Animal models for studying homeopathy and high dilutions: Conceptual critical review

Homeopathy, Acupuncture and Phytotherapy in the Veterinary Treatment or Prophylaxis of Diseases in Animals: An Overview of Systematic Reviews

INTRODUCTION

 Complementary and alternative veterinary medicine (CAVM) has been intensively used, and there is currently an increasing demand for a more rigorous approach regarding its clinical effectiveness.

AIMS

 The objectives of this overview were: first, to identify systematic reviews on homeopathy, acupuncture and phytotherapy in veterinary medicine and assess their methodological quality; and second, to map interventions and findings in the treatment or prophylaxis of any medical conditions in any animal species for which high-quality systematic reviews had identified reliable evidence of efficacy or effectiveness in randomized controlled trials (RCTs) or controlled clinical trials (CCTs).

METHOD

 The study was an overview of systematic reviews published in the years 2000 to 2022 inclusive. The following databases were used: CAB Abstracts, PubMed and Vet Index, from which the abstracts of 173 articles were extracted, 22 of which were initially included for complete analysis. After excluding 15 studies according to the exclusion/inclusion criteria, 7 review papers were comprehensively analyzed. The review quality was assessed by the Measurement Tool to Assess Systematic Reviews (AMSTAR 2) method. The reported RCTs/CCTs in these reviews were analyzed for their reliability, and the results were classified according to statistical significance and risk of bias.

RESULTS

 Seven eligible systematic reviews reported studies on dogs, horses, cats, cattle, sheep, goats, swine, rabbits and poultry. The number of primary RCTs/CCTs was 38 for homeopathy, 35 for acupuncture, and 171 for phytotherapy. The AMSTAR 2 evaluation ranked two reviews of veterinary homeopathy as high-quality, in which two placebo-controlled RCTs comprised reliable evidence, one of which reported efficacy of homeopathy as prophylaxis for diarrhea in pigs. The systematic reviews of acupuncture and phytotherapy were all of low quality, preventing formal assessment of their reviewed RCTs/CCTs.

CONCLUSION

 Only the systematic reviews of homeopathy were rated of sufficient quality to enable the assessment of reliable evidence within their reviewed RCTs. Contemporary high-quality systematic reviews of clinical trials in each of the three areas of CAVM are required.

Evaluation of the efficacy of isopathic immunotherapy in the treatment of allergic asthma in BALB/C mice

Introduction: Homeopathy is a therapeutic method based on the fundamental principle of "like cures like." Homeopathic remedies are extremely dilute but involve vigorous shaking at each dilution. Isopathy is one approach of homeopathy, in which the causative agents or products of a disease are used to treat the same disease. Allergen immunotherapy is the only potential disease-modifying treatment for allergic patients. Subcutaneous immunotherapy is more effective than sublingual immunotherapy. However, subcutaneous immunotherapy is ineffective at a low dose, whereas at high doses it can result in an unacceptably high frequency of systemic reactions. In the current study, we evaluated the efficacy of isopathic immunotherapy with highly diluted ovalbumin (HD OVA) in the treatment of OVA-induced allergic asthma in BALB/c mice.Methods: BALB/c mice were sensitized with OVA and alum. Two weeks later, the mice received HD OVA on days 21, 22, 32 and 41 (8 h after the last challenge) of the treatment. The mice were challenged with OVA (5%) aerosols on days 35, 38 and 41 for 20 minutes using an ultrasonic nebulizer and sacrificed the next day.Results: Isopathic immunotherapy significantly reduced lung tissue inflammation, the number of eosinophils in bronchoalveolar fluid, allergen-specific IgE and interleukin-4 production. It also insignificantly increased the production of transforming growth factor-beta and proliferation of regulatory T cells against the allergen.Conclusion: Isopathic immunotherapy may be a good candidate treatment for allergic asthma.

Modulation of inflammation response to murine cutaneous Leishmaniasis by homeopathic medicines: Antimonium crudum 30cH

Background: Leishmaniasis is a zoonotic disease caused by protozoan parasites of the mononuclear phagocytic system. The modulation activity of these cells can interfere in the host/parasite relationship and influences the prognosis.

Methods: We evaluated the effects of the homeopathic preparation Antimonium crudum 30cH on experimental infection induced by Leishmania (L.) amazonensis. Male Balb/c mice were inoculated with 2 × 106 Leishmania (L.) amazonensis promastigotes into the footpad and, after 48 h (acute phase) or 60 days (chronic phase), cell population of lymphocytes and phagocytes present in the peritoneal washing fluid and spleen were analyzed by flow cytometry and histopathology, with histometry of the subcutaneous primary lesion, local lymph node and spleen. Immunohistochemistry was performed to quantify CD3 (T lymphocyte), CD45RA (B lymphocyte) and CD11b (phagocytes) positive cells.

