Asphalia (Melatonin plant extract) clinical trial

Melatonin is not on general sale in Europe because it is a hormone; a powerful hormone. But it has powerful benefits in a number of chronic illnesses, especially cancer. Here we report on a clinical trial of asphalia. It is a natural plant compound, grown in Wales. And it has the properties of melatonin.

Go To: Melatonin - self-defence against cancer

DOUBLE BLIND PLACEBO-CONTROLLED CLINICAL TRIAL OF A FOOD SUPPLEMENT CONTAINING PLANT-DERIVED MELATONIN (ASPHALIA) CLAIMED TO IMPROVE SLEEP IN HEALTHY ADULTS.

Roger Coghill MA (Cantab) C Biol Mi Biol MA (Environ Mgt)

Coghill Research Laboratories, Lower Race,  NP4 5UH, Wales.

Abstract:

We report here the results of a placebo-controlled double blind trial of a food supplement (Asphalia) administered orally in powder format. Some 22 candidates (14 female, 8 male) who had signed Informed Consent letters were entered into the trial between October 2004 and March 2005. The Consent Letter asked if the applicant was affected by gluten, cereal products or colourants (a reason for exclusion). Candidates were all healthy adults living in the UK who claimed to be affected by exposure to ambient electromagnetic fields and radiation (EMF), and aged between 32 years and 58 years.

The participants matched as far as possible for age and sex were randomly given either a green flour-based powder (placebo) or a sample of the food supplement (Asphalia: the sample) to be taken just prior to bedtime in water for two weeks, and asked to complete a three part questionnaire. After this period the sample/placebo was substituted for its converse, for ingestion during the next two weeks. The first part was to be completed at commencement and asked inter alia for a description of exposure levels to EMF, the second part was to be completed 2 weeks after the start of the course, to reflect the effects of the sample/placebo. The placebo/sample was then changed for its converse. Part 3 was for completion after a further 2 weeks at the end of the trial period, to reflect the effects of its converse. The latter two questionnaires requested a subjective 8-point evaluation of changes in ten specific wellness-related parameters. 

Completed questionnaires were obtained from 16 participants (72.7 percent). The responses were coded and the sleep data extracted before codes were broken to perform statisitical analysis (see Table 1 below). None of the candidates reported any significant improvement from placebo ingestion, but whilst taking the placebo one (female) reported a significant deterioration in sleeping pattern, though this candidate turned out to have a history of psychiatric disturbance, and would have been excluded earlier were it known prior to the trial. Of those taking the sample, five (all female) reported moderate sleep improvement, and a higher level of alertness following the course, together with lowered emotional lability (feeling calmer). One candidate (female) while taking the sample reported a slight worsening of sleep disturbance (though she also reported moderately lowered nausea).  Other effects reported by those taking the sample include improved concentration and lessened memory loss. Two candidates reported slightly lower depression and another reported feeling better, but one candidate reported slightly increased depression.

We conclude there are distinct indications that ingestion of Asphalia significantly improves sleep without any observed adverse side effects. The minor beneficial effects on depression are difficult to interpret, and will be investigated separately. A further study, stratified by a wider age span, will investigate effects on the elderly, whose melatonin levels diminish with age.

INTRODUCTION

Asphalia is a melatonin-containing food supplement derived entirely from the dried and powdered leaves of gramineous species (wheatgrass, oats, barley, fescue).

Since the dawn of mankind grasses have provided us with our staple diet and many other needs. These are the opening lines of the Royal Horticultural Societys recent book on grasses (Grounds, 2005). As long ago as the third century BC Theophrastus (c. 370-287 BC) realised that grass seeds germinate with a simple seed leaf (monocotyledon), while those of most other plants germinate with two seed leaves (dicotyledon). This was the beginning of the classification system. Little further progress was made until 1704 when John Ray published a key separating grasses from sedges. The great Carl Linnaeus (1707-1778) finally brought order to the plant world with his sexual system of classification recognising grasses as a distinct group, but it was Bernard de Jussieu (1699-1777) who, in his more natural system of classification gave grasses the status of a family, which he named Gramineae. Modern usage however, requires that plant families take the name of the first genus, and since there is no genus Gramineum the family is now called Poaceae, from the genus Poa.

