A quantitative synthesis of the medicinal ethnobotany of the Malinké of Mali and the Asháninka of Peru, with a new theoretical framework

Plants used traditionally as antimalarials in Latin America: Mining the tree of life for potential new medicines

ETHNOPHARMACOLOGICAL RELEVANCE

Malaria remains a serious and challenging disease. Traditional antimalarial medicines are largely based on plants, and ethnopharmacological research has inspired the development of antimalarial pharmaceuticals such as artemisinin. Antimalarial drug resistance is an increasing problem in Plasmodium species, and new therapeutic strategies to combat malaria are needed. Although the number of malaria cases has been decreasing in Latin America, malaria remains a significant threat in many regions. Local people in Latin America have been using numerous plant species to treat malaria, some of which have been scientifically studied, but many others have not.

AIM OF THE STUDY

Our principal objective is to harness ethnobotanical data on species used traditionally to treat malaria, combined with phylogenetic approaches, to understand how ethnobotany could help identify plant genera as potential sources of new medicines.

MATERIALS AND METHODS

Plants used to treat malaria in Latin America were compiled from published and grey literature, unpublished data, and herbarium specimens. Initial assessment of potentially important species/genera/families included compiling the number of species used within the genus, the number of use reports per genus and species, and the geographic distribution of their use. The analysis of taxonomic distribution of species reported as antimalarial in Latin America (excluding the Southern Cone) was conducted, to determine which genera and families with reputed antimalarial properties are over-represented, and phylogenetic analyses were performed to identify if there was evidence for antimalarial species being dispersed/clustered throughout the tree or at its tips. This approach enabled 'hot-nodes' in certain families to be identified, to predict new genera with potential antimalarial properties.

RESULTS

Over 1000 plant species have been used to treat malaria in Latin America, of which over 600 species were cited only once. The genera with the highest number of antimalarial species were Aspidosperma, Solanum, Piper, Croton and Aristolochia. In terms of geographic distribution, the most widely used genera were Aspidosperma, Momordica, Cinchona, Senna and Stachytarpheta. Significant phylogenetic signal was detected in the distribution of native species used for malaria, analysed in a genus-level phylogenetic framework. The eudicot and magnoliidae lineages were over-represented, while monocots were not.

CONCLUSION

Analysis of ethnobotanical use reports in a phylogenetic framework reveals the existence of hot nodes for malaria across the Latin American flora. We demonstrate how species and genera currently lacking such reports could be pinpointed as of potential interest based on their evolutionary history. Extending this approach to other regions of the world and other diseases could accelerate the discovery of novel medicines and enhance healthcare in areas where new therapeutic strategies are needed.

Taxonomic affiliation influences the selection of medicinal plants among people from semi-arid and humid regions-a proposition for the evaluation of utilitarian equivalence in Northeast Brazil

Background

This study sought to investigate the occurrence of taxonomic patterns between semi-arid and humid regions, verifying how the taxonomic affiliation can influence the selection of plants for medicinal purposes and act as a selection criterion.

Methods

The relationship between the taxonomic affiliation and the selection of medicinal plants with four different communities was analyzed; two of them associated with a seasonally dry tropical forest and the other two associated with a tropical rain forest. We used the Utilitarian Equivalence Model (transposing the concept of ecological equivalence, proposed by Odum, for ethnobotany) to test the hypothesis that species that have the same taxonomic affiliation tend to have the same therapeutic applications in different environments (utilitarian equivalence). In addition, we used the Utilitarian Redundancy Model to verify whether, within the same medical system, plants of the same taxonomic affiliation tend to be redundant (treating the same diseases).

Results

We found that a pair of plants of the same genus were 9.25 times more likely to be equivalent than a different genus pair (OR = 9.25, CI [1.68-51.02], p < 0.05). When we analyzed the species used by the same population, the chances of a pair having similar therapeutic uses (utilitarian redundancy) increased when they were species of the same family (OR = 1.94, CI [1.06-3.53]; p < 0.05).

Conclusions

These findings confirm the hypothesis that there is an influence of taxonomic affiliation, in terms of genera and family, on the selection of medicinal plants in semi-arid and humid areas in Northeast Brazil. In addition, our Utilitarian Equivalence Model can be an important tool in the search for more common selection criteria, in order to identify the shared characteristics among the equivalent pairs and consequently the main types of perceptions or stimuli that led to the inclusion of such species in local pharmacopoeias.

