Historical versus contemporary medicinal plant uses in the US Virgin Islands

ETHNOPHARMACOLOGICAL RELEVANCE

Hidden in the documents of the dark past of the trans-Atlantic slavery are gems of ethnomedicinal observations, supported by herbarium specimens, which tell of the traditional medicine of a by-gone slave society in the Caribbean. In the context of the former Danish West Indies (now US Virgin Islands), we identify pre-1900 medicinal plants and their historical uses, and trace their status in the traditional medicine of St. Croix today (2014). By a combined historical and ethnobotanical approach we assess the scale of loss and preservation of traditional medicinal knowledge on St. Croix, and explore the drivers involved in the disappearance of knowledge in the oral tradition of medicine.

MATERIALS AND METHODS

Names, uses and identities of 18th and 19th century medicinal plant uses in the Danish West Indies were derived from manuscripts and publications of Von Rohr (1757/58), Oldendorp (1777), West (1793), Benzon (1822), Riise (1853), Eggers (1876;1879) and Berg and Eggers (1888). The presence of the plant species in the pre-1900 Danish West Indies was confirmed by review of herbarium specimens in the University of Copenhagen Herbarium (C). The same species were collected on St. Croix in 2014 or their ecological status discussed with local specialists. Semi-structured interviews supported by photographs and specimens were conducted with six medicinal plant specialist on St. Croix, to document and compare contemporary names and uses of the historically used medicinal plants.

RESULTS AND DISCUSSION

The historic ethnomedicinal sources revealed 102 medicinal uses of 64 plant species. Thirty-eight (37%) of the pre-1900 medicinal uses were traced in interviews, while sixty-four uses (63%) appear to be forgotten, discontinued or otherwise lost. Thirteen species appear to have entirely lost their status as medicinal plants on St. Croix, while 32 species (50%) have lost uses while retaining or gaining others. While 20% of the lost medicinal plant uses can be explained by biodiversity loss, and others likely have become obsolete due to advances in public health and scientific medicine, 33 of the 64 lost medicinal uses of non-rare species uses fall in the same categories as the preserved uses (fever, stomach, wound, laxative, pulmonary, intestinal, pain, anthelmintic, blood purifier, eye-inflammation). We therefore argue that at least half of the known pre-1900 medicinal plant uses have become culturally extinct for other reasons than to biodiversity loss or modern obsoleteness.

CONCLUSIONS

The present study utilized knowledge from an oral medicinal tradition, documented in the context of a colonial society. Without doubt, basis for further similar studies exists in the more or less accessible archives, herbaria and collections of former colonial powers. Such studies could directly benefit the descendants of the original intellectual property holders culturally and economically, or serve as stepping stones to integrate, or re-integrate, lost medicinal plant uses in both local and wider evidence-based contexts.

Historical versus contemporary medicinal plant uses in Ghana

ETHNOPHARMACOLOGICAL RELEVANCE

Three extraordinary, historical documents stemming from observations made in 1697, 1803 and 1817 quote medicinal plant uses among the Fante, Ga and Ashanti people of present-day Ghana, and can be linked to original botanical specimens in European herbaria. This provides a unique opportunity to gain insight to the historical materia medica of Ghana and compare this to contemporary medicinal plant uses. By critical literary and taxonomic review, the present study (re-)establishes the earliest known history of many important Ghanaian medicinal plants, and assesses the scale of change and loss of medicinal plant knowledge in Ghana over time. The study provides the foundation to reconstruct lost or discontinued Ghanaian plant uses in local or ethnopharmacological contexts.

MATERIALS AND METHODS

Historical botanical specimens were located in the herbaria of University of Copenhagen Herbarium (C) and British Museum of Natural History (BM). The classification and synonymy of the specimens were updated for the study, and the historical vernacular names and medicinal uses of the plants compared with 20th/21st century literature. The plants of the historical Ga materia medica were (re-)collected to aid in semi-structured interviews. The interviews aimed to document the contemporary uses and names of the plants among the Ga, and to determine to what extent the historical medicinal uses and names are extant.

RESULTS AND DISCUSSION

The study identified 100 species in historical medicinal use in Ghana, which could be linked to 134 unique uses and 105 vernacular names in Twi (Ashanti/Fante) and Ga. Most of the plants are common in Ghana. At least 52% of the historical vernacular names appear to still be in use today. Of the specific historical uses, 41 (31%) were traced among contemporary medicinal plant uses in Ghana and represent some of the most important Ghanaian medicinal plant species. However, 93 (69%) of the historical uses could not be traced and appears to be discontinued or forgotten. Among the Ga, two medicinal plants species have become rare or locally extinct, and thus the vast majority of the loss of knowledge appears to be due to cultural extinction.

CONCLUSIONS

The scientifically strong voucher material allowed for identification of a high number of historical medicinal plants and their roots in traditional Ghanaian medicine systems 2-300 years ago. The materia medica of the Fante, Ga and Ashanti of Ghana has changed considerably over time. The "forgotten" historical uses warrant further studies to determine the pharmacological activity of these plants. This could provide the foundation for reconstruction of historical medicinal plant uses in evidence-based modern contexts.