In 1994, Madeleine Bastide described experimental models in immunology that were used
during the 1980s to investigate high dilution effects on several biological systems.
She classified the available papers in four categories: High dilutions of antigens;
High dilutions of thymus, bursa and other hormones; High dilutions of cytokines; Immunopharmacological
activity of silica. The studies about high dilutions of antigens were not continued
after this period, but gave rise to a long process of a series of in vitro models on antigens and histamine dilutions, that led to the demonstration of the
biological modulation effects of these preparations on basophil degranulation. During
this process, a multi-centre study was performed, with a high degree of reproducibility
among different independent laboratories.
The studies about high diluted cytokines, thymulin and other hormones opened a new
line of scientific investigation, about the regulatory properties of endogenous substances
prepared according to homeopathic methods. The most frequently studied substance,
thymulin, when administered to mice at 5cH potency, is able to improve the activity
of phagocytes in different experimental situations, such as viral, bacterial and parasitic
infections. The immunopharmacological activity of silica was demonstrated, at that
time, as an in vivo illustration of the homeopathic ‘similia principle’. More recently, studies on silica
have assumed another focus: the putative role of silica as active contaminant present
in high dilutions. This paper presents a follow-up summary on these items, considering
the evolution of discoveries from 1994 to 2014.
Keywords
Immunology - Ultra high dilution - Homeopathy