The African cherry: A review of the botany, traditional uses, phytochemistry, and biological activities of Prunus africana (Hook.f.) Kalkman.

ETHNOPHARMACOLOGICAL RELEVANCE: Prunus africana (Hook.f.) Kalkman (Rosaceae), commonly known as "Pygeum" or "African cherry", occurs in mainland montane forests scattered across sub-Saharan Africa, Madagascar, and some surrounding islands. Traditionally, decoctions of the stem-bark are taken orally for the treatment of a wide variety of conditions, such as benign prostatic hyperplasia (BPH), stomach ache, chest pain, malaria, heart conditions, and gonorrhoea, as well as urinary and kidney diseases. The timber is used to make axe handles and for other household needs. The dense wood is also sawn for timber. AIM: The fragmented information available on the ethnobotany, phytochemistry, and biological activities of the medicinally important P. africana was collated, organised, and analysed in this review, to highlight knowledge voids that can be addressed through future research. MATERIALS AND METHODS: A bibliometric analysis of research output on P. africana was conducted on literature retrieved, using the Scopus® database. The trend in the publications over time was assessed and a network analysis of collaborations between countries and authors was carried out. Furthermore, a detailed review of the literature over the period 1971 to 2021, acquired through Scopus, ScienceDirect, SciFinder, Pubmed, Scirp, DOAJ and Google Scholar, was conducted. All relevant abstracts, full-text articles and various book chapters on the botanical and ethnopharmacological aspects of P. africana, written in English and German, were consulted. RESULTS: A total of 455 documents published from 1971 to 2021, were retrieved using the Scopus search. Analysis of the data showed that the majority of these documents were original research articles, followed by reviews and lastly a miscellaneous group comprising conference papers, book chapters, short surveys, editorials and letters. Data were analysed for annual output and areas of intense research focus, and countries with high research output, productive institutions and authors, and collaborative networks were identified. Prunus africana is reported to exhibit anti-inflammatory, analgesic, antimicrobial, anti-oxidant, antiviral, antimutagenic, anti-asthmatic, anti-androgenic, antiproliferative and apoptotic activities amongst others. Phytosterols and other secondary metabolites such as phenols, triterpenes, fatty acids, and linear alcohols have been the focus of phytochemical investigations. The biological activity has largely been ascribed to the phytosterols (mainly 3-ß-sitosterol, 3-ß-sitostenone, and 3-ß-sitosterol-glucoside), which inhibit the production of prostaglandins in the prostate, thereby suppressing the inflammatory symptoms associated with BPH and chronic prostatitis. CONCLUSIONS: Many of the ethnobotanical assertions for the biological activity of P. africana have been confirmed through in vitro and in vivo studies. However, a disparity exists between the biological activity of the whole extract and that of single compounds isolated from the extract, which were reported to be less effective. This finding suggests that a different approach to biological activity studies should be encouraged that takes all secondary metabolites present into consideration. A robust technique, such as multivariate biochemometric data analysis, which allows for a holistic intervention to study the biological activity of a species is suggested. Furthermore, there is a need to develop rapid and efficient quality control methods for both raw materials and products to replace the time-consuming and laborious methods currently in use.

The loneliness of the long-distance ethnobotanist: a constructive critique of methods used in an ethnoveterinary study in Mongolia.

BACKGROUND: Fieldwork plays an important role in research projects across a variety of fields, especially in the multidisciplinary setting of natural and social science research. As is the nature of fieldwork, things do not always work out as planned, and yet this is not often written about. In response to the need for honest and transparent accounts of fieldwork, the purpose of this article is to review the methods used during fieldwork for the first author's dissertation research on ethnoveterinary knowledge. METHODS: To critically review and reflect on the fieldwork methods used for an ethnoveterinary study in Mongolia, we compare the theory underpinning each method with the practical reality of implementing the method in the field. From this comparison, we draw out and discuss a number of key themes. RESULTS: Eighteen methods and approaches used for the research project are reviewed and compared. From this, we distil and further discuss the following five overarching themes: reflections on specific data collection methods (free listing, semi-structured interviews with interpreters, voucher specimen collection); assumptions around involving local people; power dynamics; gender relations; and researcher well-being. CONCLUSION: By juxtaposing the theory and practical reality of the methods used, we highlight many potential fieldwork challenges and, within this context, offer general pointers, especially for novice female researchers doing fieldwork in foreign countries. A critical review of this type, where the experience and use of various methods, techniques, and approaches are openly shared and evaluated, is a contribution to selecting, adapting, and fine-tuning the methods best suited to a particular research context.

