How scientific is the science in ethnopharmacology? Historical perspectives and epistemological problems

This 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.

Plant immunostimulants-Scientific paradigm or myth?

In traditional medicine, numerous plant preparations are used to treat inflammation both topically and systemically. Several anti-inflammatory plant extracts and a few natural product-based monosubstances have even found their way into the clinic. Unfortunately, a number of plant secondary metabolites have been shown to trigger detrimental pro-allergic immune reactions and are therefore considered to be toxic. In the phytotherapy research literature, numerous plants are also claimed to exert immunostimulatory effects. However, while the concepts of plant-derived anti-inflammatory agents and allergens are well established, the widespread notion of immunostimulatory plant natural products and their potential therapeutic use is rather obscure, often with the idea that the product is some sort of "tonic" for the immune system without actually specifying the mechanisms. In this commentary it is argued that the paradigm of oral plant immunostimulants lacks clinical evidence and may therefore be a myth, which has originated primarily from in vitro studies with plant extracts. The fact that no conclusive data on orally administered immunostimulants can be found in the scientific literature inevitably prompts us to challenge this paradigm.