Non-random medicinal plants selection in the Kichwa community of the Ecuadorian Amazon

The non-random selection of medicinal plants theory, which predicts taxonomical biases in ethnopharmacopeias, indirectly demonstrates that traditional medicinal systems are rational and based in part on the therapeutic efficacy of plants. This theory suggests that because members of a taxonomical group share similar characteristics, some groups will be over-utilized in pharmacopeias, while other groups bereft of therapeutic potential will be under-utilized medicinally. Empirical evidence fo this theory comes from studies that used data collected at the national level which may lead to the overestimation of medicinal plant list given that some parts of the country (e.g., protected areas) can be unavailable for medicinal plant collection. Similarly, because medicinal plant importance and knowledge can be gender-specific and depends on the degree of exposure of a community, failure to account for gender and community experience can limit our understanding of non-random selection of medicinal plants. In this study, we used the negative binomial model and an examination of studentized residuals to demonstrate that a Kichwa community in the Ecuadorian Amazon over-utilized different sets of medicinal plant families depending on the gender of the informants or the experience of the community. We showed that utilizing local data instead of nationwide data reveals new over-utilized families. Seven of the nine most over-utilized medicinal plant families we found were previously reported in different biogeographical regions. The other two families are novel reports. Overall, our study proposes a novel method to uncover the intracultural heterogeneity of traditional knowledge and people non-random selection of medicinal plants at the local level.

Revisiting the linkage between ethnomedical use and development of new medicines: A novel plant collection strategy towards the discovery of anticancer agents

The Vietnam-Laos International Cooperative Biodiversity Group (ICBG) based at the University of Illinois at Chicago (UIC) catalyzed a country-wide network of medicinal plant preserves (MPP) and medicinal biodiversity preserves (MBP) now established in ten provinces of the Lao People's Democratic Republic (Lao PDR), which are relied upon as protected sources of ethnomedicines for local villagers and traditional healers. In collaboration with the Lao PDR's Institute of Traditional Medicine (ITM), our ongoing P01 Program Project (Ohio State University) examined the anticancer bioprospecting potential for two of the most exhaustively inventoried of these sites: the Bolikhamxay MPP and the Xiengkhouang MBP. Guided by prior voucher specimens sourced from these preserves with an overwhelming emphasis on plants employed in traditional medicine, 201 distinct samples from 96 species were collected along with proper herbarium documentation. Aliquots of these plant samples were extracted in azeotropic ethanol and evaporated to dryness for initial biological evaluation. In six samples from six different species (2.99% of the collected samples, 6.25% of taxa) it was observed that extracts exhibited notable cytotoxicity against HT-29 colon adenocarcinoma cells. The wisdom behind the utilization of HT-29 cells in this preliminary biological screen is discussed. Furthermore, comparison of screening results based on longstanding considerations and ideological underpinnings of ethnobotanical vs. "random" biodiversity-based collection approaches is detailed herein. The results of this interdisciplinary study support the hypothesis that, by privileging the initial sample set in terms of human safety and pharmacological activity, ethnobotanically driven collection for biological screening efforts can produce leads unprecedented by the strict traditional usages of plants.

Do ferns and lycophytes function as medicinal plants? A study of their low representation in traditional pharmacopoeias

ETHNOPHARMACOLOGICAL RELEVANCE

Ethnobotany is becoming an important tool for understanding how traditional medical systems are organized and which variables affect their structure and dynamics. However, some phenomena observed in ethnobotanical studies led us to question whether such phenomena are real or methodological artifacts. The small proportion of ferns and lycophytes in ethnobotanical surveys of medicinal plants is one such phenomenon, and its causes should be identified using different approach levels. The present study aimed to clarify the reasons for a low representation of these two groups in studies of medicinal plants.

MATERIALS AND METHODS

The present study considered the following hypotheses: 1) ferns and lycophytes are little represented in different ethnobotanical studies because of inadequate data collection methods to record these species; 2) ferns and lycophytes are little represented because of the local perception of their low therapeutic efficacy; and 3) species of ferns and lycophytes are represented in local pharmacopoeias in proportion to the size of their families. We chose rural communities from Chapada do Araripe, Northeast Brazil to test our hypotheses. Data on the medicinal plant repertoires of the communities and on the perceived therapeutic efficacy of ferns were obtained using two different methods, semi-structured interviews associated with free lists and a checklist interview, both applied to local specialists. The resulting data were analyzed differently for each test. In addition, data regarding the total flora x medicinal flora ratio were obtained with a floristic survey and accessing data banks from previous studies performed by our research team.

