The term ‘basic science’ means the type of research in which experiments are carried out in a laboratory using samples of tissues, cells or molecules, rather than clinical experiments involving whole animals or people. Developments in this field of ‘in vitro’ research have contributed significantly to the evidence base for homeopathy.
Basic science research has demonstrated that ultrahigh dilutions such as homeopathic medicines are able to cause biological effects that can be seen clearly under experimental conditions.
Topics covered on this page include:
- What do we mean by ultrahigh dilutions?
- Biological effects of ultrahigh dilutions
- What can ultrahigh dilutions do in the lab?
- Homeopathic medicines are not ‘just water’
- The importance of succussion
What do we mean by ‘ultrahigh dilutions’?
75% of in vitro experiments have found that substances as dilute as homeopathic medicines have specific effects(2)
Scientists frequently refer to homeopathic medicines as being diluted ‘beyond Avogadro’s number’. This means that they have been diluted beyond 10(-23) – the final concentration at which molecules of the original substance would still be present. Confusingly several different expressions are used to refer to dilutions beyond this point: ‘high dilutions’, ‘ultrahigh dilutions’, ‘ultramolecular dilutions’ and ‘UHDs’; in homeopathic language they may also be referred to as ‘high potencies’.
Homeopathic medicines of the strength 12c and above are in this ultramolecular range. This is why homeopathy attracts such controversy, with sceptics saying that homeopathic medicines are ‘nothing but water’.
There are several different theories suggesting how homeopathic medicines work, but more importantly experiments have already demonstrated that ultrahigh dilutions can have biological effects and do differ from water.
Biological effects of ultrahigh dilutions
Research on ultrahigh dilutions began in the 1950s, but since the mid-1990s there has been an increase in both the number and quality of published studies.
A rigorous systematic review (systematic review = a summary of the total research evidence available on a particular subject, designed to provide more accurate information than single studies) published in 2007 assessed the entire in vitro evidence base for effects of high potency homeopathic medicines; 67 experiments published in 75 publications were evaluated and 75% of these found that ultrahigh dilutions have effects. Importantly, these positive results were seen even in high quality experiments. When experiments were repeated, the same results were achieved in nearly all cases.
- The fact that positive results seen in these UHD experiments could not be reproduced every time is not unexpected; it is much easier to detect and measure things which are already understood than to work with new phenomena for the first time. It is logical to expect that once we understand how these UHDs produce their effects, scientists will be able to refine their experiments to pick up those effects every time.
- Witt CM, Bluth M, Albrecht H, et al. The in vitro evidence for an effect of high homeopathic potencies – a systematic review of the literature. Complement Ther Med, 2007; 15: 128-138
What can ultrahigh dilutions do in the lab?
Below are just a few examples of the effects seen from UHDs under experimental conditions:
Ultrahigh dilutions of histamine can alter the activity of white blood cells
When histamine is released in the body it alters the activity of white blood cells called basophils; research involving four separate European laboratories found that when ultrahigh dilutions of histamine were added to isolated basophils they had a similar effect.
- To be of real value, experimental results should be verified and reproducible by different researchers. The work by Belon et al. is particularly important because the results were confirmed by the multiple laboratories involved, using three different types of experiments to demonstrate the same effect.
- Basophils are a type of white blood cell involved in allergic reactions. During an allergic response, an antibody called immunoglobulin E (IgE) binds to the basophil causing it to release chemicals by a process called ‘degranulation’. One of these chemicals – histamine – then inhibits further degranulation, putting the brakes on the process so that the total amount of chemicals released is controlled.
- Belon’s team found that histamine at homeopathic dilutions (10-30-10-38M) could also inhibit degranulation. Controversial French researcher Benveniste also worked with basophils in the 1980s, but his team used high dilution IgE to stimulate degranulation, rather than high dilution histamine to suppress it. Although his initial experiments were positive (Davenas E et al., Nature, 1988) they could not be sufficiently reproduced to be accepted by the scientific community.
- Belon P, Cumps J, Ennis M, et al. Histamine dilutions modulate basophil activation, Inflammation Research, 2004; 53: 181-8
The homeopathic medicine Belladonna 30c can make a piece of rat’s intestine contract 
Belladonna (also known as Deadly Nightshade) is a toxic plant widely used in ultrahigh dilution as a homeopathic medicine. In pharmacological doses, its active ingredient (atropine) is known to alter the way smooth muscle contracts. As an experimental design, use of this ‘acetylcholine-induced contraction of the rat ileum’ model is known to be reproducible and is highly recognised by the scientific community. 
