De La Pena, N., Pastor N., Martin-Cordero, C., Navarro, E., Cortes, F. and Ayuso, MJ., 2003. Anti-tumour activity of Digitalis purpurea L. subsp. heywoodii. Planta Medicalogy, 69: 701-704.
- Maffe, S., Cucchi, L., Zenone, F., Bertoncelli, C., Beldi, F., Colombo, M.L., Bielli, M., Paino, A.M., Parravicini, U,, Paffoni, P., Dellavesa, P., Perucca, A., Pardo, N.F., Signorotti, F., Didino, C. and Zanetta, M., 2009. Digitalis must be banished from the table: a rare case of acute accidental Digitalis intoxication of a whole family. Journal of Cardiovascular Medicine, 10:727–732.
- Mohammed, A., Yücesan, B., Demir-Ordu, Ö., Cihangir, C., Eker, I., Kreis, W. and Gürel, E., 2015. In vitro regeneration and cardenolide determination of an endemic foxglove, Digitalis cariensis (Aegean Foxglove). In Vitro Cellular and Developmental Biology - Plant, 51: 438-444.
- Munkert, J., Ernst, M., Muller-Uri, F. and Kreis, W., 2014. Identification and stress-induced expression of three 3b-hydroxysteroid dehydrogenases from Erysimum crepidifolium Rchb. and their putative role in cardenolide biosynthesis. Phytochemistry, 100: 26–33.
- Newman, R., Yang, P. and Pawlus, A., 2008. Cardiac glycosides as novel cancer therapeutic agents. Molecular Physiology, 8: 36-49.
- Paschold, A., Halitschke, R. and Baldwin, I.T., 2007. Co(i)-ordinating defenses: NaCOI1 mediates herbivore induced resistance in Nicotiana attenuata and reveals the role of herbivore movement in avoiding defenses. The Plant Journal, 51: 79-91.
- Perez-Bermudez, P., Garcia, A.A., Tunon, I. and Gavidia, I., 2010. Digitalis purpurea P5 beta R2, encoding steroid 5 beta-reductase, is a novel defense-related gene involved in cardenolide biosynthesis. New Phytologist, 185: 687–700.
- Piotr, C. and Sacchi, N., 2006. The single-step method of RNA isolation by acid guanidinium thiocyanate-phenol-chloroform extraction: twenty-something years on. Nature Protocols, 1: 581-585.
- Popova, L., Pancheva T. and Uzunova, A., 1997. Salicylic acid: properties, biosynthesis and physiological role. Bulgarian Journal of Plant Physiology, 23: 85–93.
- Pu, G.B., Dong-Ming, M., Chen, J.L., Ma, L.Q., Wang, H., Li, G.F. and Ye, H.C., 2009. Salicylic acid activates artemisinin biosynthesis in Artemisia annua L. Plant Cell Reports, 28:1127–1135.
- Reymond, P. and Farmer, E.E., 1998. Jasmonate and salicylate as global signals for defense gene expression. Current Opinion in Plant Biology, 1(5): 404–411.
- Rosen, S. and Skaletsky, H., 2000. Primer3 on the WWW for general users and for biologist programmers. 365-386. In: Misener, S. and Krawetz, S.A., (Eds). Bioinformatics Methods and Protocols: Methods in Molecular Biology. Humana Press, Totowa, New Jersey, 460p.
- Salem, ML. and Hossain, MS., 2000. Protective effect of black seed oil from Nigella sativa against murine cytomegalovirus infection. International Journal of Immunopharmacology, 22(9): 729-740.
- Samuelson, G., 2004. Drugs of Natural Origin, A textbook of Pharmacognosy. Swedish Pharmaceutical Press, Stockholm, 620pp.
- Seidel, S., Kreis, W. and Reinhard, E., 1990. Δ5-3β-hydroxysteroid dehydrogenase Δ5/Δ4-ketosteroid isomerase (3β-HSD), a possible enzyme of cardiac glycoside biosynthesis, in cell cultures and plants of Digitalis lanata Ehrh. Plant Cell Report, 8: 621-24.
- Smith, J.L., De Moraes, C.M. and Mescher, M.C., 2009. Jasmonate- and salicylate-mediated plant defense responses to insect herbivores, pathogens and parasitic plants. Pest Managment Science, 65: 497–503.
- Sun, J., Xiao, J., Wang, X., Yuan, X. and Zhao, B., 2012. Improved cardenolide production in Calotropis gigantea hairy roots using mechanical wounding and elicitation. Biotechnology Letters, 34(3): 563-569.
- Tamura, K., Dudley, J., Nei, M. and Kumar, S., 2007. MEGA4: Molecular Evolutionary Genetics Analysis (MEGA) software version 4.0. Molecular Biology and Evolution, 24: 1596-1599.
- Thompson, J.D., Higgins, D.G. and Gibson, T.J., 1994. CLUSTAL W: improving the sensitivity of progressive multiple sequence alignment through sequence weighting, position-specific gap penalties and weight matrix choice. Nucleic Acids Research, 22(22): 4673-80.
- Trease, G.E. and Evans, W.C., 1998. Trease and Evans Pharmacognosy. Saunders Ltd., Lodon, 616pp.
- Tripathi, L. and Tripathi, J. N., 2003. Role of biotechnology in medicinal plants. Tropical Journal of Pharmaceutical Research, 2(2): 243-253.
- Warren, B., 2005. Digitalis purpurea. The American Journal of Cardiology, 95(4): 544.
- Wu, B., Li, Y., Yan, H., Ma, Y., Luo, H., Yuan, L., Chen, S. and Lu, S., 2012. Comprehensive transcriptome analysis reveals novel genes involved in cardiac glycoside biosynthesis and mlncRNAs associated with secondary metabolism and stress response in Digitalis purpurea. BMC Genomics, 13:15.
- Yeh, J., Hunag, W., Kan, S. and Wang, P., 2001. Inhibitory effects of Digitalis on the proliferation of androgen dependent and independent prostate cancer cells. Urology, 166: 1937-1942.
Zhao, J., Davis, L. and Verpoorte, R., 2005. Elicitor signal transduction leading to production of plant secondary metabolites. Biotechnology Advances, 23(4): 283–333.