Results: In treated mice, during the acute phase, there was significant increase of the macroscopic lesion, associated to inflammatory edema, as well increase in the number of free amastigotes and B lymphocytes inside the lesion. Increase of B lymphocytes (predominantly B-2 cells) was also seen in the local lymph node, spleen and peritoneum. In the chronic phase, the inflammatory process in the infection focus was reduced, with reduced phagocyte migration and peritoneal increase of B-1a cells (precursors of B-2 immunoglobulin producers cells) and T CD8+ cells.

Conclusion: The treatment of mice with Antimonium crudum 30cH induced a predominantly B cell pattern of immune response in Leishmania (L.) amazonensis experimental infection, alongside the increase of free amastigote forms number in the infection site. The clinical significance of this study is discussed, further studies are suggested.

Differential effects of Zincum metallicum on cell models

Introduction: Zinc is an essential trace element necessary for life. Traditional and complementary medicines use zinc-based formulations to treat different classes of diseases. Basic research on homeopathic preparations of zinc are rare and there are a few published clinical cases describing its effects on patients. The use of cell-based models in drug screening is a reliable source of evidence.

Methods: We sought to investigate experimental end-points using cell-based models to determine the effects of dilutions of Zincum metallicum prepared according to the Brazilian Homeopathic Pharmacopoeia. Murine RAW 264.7 macrophages and melanoma B16-F10 cell lines were cultured according to standard procedures. Cells were treated with either 5c, 6c or 30c Zincum metallicum and control cells with its respective vehicle (5c, 6c, or 30c Lactose). Macrophage activation by CD54 immunolabeling and intracellular reactive oxygen species (ROS) using DCFH-DA (2,7-dichlorodihydrofluorescein diacetate) were detected by flow cytometry. Phagocytic capacity (endocytic index) was quantified by light microscopy. Features of melanoma cells were analyzed by colorimetric assays to determine melanin content and cell proliferation rate. All obtained data were submitted to normality test followed by statistical analysis.

Results: Zincum metallicum 6c shifted high ROS-producing macrophages to a low ROS-producing phenotype. Macrophage CD54 expression was increased by Zincum metallicum 5c. No changes in endocytic index were observed. Melanoma cells were not affected by any treatment we tested.

Conclusions: Differing responses and non-linearity were found on macrophages challenged with Zincum metallicum at high dilutions. No changes in melanoma cells were observed. Customised assays using target cells can be useful to investigate high-dilution effects. Other cell types and conditions should be explored.

In vivo evaluation of antipyretic effects of some homeopathic ultra-high dilutions on Baker's yeast-induced fever on Similia principle

BACKGROUND

Homeopathy is a controversial alternative system of medicine. The action of homeopathic medicines is considered slow and it is assumed that homeopathic medicines are ineffective in acute conditions such as fever.

OBJECTIVE

In the present study, effects of 3 homeopathic medicines on baker's yeast induced fever were investigated.

MATERIALS AND METHODS

42 local strain rabbits were equally divided into 7 groups. Normal saline was orally administered to group 1 (normal control) rabbits without fever induction. Group 2 underwent baker's yeast-induced fever (negative control). Groups 3, 4, 5, 6 and 7 underwent baker's yeast-induced fever and were thereafter treated orally with paracetamol, Nux vomica 200C and 1M, Calcarea phos 200C and Belladonna 200C respectively. Rectal temperature was checked hourly. The abdominal writhing and frequency of loose stools were also monitored. ANOVA was applied for checking statistical significance. p ≤ 0.05 was considered significant.

RESULTS

The rectal temperature increased significantly (p < 0.05) in the negative control group when compared to the normal control. Abdominal writhing and loose stools monitoring showed increased writhing and loose stools frequency of group 2, 3, 6 and 7 rabbits. However, treatment of paracetamol significantly reduced rectal temperature. Group 4 & 5 showed significant reduction of rectal temperature together with abatement of abdominal writhing and loose stools.

CONCLUSION

N. vomica ultra-high dilutions have normalized rectal temperature and prevented the abdominal writhing and loose stools in baker's yeast-induced fever model of rabbits. It could be due to antidotal activity of N. vomica ultra-high dilutions. Therefore, N. vomica ultra-high dilutions can be useful antipyretic agents and can treat conditions associated with gastrointestinal symptoms. However, fixed conclusion can't be asserted due to caveat of small sample size.