Historically the first grasses were grown for their grains, providing the staple diets of virtually every society: wheats, ryes, and barleys in Europe, maize in the Americas, millets in Africa, and rice in Asia. Grounds (2005) points out that more plants on earth are grasses than any other kind. In the old Testament God commands mankind to eat grass: And ye shall eat the herb of the field(Genesis, 3.18).

The nutraceutical value of grasses has an equally long antiquity: a few grasses (e.g. Jobs Tears (Coix lacrima-Job) were grown in monastery gardens and inter alia used for making rosaries from their hard grains, and several others are mentioned in old religious tracts and herbals. For example Gerard in his Herball (1597) included couch grass which he said was useful for healing green wounds, and meadow grass, which apparently has the capacity to glew and consolidate together new and bleeding wounds, while the roots of the common reed could be used to draw forth thorns and splinters.

Recent studies of plants reveal that gramineous species contain more melatonin than most fruits and vegetables. The discovery of melatonin as a powerful antioxidant has been comparatively recent, being first isolated by Aaron Lerner only in 1958, who named it from its ability to bleach frog skin (Lerner, Case et al., 1958). For some decades it was thought that in the animal kingdom this indoleamine was synthesised only in the pineal gland in the centre of the brain, and though its control of the circadian rhythms and of breeding cycles was quickly recognised, as well as the diminishing level with age (Sack, Lewy et al., 1987). Only in the last decade has it been realised that melatonin is also synthesised in several other organs including the cornea and the gut, and is also sequestered or synthesised by white blood cells, which when subjected to mitogenic challenge release it into the extracellular fluid at a dose nearly five times the normal physiological level (Carrillo-Vico, Calvi et al., 2004).

Scientific interest in melatonin during recent years has been intense, with many studies establishing its oncostatic, anti-ageing, immune system enhancing and sleep improvement efficacy, and concomitantly its almost complete absence of adverse side effects. No LD50 has ever been established for melatonin: its comparatively small molecular mass and its amphiphilic nature ensures its penetration into any part of the cell, making it far more powerful as a free radical scavenger than any vitamin.

Only a decade ago was it first discovered that melatonin is also present in the seeds, leaves and roots of plants, particularly in graminaceous species, and that plant melatonin is bioavailable to the animal kingdom. A 1995 study reported that among plants the graminaceous species Festuca arundinacea contained more melatonin than any other plant (Hattori, Migitaka et al., 1995). It is this plant which forms the basic ingredient of Asphalia. Though other studies and reviews have appeared since, none have reported levels as high as those found in F. arundinacea. Studies at MIT concomitantly reported that pharmacological doses of melatonin (i.e. in the milligram range) were not as effective as physiological doses (i.e. in the micro/picogram range) (Dollins, Zhdanova et al 1994; Zhdanova, Wurtman et al, 1995)).

Accordingly the rationale behind the unique development of Asphalia by this laboratory was that the natural plant-derived product is arguably more effective than the synthetic melatonin produced mainly as a by-product of chocolate manufacture, and when delivered at physiological doses would also prove to be more effective over time.

Health effects of melatonin

Melatonin (N-acetyl-5-methoxytryptamine) is a hormone and antioxidant which in mammals is largely synthesised from serotonin in the parenchymal cells of the pineal gland, but has been found in other tissues (Huether 1993. Carrillo-Vico 2004). The molecule was first isolated from bovine pineal glands by Aaron Lerner and co-workers (Lerner, Case et al., 1958).

Melatonin has been found in almost all vertebrates tested (Reiter 1991). In vertebrate subjects melatonin is secreted in a daily pattern peaking during darkness hours and subsiding during the hours of daylight. This circadian rhythm led scientists to explore the possibility of a link between melatonin levels and physiological processes such as sleep. Melatonin when administered to human subjects has been shown to modulate circadian rhythms and as a result is useful therapeutically as a treatment for jet lag and other sleep disorders (Arendt, Aldhouse et al., 1986). Several other physiological functions of melatonin have been reported including regulation of reproductive cycles, an anti-aging role, immunoresponsiveness and signal transduction of darkness (Reiter 1991).

Melatonin has been shown to have potent antioxidant action (Tan et al. 2000; Reiter, Tan et al. 2000; Reiter, Manchester et al. 2000) and free radical scavenging properties (Tan, Reiter et al 1993; Reiter, Tan et al. 2000). It has been shown to detoxify hydroxyl radicals, hydrogen peroxide, peroxynitrite anion, nitric oxide and hypochlorous acid (Reiter and Tan 2002). This discovery supported the idea that melatonin may be instrumental in the prevention, cure or control of free radical associated diseases such as Parkinsons and Alzheimers (Srinivasan 2002). It also provides some support for the possibility that electromagnetic fields may adversely affect melatonin synthesis.