RESULTS

All hypotheses were confirmed, showing that all three factors contributed to the low representation of these plant groups as medicinal resources. The present study showed that free-list interviews are not a good method to access traditional knowledge of medicinal ferns and lycophytes and that the use of visual stimuli can help the memory of the informants, thus making it possible to associate the perceived characteristics with plant use. The results also showed that individuals perceive these plants as inferior therapeutic resources compared to angiosperms, which contributes to knowledge of their use not being transmitted. The final result of the present study was that the distribution of medicinal fern and lycophyte species within families was consistent with the total flora x medicinal flora ratio. This result indicates that even if the most appropriate data collection method was used for the ethnobotanical survey, the number of species would not be as expressive as that of angiosperms.

Diversity of wetland plants used traditionally in China: a literature review

BACKGROUND

In comparison with terrestrial plants, those growing in wetlands have been rarely studied ethnobotanically, including in China, yet people living in or near wetlands can accumulate much knowledge of the uses of local wetland plants. A characteristic of wetlands, cutting across climatic zones, is that many species are widely distributed, providing opportunities for studying general patterns of knowledge of the uses of plants across extensive areas, in the present case China. There is urgency in undertaking such studies, given the rapid rates of loss of traditional knowledge of wetland plants as is now occurring.

METHODS

There have been very few studies specifically on the traditional knowledge of wetland plants in China. However, much information on such knowledge does exist, but dispersed through a wide body of literature that is not specifically ethnobotanical, such as regional Floras. We have undertaken an extensive study of such literature to determine which species of wetland plants have been used traditionally and the main factors influencing patterns shown by such knowledge. Quantitative techniques have been used to evaluate the relative usefulness of different types of wetland plants and regression analyses to determine the extent to which different quantitative indices give similar results.

RESULTS

350 wetland plant species, belonging to 66 families and 187 genera, were found to have been used traditionally in China for a wide range of purposes. The top ten families used, in terms of numbers of species, were Poaceae, Polygonaceae, Cyperaceae, Lamiaceae, Asteraceae, Ranunculaceae, Hydrocharitaceae, Potamogetonaceae, Fabaceae, and Brassicaceae, in total accounting for 58.6% of all species used. These families often dominate wetland vegetation in China. The three most widely used genera were Polygonum, Potamogeton and Cyperus. The main uses of wetlands plants, in terms of numbers of species, were for medicine, food, and forage. Three different ways of assigning an importance value to species (Relative Frequency of Citation RFC; Cultural Importance CI; Cultural Value Index CV) all gave similar results.

CONCLUSIONS

A diverse range of wetland plants, in terms of both taxonomic affiliation and type of use, have been used traditionally in China. Medicine, forage and food are the three most important categories of use, the plants providing basic resources used by local people in their everyday lives. Local availability is the main factor influencing which species are used. Quantitative indexes, especially Cultural Value Index, proved very useful for evaluating the usefulness of plants as recorded in the literature.

The globalization of traditional medicine in northern peru: from shamanism to molecules

Northern Peru represents the center of the Andean "health axis," with roots going back to traditional practices of Cupisnique culture (1000 BC). For more than a decade of research, semistructured interviews were conducted with healers, collectors, and sellers of medicinal plants. In addition, bioassays were carried out to evaluate the efficacy and toxicity of plants found. Most of the 510 species encountered were native to Peru (83%). Fifty percent of the plants used in colonial times have disappeared from the pharmacopoeia. Market vendors specialized either on common and exotic plants, plants for common ailments, and plants only used by healers or on plants with magical purposes. Over 974 preparations with up to 29 different ingredients were used to treat 164 health conditions. Almost 65% of the medicinal plants were applied in these mixtures. Antibacterial activity was confirmed in most plants used for infections. Twenty-four percent of the aqueous extracts and 76% of the ethanolic extracts showed toxicity. Traditional preparation methods take this into account when choosing the appropriate solvent for the preparation of a remedy. The increasing demand for medicinal species did not increase the cultivation of medicinal plants. Most species are wild collected, causing doubts about the sustainability of trade.

Patterns of medicinal plant use by inhabitants of Brazilian urban and rural areas: a macroscale investigation based on available literature

ETHNOPHARMACOLOGICAL RELEVANCE

Although the relationship between local people and plants may be idiosyncratic, some human behaviors are common to different communities and can be influenced by cultural and environmental factors. Thus, this study drew upon a systematic review and meta-analysis to evaluate if there are patterns of medicinal plant use in different Brazilian ethnobotanical studies and if these patterns are influenced by the urbanization or ecosystems where the studies were conducted.

