The discovery of the antimalarial agent artemisinin is considered one of the most significant success stories of ethnopharmacological research in recent times. The isolation of artemisinin was inspired by the use of Artemisia annua in traditional Chinese medicine (TCM) and was awarded a Nobel Prize in 2015. Antimalarial activity has since been demonstrated for a range of other Artemisia species, suggesting that the genus could provide alternative sources of antimalarial treatments. Given the stunning diversity of the genus (c. 500 species), a prioritisation of taxa to be investigated for their likely antimalarial properties is required. Here we use a phylogenetic approach to explore the potential for identifying species more likely to possess antimalarial properties. Ethnobotanical data from literature reports is recorded for 117 species. Subsequent phylogenetically informed analysis was used to identify lineages in which there is an overrepresentation of species used to treat malarial symptoms, and which could therefore be high priority for further investigation of antimalarial activity. We show that these lineages indeed include several species with documented antimalarial activity. To further inform our approach, we use LC-MS/MS analysis to explore artemisinin content in fifteen species from both highlighted and not highlighted lineages. We detected artemisinin in nine species, in eight of them for the first time, doubling the number of Artemisia taxa known to content this molecule. Our findings indicate that artemisinin may be widespread across the genus, providing an accessible local resource outside the distribution area of Artemisia annua.
Considered a biodiversity hotspot, the Canary Islands have been the key subjects of numerous evolutionary studies concerning a large variety of organisms. The genus Cheirolophus (Asteraceae) represents one of the largest plant radiations in the Canarian archipelago. In contrast, only a few species occur in the Mediterranean region, the putative ancestral area of the genus. Here, our main aim was to reconstruct the phylogenetic and biogeographic history of Cheirolophus with special focus on explaining the origin of the large Canarian radiation.
Changes in the amount of repetitive DNA (dispersed and tandem repeats) are considered the main contributors to genome size variation across plant species in the absence of polyploidy. However, the study of repeatome dynamism in groups showing contrasting genomic features and complex evolutionary histories is needed to determine whether other processes underlying genome size variation may have been overlooked. The main aim here was to elucidate which mechanism best explains genome size evolution in Anacyclus (Asteraceae). Using data from Illumina sequencing, we analysed the repetitive DNA in all species of Anacyclus, a genus with a reticulate evolutionary history, which displays significant genome size and karyotype diversity albeit presenting a stable chromosome number. By reconstructing ancestral genome size values, we inferred independent episodes of genome size expansions and contractions during the evolution of the genus. However, analysis of the repeatome revealed a similar DNA repeat composition across species, both qualitative and quantitative. Using comparative methods to study repeatome dynamics in the genus, we found no evidence for repeat activity causing genome size variation among species. Our results, combined with previous cytogenetic data, suggest that genome size differences in Anacyclus are probably related to chromosome rearrangements involving losses or gains of chromosome fragments, possibly associated with homoploid hybridization. These could represent balanced rearrangements that do not disrupt gene dosage in merged genomes, for example via chromosome segment exchanges.
Cannabis is one of the most versatile genera in terms of plant use and has been exploited by humans for millennia. Nowadays, Cannabis is the centre of many scientific studies, most of them focusing on chemical composition and medicinal values. While new and varied applications are continuously being developed, the knowledge surrounding less common use of the plant is slowly disappearing. We have analysed diversity of global data of Cannabis traditional uses, to investigate if certain plant parts are significantly associated with particular Cannabis use. We wanted to uncover potential associations between the plant parts used for the treatment of different body systems and ailments. We have analysed the extensive database of Cannabis traditional uses (the CANNUSE). This database contains 2330 data entries of Cannabis ethnobotanical uses from over 40 countries across the world. The dataset was divided into five general groups based on the type of use: medicinal, alimentary, psychoactive, fibre and other uses. Given the abundance of human medicinal uses, detailed analysis was done on the subset of 1167 data entries. We analysed the relationship between 16 body system categories and ailments treated with Cannabis plant parts. We used a Pearson's chi-square and Fisher's exact test, to determine which Cannabis parts are characteristic of treatment for specific ailments. In this dataset, the majority of reports were represented by medicinal (75.41%), followed by psychoactive (8.35%) and alimentary (7.29%) use. The most commonly used plant parts were leaf (50.51%), seed (15.38%) and inflorescence (11.35%). We found that different Cannabis plant parts were significantly associated with different uses; the leaf was typically used for medicinal, seed for alimentary and inflorescence for psychoactive use. Regarding the human medicinal uses, most common were reports for treatments of the digestive system and nutritional disorders (17.66%), nervous system and mental disorders (16.24%), followed by pain and inflammations (12.21%). We found a significant relationship between the use of certain Cannabis parts and treatment of ailments and body systems categories; leaf was significantly associated with treatment of two categories: skin and subcutaneous tissue disorders and circulatory system and blood disorders; seed use was associated with musculoskeletal system disorders and traumas; while inflorescence use shows a statistical support for treatment of nervous system and mental disorders. Several pharmaceutical companies are intensely working on developing new drugs with isolated chemical compounds or crude extracts, almost exclusively from Cannabis inflorescences. However, our review revealed that use of leaf or seed in traditional medicine is often more important than use of inflorescence for the treatment of certain ailments. A review of traditional medicine provides a body of knowledge and a an initial pathway to identify landraces and plant parts that could have an important role in future medicinal research. We are confident that traditional medicine still has a large potential for modern medicine. As more information on Cannabis diversity (genetics, biochemistry, and clinical studies) becomes available, ethnobotanical data are poised to be of much greater significance.