Claudia Scherr

Use of homeopathic preparations in experimental studies with healthy plants

BACKGROUND The last comprehensive review of experimental research on effects of homeopathic treatments on plants was published in 1984, and lacked formal predefined criteria to assess study quality. Since then several new studies with more advanced methods have been published. OBJECTIVES To compile a review of the literature on basic research in homeopathy with healthy plants with particular reference to studies investigating specific effects of homeopathic remedies. METHODS The literature search included English, French, German, Italian, Portuguese and Spanish publications from 1920 to April 2009, using predefined selection criteria. We included experiments with healthy whole plants, seeds, plant parts and cells. The outcomes had to be measured by established procedures and statistically evaluated. We developed a Manuscript Information Score (MIS) and included only publications which provided enough information for proper interpretation (MIS>or=5). A formalised Study Methods Evaluation Procedure (SMEP) was used to evaluate these studies, and the subgroup of studies with adequate controls to identify specific effects. RESULTS A total of 86 studies in 79 publications was identified, 43 studies included statistics, 29 had MIS>or=5, and 15 studies investigated the specificity of homeopathic preparations. Specific effects of decimal, centesimal and fifty millesimal potencies were found including dilution levels far beyond the Avogadro number. In consecutive series of potencies only some of the tested potencies showed effects. There were many individual studies with diverse methods and very few reproduction trials. CONCLUSIONS Healthy plant models seem an useful approach to investigate basic research questions about the specificity of homeopathic preparations. More investigations with more advanced methods are recommended, especially in the sectors of potentisation techniques, effective potency levels and conditions for reproducibility. Systematic negative control experiments should become a routine procedure to control the stability of the experimental systems.

Use of homeopathic preparations in phytopathological models and in field trials: a critical review.

BACKGROUND The literature on the applications of homeopathy for controlling plant diseases in both plant pathological models and field trials was first reviewed by Scofield in 1984. No other review on homeopathy in plant pathology has been published since, though much new research has subsequently been carried out using more advanced methods. OBJECTIVES To conduct an up-to-date review of the existing literature on basic research in homeopathy using phytopathological models and experiments in the field. METHODS A literature search was carried out on publications from 1969 to 2009, for papers that reported experiments on homeopathy using phytopathological models (in vitro and in planta) and field trials. The selected papers were summarized and analysed on the basis of a Manuscript Information Score (MIS) to identify those that provided sufficient information for proper interpretation (MIS>or=5). These were then evaluated using a Study Methods Evaluation Procedure (SMEP). RESULTS A total of 44 publications on phytopathological models were identified: 19 papers with statistics, 6 studies with MIS>or=5. Publications on field were 9, 6 with MIS>or=5. In general, significant and reproducible effects with decimal and centesimal potencies were found, including dilution levels beyond the Avogadros number. CONCLUSIONS The prospects for homeopathic treatments in agriculture are promising, but much more experimentation is needed, especially at a field level, and on potentisation techniques, effective potency levels and conditions for reproducibility. Phytopathological models may also develop into useful tools to answer pharmaceutical questions.

Effects of potentised substances on growth rate of the water plant Lemna gibba L.

OBJECTIVES This study investigated, whether the growth rate of Lemna gibba L. (duckweed) can be influenced by the application of homeopathic potencies of gibberellic acid, kinetin, argentum nitricum, and lemna minor. METHODS Duckweed was grown in either potencies (14x-30x, decimal steps) or water controls (unsuccussed and succussed) over seven days. Frond (leaf-like structure) growth was measured using a non-destructive image analysis system. Growth rates were calculated for three time intervals (0-7, 0-3, 3-7 days). Five to six independent, randomized and blinded experiments were analysed for each of the four tested substances. Water control experiments were performed repeatedly to test the reliability of the experimental set-up (systematic negative controls). RESULTS The systematic negative control experiments did not yield any significant effects. Hence, false positive results could be excluded. The test system had a low coefficient of variation (1.5%). Out of the four tested substances gibberellic acid had the most pronounced effect (p=0.0002, F-test) on the main outcome parameter frond growth rate (r(area) day 0-7). Potency levels 15x, 17x, 18x, 23x and 24x reduced growth rate of Lemna gibba (p<0.05 against the pooled water control, LSD test). CONCLUSIONS Lemna gibba may be considered as a suitable test organism for further studies on the efficacy of homeopathic potencies. Evidence accumulates, that adjacent potency levels may strongly differ in their biological activity. Potential consequences for therapeutical application might be worth investigating.