MATERIALS AND METHODS

The factors evaluated concerned the origin of the species used (native vs. exotic), plant habit (woody vs. non-woody) and plant parts (permanent and non-permanent). Two kinds of analysis were performed: the integrative and the meta-analytical.

RESULTS

The factors varied depending on the ecosystems in which the studies were conducted. In the Amazon, Cerrado and Caatinga, native and woody medicinal species dominated; conversely, this pattern was not the case for the Atlantic Forest and Pampas ecosystems. Permanent plant parts were predominant in the Cerrado, and considering only native plants, permanent parts dominated in the Amazon, Cerrado and Caatinga. Urbanization did not significantly affect these patterns. Additionally, the species relative importance (RI) did not change as a function of the ecosystem or the degree of urbanization.

CONCLUSIONS

The phenomena observed in this study can be explained in light of the chemical ecology and historical and cultural aspects of the species, and the findings have important implications for bioprospecting and conservation.

Phylogenies reveal predictive power of traditional medicine in bioprospecting

There is controversy about whether traditional medicine can guide drug discovery, and investment in bioprospecting informed by ethnobotanical data has fluctuated. One view is that traditionally used medicinal plants are not necessarily efficacious and there are no robust methods for distinguishing those which are most likely to be bioactive when selecting species for further testing. Here, we reconstruct a genus-level molecular phylogenetic tree representing the 20,000 species found in the floras of three disparate biodiversity hotspots: Nepal, New Zealand, and the Cape of South Africa. Borrowing phylogenetic methods from community ecology, we reveal significant clustering of the 1,500 traditionally used species, and provide a direct measure of the relatedness of the three medicinal floras. We demonstrate shared phylogenetic patterns across the floras: related plants from these regions are used to treat medical conditions in the same therapeutic areas. This finding strongly indicates independent discovery of plant efficacy, an interpretation corroborated by the presence of a significantly greater proportion of known bioactive species in these plant groups than in random samples. We conclude that phylogenetic cross-cultural comparisons can focus screening efforts on a subset of traditionally used plants that are richer in bioactive compounds, and could revitalize the use of traditional knowledge in bioprospecting.

Cross-cultural comparison of medicinal floras used against snakebites

ETHNOPHARMACOLOGICAL RELEVANCE

Envenomation causes an estimated 1.8-2.5 million incidences per year with a mortality level of 100-125,000 persons annually and more than 100,000 individuals suffer from severe complications, which may end in amputation of the attacked limb. The use of plants is a major part of the traditional practitioners' treatment of snakebites.

MATERIALS AND METHODS

A database was created for plants used to treat snakebites worldwide. From this database, we selected five countries with a high number of entries and representing different cultures, geography and floristic zones: Brazil, Nicaragua, Nepal, China and South Africa. The datasets were analysed by regression and binominal analysis to see if any family or genus used against snakebites was overrepresented in the respective traditional medicinal systems relative to the abundance in the local flora. The families from the different geographical areas were compared to ascertain whether the same plant families are preferred by different peoples.

RESULTS

Three 'hot' families (Apocynaceae, Lamiaceae and Rubiaceae) were recovered in at least two of the five compared countries in the regression analyses and one 'hot' family (Zingiberaceae) was recovered in two of the compared countries in the binomial analyses. Four out of five floras possess families identified as outliers in both regression and binomial analyses. Eight families were recovered by both the binomial and the regression analysis (40-62% of all highlighted families respectively). At the genus level, only Piper (Piperaceae) was recovered as a 'hot' genus in at least two floras. Seven genera were highlighted by both analyses (25-44% of the highlighted genera).

CONCLUSIONS

Cross-cultural comparison of medicinal floras used against snakebites appears to be useful for highlighting candidate families and genera for further studies.

The use of phylogeny to interpret cross-cultural patterns in plant use and guide medicinal plant discovery: an example from Pterocarpus (Leguminosae)

BACKGROUND

The study of traditional knowledge of medicinal plants has led to discoveries that have helped combat diseases and improve healthcare. However, the development of quantitative measures that can assist our quest for new medicinal plants has not greatly advanced in recent years. Phylogenetic tools have entered many scientific fields in the last two decades to provide explanatory power, but have been overlooked in ethnomedicinal studies. Several studies show that medicinal properties are not randomly distributed in plant phylogenies, suggesting that phylogeny shapes ethnobotanical use. Nevertheless, empirical studies that explicitly combine ethnobotanical and phylogenetic information are scarce.

