''Mesembryanthemum tortuosum'' (many

synonyms A synonym is a word, morpheme, or phrase that means exactly or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are ...

, including ''Sceletium tortuosum'') is a

succulent plant In botany, succulent plants, also known as succulents, are plants with parts that are thickened, fleshy, and engorged, usually to retain water in arid climates or soil conditions. The word ''succulent'' comes from the Latin word ''sucus'', meani ...

in the family

Aizoaceae The Aizoaceae, or fig-marigold family, is a large family of dicotyledonous flowering plants containing 135 genera and about 1800 species. They are commonly known as ice plants or carpet weeds. They are often called vygies in South Africa and New ...

native to the

Cape Provinces The Cape Provinces of South Africa is a biogeographical area used in the World Geographical Scheme for Recording Plant Distributions (WGSRPD). It is part of the WGSRPD region 27 Southern Africa. The area has the code "CPP". It includes the Sou ...

of South Africa. It is known as kanna, channa, kougoed (kauwgoed/ 'kougoed', prepared from 'fermenting' ''M. tortuosum'')—which literally means, 'chew(able) things' or 'something to chew'. Eight species related to ''M. tortuosum'' have also been placed in the genus ''Sceletium'': ''M. crassicaule'', ''M. emarcidum'', ''M. exalatum'', ''M. expansum'', ''M. archeri'' (''S. rigidum''), ''M. ladismithiense'' (''S. strictum''), ''M. tortuosum'' and ''M. varians''.

History

The plant has been used by South African pastoralists and hunter-gatherers as a mood-altering substance from prehistoric times. The first known written account of the plant's use was in 1662 by

Jan van Riebeeck Johan Anthoniszoon "Jan" van Riebeeck (21 April 1619 – 18 January 1677) was a Dutch navigator and colonial administrator of the Dutch East India Company. Life Early life Jan van Riebeeck was born in Culemborg, as the son of a surgeon. H ...

. The traditionally prepared dried plant was often chewed and the saliva swallowed, but it has also been made into gel caps, teas and

tincture A tincture is typically an extract of plant or animal material dissolved in ethanol (ethyl alcohol). Solvent concentrations of 25–60% are common, but may run as high as 90%.Groot Handboek Geneeskrachtige Planten by Geert Verhelst In chemist ...

s. It has also been used as a

snuff Snuff may refer to: Tobacco * Snuff (tobacco), fine-ground tobacco, sniffed into the nose ** Moist snuff or dipping tobacco ** Creamy snuff, an Indian tobacco paste Media and entertainment * Snuff film, a type of film that shows a murder Literat ...

and smoked.

Uses

''M. tortuosum'' is traditionally used to fight stress and depression, relieve pain and alleviate hunger. ''M. tortuosum'' has been studied to alleviate excessive nocturnal barking in dogs, or meowing in cats, in pets diagnosed with

dementia Dementia is a disorder which manifests as a set of related symptoms, which usually surfaces when the brain is damaged by injury or disease. The symptoms involve progressive impairments in memory, thinking, and behavior, which negatively affe ...

Cultivation

''M. tortuosum'' can be grown from seeds and be propagated from cuttings. Its cultivation and care are similar to cactaceae like ''

Echinopsis ''Echinopsis'' is a large genus of cacti native to South America, sometimes known as hedgehog cactus, sea-urchin cactus or Easter lily cactus. One small species, ''E. chamaecereus'', is known as the peanut cactus. The 128 species range from lar ...

''. The optimal temperature is at least 16°C and it does not tolerate frost.

Pharmacology

''M. tortuosum'' contains about 1–1.5% total

alkaloid Alkaloids are a class of basic BASIC (Beginners' All-purpose Symbolic Instruction Code) is a family of general-purpose, high-level programming languages designed for ease of use. The original version was created by John G. Kemeny and Th ...

s. A standardised ethanolic extract of dried ''M. tortuosum'' had an IC₅₀ for SERT of 4.3 μg/ml and for PDE4 inhibition of 8.5 μg/ml.

Mesembrine

Mesembrine Mesembrine is an alkaloid present in ''Sceletium tortuosum'' (kanna). It has been shown to act as a serotonin reuptake inhibitor (Ki = 1.4 nM), and more recently, has also been found to behave as a weak inhibitor of the enzyme phos ...

is a major alkaloid present in ''M. tortuosum''. There is about 0.3% mesembrine in the roots and 0.86% in the leaves, stems, and flowers of the plant.

Safety

General

Traditional and contemporary methods of preparation serve to reduce levels of potentially harmful

oxalate Oxalate (IUPAC: ethanedioate) is an anion with the formula C2O42−. This dianion is colorless. It occurs naturally, including in some foods. It forms a variety of salts, for example sodium oxalate (Na2C2O4), and several esters such as dimethyl ...

s found in ''M. tortuosum''. An analysis indicated levels of 3.6-5.1% oxalate, which falls within the median range for crop plants, just like spinach or kale. It is speculated that physical crushing of the plant and the fermentation process reduce the potentially harmful effects of

oxalic acid Oxalic acid is an organic acid with the systematic name ethanedioic acid and formula . It is the simplest dicarboxylic acid. It is a white crystalline solid that forms a colorless solution in water. Its name comes from the fact that early inve ...

. In particular, free oxalic acid is likely to complex with cell wall-associated calcium salts and precipitate as

calcium oxalate Calcium oxalate (in archaic terminology, oxalate of lime) is a calcium salt of oxalic acid with the chemical formula . It forms hydrates , where ''n'' varies from 1 to 3. Anhydrous and all hydrated forms are colorless or white. The monohydrate ...

when plant material is crushed.

Animal studies

No treatment-related adverse effects were observed in an oral toxicity study in rats of a standardized hydroethanolic extract of ''M. tortuosum''. The extract, although not mesembrine itself, produced

ataxia Ataxia is a neurological sign consisting of lack of voluntary coordination of muscle movements that can include gait abnormality, speech changes, and abnormalities in eye movements. Ataxia is a clinical manifestation indicating dysfunction of t ...

in rats, thereby possibly limiting the usefulness of the extract as an antidepressant.

Human studies

In a study evaluating its safety, a 2:1 standardised extract consumed by healthy adults at a dose of up to 25 mg once daily over a three-month period was well tolerated, with adverse effects such as headache not occurring more than when taking a placebo.

Gallery

File:Kanna flower.jpg, Flower File:Sceletium tortuosum commercial sale.JPG, Being sold commercially in

Cape Town Cape Town ( af, Kaapstad; , xh, iKapa) is one of South Africa's three capital cities, serving as the seat of the Parliament of South Africa. It is the legislative capital of the country, the oldest city in the country, and the second larges ...

South Africa South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring count ...

. It is ground into a brown powder and ingested orally. File:3D anaglyph of sceletium tortuosum.jpg, Seedling

References

External links

Monograph on ''Sceletium tortuosum''

''The past, present and possible future of kanna''
Video. Talk of Nigel Gericke at Ethnopharmacologic Search for Psychoactive Drugs. 2017.