Digitalis purpureae folium
Microscopy Images
Microscopy

Digitalis purpureae folium

Foxglove Leaf

πŸ‡ΉπŸ‡· Parmakotu Yaprağı

Class 3 - Expert Supervision
Source Plant: Digitalis purpurea L. (digitalis english)
Family: Plantaginaceae
Plant Parts Used:
Leaf
1
Compounds
1
Activities
3
Pharmacopeias
12
Months Shelf Life
Collection
Collection Seasons Spring Summer
Collection Time Before Flowering
Collection Method Hand-picking
Notes Harvest fully developed leaves Best from first-year rosette or early second year before flowering Collect in dry weather; avoid wet or dew-covered leaves Handle gently β€” bruising accelerates glycoside breakdown Rapid drying essential to preserve cardiac glycosides Toxic plant β†’ only trained collection personnel
Processing
Processing Methods Sorting/Grading Cutting/Slicing
Drying Methods Shade Drying
Drug Yield 25.0%
Storage
Storage Conditions Cool Dark Airtight Protected from Light
Shelf Life 12 months
Commercial Data
Cultivation Status endangered
Major Producers India, China, US, Turkey
Sustainability SUSTAINABILITY ENGLISH
Color
Green Dark Green
Odor
Earthy Characteristic
Taste
Bitter
Texture
Leathery
Fracture Type
Short
Microscopic Elements
Vessels (xylem vessels) Tracheids Fibres Trichomes (hairs) Stomata
Trichome Type
Multicellular (unbranched or branched)
Stomata Type
Anomocytic
Crystal Type
Needles
Microscopy Description

Leaf is dorsiventral. Upper epidermis consists of polygonal cells with sinuous anticlinal walls covered by a wrinkled cuticle. Stomata are present mainly on the lower epidermis and are predominantly anomocytic. Numerous trichomes are present β€” long, uniseriate, multicellular non-glandular hairs and capitate glandular hairs. Palisade tissue forms 1–2 layers; spongy parenchyma well developed. Vessels are mainly spiral and reticulate. Calcium oxalate crystals are absent.

Phytochemical Compounds
Digitoxin
Chemical Description

Digitoxin is a cardiac glycoside (cardenolide type) predominantly found in the leaves of Digitalis purpurea. Chemically, it consists of a steroidal aglycone (digitoxigenin) linked to three molecules of the deoxy sugar digitoxose through glycosidic bonds. Structurally, it possesses a characteristic steroid nucleus with a five-membered unsaturated lactone ring at C-17, which is crucial for its cardiotonic activity. The multiple hydroxyl groups and glycosidic side chains contribute to its polarity, while the steroid core provides lipophilicity, resulting in moderate lipid solubility and relatively poor water solubility.

Pharmacological Activities
Cardiotonic
Therapeutic Uses
Heart Failure Atrial Fibrillation
Mechanism of Action
Digitalis purpurea leaves contain cardiac glycosides, primarily digitoxin, digoxin, gitoxin, and their aglycones. These compounds exert their pharmacological effect mainly through selective inhibition of the Na⁺/K⁺-ATPase enzyme in cardiac myocytes. Inhibition of this membrane pump leads to increased intracellular sodium concentrations, which subsequently reduces the activity of the Na⁺/Ca²⁺ exchanger. As a result, intracellular calcium levels increase, enhancing calcium availability within the sarcoplasmic reticulum and producing a positive inotropic effect (increased force of myocardial contraction).
Pharmacokinetics
Absorption Glycosides are generally well absorbed orally Digitoxin: Highly lipophilic, nearly complete GI absorption Digoxin: Moderately absorbed, bioavailability varies Distribution Extensive tissue binding, especially cardiac tissue High protein binding (particularly digitoxin) Volume of distribution influenced by lean body mass and renal function Metabolism Digitoxin: Primarily metabolized hepatically Digoxin: Limited hepatic metabolism, more renal handling Elimination Digitoxin: Mainly fecal and biliary excretion; very long half-life Digoxin: Primarily renal excretion Half-life Digitoxin: ~5–7 days (long; accumulates easily) Digoxin: ~36–48 hours (shorter but still significant)
Traditional Uses
Historically, Digitalis purpurea leaf was one of the most important medicinal plants in cardiology. Traditional and early pharmacological uses include: Treatment of congestive heart failure Management of edema (dropsy) due to cardiac insufficiency Control of certain tachyarrhythmias Diuretic effect observed secondarily due to improved cardiac output Digitalis was famously introduced into medical practice by William Withering (1785) after observing its successful use in traditional English herbal medicine for β€œdropsy.” However, traditional use came with significant risks due to inconsistent dosage and lack of standardization. Important Note Because of its narrow therapeutic window, toxicity risk, and more predictable synthetic or purified glycoside preparations, crude Digitalis leaf is no longer used in modern clinical practice, though it remains a cornerstone historical drug and a critical pharmacognostic plant.
Safety Overview
Safety Class Class 3 - Expert Supervision
Pregnancy Category Contraindicated
Lactation Safety Contraindicated
Max Daily Dose 500.0 mg
LD50 No specific LD50 value available for crude Digitalis purpurea leaf in humans. Estimated fatal ingestion: 2–3 dried leaves (or equivalent) in adults due to cardiac glycoside content (primarily digitoxin). Animal data for digitoxin (main glycoside): LD50 ~0.18 mg/kg in cats.
Warnings
Contraindications
  • Pregnancy
  • Lactation
  • Children under 12
  • Liver Disease
  • Kidney Disease
  • Heart Disease
Side Effects
Nausea Vomiting Xanthopsia
Herb-Drug Interactions 1 interaction(s)

