The discovery of organic residues in or on ancient artifacts presents exciting opportunities for archaeologists. Analysis of such residues has suggested purposes as cosmetics, adhesives, medicines and even poisons, with the majority apparently derived from Plants. The earliest organic residues date from about 200 000 years ago, and apparently reflect Plants chosen for the Insect-repellent smoke they produced when burned,. This marks the beginning of a long history of Humans utilizing the chemical properties of Plants, which has enabled us to move out of Africa and colonise every continent except Antarctica. The oldest of these studied residues come from Southern Africa, where we have a record of Human Plant usage spanning almost the entire history of our species, and including a wide range of uses, though, surprisingly, including very few residues associated with medicines.
Traditional African medicine is still widely used on the continent, and is heavily dependent on Plants, something which was recorded by the earliest European visitors to the continent, and which therefore was probably the case long before their arrival. Unfortunately, from an anthropological point of view, traditional African medicine practitioners are flexible and adaptable in their approach to Plant selection, and today use many Plants imported from other parts of the world, something which makes it hard to assess which Plants might have been used in medicine in the remote past. This is complicated by the fact that not all traditional medicines are effective, with only 33 of the 166 Plants used in traditional medicine in Eastern Cape Province today having been shown to have pharmacological effects. This is not simply a sign of incompetence on the behalf of the practitioners of this medicine, but rather a slightly different perspective on how Plants are used, with much medicine being used to protect against, or treat the effects of, harmful magic rather than disease.
The lack of archaeological evidence makes it hard to assess how old modern traditional medicine practices are, and how (or if) they have changed over time. The remains of Plants which would be considered to have medicinal properties today have been found associated with archaeological sites dating back to the Middle Stone Age in South Africa (i.e. more than 130 000 years old), although it not possible to say if they were being used for medicinal purposes, or how they were used if they that was their purpose.
In a paper published in the South African Journal of Science on 31 January 2023, Justin Bradfield of the Palaeo-Research Institute at the Universityof Johannesburg, Stephan Woodborne of iThemba LABS, Jeremy Hollmann of the Rock Art Research Institute at the University of the Witwatersrand, and Ian Dubery of the Research Centre for PlantMetabolomics and the Departmentof Biochemistry at the University of Johannesburg, describe a 500-year-old medicine horn found in a rock shelter on a farm in Eastern Cape Province, South Africa, the results of an analysis of its contents.
The horn was discovered on a farm called La vie D’Antan, in the Langkloof Mountains, about 40 km to the north of Plettenberg Bay, and about 40 km to the east of Uniondale. The object is a Cattle horn sealed with leaves, which contained a solid residue, thought likely to have been a liquid or gel when the horn was deposited, due to its orientation. This residue was readily soluble, making it suitable for gas chromatography-mass spectrometry analysis.
The site from which the horn was recovered is a rock shelter with rock art, about 3 m high and cutting 3 m deep into the conglomerate Enon Formation. The shelter has a shallow floor deposit, which is only a few centimetres thick, within which the horn had been deposited. The horn was discovered after apparently being exposed by Animal activity, and removed by a passer-by to prevent further damage. It was sealed with a bundle of Century Plant, Boophane disticha, leaves and Grass, which were attached to the horn by a twisted Plant-fibre rope. The leaves of the Century Plant are known to have antiseptic properties, which may have helped to preserve the horn and its contents; the same leaves were used to bind the 2000-year-old Kouga Mummy, which was discovered about 10 km from the La vie D'Antan site. The site also produced a few shards of ceramic, but no signs of ever having been occupied, The area around the site contained numerous Everlasting Plants, Helichrysum spp., and Ragworts, Senecio spp., both of which are sometimes used to make teas in Southern Africa.
The rock shelter is within a conglomerate made up of sandstone boulders, which is covered by between 20 and 30 paintings, executed in red and yellow ochre paints, apparently made with a brush (with the exception of some handprints), and depicts Human figures armed with hunting equipment, and a range of Animals, most of which are hard to identify, but which include at least one Eland and one Antelope. This art is fairly typical of the San people who occupied the region before being largely driven out by Dutch settlers in the late eighteenth century; similar art has been found at two other rock shelters within 2 km of the site.
Prior to the eighteenth century, the area was occupied by hunter gatherers who belonged to the San ethnic group, and pastoralists from the Khoi ethnic group, who typically owned large herds of Sheep and Cattle. By 1775 much of the land had been partitioned among Dutch settlers, with the few remaining Inqua Khoi largely being employed as herdsmen on Dutch owned farms. A mixed population, descended from San and Khoi refugees and deserters from the Dutch army (which included non-European conscripts from colonies in Africa and Asia) may have survived in the mountains as late as the 1880s, but the last independent San bands disappeared in the 1760s. Little is known about this hunter gatherer population, though they were resident in the area for at least 10 000 years, and used a technology which modern archaeologists classify as Later Stone Age.