Test System Stability and Natural Variability of a Lemna Gibba L. Bioassay

Background In ecotoxicological and environmental studies Lemna spp. are used as test organisms due to their small size, rapid predominantly vegetative reproduction, easy handling and high sensitivity to various chemicals. However, there is not much information available concerning spatial and temporal stability of experimental set-ups used for Lemna bioassays, though this is essential for interpretation and reliability of results. We therefore investigated stability and natural variability of a Lemna gibba bioassay assessing area-related and frond number-related growth rates under controlled laboratory conditions over about one year. Methology/Principal Findings Lemna gibba L. was grown in beakers with Steinberg medium for one week. Area-related and frond number-related growth rates (r(area) and r(num)) were determined with a non-destructive image processing system. To assess inter-experimental stability, 35 independent experiments were performed with 10 beakers each in the course of one year. We observed changes in growth rates by a factor of two over time. These did not correlate well with temperature or relative humidity in the growth chamber. In order to assess intra-experimental stability, we analysed six systematic negative control experiments (nontoxicant tests) with 96 replicate beakers each. Evaluation showed that the chosen experimental set-up was stable and did not produce false positive results. The coefficient of variation was lower for r(area) (2.99%) than for r(num) (4.27%). Conclusions/Significance It is hypothesised that the variations in growth rates over time under controlled conditions are partly due to endogenic periodicities in Lemna gibba. The relevance of these variations for toxicity investigations should be investigated more closely. Area-related growth rate seems to be more precise as non-destructive calculation parameter than number-related growth rate. Furthermore, we propose two new validity criteria for Lemna gibba bioassays: variability of average specific and section-by-section segmented growth rate, complementary to average specific growth rate as the only validity criterion existing in guidelines for duckweed bioassays.

Use of homeopathic preparations in experimental studies with abiotically stressed plants.

BACKGROUND Experimental research on the effects of homeopathic treatments on impaired plants was last reviewed in 1990. OBJECTIVES To compile a systematic review of the existing literature on basic research in homeopathy with abiotically stressed plants using predefined criteria. METHODS The literature search was carried out on publications that reported experiments on homeopathy using abiotically stressed whole plants, seeds, plant parts and cells from 1920 to 2010. Outcomes had to be measured by established procedures and statistically evaluated. Using of a Manuscript Information Score (MIS) we identified those publications that provided sufficient information for proper interpretation (MIS≥5). A further evaluation was based on the use of adequate controls to investigate specific effects of homeopathic preparations and on the use of systematic negative control experiments. RESULTS A total of 34 publications with abiotically stressed plants was identified, published between 1965 and 2010. The 34 publications described a total of 37 experimental studies. Twenty-two studies included statistics, 13 had a MIS≥5, 8 were identified with adequate controls and 4 with negative control experiments. Significant and reproducible effects with decimal and centesimal potencies were found, including dilution levels beyond Avogadros number. One experimental model was independently assessed by another research team and yielded inverted results compared to the original trial. CONCLUSIONS Abiotically stressed plant models seem to be a useful approach to investigate homeopathic basic research questions, but more experimentation and especially more independent replication trials are needed. Systematic negative control experiments should be implemented on a routine basis to exclude false-positive results.

Development of a biocrystallisation assay for examining effects of homeopathic preparations using cress seedlings.

A major challenge in basic research into homeopathic potentisation is to develop bioassays that yield consistent results. We evaluated the potential of a seedling-biocrystallisation method. Cress seeds (Lepidium sativum L.) germinated and grew for 4 days in vitro in Stannum metallicum 30x or water 30x in blinded and randomized assignment. 15 experiments were performed at two laboratories. CuCl2-biocrystallisation of seedlings extracted in the homeopathic preparations was performed on circular glass plates. Resulting biocrystallograms were analysed by computerized textural image analysis. All texture analysis variables analysed yielded significant results for the homeopathic treatment; thus the texture of the biocrystallograms of homeopathically treated cress exhibited specific characteristics. Two texture analysis variables yielded differences between the internal replicates, most probably due to a processing order effect. There were only minor differences between the results of the two laboratories. The biocrystallisation method seems to be a promising complementary outcome measure for plant bioassays investigating effects of homeopathic preparations.

Models with Plants, Microorganisms and Viruses for Basic Research in Homeopathy

Most criticism about homeopathy concerns the lack of a scientific basis and theoretical models. In order to be accepted as a valid part of medical practice, a wellstructured research strategy for homeopathy is needed. This is often hampered by methodological problems as well as by gross underinvestment in the required academic resources. Fundamental research could make important contributions to our understanding of the homeopathic and high dilutions mechanisms of action. Since the pioneering works of Kolisko on wheat germination (Kolisko, 1923) and Junker on growth of microorganisms (paramecium, yeast, fungi) (Junker, 1928), a number of experiments have been performed either with healthy organisms (various physiological aspects of growth) or with artificially diseased organisms, which may react more markedly to homeopathic treatments than healthy ones. In the latter case, the preliminary stress may be either abiotic, e.g. heavy metals, or biotic, e.g. fungal and viral pathogens or nematode infection. Research has also been carried out into the applicability of homeopathic principles to crop growth and disease control (agrohomeopathy): because of the extreme dilutions used, the environmental impact is low and such treatments are well suited to the holistic approach of sustainable agriculture (Betti et al., 2006). Unfortunately, as Scofield reported in an extensive critical review (Scofield, 1984), there is little firm evidence to support the reliability of the reported results, due to poor experimental methodology and inadequate statistical analysis. Moreover, since there is no agricultural homeopathic pharmacopoeia, much work is required to find suitable remedies, potencies and dose levels.