METHODOLOGY/PRINCIPAL FINDINGS

In this study, we borrowed tools from community ecology phylogenetics to quantify significance of phylogenetic signal in medicinal properties in plants and identify nodes on phylogenies with high bioscreening potential. To do this, we produced an ethnomedicinal review from extensive literature research and a multi-locus phylogenetic hypothesis for the pantropical genus Pterocarpus (Leguminosae: Papilionoideae). We demonstrate that species used to treat a certain conditions, such as malaria, are significantly phylogenetically clumped and we highlight nodes in the phylogeny that are significantly overabundant in species used to treat certain conditions. These cross-cultural patterns in ethnomedicinal usage in Pterocarpus are interpreted in the light of phylogenetic relationships.

CONCLUSIONS/SIGNIFICANCE

This study provides techniques that enable the application of phylogenies in bioscreening, but also sheds light on the processes that shape cross-cultural ethnomedicinal patterns. This community phylogenetic approach demonstrates that similar ethnobotanical uses can arise in parallel in different areas where related plants are available. With a vast amount of ethnomedicinal and phylogenetic information available, we predict that this field, after further refinement of the techniques, will expand into similar research areas, such as pest management or the search for bioactive plant-based compounds.

Cross-cultural comparison of three medicinal floras and implications for bioprospecting strategies

ETHNOPHARMACOLOGICAL RELEVANCE

One of the major drawbacks of using ethnomedicinal data to direct testing of plants which may find pharmaceutical use is that certain plants without bioactivity might be traditionally used. An accepted way of highlighting bioactive plants is to compare usage in different cultures. This approach infers that presumed independent discovery by different cultures provides evidence for bioactivity. Although several studies have made cross-cultural comparisons, they focussed on closely related cultures, where common patterns might be the result of common cultural traditions. The aim of this study was to compare three independent ethnomedicinal floras for which similarities can be more robustly interpreted as independent discoveries, and therefore likely to be indication for efficacy.

MATERIALS AND METHODS

Data from the literature were compiled about the ethnomedicinal floras for three groups of cultures (Nepal, New Zealand and the Cape of South Africa), selected to minimise historical cultural exchange. Ethnomedicinal applications were divided in 13 categories of use. Regression and binomial analyses were performed at the family level to highlight ethnomedicinal "hot" families. General and condition-specific analyses were carried out. Results from the three regions were compared.

RESULTS

Several "hot" families (Anacardiaceae, Asteraceae, Convolvulaceae, Clusiaceae, Cucurbitaceae, Euphorbiaceae, Geraniaceae, Lamiaceae, Malvaceae, Rubiaceae, Sapindaceae, Sapotaceae and Solanaceae) were recovered in common in the general analyses. Several families were also found in common under different categories of use.

CONCLUSIONS

Although profound differences are found in the three ethnomedicinal floras, common patterns in ethnomedicinal usage are observed in widely disparate areas of the world with substantially different cultural traditions. As these similarities are likely to stem from independent discoveries, they strongly suggest that underlying bioactivity might be the reason for this convergent usage. The global distribution of prominent usage of families used in common obtained by this study and the wider literature is strong evidence that these families display exceptional potential for discovery of previously overlooked or new medicinal plants and should be placed in high priority in bioscreening studies and conservation schemes.

Ethnomedicinal practices and medicinal plant knowledge of the Yuracarés and Trinitarios from Indigenous Territory and National Park Isiboro-Sécure, Bolivian Amazon

AIM OF THE STUDY

We investigated the ethnomedical practices and knowledge of medicinal plant and fungus species of contemporary Yuracaré and Trinitario ethnic groups from Indigenous Territory and National Park Isiboro-Sécure (TIPNIS), located in the Bolivian Amazon region. Our aim was to identify the culturally most significant medicinal plant families, growth forms and species, as well as to assess the current state of knowledge regarding the bioactivity of the most important species, based on available literature data.

MATERIALS AND METHODS

Medicinal plant and fungus species were inventoried during homegarden and swidden sampling, walk-in-the-woods and transect sampling. Data on medicinal uses were obtained from 12 Yuracaré and 14 Trinitario participants.