Blue genome: chromosome-scale genome reveals the evolutionary and molecular basis of indigo biosynthesis in Strobilanthes cusia.

Natural plant dyes have been developed and used across many traditional societies worldwide. The blue pigment indigo has seen widespread usage across South America, Egypt, Europe, India and China for thousands of years, mainly extracted from indigo-rich plants. The utilization and genetic engineering of indigo in industries and ethnobotanical studies on the effects of cultural selection on plant domestication are limited due to lack of relevant genetic and genomic information of dye plants. Strobilanthes cusia (Acanthaceae) is a typical indigo-rich plant important to diverse ethnic cultures in many regions of Asia. Here we present a chromosome-scale genome for S. cusia with a genome size of approximately 865 Mb. About 79% of the sequences were identified as repetitive sequences and 32 148 protein-coding genes were annotated. Metabolic analysis showed that the main indigoid pigments (indican, indigo and indirubin) were mainly synthesized in the leaves and stems of S. cusia. Transcriptomic analysis revealed that the expression level of genes encoding metabolic enzymes such as monooxygenase, uridine diphosphate-glycosyltransferase and ß-glucosidase were significantly changed in leaves and stems compared with root tissues, implying their participation in indigo biosynthesis. We found that several gene families involved in indigo biosynthesis had undergone an expansion in number, with functional differentiation likely facilitating indigo biosynthesis in S. cusia. This study provides insight into the physiological and molecular bases of indigo biosynthesis, as well as providing genomic data that provide the basis for further study of S. cusia cultivation by Asia's traditional textile producers.

Scientists' Warning on Climate Change and Medicinal Plants.

The recent publication of a World Scientists' Warning to Humanity highlighted the fact that climate change, absent strenuous mitigation or adaptation efforts, will have profound negative effects for humanity and other species, affecting numerous aspects of life. In this paper, we call attention to one of these aspects, the effects of climate change on medicinal plants. These plants provide many benefits for human health, particularly in communities where Western medicine is unavailable. As for other species, their populations may be threatened by changing temperature and precipitation regimes, disruption of commensal relationships, and increases in pests and pathogens, combined with anthropogenic habitat fragmentation that impedes migration. Additionally, medicinal species are often harvested unsustainably, and this combination of pressures may push many populations to extinction. A second issue is that some species may respond to increased environmental stresses not only with declines in biomass production but with changes in chemical content, potentially affecting quality or even safety of medicinal products. We therefore recommend actions including conservation and local cultivation of valued plants, sustainability training for harvesters and certification of commercial material, preservation of traditional knowledge, and programs to monitor raw material quality in addition to, of course, efforts to mitigate climate change.

Island blues: indigenous knowledge of indigo-yielding plant species used by Hainan Miao and Li dyers on Hainan Island, China.

BACKGROUND: Historically, indigo-yielding plant species were important cash crops from Central Asia to the southern United States and Central America. Indigo-dyed textiles were widely traded along the legendary Silk Road that linked China to Europe. Today, due to the labor-intensive nature of indigo extraction at the household level, lifestyle changes and the widespread availability of commercially produced indigo paste, traditional indigo extraction methods have declined in villages. Yet Li textile weavers on Hainan Island are internationally recognized as producers of indigo-dyed textile using warp ikat techniques. In contrast, Hainan Miao weavers produce indigo-dyed textiles using batik (wax resist) techniques. The aim of this study was to document the indigenous knowledge on indigo-yielding plant species used by both Hainan Miao and Li people on Hainan Island, China. METHOD: Ethnic uses were documented during three field surveys, through a questionnaire survey of 193 respondents, comprising 144 Hainan Miao and 49 Li traditional dyers. Mention index (QI), Availability index (AI), and Preference ranking (PR) of each indigo-yielding plant species were calculated to screen out plant resources with potential development value. RESULTS: Five indigo-yielding plant species (from four plant families and four genera) were historically used by Hainan Miao and Li dyers. However, just four species are still in use. Strobilanthes cusia was the main indigo source for Hainan Miao dyers. Li dyers also commonly use Indigofera species (I. tinctoria and I. suffruticosa) for indigo extraction. Wrightia laevis is less commonly used as a contemporary indigo source. Indigo extraction by steeping in water to which lime is added to increase the pH is sharing by the five indigo-yielding plant species. Strobilanthes cusia had the highest QI, AI and PR values in Hainan Miao villages. Indigofera tinctoria had the highest QI and AI values, but Indigofera suffruticosa was preferred by Li dyers. CONCLUSION: In the process of modernization and urbanization, some Hainan Miao and Li dyers retain the traditional indigo extraction methods. We found that Strobilanthes cusia and Indigofera tinctoria have the most potential for sustainable indigo production in the future. Furthermore, this study documents the details of extraction method from Wrightia laevis for the first time and the use of Ricinus communis seeds in that process. As one of the last places globally where Wrightia laevis is still used for indigo production, the may also be a nice market among textile collectors and museums that keeps the tradition of Wrightia laevis production and use for indigo extraction alive.