Effects of Homeopathic Arsenicum Album, Nosode, and Gibberellic Acid Preparations on the Growth Rate of Arsenic-Impaired Duckweed (Lemna gibba L.)

This study evaluated the effects of homeopathically potentized Arsenicum album, nosode, and gibberellic acid in a bioassay with arsenic-stressed duckweed (Lemna gibba L.). The test substances were applied in nine potency levels (17x, 18x, 21x–24x, 28x, 30x, 33x) and compared with controls (unsuccussed and succussed water) regarding their influence on the plant’s growth rate. Duckweed was stressed with arsenic(V) for 48 h. Afterwards, plants grew in either potentized substances or water controls for 6 days. Growth rates of frond (leaf) area and frond number were determined with a computerized image analysis system for different time intervals (days 0–2, 2–6, 0–6). Five independent experiments were evaluated for each test substance. Additionally, five water control experiments were analyzed to investigate the stability of the experimental setup (systematic negative control experiments). All experiments were randomized and blinded. The test system exhibited a low coefficient of variation (≈1%). Unsuccussed and succussed water did not result in any significant differences in duckweed growth rate. Data from the control and treatment groups were pooled to increase statistical power. Growth rates for days 0–2 were not influenced by any homeopathic preparation. Growth rates for days 2–6 increased after application of potentized Arsenicum album regarding both frond area (p < 0.001) and frond number (p < 0.001), and by application of potentized nosode (frond area growth rate only, p < 0.01). Potencies of gibberellic acid did not influence duckweed growth rate. The systematic negative control experiments did not yield any significant effects. Thus, false-positive results can be excluded with high certainty. To conclude, the test system with L. gibba impaired by arsenic(V) was stable and reliable. It yielded evidence for specific effects of homeopathic Arsenicum album preparations and it will provide a valuable tool for future experiments that aim at revealing the mode of action of homeopathic preparations. It may also be useful to investigate the influence of external factors (e.g., heat, electromagnetic radiation) on the effects of homeopathic preparations.

Effects of Potentised Substances on Growth Kinetics of Saccharomyces cerevisiae and Schizosaccharomyces pombe

Homeopathic potencies are used as specific remedies in complementary medicine. Since the mode of action is unknown, the presumed specificity is discussed controversially. Objective: This study investigated the effects of potentised substances on two yeast species, Saccharomyces cerevisiae and Schizosaccharomyces pombe, in a stable and reliable test system with systematic negative controls. Materials and Methods: Yeast cells were cultivated in either potentised substances or water controls in microplates and their growth kinetics were measured photometrically. Water control runs were performed repeatedly to investigate the stability of the experimental set-up (systematic negative controls). Results: 4 out of 14 screened substances seem to have affected the growth curve parameters slope or yield. Out of these substances, azoxystrobin and phosphorus were chosen for 8 further replication experiments, which partly confirmed the results of the screening. On the average of all experiments, azoxystrobin affected the slope of the growth curve of Saccharomyces cerevisiae (p < 0.05), and phosphorus affected the slope of the growth curve of Schizosaccharomyces pombe (p < 0.05). No effects were seen in the water control runs. In addition, significant interactions between treatment with potentised substances and experiment number were observed in all experiments with potentised substances (p < 0.01), but not in the water control runs. Conclusions: Both yeast species reacted to certain potentised substances by changing their growth kinetics. However, the interactions found point to additional factors of still unknown nature, that modulate the effects of potentised substances. This stable test system with yeasts may be suitable for further studies regarding the efficacy of homeopathic potencies.

Development of a Test System for Homeopathic Preparations Using Impaired Duckweed (Lemna gibba L.)

OBJECTIVES A bioassay with arsenic-stressed duckweed (Lemna gibba L.) was developed to study potentially regulative effects of homeopathic preparations. We compared potentized substances (nine different potency levels between 17 x and 33 x ) with two controls (unsuccussed and succussed water) regarding their influence on number- and area-related growth rate and color of fronds (leaves). Screening included 11 potentized substances: Arsenicum album, gibberellic acid, nosode, arsenic(V), phosphorus, Conchae, Acidum picrinicum, Argentum nitricum, Crotalus horridus, Hepar sulfuris, and Mercurius vivus naturalis. DESIGN Duckweed was stressed with arsenic(V) for 48 hours. Afterwards, plants grew in either potentized substances or water controls for 6 days. Growth rate and color of fronds were determined with a computerized image analysis system for different time intervals (days 0-2, 2-6, 0-6). A systematic negative control experiment with unsuccussed water was used to investigate the stability of the bioassay. All experiments were randomized and blinded. RESULTS Arsenicum album and nosode potencies increased frond number-related growth rate compared to controls (succussed water controls or pooled water controls [succussed and unsuccussed], p < 0.05, t test). Regarding color classification, no effects were observed. CONCLUSIONS The experimental setup with L. gibba stressed by arsenic(V) provides a valuable tool to investigate regulative effects of potentized substances. In order to verify the effects of Arsenicum album and nosode potencies, further independent replication experiments are necessary.