- Smooth muscle is found in the wall of the intestines, including parts of the small intestine called the ileum and duodenum. When a chemical called acetylcholine is released it causes smooth muscle to contract. When smooth muscle is inactive it remains partially contracted. Atropine influences the action of acetylcholine, either enhancing or preventing muscle contraction depending on the specific circumstances e.g. the level of dilution (Wali A et al., Actea Anaestesiologica Scan, 1987; 31: 587-592).
- This study by Romanian researcher A. Cristea found that Belladonna prepared as a homeopathic medicine has a similar effect on the rat duodenum, causing it to either relax or contract depending on the level of dilution – Belladonna 1c to 20c caused relaxation; Belladonna 30c to 45c (higher dilutions) caused contraction.
- ‘Pharmacodynamic effects of very high dilutions of belladonna on the isolated rat duodenum’ by A Cristea et al. In Signals and Images, Bastide M (ed). Kluwer Academic Publishers 1997: 161-170
Ultrahigh dilution Thyroxine can slow down metamorphosis of tadpoles into frogs 
The hormone thyroxine is known to influence the rate of metamorphosis in frogs. In this study tadpoles were exposed to either conventionally prepared thyroxine, homeopathically prepared Thyroxine or a control (control = provides a basis for comparison in a trial e.g. an established treatment or inactive ‘dummy’ treatment) liquid. Standard thyroxine was found to stimulate metamorphosis, causing the tadpoles to turn into adult frogs faster. The homeopathic Thyroxine had a clear but opposite effect – significantly slowing down metamorphosis. (This study uses whole living organisms, rather than isolated tissues.)
- These results were replicated by five separate laboratories in Austria and confirmed by the results of similar experiments carried out by an independent team in Brazil (Guedes JR et al, Homeopathy, 2004; 93(3): 132-7).
- The species of frog used was Rana temporaria and the ultramolecular thyroxine used was in a 10-30 dilution. More recently the team in Brazil found that a homeopathic preparation made from frog thyroid glands used in a similar way could also alter the rate of metamorphosis.
Homeopathic medicines are not ‘just water’
“The facts are indisputable, statistically significant and reproducable, even if they cannot be explained by the molecular paradigm.”(1)
Experimental results from many different independent laboratories have confirmed that there are physical differences between homeopathically prepared samples and control (control = provides a basis for comparison in a trial e.g. an established treatment or inactive ‘dummy’ treatment) samples (such as plain water or other solvents). These differences can be measured using scientific techniques such as:
Calorimetry  Measuring the amount of heat given off by a sample
Spectroscopy ,  Measuring how a substance absorbs, emits or scatters electromagnetic radiation
Thermoluminescence  The amount of light produced by a sample when it is heated (due to the release of stored energy) can also be measured.
Experiments of this kind demonstrate that the homeopathic preparation process (serial dilution and violent agitation) creates samples that have specific physical properties, despite the fact that they do not contain molecules.
They do not tell us how homeopathic medicines interact with the living body, but the more we learn about the properties of these ultrahigh dilutions in the laboratory, the closer we can come to understanding exactly how homeopathic medicines work in practice.
The importance of succussion
The manufacture of homeopathic medicines involves two processes – serial dilution and succussion (succussion = a specific form of vigorous agitation). Researchers believe that the succussion is an essential component in creating biologically effective samples, so experiments investigating ultrahigh dilutions always use succussed samples. Some experiments even compare diluted and succussed samples to samples that have been diluted to the same level but not succussed, as well as other controls. 
In the wording used by researchers in this field, the fact that a sample has been succussed is therefore often implied rather than being stated clearly e.g. ‘high dilution thyroxine’ in the frog experiments actually means thyroxine that has been diluted and succussed.
1. Van Wassenhoven M. Priorities and methods for developing the evidence profile of homeopathy. Homeopathy, 2005; 94: 107–124
2. Witt CM, Bluth M, Albrecht H, et al. The in vitro evidence for an effect of high homeopathic potencies – a systematic review of the literature. Complement Ther Med, 2007; 15: 128–138
3. Belon P, Cumps J, Ennis M, et al. Histamine dilutions modulate basophil activation, Inflammation Research, 2004; 53: 181-8
4.Bastide M (ed). Cristea A, Nicula S, Darie V. Pharmacodynamic effects of very high dilutions of belladonna on the isolated rat duodenum. In: Signals and Images. Kluwer Academic Publishers 1997: 161-170
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