LEONOTIS LEONURUS HERBA

Definition
Leonotis herba consists of the dried aerial parts of Leonotis leonurus (L.) R. Br. (Lamiaceae).

Synonyms
Phlomis leonurus L.
Leonotis leonurus (L.) R. Br. var. albiflora Benth.

Vernacular names
wild dagga (A), lion's ear, minaret flower (E), unfincafincane (X), lebake (S), umhlalampetu (Sh)

Description

Macroscopical
Shrub 2-5 m tall, branching from a thick woody base; stem pale brown and densely pubescent; leaves simple, opposite, petiolate, coriaceous, 50-100 10-20 mm, linear, acute at apex and base, serrate in the distal half; upper surface bright green, lower surface densely pubescent; inflorescence of 3-11 compact verticils; calyx 12-16 mm long, 4 mm in diameter, calyx teeth 10, subequal, spreading; corolla tubular, bright orange, 40-49 mm long, covered with orange hairs; fruit a nutlet 5-6 1.5-2 mm, brown.

Microscopical
Characteristic features are: the numerous uniseriate, curved, thick-walled, warty, 2-3 celled non-glandular trichomes of leaf and stem, 60-100 m in length, particularly abundant on margin of lamina and main veins of lower leaf surface; the numerous glandular hairs of leaf and stem, with unicellular stalk and 4-celled head (up to 20 m in diameter) and yellow-brown contents; the less numerous glandular trichomes of leaf lamina, with unicellular stalk and 6-8 celled head, thick-walled, head about 40 m in diameter; cells of the lower epidermis with sinuous walls and striated cuticle, lacking stomata; cells of the upper epidermis with sinuous walls and numerous raised anomocytic stomata; single palisade layer; abundant crystal sand in cells of the mesophyll; occasional yellow hairs of the corolla.

Crude drug
Supplied in bundles comprising young leafy twigs, the leaves having a characteristic aromatic-pungent odour, bright yellow-green colour and rough texture; occasional flowers and fruits are present.

Figure 1

Geographical distribution
Locally common at forest margins, on rocky hillsides and river banks and in tall grassland of the Eastern and Western Cape Provinces, Kwazulu-Natal and Mpumalanga.

 

Identity test
Thin layer chromatography on silica gel using as solvent a mixture of toluene:diethyl ether:1.75m acetic acid (1:1:1). Reference compound: thymol (0,1% in chloroform)

Method according to the current edition of the British Herbal Medicines Pharmacopoeia, using Spray Reagent D for visualisation.

Major compounds:
yellow-mustard (Rf :0,19); yellow-mustard (Rf: 0,38); blue-mauve (Rf: 0,4); thymol (pink): Rf:0,8.

Ethanol (70%) extractive value: not less than 22%

Volatile oil content: not less than 0,15% (0,15-0,18%).

Purity tests 1
1. Diterpenoid labdane lactones: premarrubiin 0.00933-0.01567%, marrubiin (possibly an artifact derived from premarrubiin during extraction)

Assay 2
2. Tannins, quinones, saponins, alkaloids and triterpene steroids were detected in preliminary tests; iridoids were not detected.

 

Dosage forms
Used mainly in the form of an aqueous decoction, orally, per rectum and as a topical application.

Medicinal uses (traditional)

Internal
For the treatment of cough, cold, influenza, chest infections, diabetes, hypertension, eczema, epilepsy, delayed menstruation, intestinal worms, constipation, spider bites and scorpion stings and as an antidote for snakebite.

External
For the relief of hemorrhoids, eczema, skin rashes and boils.

Pharmacology/bioactivity

Brine shrimp lethality assay: preliminary results showed no effect on brine shrimps in the concentrations tested.

Antibiotic activity assay
No antimicrobial activity was observed in preliminary assays, in the concentrations used.

Contraindications
Not recommended for use by pregnant women

Adverse reactions
First time users may experience dizziness, nausea or sweating

Precautions

Treatment should be continued for one week. If symptoms persist, additional or alternative therapy should be sought. The use of this herb to treat diabetes, hypertension epilepsy or snakebite cannot at this stage be recommended, owing to lack of clinical data.

Dosage
1 table spoonful of chipped dried herb (.10,0g ) added to  3 cupfuls (.500ml ) of boiling water, boil for 10 minutes, allow to cool overnight, strain and use clear liquid for both internal and external use. If fresh material is used, 3-4 young twigs (leaf and stem) are boiled with one litre of water.

Dosage: (internal use)
Adults: Half a cupful (.90ml)
Elderly patients: Quarter of a cupful (.45ml)
Children 6-12 yrs: Quarter of a cupful (.45ml)
Children 2-6 yrs : Two teaspoonsful (.8ml)
To be taken two to three times daily.
For external use, the decoction may be applied to the affected area using a clean cloth.

References

1. Iwarsson, M. (1985). Leonotis, in Flora of Southern Africa 28,4: 31-37. Botanical Research Institute, Pretoria

Further Articles for Wild Dagga

Dispelling Wild Dagga Species Confusion - An easy to read comparison.

The Diterpenoids of Leonurus leonotus - An interesting clinical study.

Dagga/Yopo Experience Report - A positive story by an unknown author.

Folk, Traditional, and Medical Uses for Wild Dagga - Explained in detail.

Growing Wild Dagga - Cultivating Leonotis leonurus plants.

Botany of Leonurus (Mint Family) - From the Herba database.

Hottentot Tribes and Wild Dagga - Brief history of who the Hottentot's were.

South Africa's Nature - One explorer's account.

Synthesis of Leonurine - A brief abstract.

Motherwort - The True Dagga Plant - Ancient plant with many uses.