Recent research suggests that melatonin also has a place in the diagnosis (Coudert, B 2002) and treatment of some cancers (Bartsch, Bartsch et al 2002; Vijayalaxmi, Thomas et al 2002; Blask, Sauer et al 2002), with a definite link between physiological melatonin levels and cancer incidence. Suppression of the normal light/dark melatonin cycle by light during darkness hours can lead to an increase in the progression of cancerous tissue (Blask, Dauchy et al 2002; Reiter, 2002; Sanchez-Barcelo, Cos et al 2003).Cancer patients tend to have a lower secretion of melatonin compared to healthy subjects (Kos-Kudla, Ostrowska et al 2002). Melatonin has been shown to have an inhibitory effect on the growth of endometrial (Kobayashi, Itoh et al 2003), breast (Dillon, Easley et al 2002; Anisimov 2003; Bizzarri, Cucina et al 2003) and prostate (Shiu, Law et al 2003) cancer tumours.

It seems that not only can melatonin inhibit the growth of cancer tumours but has been shown by Lissoni et al. to reduce the toxic effects of chemotherapies (Lissoni, Chilelli et al 2003). This trial showed that both tumour regression and 5-year survival rates were higher in those concomitantly treated with melatonin. No patient treated with chemotherapy alone was alive after 2 years; in contrast 5-year survival was achieved in 6% of patients treated with melatonin.

Recent research has shown that children receiving chemotherapy for acute lymphoblastic leukaemia (ALL) have a lowered blood antioxidant status compared to that before the commencement of treatment making them more prone to complications from oxidative stress (Kennedy, Ladas et al., 2004). In view its beneficial action in situations of oxidative stress (Maestroni, 1988) there may be a place for melatonin therapy administration alongside ALL treatments.

Notwithstanding that melatonin has been reported to have a number of beneficial medical effects for human subjects, inter alia with primary and secondary sleep disorders, this study is confined to the sleep improvement reported in normal healthy subjects by a number of recent studies as a consequence of melatonin administration. Accordingly the effects of melatonin on primary and secondary sleeping disorders are not addressed by this study.

Brief literature review of clinical trials (melatonin and sleep)

Scientific literature on melatonin has quickly grown to extend to more than ten thousand peer reviewed studies, so great is scientific interest in this indoleamine. Confining attention to clinical trials on sleep in normal healthy subjects following  melatonin administration reveals at least 22 clinical trials in the last 20 years, of which nearly all report a positive effect of melatonin on various sleep parameters. In all cases however, only synthetically-produced  melatonin was trialled, so our study is the first to report biological effects of melatonin derived from natural plant materials.

Table 1: Clinical trials of melatonin and sleep patterns in normal healthy subjects

This table is instructive in that a quarter of these studies report virtually an immediate significant effect on sleep at doses at or below 500 mgrams, and 300mg doses can induce serum melatonin concentrations in excess of 100pg/ml. This is important, since although some animal studies have found effects after ingestion of melatonin-rich plants, levels of the indole reported in plants is several orders of magnitude below doses administered at pharmacological levels in the clinical trials listed above. This is illustrated in the brief review of the plant melatonin literature below.

Brief literature review relating to plant-derived melatonin.

In response to the reported health benefits of melatonin there are many synthetically produced melatonin tablets on the market. These are taken by a wide range of people including sufferers of insomnia and jet lag as well as those who simply want to preserve their good health. Some people cannot freely obtain supply since in some countries (e.g. UK) melatonin is a prescription-only medicine (POM). In addition there are those people who do not wish to take synthetic medicines but would like the ability to supplement their endogenous melatonin.

Epidemiological studies indicate that consumption of fruit and vegetables can protect against a variety of diseases (Doll 1990; Dragsted, Strube et al 1993). The chemical components responsible for these preventative properties are thought to be antioxidants such as vitamins C and E,-carotene and flavonoids. However, some plant tissues contain melatonin and therefore the consumption of such tissues could alter blood melatonin levels and offer antioxidant protection in addition to endogenously produced melatonin (Hattori, Migitaka et al 1995).