RESULTS

We commence by providing a brief overview of Yuracaré and Trinitario ethnomedical systems, highlighting the important shamanistic component of particularly Trinitario traditional medicine. The rest of the paper is dedicated to an analysis and discussion based on the 349 inventoried medicinal plant and fungus species. Contingency table and binomial analyses of medicinal plants used versus the total number of inventoried species per family showed that several plant families are significantly over (Piperaceae, Araceae, Solanaceae, Asteraceae and Siparunaceae) and underused (Chrysobalanaceae, Sapotaceae, Lauraceae, Celastraceae and Annonaceae) in traditional medicine in TIPNIS. Also herbaceous plants are significantly overrepresented in the medicinal plant inventory, which is in line with relevant literature. Our ranking of medicinal species according to cultural significance is based on the Quality Use Agreement Value (QUAV) index we developed and presented in a previous paper. Results indicate that the QUAV index's property to mainly select species that combine multiple ethnomedical uses with high informant consensus, justifies its use as a measure of cultural significance of medicinal plants in TIPNIS. Results of a literature search suggest, on the other hand, that the QUAV(s) score of a species could also be indicative of its bioactivity.

CONCLUSIONS

In addition to the QUAV index's value as a tool for assessing the cultural significance of medicinal species, it might also be useful to identify species with a higher likeliness of being bioactive.

Asháninka medicinal plants: a case study from the native community of Bajo Quimiriki, Junín, Peru

BACKGROUND

The Asháninka Native Community Bajo Quimiriki, District Pichanaki, Junín, Peru, is located only 4 km from a larger urban area and is dissected by a major road. Therefore the loss of traditional knowledge is a main concern of the local headman and inhabitants. The present study assesses the state of traditional medicinal plant knowledge in the community and compares the local pharmacopoeia with the one from a related ethnic group.

METHODS

Fieldwork was conducted between July and September 2007. Data were collected through semi-structured interviews, collection of medicinal plants in the homegardens, forest walks, a walk along the river banks, participant observation, informal conversation, cross check through voucher specimens and a focus group interview with children.

RESULTS

Four-hundred and two medicinal plants, mainly herbs, were indicated by the informants. The most important families in terms of taxa were Asteraceae, Araceae, Rubiaceae, Euphorbiaceae, Solanaceae and Piperaceae. Eighty-four percent of the medicinal plants were wild and 63% were collected from the forest. Exotics accounted to only 2% of the medicinal plants. Problems related to the dermal system, digestive system, and cultural belief system represented 57% of all the medicinal applications. Some traditional healers received non-indigenous customers, using their knowledge as a source of income. Age and gender were significantly correlated to medicinal plant knowledge. Children knew the medicinal plants almost exclusively by their Spanish names. Sixteen percent of the medicinal plants found in this community were also reported among the Yanesha of the Pasco Region.

CONCLUSIONS

Despite the vicinity to a city, knowledge on medicinal plants and cultural beliefs are still abundant in this Asháninka Native Community and the medicinal plants are still available in the surroundings. Nevertheless, the use of Spanish names for the medicinal plants and the shift of healing practices towards a source of income with mainly non-indigenous customers, are signs of acculturation. Future studies on quantification of the use of medicinal plants, dynamics of transmission of ethno-medicinal knowledge to the young generations and comparison with available pharmacological data on the most promising medicinal plants are suggested.

American palm ethnomedicine: a meta-analysis

BACKGROUND

Many recent papers have documented the phytochemical and pharmacological bases for the use of palms (Arecaceae) in ethnomedicine. Early publications were based almost entirely on interviews that solicited local knowledge. More recently, ethnobotanically guided searches for new medicinal plants have proven more successful than random sampling for identifying plants that contain biodynamic ingredients. However, limited laboratory time and the high cost of clinical trials make it difficult to test all potential medicinal plants in the search for new drug candidates. The purpose of this study was to summarize and analyze previous studies on the medicinal uses of American palms in order to narrow down the search for new palm-derived medicines.

METHODS

Relevant literature was surveyed and data was extracted and organized into medicinal use categories. We focused on more recent literature than that considered in a review published 25 years ago. We included phytochemical and pharmacological research that explored the importance of American palms in ethnomedicine.

RESULTS

Of 730 species of American palms, we found evidence that 106 species had known medicinal uses, ranging from treatments for diabetes and leishmaniasis to prostatic hyperplasia. Thus, the number of American palm species with known uses had increased from 48 to 106 over the last quarter of a century. Furthermore, the pharmacological bases for many of the effects are now understood.

CONCLUSIONS

Palms are important in American ethnomedicine. Some, like Serenoa repens and Roystonea regia, are the sources of drugs that have been approved for medicinal uses. In contrast, recent ethnopharmacological studies suggested that many of the reported uses of several other palms do not appear to have a strong physiological basis. This study has provided a useful assessment of the ethnobotanical and pharmacological data available on palms.