The relevance of quantitative ethnobotanical indices for ethnopharmacology and ethnobotany

Ethnopharmacological relevance: As an interdisciplinary field of research ethnopharmacology draws on methodologies and methods from a variety of disciplines. A range of ethnobotanical indices are frequently used to transform primary data obtained through field studies into statistical measures. These indices are claimed to serve as a proxy for efficacy or drug discovery (Fidelity Level ‘FL’) and to show the importance of botanical drugs and plants used as medicines (Relative Importance ‘RI’, Use Value ‘UV’ or Cultural Importance Index ‘CI’, Cultural Value Index ‘CV’, Relative Frequency of Citation ‘RFC’). This is, however, doubtful, as these indices have not been developed by statisticians, nor by pharmacologists while a proof of concept is lacking. Moreover, the question whether a simple number can summarize the cultural value or importance of plants is not only mathematical but also epistemological. Material and methods: The FL, RI, UV/CI, CV and the RFC are shortly reviewed. Their statistical rigour is explained and the relevance for ethnobotany, ethnopharmacology and drug discovery discussed. Results: The effect of the sample size on the dispersal of data and the differential probability of botanical drugs being used for the different categories of use are not being considered by these indices. They lack statistical rigour and are simple percentage calculations. Moreover, important factors influencing plant use, such as the availability of pharmaceutical drugs, or the severity of diseases covered by the use-categories, are not accounted for. Conclusion: Especially unexperienced and young researchers may be ensnared by using ethnobotanical indices to describe their field data. However, the cultural value and importance of plants in general, and more specifically, of medicinal plants and botanical drugs cannot be summed up by numbers. The discussed indices encrypt parts of the primary data but fail to show the value or importance of plant use because the reasons for which plants are valued or important to people are far more complex than what the formulations of these indices suggest. The indices also lack the power to pinpoint plant species or botanical drugs for drug discovery that contextualized primary data has. Botanical drugs may be useful for a range of disorders or only for specific indications, according to their pharmacologic properties. Therefore, the exclusiveness of therapeutical applications (FL) does not serve as a proxy for effectiveness. The solution is to use and understand the contextualized primary data

Are we romanticizing traditional knowledge? A plea for more experimental studies in ethnobiology

In answer to the debate question "Is ethnobiology romanticizing traditional practices, posing an urgent need for more experimental studies evaluating local knowledge systems?" I suggest to follow-up on field study results adopting an inclusive research agenda, and challenge descriptive data, theories, and hypotheses by means of experiments. Traditional and local knowledge are generally associated with positive societal values by ethnobiologists and, increasingly also by stakeholders. They are seen as a way for improving local livelihoods, biocultural diversity conservation and for promoting sustainable development. Therefore, it is argued that such knowledge needs to be documented, protected, conserved in situ, and investigated by hypothesis testing. Here I argue that a critical mindset is needed when assessing any kind of knowledge, whether it is modern, local, indigenous, or traditional

Trends of Medicinal Plant Use over the Last 2000 Years in Central Europe

Medicinal plant knowledge in Central Europe can be traced back from the present to antiquity, through written sources. Approximately 100 medicinal plant taxa have a history of continuous use. In this paper, we focus on use patterns over time and the link between historical and traditional uses with the current scientific evidence. We discuss our findings against the backdrop of changing eras and medicinal concepts. Based on use-records from totally 16 historical, popular and scientific herbals, we analyze how use categories of 102 medicinal plant taxa developed over time. Overall, 56 of the 102 taxa maintained continuous use throughout all time periods. For approximately 30% of the continuous uses, scientific evidence supporting their use exists, compared to 11% for recently added uses and 6% for discontinuous uses. Dermatology and gastroenterology are use categories that are relevant across all time periods. They are associated with a high diversity of medicinal taxa and continuously used medicinal species with scientific evidence. Antidotes, apotropaic (protective) magic, and humoral detoxification were important use categories in the past. New applications reflecting biomedical progress and epidemiological challenges are cardiovascular and tonic uses. Changes in medicinal concepts are mirrored in plant use and specifically in changes in the importance of use categories. Our finding supports the concept of social validation of plant uses, i.e., the assumption that longstanding use practice and tradition may suggest efficacy and safety

Food drugs as drivers of therapeutic knowledge and the role of chemosensory qualities