The discovery of melatonin in algae (Poeggeler and Hardeland, 1994) led to speculation that melatonin may be found in a wider range of plant tissues. Melatonin in higher plants was first reported by Hattori et al. (Hattori, Migitaka et al 1995). Hattori determined the melatonin level of twenty four edible plants; selected examples are listed in Table 2. The same paper reported that plasma melatonin levels in birds increase after feeding plant products which are rich in melatonin it also showed that plant derived melatonin binds to melatonin receptors in rabbit brain. These findings are important as they indicate that vertebrates can supplement their endogenous melatonin according to the plant material they consume.

More recently Badria has published data on the levels of the indoles tryptamine, melatonin and serotonin in what he describes as Egyptian food and medicinal plants (Badria 2002). In total nineteen plants were tested, many of the plants were the same as tested by Hattori, a selection of these are listed in Table 2 for comparison.

Analysis of melatonin in seeds has been investigated (Manchester, Reiter et al 2000). Melatonin was found in all fifteen seeds sampled, the highest levels were found in mustard seeds. It has been suggested (Manchester, Reiter et al 2000) that the high  levels of melatonin offer protection to the germ tissue of the seed from environmental factors such as UV light, drought, extremes of temperature and chemical pollution.

Table 2: Melatonin  levels  detected in  selected  edible  plants.

Table 3: Melatonin  levels  in  Chinese  and  Alpine  medicinal  plants.

a flower

b leaf

c flower

d leaves

e young plant

f dried leaves

The highest melatonin levels have been measured in plants traditionally used for medicinal purposes. Chinese medicinal herbs have been used for centuries to alleviate or cure many diseases. Zhang et al (Zhang, Chen et al 2003) analysed melatonin levels in 108 Chinese medicinal herbs. Over half of the herbs tested contained melatonin levels in excess of 10ng/gm, some herbs contained levels in the g/gm range. Of particular interest was that many of the herbs containing the highest melatonin levels are traditionally used to treat diseases associated with free radicals.

Alpine medicinal plants have been found to contain high levels of melatonin (Tettamanti, Cerabolini et al. 2000). It has been suggested that melatonin may be required by these plants to allow them to survive at high altitude. UV and ozone are at higher levels in these environments, and it is already known that ozone in high concentrations decreases plant height and causes foliar damage.

It is apparent from the data that there are marked differences in the mean amounts of melatonin between plants of the same species. There could be a number of reasons for this. Firstly, the methods of quantification differ amongst research groups. The common methods of quantitation are radioimmunoassay (RIA), high performance liquid chromatography (HPLC) and gas chromatography mass spectrometry (GC-MS). RIA, HPLC and GC-MS are capable of detecting daytime (10pg/ml) and night-time (30-120pg/ml) melatonin in plasma/serum (Saunders, Chaturvedi et al., 1998).

Radio immunoassay (RIA) is a favoured method of melatonin determination in biological fluids due to its simplicity and sensitivity. Wide usage of RIA can also be attributed to the wide availability of commercial melatonin kits. Levels of melatonin in plant tissue were determined by Hattori et al. using RIA (Hattori, Migitaka, et al., 1995). The problem with RIA is lack of specificity of the antibody causing erroneous results due to cross reaction with other closely related indolic analogues e.g serotonin, tryptophan, 5 hydroxy-indoleacetic acid. Extraction of melatonin from the sample in question followed by the RIA goes some way towards alleviating this problem.

HPLC has often been coupled with fluorescence detection. It is possible that interfering species may give erroneous results in the fluorescence.

GC-MS techniques for the determination of melatonin are used to a lesser extent mainly due to their being difficult to fully automate compared with bioassays. However, GC-MS is far more specific, especially in view of todays mass spectrometry technology such as selected ion monitoring and MSⁿ techniques, which ensure accurate identification and quantification of samples. RIA analyses on plants have been verified by GC-MS of the residual extracts (Dubbels, Reiter et al 1995). Measurement of melatonin in Egyptian food plants (Badria 2002)  used GC-MS methods.

Secondly the environment of the growing plant may have an effect on the melatonin levels. The main factor which may differ is the time of year at which the plant was harvested and the resulting conditions it was grown under. For example plants grown under glass would experience different conditions compared to those grown outdoors, similarly plants grown in different climates would be subject to different environmental influences.

