Wild Dagga

A mint of southern Africa

Leonotis leonurus is a shrub that can exceed two to three metres, with opposite hairy leaves and orange-coral bilabiate tubular flowers raised in tiered crowns (Dale Pendell, Pharmako/Poeia, p. 220-221). She belongs to the family of Lamiaceae — the mints, like sage, lavender and horehound.

The flower is the fruit of a co-evolution with the African sunbirds, nectarivores with a long curved beak that fits exactly into the floral tube. The plant sculpted her calyx around the bird's beak, and the bird her beak around the calyx. The plant grows easily from seeds and is today mainly cultivated as ornamental beyond her area of origin (Pendell, p. 221). A sister species, Leonotis nepetifolia (« Klip Dagga », lion's ear), has naturalised in the tropics of the whole world; in the West Indies she is called Christmas candlestick for her crowns of flowers that look like lit candles. It is she, the Klip Dagga, that is wild-harvested in Peru: our petals come from her. The extract and the resin, for their part, are drawn from the true *Leonotis leonurus* of southern Africa.

Where the name dagga comes from

The word dagga comes from the Khoikhoi dachab, transcribed by the Dutch settlers. The old sources use it for several plants that were smoked in the evening, and the reference dictionary of South African English does not settle which one carried the name first. Today we say wild dagga to name the orange flower.

Phytochemistry — the labdane diterpenes

The plant's major active compounds belong to the class of labdane diterpenes.

• —Marrubiin — labdane diterpene shared with the European white horehound; profile described as bronchodilator, expectorant and mild hypotensive, which illuminates the traditional respiratory use.
• —Leoleorins A to J — series of at least ten labdane diterpenes isolated in recent decades. Leoleorin C shows a moderate affinity for the Sigma-1 receptor (Ki ≈ 2.9 µM), receptor of the central nervous system.
• —Leonurine — alkaloid related to that of the motherwort (Leonurus cardiaca), with mild cardiac and uterotonic tropism (hence the contraindication in pregnancy).
• —Tannins, saponins, phenolic acids, flavonoids — accompanying cortège.

What the studies report

Modern research remains preliminary and largely preclinical. Studies report antinociceptive, anti-inflammatory, hypotensive, anticonvulsant, antioxidant activities, as well as a hypoglycaemic effect in the rat and a moderate inhibition of acetylcholinesterase. The most discussed contemporary lead concerns the bronchodilator profile of marrubiin and the Sigma-1 tropism of leoleorins. None of this constitutes proof of efficacy in humans: these are leads. Dale Pendell, who has tried to test the effects of the smoke, reports « mixed and most often unspectacular » results, one person however finding the smoke « very relaxing and clarifying » (Pharmako/Poeia, p. 221).

Living lineage — Khoisan, Zulu, Xhosa, Sotho

Leonotis leonurus grows throughout southern Africa, from the Cape province to KwaZulu-Natal. The pastoral Khoikhoi and the hunter-gatherer San, whose presence on these lands goes back tens of thousands of years, smoked the dachab alone or in blends — a companion of the evening. The Bantu peoples of southern Africa then integrated her into their popular medicine: decoctions of leaves and flowers for cough, cold and bronchitis, topical applications on bites and stings (Nsuala, Enslin & Viljoen, review on the traditional use and phytochemistry of Leonotis leonurus, J. Ethnopharmacol., 2015). Reported uses, never guaranteed benefits. In the traditional blends, one finds her alongside buchu, wild rosemary and kanna (Sceletium tortuosum), the other great Khoisan plant.

Safety

To be avoided during pregnancy and breastfeeding (uterotonic tropism of leonurine, insufficient safety data). Caution in case of hypotension, unstable diabetes, and with hypotensive, hypoglycaemic or sedative medications, whose effect she can potentiate. Possible allergy to Lamiaceae. Any smoke, whatever the plant, irritates the respiratory tract: for regular use, the infusion is the soft path. Leonotis leonurus is not a threatened species (SANBI red list: least concern), but respect for the communities and territories of origin remains a vigilance. This page is informative and does not replace the advice of a health practitioner. Do your own research (DYOR).