High-dilution effects revisited. 1. Physicochemical aspects

Several lines of evidence suggest that homeopathic high dilutions (HDs) can effectively have a pharmacological action, and so cannot be considered merely placebos. However, until now there has been no unified explanation for these observations within the dominant paradigm of the dose-response effect. Here the possible scenarios for the physicochemical nature of HDs are reviewed. A number of theoretical and experimental approaches, including quantum physics, conductometric and spectroscopic measurements, thermoluminescence, and model simulations investigated the peculiar features of diluted/succussed solutions. The heterogeneous composition of water could be affected by interactive phenomena such as coherence, epitaxy and formation of colloidal nanobubbles containing gaseous inclusions of oxygen, nitrogen, carbon dioxide, silica and, possibly, the original material of the remedy. It is likely that the molecules of active substance act as nucleation centres, amplifying the formation of supramolecular structures and imparting order to the solvent. Three major models for how this happens are currently being investigated: the water clusters or clathrates, the coherent domains postulated by quantum electrodynamics, and the formation of nanoparticles from the original solute plus solvent components. Other theoretical approaches based on quantum entanglement and on fractal-type self-organization of water clusters are more speculative and hypothetical. The problem of the physicochemical nature of HDs is still far from to be clarified but current evidence strongly supports the notion that the structuring of water and its solutes at the nanoscale can play a key role.

Immunomodulation of Homeopathic Thymulin 5CH in a BCG-Induced Granuloma Model

The present study analyzed the immune modulation mechanisms of thymulin 5CH in a granuloma experimental model. Male adult Balb/c mice were inoculated with BCG into the footpad to induce granuloma, which was quantitatively evaluated. The phenotypic characterization of phagocyte, T- and B-lymphocyte populations in the peritoneum, and local lymph node was done by flow cytometry. During all experimental periods, thymulin 5CH and vehicle (control) were given ad libitum to mice, diluted into the drinking water (1.6 × 10⁻¹⁷ M). After 7 days from inoculation, thymulin-treated mice presented reduction in the number of epithelioid cytokeratine-positive cells (P = 0.0001) in the lesion, in relation to young phagocytes. After 21 days, the differentiation of B1 peritoneal stem cells into phagocytes reached the peak, being higher in thymulin-treated mice (P = 0.0001). Simultaneously, the score of infected phagocytes in the lesion decreased (P = 0.001), and the number of B1-derived phagocytes, CD4+ and CD8+ T lymphocytes in the local lymph node increased in relation to control (P = 0.0001). No difference was seen on the CD25+ Treg cells. The results show that thymulin 5CH treatment is able to improve the granuloma inflammatory process and the infection remission, by modulating local and systemic phagocyte differentiation.

Serial dilutions: a new area of research for animal behavior

This paper attempts to stimulate the psychological investigation of homeopathy and serially agitated dilutions. The history of homeopathy and serial dilutions is provided in a literature review of selected research areas. Two original illustrative experiments are also presented and discussed. The first examined the effect of serially agitated dilutions of Sevin on the mortality rate of honey bees (Apis mellifera). In a second experiment, the effect of serially agitated dilutions of sucrose on proboscis extension in honey bees was assessed. No differences were found between serially agitated dilutions of pesticides and sucrose compared with dilutions alone. Implications, limitations, and proposed further work are discussed.

Toxicodendron pubescens retains its anti-arthritic efficacy at 1M, 10M and CM homeopathic dilutions

BACKGROUND

Our previous studies of Toxicodendron pubescens (Rhus tox) in homeopathic dilutions have shown anti-inflammatory activity in line with the principle of similia. The present study aimed to evaluate its anti-inflammatory activity in 1M, 10M and CM dilutions in rats.

METHOD

Arthritis was induced by subplantar injection of 0.1 ml of Complete Freund's Adjuvant (CFA) in the right hind paws of rats. The severity of inflammatory lesions was measured plethysmometrically on 21st day post CFA injection. The intensity of pain was measured using digital Von Frey apparatus. Other estimations included serum C-reactive protein (CRP), hematological parameters, body weight changes, arthritic pain score and radiological analysis of the arthritic paws.

RESULT

The 1M, 10M and CM homeopathic dilutions of Rhus tox reduced primary and secondary arthritic lesions, improved body weight gain and protected rats against CFA-induced hematological and radiological perturbations. A significant reduction in the serum levels of CRP and an improvement in pain threshold of injected paws was observed in the groups treated with the Rhus tox dilutions.

CONCLUSION

The anti-arthritic potential of Rhus tox is retained at 1M, 10M and CM dilutions.