Description

Concomitant use of Digitalis purpureae folium (natural cardiac glycosides) with P-glycoprotein (P-gp) inhibitors can significantly increase systemic exposure to digitalis glycosides, leading to elevated serum digitalis activity and a higher risk of toxicity. Clinical manifestations include nausea, vomiting, anorexia, dizziness, confusion, visual disturbances (yellow/green halos), arrhythmias, bradycardia, and potentially life-threatening cardiac conduction abnormalities.

Mechanism

P-glycoprotein inhibitors reduce the efflux transport of cardiac glycosides such as digoxin-like compounds present in Digitalis purpureae folium. This results in increased intestinal absorption and reduced renal and biliary elimination, thereby increasing systemic concentrations and enhancing pharmacodynamic effects on the myocardium.

Pharmacokinetics

β€’ ↑ Oral absorption β€’ ↓ Clearance (renal and biliary) β€’ ↑ Plasma concentration β€’ ↑ Half-life β†’ Overall increased exposure and toxicity risk

Monitoring

β€’ Monitor heart rate and ECG regularly β€’ Monitor serum potassium and magnesium β€’ Monitor serum digitalis levels if available β€’ Watch for early toxicity symptoms (GI + neuro + visual)

Recommendation

Avoid combination when possible. If unavoidable, use the lowest effective dose, ensure electrolyte balance, and closely monitor ECG and clinical status.

Alternatives

β€’ Consider non-P-gp inhibiting alternatives for rate/rhythm control (depending on clinical context) β€’ Consider non-digitalis-based herbal cardiac remedies ONLY with medical supervision β€’ Prefer standard prescribed digoxin with therapeutic monitoring rather than uncontrolled crude foxglove preparations

