1,721,153 research outputs found
Travelogues from the Rainforest: Notes on Prof. Otto Sticher's 85th birthday.
No full textInstead of following the cherished tradition of publishing a scientific paper to honor Professor Otto Sticher, my doctoral adviser, on his 85th birthday, I want to share the story of his remarkable visit to the inhospitable Venezuelan rainforest, where I was conducting my research. More than any new scientific finding, this account will pay tribute to the man who became the father of the most influential German textbook and some of the most essential scientific work of our time in the field of pharmacognosy
How scientific is the science in ethnopharmacology? Historical perspectives and epistemological problems
No full textThis commentary is based on a general concern regarding the low level of self-criticism (-evaluation) in the interpretation of molecular pharmacological data published in ethnopharmacology-related journals. Reports on potentially new lead structures or pharmacological effects of medicinal plant extracts are mushrooming. At the same time, nonsense in bioassays is an increasing phenomenon in herbal medicine research. Only because a dataset is reproducible does not imply that it is meaningful. Currently, there are thousands of claims of pharmacological effects of medicinal plants and natural products. It is argued that claims to knowledge in ethnopharmacology, as in the exact sciences, should be rationally criticized if they have empirical content as it is the case with biochemical and pharmacological analyses. Here the major problem is the misemployment of the concentration-effect paradigm and the overinterpretation of data obtained in vitro. Given the almost exponential increase of scientific papers published it may be the moment to adapt to a falsificationist methodology
Cannabimimetic phytochemicals in the diet - an evolutionary link to food selection and metabolic stress adaptation?
No full textThe endocannabinoid system (ECS) is a major lipid signalling network that plays important pro-homeostatic (allostatic) roles not only in the nervous system but also in peripheral organs. There is increasing evidence that there is a dietary component in the modulation of the ECS. Cannabinoid receptors in hominids co-evolved with diet, and the ECS constitutes a feedback loop for food selection and energy metabolism. Here, it is postulated that the mismatch of ancient lipid genes of hunter-gatherers and pastoralists with the high-carbohydrate diet introduced by agriculture could be compensated for via dietary modulation of the ECS. In addition to the fatty acid precursors of endocannabinoids, the potential role of dietary cannabimimetic phytochemicals in agriculturist nutrition is discussed. Dietary secondary metabolites from vegetables and spices able to enhance the activity of cannabinoid-type 2 (CB2 ) receptors may provide adaptive metabolic advantages and counteract inflammation. In contrast, chronic CB1 receptor activation in hedonic obese individuals may enhance pathophysiological processes related to hyperlipidaemia, diabetes, hepatorenal inflammation and cardiometabolic risk. Food able to modulate the CB1 /CB2 receptor activation ratio may thus play a role in the nutrition transition of Western high-calorie diets. In this review, the interplay between diet and the ECS is highlighted from an evolutionary perspective. The emerging potential of cannabimimetic food as a nutraceutical strategy is critically discussed
Immunomodulatory lipids in plants: plant fatty acid amides and the human endocannabinoid system
No full textSince the discovery that endogenous lipid mediators show similar cannabimimetic effects as phytocannabinoids from CANNABIS SATIVA, our knowledge about the endocannabinoid system has rapidly expanded. Today, endocannabinoid action is known to be involved in various diseases, including inflammation and pain. As a consequence, the G-protein coupled cannabinoid receptors, endocannabinoid transport, as well as endocannabinoid metabolizing enzymes represent targets to block or enhance cannabinoid receptor-mediated signalling for therapeutic intervention. Based on the finding that certain endocannabinoid-like fatty acid N-alkylamides from purple coneflower ( ECHINACEA spp.) potently activate CB2 cannabinoid receptors we have focused our interest on plant fatty acid amides (FAAs) and their overall cannabinomodulatory effects. Certain FAAs are also able to partially inhibit the action of fatty acid amide hydrolase (FAAH), which controls the breakdown of endocannabinoids. Intriguingly, plants lack CB receptors and do not synthesize endocannabinoids, but express FAAH homologues capable of metabolizing plant endogenous N-acylethanolamines (NAEs). While the site of action of these NAEs in plants is unknown, endogenous NAEs and arachidonic acid glycerols in animals interact with distinct physiological lipid receptors, including cannabinoid receptors. There is increasing evidence that also plant FAAs other than NAEs can pharmacologically modulate the action of these endogenous lipid signals. The interference of plant FAAs with the animal endocannabinoid system could thus be a fortunate evolutionary cross point with yet unexplored therapeutic potential
The Metabolic Plant Feedback Hypothesis: How Plant Secondary Metabolites Nonspecifically Impact Human Health.
No full textHumans can ingest gram amounts of plant secondary metabolites daily through diet. Many of these phytochemicals are bioactive beyond our current understanding because they act through weak negative biological feedback mechanisms, undetectable in vitro. Homeostatic-type assessments shed light on the evolutionary implications of the human diet from plants, giving rise to the metabolic plant feedback hypothesis. The hypothesis states that ancient diets rich in carbohydrates coincide with bulk dietary phytochemicals that act as nonspecific inhibitors of metabolic and inflammatory processes. Consequently, food-derived phytochemicals are likely to be equally effective as herbal medicines for these indications. In addition to the ubiquitous flavonoids, terpenoids, and fatty acids in the diet, the likely impact of chronic chlorophyll ingestion on human health is discussed, and data on its modulation of blood glucose levels are presented. A major deduction of this hypothesis is that starchy diets lacking plant secondary metabolites are associated with multimorbidity (lifestyle diseases) including obesity, type 2 diabetes, and cardiovascular disease. It is proposed that the intake of leafy vegetables, spices, and herbal remedies rich in phytochemicals matches the transition and genetic adaptation to early agriculture, playing a compensatory role in the mismatch of old genes and new diets
Botanical drugs, synergy, and network pharmacology: forth and back to intelligent mixtures
No full textFor centuries the science of pharmacognosy has dominated rational drug development until it was gradually substituted by target-based drug discovery in the last fifty years. Pharmacognosy stems from the different systems of traditional herbal medicine and its "reverse pharmacology" approach has led to the discovery of numerous pharmacologically active molecules and drug leads for humankind. But do botanical drugs also provide effective mixtures? Nature has evolved distinct strategies to modulate biological processes, either by selectively targeting biological macromolecules or by creating molecular promiscuity or polypharmacology (one molecule binds to different targets). Widely claimed to be superior over monosubstances, mixtures of bioactive compounds in botanical drugs allegedly exert synergistic therapeutic effects. Despite evolutionary clues to molecular synergism in nature, sound experimental data are still widely lacking to support this assumption. In this short review, the emerging concept of network pharmacology is highlighted, and the importance of studying ligand-target networks for botanical drugs is emphasized. Furthermore, problems associated with studying mixtures of molecules with distinctly different pharmacodynamic properties are addressed. It is concluded that a better understanding of the polypharmacology and potential network pharmacology of botanical drugs is fundamental in the ongoing rationalization of phytotherapy
Cross-cultural comparisons of medicinal floras--what are the implications for bioprospecting?
No full textScaffold and organism hopping with chemical probes.
No full textChemical probes that irreversibly inhibit protein function may be used across species to discover proteins. Combining phenotypic screening and activity-based protein profiling, a new study uncovers a discrete lipid signaling pathway regulating lifespan in the worm Caenorhabditis elegans
- …
