I read the recent article by Prof. Hansson about the inaccuracy of label on homeopathic drugs, to which I feel fully in agreement 1, 2; however, labels should refer to a well-known chemistry and pharmacology, from which homeopaths are used to fly off ‘quite aghast’. Due to the formal absence of any molecule, when the homeopathic remedy exceeds the Avogadro-Loschmidt constant, any label trying to inform the consumer about the chemical composition of the remedy should appear quite weird. A good possibility may come from manufacturers when declaring step by step the starting biochemical composition, the process of serial dilutions and the resulting molar concentrations, as well as the physical treatment which the remedy underwent during the dilution process (temperature, pressure, gases partial pressure in the solution, etc..) and the natural source of biochemical components. For example, any label indicating homeopathic remedy Gelsemium 9cH would mean that a 1 : 1018 solution of Gelsemium was finally made, through serial 1 : 100 dilutions, starting from an unknown (for the consumer) concentration of steroids, alkaloids, polyphenols and coumarins contained in an alcoholic extract of Gelsemium sempervirens plant 3. The simplistic way to calculate the theoretical concentration of a homeopathic dilution has some concern. The extract usually contains cytotoxic steroids and at least nine indole alkaloids 4, such as gelsemine, gelsevirine, 21-oxogelsemine, gelsedine, 14 beta-hydroxygelsedine, gelsenicine, humantenidine, humantenirine and koumidine, many of which may be cause of potential adverse effects 5. In order to calculate the dilution ratio of the compound into water, the structure of which is considered of utmost importance for the ‘transfer of information’ according to homeopathic pharmacopeia, the molecule should be completely miscible into liquid water or, at least, its affinity with water respect to alcohol should be evaluated. Most of plant-derived substances are de facto hydrophobic components, which need methanol (MeOH) or ethanol (EtOH) to be completely mixed into a water solvent, therefore hampering a linear evaluation of the molar concentration into water, attributed to the many components making the diluted extract 6. For Gelsemium sempervirens Ait., total alkaloids can be extracted with 95% EtOH, with an extract purity ranging from 87% (ethyl acetate) to 88% (chloroform), often giving koumine of gelsemine, as most represented alkaloids. Gelsemine is a genotoxic and nefrotoxic compound 7. Whilst starting from a gelsemine concentration of 6.5 × 10−4 mol L−1 8, the theoretical concentration of the alkaloid into pure water will be about 6 × 10−20 mol L−1; however, ethanol has a significantly higher coefficient of expansion than water. This means that as the temperature varies, the volume of the ethanol portion of the mixture changes faster than that of the water portion. The evaluation of molecule affinity for ethanol respect to pure water is of paramount interest to calculate how much gelsemine is ‘really’ present, as molar mass, in any serial water/ethanol dilution, depending on many physical factors, such as ethanol density at different temperatures (about 0.8815 g cm−3 for 70% EtOH at 298 16 K), because this chemical microenvironment may influence how much gelsemine is effectively withdrawn during a serial-dilutive process. Furthermore, soluble compounds can be captured by nanosized structure, often nanobubbles, lining the boron-silicate glasses with which dilutions, subjected to mechanical stresses, are made 9. Therefore, an imprecise fraction of compound may be dispersed into the solvent from the glass wall whenever a mechanical stress is applied to the dilution, possibly giving gelsemine concentration far from the theoretical evaluation into pure water 6. These simple considerations do not make sure any theoretical linear calculation about the presence or absence of a particular compound, especially if toxic, unless a spectrometry or quantitative chemical analysis on serial dilutions is performed. This is the only way to ensure consumers about the presence or not of potentially toxic substances in homeopathic remedies. Of 1.67 yM active principle, people could undergo effects due to contaminants or 30% ethanol. The authors have no conflict of interest to declare.
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Dec 2, 2015
Nadine Wehmeier + 5
Open Access