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.
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 |