A Review of Use of Enantiomers in Homeopathy

This paper reviews publications of laboratory experiments using pairs of enantiomers in homeopathy. Many molecules in nature have geometry which enables them to exist as nonsuperimposable mirror images or enantiomers. Modulation of toxicity of such molecules provides possibility for therapeutics, since they target multiple points in biochemical pathways. It was hypothesized that toxicity of a chemical agent could be counteracted by a homeopathic preparation of the enantiomer of the chemical agent (patents applied for: PCT/AU2003/000219-PCT/AU2008/001611). A diverse body of data, including controlled laboratory studies, supports the conclusion that toxicity of optical isomers may be inhibited by homeopathic enantiomer preparations. These data were obtained with minimal or no pretesting to determine optimal test solutions. Inhibition of the excitotoxic neurotransmitter L-glutamic acid with homeopathic preparations of D-glutamic acid indicates the latter may be of use for amelioration of symptoms of disturbances of mood. Similarly, homeopathic preparation of (+)-nicotine may be of use for inhibition of effects of nicotine in tobacco.

Rats Born to Mothers Treated with Dexamethasone 15 cH Present Changes in Modulation of Inflammatory Process

As little information about the effect of ultra high dilutions of glucocorticoid in reproduction is available in the literature, pregnant female Wistar rats (N = 12) were blindly subcutaneously treated during all gestational and lactation period with: dexamethasone 4 mg/kg diluted into dexamethasone 15 cH (mixed); or dexamethasone 4 mg/kg diluted in water; or dexamethasone 15 cH, or vehicle. Parental generation had body weight, food and water consumption monitored. The F1 generation was monitored regarding to newborn development. No birth occurred in both groups treated with dexamethasone 4 mg/kg. After 60 days from birth, 12 male F1 rats were randomly selected from each remaining group and inoculated subcutaneously with 1% carrageenan into the footpad, for evaluation of inflammatory performance. Edema and histopathology of the footpad were evaluated, using specific staining methods, immunohistochemistry and digital histomorphometry. Mothers treated with mixed dexamethasone presented reduced water consumption. F1 rats born to dexamethasone 15 cH treated females presented significant increase in mast cell degranulation, decrease in monocyte percentage, increase in CD18+ PMN cells, and early expression of ED2 protein, in relation to control. The results show that the exposure of parental generation to highly diluted dexamethasone interferes in inflammation modulation in the F1 generation.

An analogy between effects of ultra-low doses of biologically active substances on biological objects and properties of spin supercurrents in superfluid 3He-B

The effects of ultra-low doses (ULDs) of biologically active substances (BASs) (with concentrations of 10(-13)M or lower) on biological objects (BOs), such as cells, organisms, etc., and the properties of spin supercurrents in superfluid (3)He-B are discussed. It is shown that the effects of ULDs of BASs on biologic objects can be specified by the same set of physical characteristics and described by the same mathematical relations as those used for the specification and description of the properties of spin supercurrents between spin structures in superfluid (3)He-B. This is based on the up-to-date physical concepts: 1) the physical vacuum has the properties of superfluid (3)He-B; 2) all quantum entities (hence, the BAS and the BO, which consist of such entities) produce spin structures in the physical vacuum. The photon being a quantum entity, the features of the effects of low-intensity electromagnetic radiation on BOs can be explained using the same approach.

Inflammatory Process Modulation by Homeopathic Arnica montana 6CH: The Role of Individual Variation

The effects of Arnica montana 6cH on the individual modulation of acute inflammation kinetics in rats were evaluated. Adult male Wistar rats were inoculated with 1% carrageenan into the footpad and treated with Arnica montana 6cH, dexamethasone (4.0 mg/kg; positive control) or 5% hydroalcoholic solution (negative control), per os, each 15 minutes, between 30 and 180 minutes after the irritant inoculation. Histopathological and immunohistochemistry procedures were done in order to get a panel of inflammatory positive cells for CD3 (T lymphocytes), CD45RA (B lymphocytes), CD18 (beta 2 integrin), CD163 (ED2 protein), CD54 (ICAM-1), and MAC 387 (monocytes and macrophages). The statistical treatment of data included a posteriori classification of animals from each group (N = 20) in two subgroups presenting spontaneous precocious or late oedema. Animals that presented precocious oedema were less responsible to Arnica montana 6cH in relation to hemodynamic changes. Instead, rats that exhibited late oedema presented less intense oedema (P = .01), lower percentage of mast cell degranulation (P = .0001), and increase in lymphatic vessels diameter (P = .05). The data suggest an individually qualitative adjustment of inflammatory vascular events by Arnica montana 6cH.