Leonotis leonurus (L.) R. Br. is a shrub belonging to the Lamiaceae (mint) family, which comprises of about 3,200 species in 200 genera. L. leonurus is commonly called ‘wild dagga’ or ‘lion ear’. and is found in tropical Asia, Africa and southern India. The plant stems emanates from a thick wood base. The green leaves are opposite each other on the stems and have abundant glandular trichomes on the leaf lamina. The plant produce orange, apricot or white flowers in clusters and the hairy flowers a resemble lion’s ears, hence the name “leonurus (lion coloured)”. The flowers produce nectar which attracts birds, bees and butterflies. The fruits are 2 mm nutlets. All the plant parts have a strong mint smell similar to other Lamiaceae species.
Leonotis nepetifolia can grow from the southern tip of the Appalachian Mountains to Florida, and from Texas to the Atlantic Ocean. To grow in these areas, however, they need mostly full sun, moist soil, and high humidity. Extended periods of below freezing temperatures will kill this plant.
Traditional uses of the Klip Dagga
L. leonurus has many reputed traditional medicinal applications and is mainly taken orally or per rectum and as a topical application. Hottentots were particularly fond of smoking it instead of tobacco and used a decoction of the leaf as a strong purgative and as an emmenagogue. Early colonialists employed it in the treatment of leprosy. The leaf tea has a hypnotic effect, is diuretic and relieves headache. The leaf and stem decoction or inhalations have been used internally for cough, common cold, influenza, bronchitis, wound healing and asthma. The fresh stem juice is an infusion drunk for ‘blood impurity’. The infusions made from flowers and seeds, leaves or stems are widely used as tonics for tuberculosis, jaundice, muscular cramps, high blood pressure, diabetes, viral hepatitis, dysentery, and diarrhoea. Tea made from the whole plant is used for arthritis, piles, bladder and kidney disorder, obesity, cancer and rheumatism. The leaves and stems decoction are applied topically as a treatment for eczema, skin infections and itchiness. The leaves, roots and bark are widely used as an emetic for snakebites, bee and scorpion stings. The L. Leonurus smoke has marijuana-like effects.-pungent odour and is occasionally mixed with flowers and fruits. In ethnoveterinary the roots and leaves water drink is used in poultry, against cattle gall sickness and eye inflammation. Generally the plant is a general tonic, having reputed dermatological, hypertension, anti- inflammatory, pain and wound healing properties.
On the island of Trinidad the leaves are brewed as a tea for fever, coughs, womb prolapse and malaria. Sense it contains compounds that produce sedative effects it is utilized as a sedative in alternative medicine. This species is also known for its antispasmodic effects and appears to inhibit acetylcholine and histamine which is why it’s considered a natural anti-histamine. Antispasmodic is a term that refers to herbs, substances, drugs, compounds, or medicines that suppress muscle spasms.
Wild dagga is also much respected in the treatment of animals. The Tswana, Zulu and Xhosa make a strong brew of leaves, flowers and stems to use as an enema in sheep, goats and cattle, as well as humans. This brew is given to animals with respiratory problems and applied as a lotion to sores on stock and dogs, and as a wash for wounds, scratches, bites and stings.
The Zulu people use the root for snakebite and they sprinkle a concoction of the plant around their houses to keep snakes away. The Zulu and Xhosa make a strong brew of the leaves and use as a poultice for snakebites. They also use a tincture of the root bark internally for snake bite.
Cyclooxygenase (COX-1) inhibition was consistent for up to 1 year (92% inhibition) of plant material storage, while the inhibition deteriorated rapidly when the plant ageing process was accelerated. The flowering parts ethanol and chloroform extracts show strong hepatoprotective and anti- inflammatory activities in rats. The leaf and stems extracts (methanol and water) and essential oils also indicated anti- inflammation activity using the 5-lipoxygenase assay. The inflammatory cascade is complex and diverse, hence the need to do bioactivity guided fractionation to establish simpler fractions that exert COX-1, 5-lipoxygenase and antioxidant activity rather than isolating molecules that show a singular property. It is also common phenomena to find extracts that exert better activities than their purified components. Therefore, simple fractions would enable other pharmacological effects on a number of targets involved in effective trans-membrane drug delivery and place high concentrations of the active agent at the pathophysiologically relevant site. The dose ranges for the anti-inflammatory and analgesic properties are 25-75 mg/ml.
Klip Dagga in a nutshell
This literature survey of the phytochemistry, pharmacological and traditional applications of Leonotis leonurus L. R. has shown that the plant has diverse activities such as anticonvulsant, antinociceptive, anti-inflammatory, antidiabetic, antibacterial, anti-oxidant, anthelmintic activities and hypoglycemic properties, which justifies the herb use in the management and control of pain, arthritic, diabetes, dermatological, hypertension, anti-inflammatory and wound healing properties. Thirty seven secondary metabolites were reported, which includes 21 labdane diterpenes which are chemotaxonomic markers for the Leonotis genus and the mint family, Lamiaceae. The leaf, flowers and sepals essential oils are mostly constituted by monoterpenoids and sesquiterpenoids. The isolation of metabolites responsible for extracts activities is recommended and the data on clinical trials about the Leonotis leonurus herb and its extracts is of fundamental importance.