Identity blues: the ethnobotany of the indigo dyeing by Landian Yao (Iu Mien) in Yunnan, Southwest China.

BACKGROUND: Indigo-dyed textiles have been central to the cultural identity of Landian Yao (literally "blue clothes Yao") people in Southwest China for centuries, driving a significant local market for naturally dyed indigo cloth. In the past two decades, local indigo production for traditional textiles has declined for several reasons: Firstly, the younger generation of Landian Yao has shifted to using western style jeans and T-shirts. Secondly, due to its labor-intensive nature. In contrast, at a global scale, including in China, there has been a revival of interest in natural indigo use. This is due to a growing awareness in the fashion industry about human and environmental health issues related to synthetic dye production. Ironically, this new awareness comes at a time when traditional knowledge of indigo dyeing is being lost in many places in China, with weaving and use of natural dyes now limited to some remote areas. In this study, we recorded indigo dyeing processes used by Landian Yao people and documented the plant species used for indigo dyeing. METHODS: Field surveys were conducted to the study area from September 2015 to November 2016, supplemented by follow-up visits in July 2018 and November 2018. We interviewed 46 key informants between 36 and 82 years old who still continued traditional indigo dyeing practices. Most were elderly people. Semi-structured interviews were used. During the field study, we kept a detailed account of the methods used by Landian Yao dyers. The data were then analyzed by using utilization frequency to determine the best traditional recipe of indigo dye extraction. All the specimens of documented species were collected and deposited at the herbarium of Kunming Institute of Botany. RESULTS: Our results showed that indigo dyeing was divided into two main steps: (1) indigo pigment extraction and (2) dyeing cloth. The general procedures of indigo dye extraction included building or buying a dye vat, fermentation, removal of the leaves of indigo producing plant species, addition of lime, oxygenation, followed by collection, and the storage of the indigo paste. The procedures of dyeing cloth included preparing the dye solutions, dyeing cloth, washing, and air drying. It is notable that Landian Yao dyers formerly only performed the dyeing process on the goat days in the lunar calendar from June to October. After comparing the range of local indigo extraction methods, our results showed that the following was best of these traditional recipes: a indigo-yielding plant material to tap water ratio of 30 kg: 200 l, lime 3 kg, a fermentation time of 2-3 d, aeration by agitation for up to 60 min, and a precipitation time of 2-3 h. Our results show that 17 plant species in 11 families were recorded in the indigo dyeing process. With the exception of the indigo sources, only Dioscorea cirrhosa Lour. and Artemisia argyi H.Lév. & Vaniot were previously recorded in dyeing processes. Other species given in this paper are recorded for the first time in terms of their use in the indigo dyeing process. In the study area, Landian Yao men were in charge of indigo dye extraction, and the women were responsible for dyeing cloth. CONCLUSIONS: The Landian Yao has completely mastered the traditional indigo dyeing craft and are one of the well-deserved identity blues. Indigo production from plants using traditional methods is a slow process compared to synthetic dyes and is not suitable for modern and rapid industrial production. Therefore, our study records the detailed information of traditional indigo dyeing to protect and inherit it. Strobilanthes cusia (Nees) Kuntze is the main indigo source in Landian Yao that is widely used in the world and can be commercially exploited as an indigo plant. For commercial and environment benefits, we suggest that producing natural indigo for the commercial market is a good choice.

A billion cups: The diversity, traditional uses, safety issues and potential of Chinese herbal teas.