Ethnopharmacological relevance: Chemosensory qualities of botanical drugs are important cues for anticipating physiologic consequences. Whether a botanical drug is used for both, food and medicine, or only as medicine depends on taste preferences, nutritional content, cultural background, and the individual and overall epidemiological context. Material and methods: We subjected 540 botanical drugs described in De Materia Medica having at least one oral medical application to a tasting panel. The 540 drugs were grouped into those only used for medicine (388) and those also used for food (152). The associations with chemosensory qualities and therapeutic indications were compared across the two groups. We considered 22 experimentally assessed chemosensory qualities and 39 categories of therapeutic use groups. We wanted to know, 1): which chemosensory qualities increase the probability of an orally applied botanical drug to be also used for food ? 2): which chemosensory qualities augment the probability of an orally applied botanical drug to be only used for medicine? and 3): whether there are differences in therapeutic indications between orally applied botanical drugs also used for food (food drugs) and botanical drugs applied exclusively for medicinal purposes (non-food drugs) and, if yes, how the differences can be explained. Results: Chemosensory qualities augmenting the probability of an orally applied botanical drug to be also used for food were sweet, starchy, salty, burning/hot, fruity, nutty, and cooling. Therapeutics used for diarrhoea, as libido modulators, purgatives, laxatives, for expelling parasites, breast and lactation and increasing diuresis, were preferentially sourced from food drugs while drugs used for liver and jaundice, vaginal discharge and humoral management showed significant negative associations with food dugs in ancient Greek-Roman materia medica. Conclusion: Therapeutics used for ailments of body organs involved in the digestion of food and the excretion of waste products showed a tendency to be sourced from food drugs. Arguably, the daily consumption of food offered the possibility for observing post-prandial physiologic and pharmacologic effects which led to a high therapeutic versatility of food drugs and the possibility to understand benefits of taste and flavour qualities. The difference in chemosensory qualities between food drugs and non-food drugs is demarcating the organoleptic requirements of food rather than that of medicine

Traditional Herbal Medicine in Mesoamerica: Toward Its Evidence Base for Improving Universal Health Coverage

The quality of health care in Mesoamerica is influenced by its rich cultural diversity and characterized by social inequalities. Especially indigenous and rural communities confront diverse barriers to accessing formal health services, leading to often conflicting plurimedical systems. Fostering integrative medicine is a fundamental pillar for achieving universal health coverage (UHC) for marginalized populations. Recent developments toward health sovereignty in the region are concerned with assessing the role of traditional medicines, and particularly herbal medicines, to foster accessible and culturally pertinent healthcare provision models. In Mesoamerica, as in most regions of the world, a wealth of information on traditional and complementary medicine has been recorded. Yet these data are often scattered, making it difficult for policy makers to regulate and integrate traditionally used botanical products into primary health care. This critical review is based on a quantitative analysis of 28 survey papers focusing on the traditional use of botanical drugs in Mesoamerica used for the compilation of the “Mesoamerican Medicinal Plant Database” (MAMPDB), which includes a total of 12,537 use-records for 2188 plant taxa. Our approach presents a fundamental step toward UHC by presenting a pharmacological and toxicological review of the cross-culturally salient plant taxa and associated botanical drugs used in traditional medicine in Mesoamerica. Especially for native herbal drugs, data about safety and effectiveness are limited. Commonly used cross-culturally salient botanical drugs, which are considered safe but for which data on effectiveness is lacking constitute ideal candidates for treatment outcome studies

Phylobioactive hotspots in plant resources used to treat Chagas disease

Globally, more than six million people are infected with Trypanosoma cruzi, the causative protozoan parasite of the vector-borne Chagas disease (CD). We conducted a cross-sectional ethnopharmacological field study in Bolivia among different ethnic groups where CD is hyperendemic. A total of 775 extracts of botanical drugs used in Bolivia in the context of CD and botanical drugs from unrelated indications from the Mediterranean De Materia Medica compiled by Dioscorides two thousand years ago were profiled in a multidimensional assay uncovering different antichagasic natural product classes. Intriguingly, the phylobioactive anthraquinone hotspot matched the antichagasic activity of Senna chloroclada, the taxon with the strongest ethnomedical consensus for treating CD among the Izoceño-Guaraní. Testing common 9,10-anthracenedione derivatives in T. cruzi cellular infection assays demarcates hydroxyanthraquinone as a potential antichagasic lead scaffold. Our study systematically uncovers in vitro antichagasic phylogenetic hotspots in the plant kingdom as a potential resource for drug discovery based on ethnopharmacological hypotheses

The historical development of pharmacopoeias and the inclusion of exotic herbal drugs with a focus on Europe and Brazil