In short, from the published data it can be seen that melatonin is found in a wide range of plants at varying concentrations. The variation of amounts measured in plants of the same species could be due to either differing growing environments or use of different analytical techniques for detecting melatonin. The highest amounts of melatonin have been observed in grasses and those plants traditionally used for medicinal purposes, which could help explain their therapeutic action. Although the function of melatonin in plants has not been established it seems that its antioxidant properties may have a protective role on vulnerable tissues.

The discovery that the consumption of high melatonin foodstuff raises plasma melatonin and binds to brain receptors of vertebrates opens a new avenue of investigation into whether dietary melatonin is more or less effective than synthetic tablets, and it could be that supplementing endogenously synthesised melatonin with high melatonin foodstuffs is more desirable than recourse to synthetic tablets. This consideration lies behind the rationale for present trial.

METHOD AND MATERIALS

The study protocol is of randomised double blind placebo-controlled design.

The safety of short term melatonin administration was confirmed by reference to a recent meta-analysis which reported that 17 randomised controlled trials showed no adverse effects of melatonin with short term use of three months or less (Buscemi, Vandermeer et al.,  2005). The separate ingredients of Asphalia are all well established as non-toxic traditional cereal-related foods or grazing forage for livestock. The variety of fescue seed supplied was of an endophyte-free strain (Barenbrug UK) and this was cultured for two years in organic soil. Only the air-dried leaf was used to mill the final powder, and at slow speed to avoid denaturing the protein content of the plant. When ground the powder was maintained at 4 degrees Centigrade until posted to the subject for administration.

Candidates were recruited into the study via a heterogeneous population spread across the UK who identified themselves to a website (www.mastsanity.co.uk) advising the general public on putative health effects from chronic exposure to radiations emitted by cellphone masts. This website was contacted seeking volunteers for testing a radioprotective food supplement. Candidates were provided with an informed consent form describing it as a meadowgrass powder similar to barley and wheatgrass powders. No mention was made that the aim of the study was to assess sleep improvement effects, and the questionnaire buried the sleep-related questions within a list of ten unrelated symptoms or minor ailments commonly associated with EMF exposure in epidemiological studies of radiation sickness (Silverman, 1980).

Blindedness was obtained by ensuring that the subjects were unaware whether they were receiving a placebo or a sample, and the analysis of questionnaires was carried out by one of us (RWC) without knowing whether the response related to placebo or sample. No reports indicated that the subjects were able to unblind the study through their own immediate subjective responses to soporific effects, as some studies have reported with much higher melatonin doses. The placebo was produced from a gluten-free green food colourant (Supercook, Sherburn in Ermet, Leeds UK) mixed with domestic baking flour to a shade indistinguishable from the sample.

 Successful candidates were asked to take one dose of the sample/placebo (one level teaspoon each evening at bedtime, equivalent to 0.8 gm of dried powder), allocated randomly between subjects so that though overall they underwent one fortnight period of taking the sample and one fortnight taking the placebo, the order was randomly allocated. In considering whether to include a washout period we followed other trials which had not done so on the basis that melatonin synthesis/administration and excretion is of short term duration (a few hours), so the two test periods were contiguous.

Calculation of melatonin content of dose, derived from our own spectrophotometric analysis (ATI Unicam UV2), confirmed by GC/MS/MS (Finnigan Polaris Q, Thermo Electron) and supported by an independent study (Hattori et al 1995) indicated that each dose contained approx 1.12 mgrams of melatonin, hence is two orders of magnitude lower than the lowest dose administered in previously reported clinical trials. This issue is addressed in the discussion.

Questionnaires were in three parts (see Appendix 1), the first to be completed before starting the four week course, the second two weeks into the course and the third at the end of the second two week period. Questionnaire 1 captured location, age, and sex-related data, and brief information on EMF exposure levels, medical history, and the putative radiation derived symptoms complained of. Questionnaires 2 and 3 collected subjective details of changes in a list of ten symptoms including sleep disturbance noted after taking the sample/placebo for two weeks, and asked to record any lapses in the administration regime. Appended to Questionnaire 3 was a further overall question asking for any change noted in health condition on a seven point scale since starting the course, from considerably worse to considerably better, passing through no difference. It also asked for details of any major lifestyle changes during the course.

