Replication and Meta-Analysis of Specific Effects of Homeopathically Prepared Tin (Stannum metallicum 30x) with a Cress Seedling, CuCl2 Crystallisation ‘Fingerprint’, Approach
05 February 2020 (online)
Background and Aims: Basic homeopathic research requires stable and reliable test systems to detect biological effects of homeopathic preparations. Baumgartner et al. (2012) described a test system, which revealed specific effects of a potentized Stannum met. 30x preparation (nominal dilution of 10−30 of the original substance) compared to water 30x as control in a bio-assay using cress (Lepidium sativum L.). The bio-assay is based on cress seed germination, CuCl2x2H2O crystallization of the cress extracts, and subsequent computerized image analysis of the crystallization patterns.
In the present study we performed a replication trial at two independent laboratories, employing meticulous methodology, among which the integration of Systematic Negative Control (SNC) experiments.
Results: Analysis of the data of the replication trial revealed the same data structure in both projects regarding directionality and relative effect size of the homeopathic treatment. SNC experiments did not yield evidence for experimental instabilities, indicative of a robust test system. A meta-analysis of the pooled data of both trials revealed a highly significant treatment effect of Stannum met. 30x, and no interaction with experimental day. In a subgroup analysis we identified that the spatial region of the crystallization patterns, where the potency treatment effect manifests, was predominantly confined to the geometrical centre of the crystallization plates – which is in agreement with the precursor study.
Conclusions: We were able to establish a test system yielding reproducible biological effects of an ultra-molecular homeopathic preparation when replicated in ten independent experiments in two laboratories. Meta-analysis of the data of both trials yielded a highly significant treatment effect. These ground-breaking results point to a promising potential of the method to contribute to basic homeopathic research and call for developing a theoretical model to understand the effects observed.
Keywords: Pattern formation, bio-assay, meta-analysis, reproduction trial, systematic negative control experiments