ETHNOPHARMACOLOGICAL RELEVANCE: Herbal teas have long been consumed by Chinese people for preventive and/or therapeutic healthcare. Although herbal teas are widely consumed by many cultural groups in different regions of China, no thorough review has been undertaken to assess the diversity of the country's herbal tea usage. This literature review, complemented by a quantitative survey in an important tea market in Kunming, begins to fill this knowledge gap. AIMS OF THE STUDY: The study aims to summarize the current knowledge of plant species used as herbal teas by different cultural groups in different regions of China, with a focus on the teas' perceived traditional healthcare functions, related phytochemical/pharmaceutical research, and safety issues. MATERIALS AND METHODS: The study involved a comprehensive literature review and a market survey. The literature review was based on published ethnobotanical studies of herbal teas in China. We searched the Web of Science™, ELSEVIER, the China National Knowledge Infrastructure (CNKI) and the China Science and Technology Journal Database to locate relevant studies (including journal articles, Masters/PhD dissertations and books) that were published before March 2017. A species list was compiled based on the review and supplemented with information retrieved from the Scifinder database (https://scifinder.cas.org) and the Chinese Pharmacopoeia (2010). A Use Value Index was employed for ranking the most cited species. Based on the 29 most cited species, we discussed the current research status in relation to healthcare benefits and safety concerns of herbal teas in China. To better understand the current status of the herbal tea market in China, we also surveyed 136 tea vendors at the Xiongda Tea Market in Kunming. Information gathered from the survey included the species sold, the sale prices and the form of the herbal tea product. RESULTS: The literature identified 759 plant species used as herbal tea in China and the market survey identified an additional 23 species. Most of the species used were from the Leguminosae, Compositae and Lamiaceae families. Twenty two provinces and fourteen ethnic minority groups have records on the consumption of herbal teas. Southern China uses up to 82% of the total species, and 211 out of 759 species are used by minority groups. Thirty categories of traditional healthcare functions are linked with herbal teas, with clearing away heat, relieving toxicity and suppressing cough being the most important functions. There is phytochemical/pharmaceutical evidence to support the claimed healthcare benefits of some Chinese herbal teas. Although Chinese herbal teas are generally safe to consume, overdoses of some herbal teas and some unapproved mixtures of species may cause health risks. Based on our market survey, the prices of most herbal teas range between 100 and 200 RMB (US$15-30) per kg. CONCLUSIONS: A rich array of herbal tea species with various traditional healthcare functions have long been used in China, and as such there is a huge market potential for Chinese herbal teas. More pharmaceutical/phytochemical research is needed to assess a wide range of perceived healthcare benefits of Chinese herbal teas. Our research highlights the need to study herbal teas through an ethnopharmacological perspective and by employing a holistic approach, which requires greater consideration of traditional knowledge in the pharmacological research design. Product safety and sustainability issues should also be considered, so the traditional applications of herbal teas can be transformed to efficient health boosting functional products.

Risks to birds traded for African traditional medicine: a quantitative assessment.

Few regional or continent-wide assessments of bird use for traditional medicine have been attempted anywhere in the world. Africa has the highest known diversity of bird species used for this purpose. This study assesses the vulnerability of 354 bird species used for traditional medicine in 25 African countries, from 205 genera, 70 families, and 25 orders. The orders most represented were Passeriformes (107 species), Falconiformes (45 species), and Coraciiformes (24 species), and the families Accipitridae (37 species), Ardeidae (15 species), and Bucerotidae (12 species). The Barn owl (Tyto alba) was the most widely sold species (seven countries). The similarity of avifaunal orders traded is high (analogous to "morphospecies", and using Sørensen's index), which suggests opportunities for a common understanding of cultural factors driving demand. The highest similarity was between bird orders sold in markets of Benin vs. Burkina Faso (90%), but even bird orders sold in two geographically separated countries (Benin vs. South Africa and Nigeria vs. South Africa) were 87% and 81% similar, respectively. Rabinowitz's "7 forms of rarity" model, used to group species according to commonness or rarity, indicated that 24% of traded bird species are very common, locally abundant in several habitats, and occur over a large geographical area, but 10% are rare, occur in low numbers in specific habitats, and over a small geographical area. The order with the highest proportion of rare species was the Musophagiformes. An analysis of species mass (as a proxy for size) indicated that large and/or conspicuous species tend to be targeted by harvesters for the traditional medicine trade. Furthermore, based on cluster analyses for species groups of similar risk, vultures, hornbills, and other large avifauna, such as bustards, are most threatened by selective harvesting and should be prioritised for conservation action.