RESULTS

Of the 22 candidates who completed Consent Forms, completed questionnaires were obtained either postally or by telephone interview from 16 (72.7 percent). Of these 8 were female and 8 were male. The average age was 48.4 ( males 46.2, females 52.6) and the range of ages was between 32 and 58. 3 subjects did not take the entire course but missed upto 3 days administration. One female subject completed the questionnaire but not the course, having suffered a headache on day 2 (she attributed this to operation of a new 3G mast in the vicinity). 5 subjects reported an improvement in sleep and 2 subjects reported a slight improvement. One subject also reported feeling calmer. 7 subjects reported no change or noticeable effect.

Scoring was on a ten point scale, from -5 to +5, representing a range from Considerably worse to Considerably better sleep during the two active study periods.

The nul hypothesis predicts that the mean overall score would be +/-0.00, i.e. that there would be no improvement or deterioration in sleep parameters from the administration of either the active sample or the placebo. The results showed, however, that the mean overall score for the active sample was calculated to be +1.81 (SD -2.83), (with +5 representing considerably better sleep, 0.00 representing no change, and -5 representing considerably worse), and the placebo overall mean score was 0.13 (SD -0.62). Due to the scoring system deployed, which was conservative to allow for the subjective nature of responses, the consequent  SDs clearly showed a wide spread.

Estimated effect size (Yi) was calculated according to the method of Brzezninski et al (2005), where Y _i = Xbar _a- Xbar _p these being the mean responses on active and placebo respectively. This produces Yi = 1.68 and an SEM(Yi) of  2.62.

No candidate reported deterioration in health condition at the conclusion of the trial period, but seven subjects reported improvement. Follow-up at six months established that this lack of deterioration had continued and that several of the subjects were now regular satisfied users of Asphalia. We interpret the mean positive overall score to indicate a moderately successful sleep improvement trend overall during the active period compared with placebo (the placebo mean overall score was  0.13).

Individual overall scores are shown in Table 4. Applying a test of matched pairs (see Colton, Statistics in Medicine, 1974, p135) indicates that the effect is significant (p = <0.01).

Table 4: Summary of individual trial subjects data.        

* score on a ten point scale of the active sample effects relating to subjectively reported sleep improvement (see above for definitions);

(sum of squares: 121; (sum)²/n : 60.06; sum of squares about the mean: 60.94; s²d: 4.06)

Applying the t test of significance for paired samples

  == 3.88

With 15 degrees of freedom t is more than 2.947, therefore significant (p=<0.01).

DISCUSSION

When comparing the active sample effects these results, though based on self-reported subjective data, suggest that an otherwise distinct improvement in sleeping pattern as a result of melatonin-rich plant administration may be adversely affected if dose is discontinued for some days. The cessation of beneficial effect when melatonin treatment was stopped was also reported (Dahlitz et al, 1991). Several studies have reported inhibition of melatonin by electric fields, but whether the absence of improvement is due to any chronic EMF exposure of this particular group is not clear. A disadvantage was that some subjects wrote copiously of their trial experience rather than complete the questionnaire rigorously and fully, and this might have influenced the interpretation of scoring. If the three subjects who missed days administration are excluded, the overall score rises moderately to +2.23 in favour of a beneficial effect on sleep (placebo +0.13).

Questions of very low dosage

Addressing the question of the very low dose (some two orders of magnitude below all other studies) it must be surprising to see that such low dose (at physiological rather than pharmacological levels) can nevertheless have a usefully positive effect on sleep quality, and brings into question the possibly confounding effect of placebo: any administration offered ostensibly as a sleeping aid might benefit from the placebo effect. In this study however the subjects were unaware of the true aim of the study, and the other nine masking parameters offered for response (e.g. depression, memory loss, nose bleed, emotional lability, lack of concentration) did not report a similar overall level of improvement.

Some studies of elderly subjects given low (100mg) doses also confirm that these translate into increases of serum melatonin concentrations of around 40mg/ml (Shah, Langmuir et al, 1999). In a recent meta analysis moreover out of 15 studies of healthy subjects 11 reported effects at <500mg concentrations (Brezezinski, Vangel et al., 2005). These authors comment that The dose response relationships in 11 of the studies support the existence of a plateau, with maximum effect being achieved at low doses (e.g. 0.3mg) and maintained or diminished at higher doses. This finding gives some support to the hypothesis that low dose can be even more effective than higher dose.