The Kouga Mummy was found about 10 km from the La vie D'Antan rockshelter, and comprises a man aged between 30 and 40 and thought to be a member of the San ethnic group due to his stature, and dated to about 1930 years before the present. The Mummy was wrapped in the leaves of a Century Plant, and covered with a mass of twigs and branches, which may have formed a burial basket. Within the leaf-bindings were found some Century Plant bulbs, as well as some beads made from marine shells. The feet of the Mummy had been bound, and the last joint of the left little finger removed, both burial customs known to have been practiced by some San societies. The burial site was covered by a painted stone slab.
The use of horns as medicine containers is fairly common across Africa as a whole, but somewhat unusual in Southern Africa, where the shells of Tortoises or the eggs of Ostriches have been the favoured traditional containers. A number of Cattle horn snuff containers attributed to Sotho or Shona makers are housed in the collection of the British Museum, but these date from the nineteenth century. The Harvard Peabody Museum has similar containers, reportedly from southern Tanzania or northern Zimbabwe, but again from the nineteenth century. Bradfield et al. also note having found reference to a medicine horn collected in the Belgian Congo between 1890 and 1930, on which they could find no further information, possibly in reference to this specimen from the Welcome Collection. They also note that some San groups living in the Kalahari use horns to store medicine, as do the Bemba of Zimbabwe, althought the Kalahari San generally use Duiker horns to store medicine used against witchcraft, while the Bemba use a variety of Antelope horns, including Duiker and Bushbuck,
Bradfield et al. first examined the contents of the horn under a light microscope, finding a mixture of Insect and Plant remains in the surface layer. The majority of the Insect remains could not be identified with any confidence, but were not inconsistent with having come from Dermestid Beetles (Skin Beetles) a group which are known to have been attacking the Horn and its contents when it was found, though some scales of Lepidopteran Insect (Butterfly or Moth) wings were also found. Beneath the surface the residue contained no Insect or Plant remains, and comprised a shiny brown crystalline substance which dissolved readily in water and smells faintly of Liquorice.
Gas chromatography-mass spectrometry analysis of the brown residue revealed it to be a mixture of organic compounds, with the largest proportion being mono-methyl inositol and its isomers, as well as lupeol, and lesser amounts of di- and tri-terpenes, a sterol derivative and fatty acid methyl ester. Curiously, no volatile aromatic associated with a Liquorice smell was found.
Inositol is a natural polysaccharide sugar synthesized in plant cells and used in the production of plasma lipo-proteins to aid cell growth. It is produced by a range of Plants, including Legumes and Citrus fruits, and used in medicines used to control diabetes, and treat high cholesterol, bronchopulmonary dysplasia and various mood disorders, as well as to reduce the symptoms of polycystic ovarian syndrome. Importantly, it is considered to be a pharmacologically stable compound, upon which it is impossible to overdose.
Mono-methyl inositol and inositol isomers are produced by a number of Southern African plants used medicinally, including the Balloon Pea, Sutherlandia frutescens, an antioxidant which has traditionally been used to wash wounds and treat eye infections, as well as as a tonic to treat rheumatism and pulmonary ailments and boost immune function, the Honeybush, Cyclopia intermedia, from which an antioxidant rich tea is made, which is held to have anti-inflammatory and possibly cancer-fighting effects, Lotonius laxa, and Bluebellvine, Clitoria ternatea, which is not used in medicine in Southern Africa today, but which is used in Asia to treat sexually transmitted diseases and anxiety.
Lupeol is a pentacyclic triterpenoid produced by a wide range of Plants, and is commonly a constituent of resins and plant waxes. Medicinally, it has anti-inflammatory and antimicrobial properties, and is used in some cancer treatments. In Southern Africa it is produced by a number of Plants, including the Namaqua Rock Fig, Ficus cordata, the Kokilaksha, Asteracantha longifolia, which is used by the Pedi people of northern South Africa as a treatment for rheumatism, urinary tract infections, and jaundice, as well as an aphrodisiac, as well as by a number of species of Euphorbia,
Kaurenoic acid is an antibacterial compound produced by a variety of Plants, which is particularly effective against Gram-positive Bacteria such as Listeria, Staphylococcus and Streptococcus. It has also been shown to offer some protection against liver damage. Again, this is produced by a number of Plants found in Southern Africa, including the Bears Foot, Arctopus sp., the medicinal use of which has been recorded since the 1770s, as a treatment for gout, various infections and respiratory ailments, Alepidea sp., which has been used to treat colds, coughs, sore throats, influenza, and abdominal cramps, and Aster bakeranus, which has been used to treat venereal diseases, urinary tract infections, chronic coughs, and intestinal complaints.