Ethnopharmacological relevance: In spite of the rich bio-cultural diversity found in the Neotropics relatively few herbal drugs native to South America are included in the global pharmacopoeia. Material and methods: In the attempt to historically explain the inclusion of herbal drugs into official pharmacopoeias we consider the disparate epidemiology and cultural evolution of the New and the Old World. We then trace the development of pharmacopoeias and review forces that worked towards and against the synchronization of pharmacopoeias and highlight the role of early chemical and pharmacological studies in Europe. Finally, we compare the share of exotic and native herbal drug species included in the Brazilian Pharmacopoeia with the share of exotic and native species included in the European Pharmacopoeia as well as those used for products registered with ANVISA. Results: The domination of Eurasian herbal drugs in the European Pharmacopoeia seems to be conditioned by the geographical extension of Eurasia, which facilitated the interchange of materia medica and the creation of a consensus of use since ancient times. At the time of the Conquest the epidemiology of the Amerindian populations resembled that of pre-agriculturalist societies while no written consensus around efficacious medicine existed. Subsequently, introduced and well-tried plant species of the Old World gained therapeutic importance in the New World. Conclusion: The research focus in Europe and the US resulted in a persistence of herbal drugs with a historic importance in the European and US pharmacopoeias, which gained a status as safe and efficacious. During the last decades only few ethnopharmacological field-studies have been conducted with indigenous Amerindian groups living in the Brazilian Amazon, which might be attributable to difficulties in obtaining research permissions. Newly adopted regulations regarding access to biodiversity and traditional knowledge as well as the simplified procedure for licencing herbal medicinal products in Brazil prospects an interesting future for those aiming at developing herbal medicine based on bio-cultural diversity and respecting the protocols regulating benefit sharing

Does the taste matter? Taste and medicinal perceptions associated with five selected herbal drugs among three ethnic groups in West Yorkshire, Northern England

In recent years, diverse scholars have addressed the issue of the chemosensory perceptions associated with traditional medicines, nevertheless there is still a distinct lack of studies grounded in the social sciences and conducted from a cross-cultural, comparative perspective. In this urban ethnobotanical field study, 254 informants belonging to the Gujarati, Kashmiri and English ethnic groups and living in Western Yorkshire in Northern England were interviewed about the relationship between taste and medicinal perceptions of five herbal drugs, which were selected during a preliminary study. The herbal drugs included cinnamon (the dried bark of Cinnamomum verum, Lauraceae), mint (the leaves of Mentha spp., Lamiaceae), garlic (the bulbs of Allium sativum, Alliaceae), ginger (the rhizome of Zingiber officinale, Zingiberaceae), and cloves (the dried flower buds of Syzygium aromaticum, Myrtaceae). The main cross-cultural differences in taste perceptions regarded the perception the perception of the spicy taste of ginger, garlic, and cinnamon, of the bitter taste of ginger, the sweet taste of mint, and of the sour taste of garlic. The part of the study of how the five selected herbal drugs are perceived medicinally showed that TK (Traditional Knowledge) is widespread among Kashmiris, but not so prevalent among the Gujarati and especially the English samples. Among Kashmiris, ginger was frequently considered to be helpful for healing infections and muscular-skeletal and digestive disorders, mint was chosen for healing digestive and respiratory troubles, garlic for blood system disorders, and cinnamon was perceived to be efficacious for infectious diseases. Among the Gujarati and Kashmiri groups there was evidence of a strong link between the bitter and spicy tastes of ginger, garlic, cloves, and cinnamon and their perceived medicinal properties, whereas there was a far less obvious link between the sweet taste of mint and cinnamon and their perceived medicinal properties, although the link did exist among some members of the Gujarati group. Data presented in this study show how that links between taste perceptions and medicinal uses of herbal drugs may be understood as bio-cultural phenomena rooted in human physiology, but also constructed through individual experiences and culture, and that these links can therefore be quite different across diverse cultures

Best Practice in Research: Consensus Statement on Ethnopharmacological Field Studies - ConSEFS

BACKGROUND: Ethnopharmacological research aims at gathering information on local and traditional uses of plants and other natural substances. However, the approaches used and the methods employed vary, and while such a variability is desirable in terms of scientific diversity, research must adhere to well defined quality standards and reproducible methods OBJECTIVES: With ConSEFS (the Consensus Statement on Ethnopharmacological Field Studies) we want to define best-practice in developing, conducting and reporting field studies focusing on local and traditional uses of medicinal and food plants, including studies using a historical approach. METHODS: After first developing an initial draft the core group invited community-wide feedback from researchers both through a web-based consultation and a series of workshops at conferences during 2017. OUTCOMES: The consultation resulted in a large number of responses. Feedback was received via a weblink on the Journal of Ethnopharmacology's website (ca. 100 responses), other oral and written responses (ca. 50) and discussions with stakeholders at four conferences. The main outcome is a checklist, covering best practice for designing, implementing and recording ethnopharmacological field studies and historical studies. CONCLUSIONS: Prior to starting ethnopharmacological field research, it is essential that the authors are fully aware of the best practice in the field. For the first time in the field of ethnopharmacology a community-wide document defines guidelines for best practice on how to conduct and report such studies. It will need to be updated and further developed. While the feedback has been based on responses by many experienced researchers, there is a need to test it in practice by using it both in implementing and reporting field studies (or historical studies), and peer-review