Moreover there is also some support from animal studies, in that physiological doses of melatonin-rich feeds are capable of inducing beneficial effects in laboratory, livestock, and domestic animals. For example, a dose of 0.3 mg/g via feed pellets produced 15nM in the serum of chickens, which is more than ten times higher than the nocturnal peak melatonin concentration, within 2 hours (Noddegaard and Kennaway, 1999). Hattoris 1995 groundbreaking paper on melatonin in plants included a study where two-week female chicks were fed on prepared melatonin-rich (3.5ng/gm) and melatonin-poor (<100pg/gm) feedcorn, and found the difference was significantly reflected in their plasma melatonin levels within hours. The results demonstrate that even this extremely low melatonin concentration passes through the gastrointestinal wall and enters the blood, thereby increasing plasma melatonin levels detectably. The previous year a group from MIT had reported similar effects with 100mg doses on humans.

Another issue concerns the study population itself. All participants are self-classed as healthy in terms of their physical state, but since they were all from a population which believes that cellphone masts have adversely affected their health, the question arises over the psychological condition of the study sample. To address this issue a review of the literature reporting health conditions among populations vicinal to radio transmitters is needed. Though the topic is controversial there are a continuing majority of studies now being published reporting adverse health effects well below the ICNIRP (thermal) guidelines, and the possibility that environments vicinal to masts and high voltage powerlines are malign in the long term can no longer be dismissed (see Cherry 2000 for review). For example a recent large UK study reported near-doubled incidence of childhood leukaemia near high voltage powerlines (Draper, Vincent et al., 2005).

The topic of adverse health effects from chronic exposure to RF/MW/ELF fields and radiation is highly controversial with large research initiatives completed or in progress without so far any consensus, and opposite positions being taken by equally reputable scientific institutions. Of 307 published studies relating to weak non-ionising RF/MW radiation, however, in considering how such a vanishingly small administration of melatonin could have such potent effects (without invoking homeopathic principles) one must remember that the initial target tissue is blood. Oral ingestion of melatonin is detected in the bloodstream very soon after administration, for example in chickens  within an hour (Nodeggard and Kennaway, 1999). Moreover other small biomolecules affecting blood can also exert powerful effects with extremely small doses: the anticoagulant heparin for example has no known lower limit to its efficacy, and snakebite envenomation of the Indian King Cobra is lethal to mice at doses of 2.5 mg/20 gm (Saha, Gomes et al, 2006).

Unfortunately the mechanism of protective free radical scavenging action by melatonin is still not well understood, but it could well operate as a reactive chain reaction. Plant-derived  melatonin has also recently been shown to inhibit the damaging effects of intra-mitochondrial peroxynitrite at less than 200mg/ml for example (Basu and Hasra, 2006), and natural compounds and polyherbal formulations to act radioprotectively even against ionising radiation (Maurya, Devaagayam et al., 2006). Other recent studies report synthesis of this free radical as well as nitrites and nitrates from exposure of aerated biological fluids to weak electric fields.

Melatonin is also known to upregulate the expression of other anti-oxidants (Mayo, Sainz et al., 2002: and see Hardeland and Pandi-Perumal (2005) for recent review). This characteristic is also therefore a candidate for a causal mechanism of interaction at ultra low concentrations.

The homeostatic role of nitric oxide in controlling oxidative phosphorylation is also assisted by melatonin, suggesting its action is at a submolecular level. Finally many studies confirm that the normal peak level of melatonin in human serum is in the 20-120 picogram/ml range, making it the smallest of all hormones in terms of body volume. Against this background the potential ability of melatonin to act effectively at very minute doses cannot be ruled out.

CONCLUSIONS

This is the first clinical trial to investigate the somniferous action of plant-derived melatonin at picogram/ml administration levels on humans. We conclude that these results, significant at the p=0.01 level, show a sufficient trend to support the view that melatonin can exert a somniferous effect at levels far below current pharmacological doses, and that Asphalia is a suitable candidate as a melatonin delivery agent at these low concentration levels. Further in vitro work is necessary to understand better the mode of action from among several plausible candidates, and to investigate its effect in vivo on younger and more elderly groups than those considered here. At Last - the definitive, research based book on how to build a diet to help beat cancer. Click here to read about it.

 Acknowledgements

We are grateful to Children with Leukaemia for financial assistance, to Dr Chris Busby for helpful conversations, to Dr Rebecca Baghurst for clerical assistance and questionnaire design, and to Electro Magnetic Products Ltd for donated samples of Asphalia.

Competing interests:

RWC is a director of  Medcross Ltd., the ultimate holding company of Asphalia.

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