Another chemical present is cyclolanostenol acetate, which can be produced by a variety of Dicotyledonous Plants and Animals. Notably, in Southern Africa, it is produced by Rafnia amplexicaulis, which has been used to make a tea used to treat pulmonary conditions, and as a substitute for liquorice.
Small amounts of three decanoic acids were found within the resin. These are are produced by a range of Plants held to have medicinal compounds. Also present were hexadecane and octadecanoic acid, both of which have antifungal, antibacterial, and antioxidant properties.
While all of the identified chemicals are produced by a range of Plants across Southern Africa, Bradfield et al. feel confident in narrowing the field to plants found close to the site where the horn was discovered. When this is done, three species stand out as being highly likely to have contributed to the contents of the horn; the Prostrate Purslane, Corbichonia decumbens, which comprises 75% mono methyl inositol, 17% hexadecenoic acid and 16% octadecanoic acid, and which is liquefied for use as an emetic by members of the Zulu people today, the Liquorice Plant, Glycyrrhiza glabra, which contains 28% of mono-methyl inositol, 3.4% octadecanoic acid, and 4.9% hexadecenoic acid, which is widely used by traditional medicine practitioners across Africa, but which has generally been assumed to have been introduced to the continent by Europeans, and the Horse Gram, Macrotyloma uniflorum, which also contains mono-methyl inositol, hexadecanoic acid and octadecanoic acid, and which, while not used in African traditional medicine today, is used in India as an antioxidant and a treatment for insulin resistance. Another possibility is Mikania sp., which contains lupeol and kaurenoic acid, and which is used to treat Snake bites and venereal disease today.
Bradfield et al. conclude that the horn contains a mixture of extracts from at least two plants, almost certainly intended to have a medicinal use. The major components of this mixture are used to treat a wide range of ailments today, either by drinking or applying as an ointment; San people today often apply ointments to small cuts intentionally made for that purpose, which may also have been the case when the horn medicine was in use. There is no way to know what ailment(s) the mixture found in the horn was actually intended to treat, or whether that treatment would have been of any benefit to the patient. The medicine contains a number of active ingredients, but the medicine maker is likely to have had a world view very different to our own, including a belief in supernatural as well as (or instead of( physical causes for ailments, which would have affected the choice of ingredients to be used in a medicinal potion in ways difficult for us to understand.
Notably, two plants found to be growing abundantly in the area around the rock shelter today, Helichrysum sp. and Senecio sp., are both used in traditional medicine today to treat both physical and spiritual ailments, are unlikely to have been components of the medicine, based upon the gas chromatography-mass spectrometry analysis, although both the medicine and Helichrysum sp. have a Liquorice-smell, so it is possible that this was a component of the medicine but not detected instrumentally for some reason. The alternative explanation, that the Liquorice-smell derives from the Liquorice Plant, Glycyrrhiza glabra, runs counter to the current belief that the Plant was introduced to Africa by Europeans, although this Plant matches the chemical contents of the horn much more closely, and other Plants thought to have been introduced to Africa by Europeans have subsequently been shown to have been on the continent before Europeans arrived.
The careful wrapping and burial of the horn and its contents implies that this was a valued object. It is likely that it was buried in the rock shelter with the intention that its owner would return and retrieve it at some point, but never did so. Similar finds of items probably buried for storage purposes have been found elsewhere in Southern Africa, for example a full hunting kit was found Eland Cave in the Drakensberg Mountains. Other than this item, the rock shelter contains only a few ceramic shards and the rock paintings, with no indication that it was ever used as a dwelling.
As far as Bradfield et al. are aware, the horn from the La vie D'Antan rock shelter is the oldest medicine container ever discovered in Southern Africa. The occupation of the region where the horn was found appears to have been ephemeral after about 2000 years ago, with nearby rock shelters at Boomplaas, Nelson Bay Cave and Matjes River, all of which were once occupied, having been abandoned during the first millennium AD. The information available does not allow the identification of the medicine-maker. The art in the rock shelter is clearly of San origin, but there is no evidence that the horn and the paintings were contemporary in origin. The choice of a Domestic Cattle horn would seem to imply the medicine was left by a Khoi herder, but there is no real reason to assume this. The San people sometimes kept Cattle, and even if this was not the case, the horn could have been acquired by a San medicine maker through scavenging, theft, or trade. Bradfield et al. note that nineteenth century records from the Western Cape state that the Khoi and San peoples there shared a belief in a mythical being called the Water Bull, which resembled a Domestic Bull, and which had horns with magical healing properties.
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