Homoeopathica November 2004

by B. Hamman¹, G. Koning¹ and K. Him Lok²

1 Department of Botany, University of Pretoria, Pretoria, South Africa.
2 Department of Homœopathy, Technikon of Natal, Durban, South Africa.

The potentisation process by which homœopathic preparations are produced raises the concern that these medicines have placebo effects only, since they theoretically no longer contain active molecules of the diluted substance. Plant models offer a method of examining the efficacy of homœopathically prepared solutions. This study examined the effects of homœopathically prepared gibberellic acid on the germination performance of barley seeds. The effect of the potentised gibberellic acid on seed germination rate and seedling development was compared to that of the most commonly used form of gibberellic acid, and distilled water.

Introduction

Although human subjects have been used to demonstrate the validity of homœopathy, the scientific community remains sceptical that homœopathy does, indeed, work. The use of plant models allows the observation of direct responses, while eliminating the subjectivity and speculation with regard to placebo effects which are the main criticism when human subjects are used. Plant hormones are substances produced in one part of the plant and transported to another, where they elicit a specific response. One such response is the role that gibberellic acid (GA) plays in the germination of seeds: the embryo is a source of GA, supplying the aleurone layer with the stimulus for the production of a-amylase, a hydrolytic enzyme responsible for the digestion of food reserves within the seed, required by the growing embryo and developing seedling during germination. For many years, the germinating barley caryopsis has provided the classical example for the hormonal action of a plant growth substance, with GA3 (the most commonly used form of GA) successfully substituting for the embryo in deembryonated half-seeds. Commercially prepared GA3 is routinely used as an exogenously applied seed treatment, usually in order to break dormancy.
This study sought to demonstrate effects of homœopathic preparations, with a plant model. The effect of homœopathically prepared dilutions of GA on the germination rate and seedling development of barley seeds was explored. Since the germination response of seeds is dependent on the quality (vigour) of the seed, three independent seedlots, representing a range of vigour were used.

Materials and methods

Treatments

Three barley seedlots were used, all having acceptable levels (> 80%) of germination (measured by the standard method) but exhibiting a range of vigour.
Seeds were treated with one of six treatment solutions: distilled water (control), GA3 0.5gl-1, or four potencies of homœopathically prepared gibberellic acid (HGA3): 4, 15, 30 and 20cH.

Cultural practices, data collected and statistical analysis

Germination rate

Five hundred seeds (five replicates of 100 seeds each) per treatment were allowed to imbibe in petri-dishes lined with filter paper
(moistened with 12.5 ml of one of the treatment solutions), at 20°C in the dark. Germination counts were done every 4 hours, with seeds considered germinated once the radicle had emerged and was 1mm in length.

Seedling development

Two hundred seeds per treatment (four replicates of 50 seeds each) were allowed to imbibe in petri-dishes as described above for 24 hours, after which seeds were transferred to moist germination towels, enclosed in polyethylene bags, and incubated for 6 days at 20°C in the dark. Final germination counts (% normal seedlings) were taken 7 days after the start of imbibition, at which time shoot and root lengths were measured. Seedling dry mass was determined using the dry oven method (60°C for 30 hours). There were three replications.

Results

Germination rate

Both HGA3 dilutions and commercial GA3 (0.5gl-1) increased the germination rate of high vigour barley seed, although no significant differences were evident between the individual potencies (Table 1). However, when medium- and low-vigour seed was used, germination rate was no different to that of the control group, with the exception of HGA3 4cH, which significantly reduced the rate at which low-vigour seeds germinated (Table 1).

Final germination

With the exception of HGA3 15cH, all homœopathically-prepared dilutions increased the final germination percentage of medium vigour seeds. No significant effects on the germination percentage of high- and low-vigour seeds were observed.

Seedling development

Responses within vigour levels are considered separately, since cultivar differences in seed size contribute to differences in the size of seedling components.
Seedling shoot growth of high- and medium-vigour seeds responded positively to GA, although the increase in length was not significant (Table 2). When low-vigour seed was used however, there was no response to any of the HGA3 potencies, while shoots of seeds treated with GA3 were significantly longer than those of the control.
No response to HGA3 potencies in terms of root length was discernible, with the exception of HGA3 15cH which significantly increased the seedling root length of medium-vigour seeds (Table 2). Unexpectedly, treatment with GA3 had an inhibitory effect on root length, although significantly so only with low-vigour seed. With the exception of HGA3 30cH, homœopathically prepared GA3 significantly increased seedling size (mass) of seeds of all vigour levels. Differences were also significant among the HGA3 potencies when high-vigour seed was used, with seeds treated with the most “dilute” of the potencies (HGA3 200cH), producing longest seedlings (combined root and shoot length) within that vigour group. No statistically significant differences among treatments were observed with regard to the number of normal and abnormal seedlings formed, and dead seeds (data not shown).

Discussion

Germination rate

Both GA3 and HGA3, supplied exogenously, increased barley seed germination. Even a concentration of 200c increased the rate at which high-vigour seeds germinated (Table 1). None of the HGA3 potencies had any effect on the germination rates of medium- and low-vigour seed, but neither did crude GA3. The seeds simply do not respond to additional GA3.
Avogadro’s dilution limit is reached in the process of homœopathic centesimal serial dilution at 12 cH. Homœopathic dilutions below this may still have molecules of the original base substance in solution, but beyond this no molecule of the original base substance is expected to remain. In our experiments potencies both above and below the Avogadro limit demonstrated biological activity.

Seedling development

Although not always statistically significant, developing barley seedlings responded to an exogenous supply of GA3: shoots were longer, and roots shorter, with no significant effect on whole seedling size (Table 2). Conceivably, GA3 is responsible for changes in reserve allocation, diverting more to shoots and less to roots. In contrast, the effect of HGA3 solutions on seedling mass was significantly positive, across all vigour levels, with significant differences between the individual HGA3 solutions, especially when high-vigour seed was used. There was no differential effect on shoots or roots (unlike GA3), with the exception of HGA3 15 cH which resulted in significantly longer roots.
Of special significance is the effect of the ultra-high dilutions ofHGA3 (HGA3 200cH), on the size of developing seedlings; these seedlings were significantly larger than the control seedlings, for all three vigour groups (Table 2). Theoretically, no molecules of the original substance should remain in this solution. A sceptic would not expect the effect of HGA3 200 cH on seedling development to be different to that of distilled water.
If it were true that homœopathic preparations are not capable of eliciting biological responses there should have been no differences in terms of root-and-shoot development, seedling mass and germination rate between those seeds treated with HGA3, and those that were not. Yet many such significant differences were observed.

Conclusions

Solutions of homœopathically potentised gibberellic acid, at dilution levels from 4cH to ultra-high dilutions of 200cH, demonstrated a biological response, as observed in their effects on germinating seeds and developing seedlings of barley. The effects of GA3, in a range of dilutions, on root development and seedling size demonstrated biphasic action.
Acknowledgements

We thank the Department of Botany at the University of Pretoria, South Africa, for the use of its facilities.
Condensed from Homeopathy (2003) 92.