Routes Affected
Oral
Timing
Onset: 24.0 hours Peak: 60.0 hours
Verified References available
Important: This information is for educational purposes only. Always consult a healthcare professional before combining herbal remedies with medications.
Pediatric Use
Contraindicated/Not recommended. Crude leaf material is unsafe in children due to extreme sensitivity to cardiac glycosides and high risk of fatal toxicity. No pediatric dosing exists. Purified digoxin may be used cautiously in children under specialist supervision, but leaf forms are never appropriate.
Geriatric Use
Contraindicated/Not recommended. Elderly patients are at higher risk of toxicity due to reduced renal function, comorbidities, and polypharmacy. Crude leaf is particularly dangerous; no safe use. Purified digoxin requires careful monitoring and lower doses in geriatrics.
Toxicity Notes
Digitalis purpurea leaf is highly toxic due to its content of cardiac glycosides (digitoxin, digoxin, etc.). It has a very narrow therapeutic index, and small differences in dose can lead to serious or fatal intoxication. Symptoms of toxicity include nausea, vomiting, diarrhea, abdominal pain, confusion, visual disturbances (yellow or green vision, halos), bradycardia, and a wide range of cardiac arrhythmias, including life-threatening ventricular arrhythmias and cardiac arrest. Crude plant material shows significant variability in glycoside content, making dose standardization impossible in routine clinical use. Therefore, Digitalis leaf should never be used as a self-medication remedy, and in modern medicine only standardized, purified digitalis glycoside preparations (e.g., digoxin) are used under strict medical supervision.
Overdose Symptoms
Gastrointestinal: severe nausea, persistent vomiting, diarrhea, abdominal pain. Neurological: confusion, headache, dizziness, visual disturbances (xanthopsiaβ€”yellow/green vision, blurred vision, halos). Cardiac: bradycardia, AV block, ventricular arrhythmias (e.g., PVCs, ventricular tachycardia/fibrillation), hyperkalemia, potentially leading to asystole and death.
Antidote
Digoxin-specific antibody fragments (Digoxin Immune Fab, e.g., DigiFab). Effective for life-threatening digitalis glycoside toxicity (including from Digitalis purpurea, though higher doses may be needed due to primary digitoxin content). Administered IV based on ingested amount or clinical severity.
Pharmacopeias
BP EP USP
Identity Tests
  • Thin Layer Chromatography (TLC)
Quality Parameters
Total Ash 25.0% - 8.0%
Acid-Insoluble Ash ≀ 2.0%
Water-Soluble Ash β‰₯ 12.0%
Loss on Drying ≀ 11.0%
Water-Soluble Extractive β‰₯ 20.0%
Alcohol-Soluble Extractive β‰₯ 15.0%
Foreign Matter ≀ 2.0%
Minimum Content 0.4
Assay

Method: High Performance Liquid Chromatography (HPLC)

Marker Compound: Digitoxin

Adulteration

Known Adulterants:
Reported or suspected adulterants/substitutions: Digitalis lanata leaves (similar but chemically different profile) Other foxglove species Misidentified Scrophulariaceae / Plantaginaceae species Low-grade material mixed with inert plant matter

Detection Methods:
Common Adulterants: Verbascum thapsus (Mullein) leaves – densely covered with large, branched, woolly hairs. Symphytum officinale (Comfrey) leaves – detected by multicellular trichomes. Primula vulgaris (Primrose) leaves – detected by uniseriate covering trichomes. Other possible: Inula helenium (Elecampane), Inula conyza (Ploughman's spikenard), Urtica dioica (Nettle). Detection Methods: Macroscopic/Microscopic Examination: Authentic Digitalis purpurea leaves have uniseriate covering trichomes (3-4 cells, collapsed, warty cuticle) and glandular trichomes (unicellular stalk, bicellular head). Margin, venation, and trichome features distinguish from adulterants. Chemical Tests: Positive Baljet test (orange-red color with sodium picrate due to cardenolides); adulterants typically negative. Modern Methods: HPLC/TLC for cardiac glycosides profile; DNA-based sequencing for low-level contamination. Crude leaf is obsolete for therapy; use only standardized preparations. Adulteration risks severe toxicity.

Ayurveda
Sanskrit Name None
Rasa (Taste) Sweet
Guna (Quality) Guru (Heavy)
Virya (Potency) Hot
Vipaka (Post-digestive) Sour
Karma (Action) Pachana
Prabhava SPECIAL EFFECT TESTT
Dosha Effect May reduce Kapha & Pitta, but highly toxic, not recommended
Uses

Not recommended in Ayurveda; Historically no internal therapeutic indication due to extreme toxicity. Modern Ayurvedic practice does not use Digitalis leaf; cardiology uses standardized pharmaceutical glycosides instead.

Traditional Chinese Medicine
Pinyin None
Chinese ζ΄‹εœ°ι»„
Nature Cold
Flavor Sweet
Meridians KidneyHeart
Actions Clear Heat
Uses

Strong cardiotonic Narrow safety margin Used only as standardized purified glycosides under medical supervision

Unani Medicine
Unani Name Western cardiac drug
Mizaj (Temperament) Cold-Wet
Actions Aphrodisiac
Uses

Traditionally not prescribed as leaf; Any mention is in modern pharmacognosy settings rather than clinical Unani use. Highly toxic crude plant avoided; cardiotonic effects only acknowledged within modern pharmacology context.

Research & Evidence
PubMed References
PMID: 123456789 PMID: 987654321
Clinical Trials
NCT123456 NCT654231
Evidence Summary

ASDASADS

Research Gaps

ASDASDASDAS

Sources: ASDASDASDASD
Verified
Updated: 2025-12-31