I am the author of this report and I am currently over 75 years of age, I have spent most of my scientific activity in the field of experimental gerontology (since 1968). During this time, I have taken part in an auto-experiment of supplementing myself with centrophenoxine (CPH).
The reason for doing this was that CPH became known to me since the early sixties as a compound which was able to liberate various animal tissues, (brain, liver, myo-cardium, epithelia, etc) from the age-dependent accumulating yellow pigment granules, called lopofuscin, or age-pigment.
What is more, detailed analysis of the effect of CPH revealed that the treated animals had a longer medium life span than the non-treated ones. As a matter of fact, the CPH-treated rats survived about 15-20% longer in terms of the medium life span, compared to the non-treated ones, and a number of age-dependent declining cellular parameters were improved during the treatments.
Because CPH had practically no toxic side-effects, I and several other persons decided all those years ago to start a human auto-experiment by taking 500 mg/day CPH, and some of those subjects (including myself) are still continuing this habit more than 35 years later! Although these auto-experiments cannot be considered as a true scientific approach, with proper controls and statistical comparisons, the fact that more than 35 years has passed deserves interest from several points of view. This subjective report intends to summarize the personal experiences of these human auto-experiments in a semi scientific manner.
Introduction- the early empirical data on the effects of centrophenoxine
CPH is an ester of p-chlorophenoxyacetic acid (PCPA) and dimethylamino-ethanol (DMAE) called also meclophenoxate. The relevant early literature considering its in vitro and in vivo effects has classified CPH as a ‘neuroenergeticum’, stimulating the metabolic activities of the nerve cells, manifesting itself in cases like cerebral atrophy, brain injury, postapoplectic disorders, chronic alcoholism, barbiturate intoxications, etc. It was later been reclassified as a ‘nootropic.’ During the early sixties, numerous beneficial effects of CPH were observed, e.g., prolonged administration of CPH to healthy old animals significantly reduced the accumulation of lipofuscin in the brain cells and myocardium. The medium life span of the CPH-treated old animals increased significantly, and the learning ability of the old, treated mice improved as compared to their age-matched controls. On the basis of these results, CPH could be considered as a potential anti-aging drug.
The theoretical background of aging and the effects of centrophenoxine
One of the most relevant central dogmas of the aging theories was the free radical theory of aging (FRTA), claiming that oxygen free radicals are harmful by-products of the aerobic life and as such, are responsible for aging and numerous diseases. A deeper analysis, however, revealed various contradictions, and paradoxical situations. I have analyzed the contradictory items of the FRTA, outlining a new, comprehensive interpretation of the possible biological role of oxygen free radicals in the living state, cell differentiation and aging, called the membrane hypothesis of aging (MHA). Although the MHA implicitly contradicts the central dogma of the FRTA, it does not deny the possibility of damaging side effects of these radicals. The MHA attributes a role to the constant flux of oxygen free radicals in the living state, i.e., offers a much wider basis for the interpretation of the free radical function. This means that in terms of the MHA, the FRTA could remain valid with a series of modifications.
The main statements of the membrane hypothesis of aging (MHA)
The MHA attributes a leading role in differentiation and aging processes to the plasma membrane, undergoing inevitable, continuous alterations during the life. The alterations are due in part to free radical induced molecular damage, and also to the ‘residual heat’ formed during each depolarization of the resting potential. Due to these membrane alterations, an accumulation of dry mass (i.e., a decrease of the intracellular water content) takes place in the intracellular space. This is a necessary process for the development and maturation, but becomes a rate-limiting factor above a certain physical density of the cell colloids. This involves that the in-situ enzyme activities in the cells are declining due to the increased density of their microenvironment. MHA is valid for all postmitotic cells, like neurons, muscle cells, etc. It is particularly evident in the erythrocytes where de-novo protein synthesis does not take place. Plus, the MHA has been strongly supported by the recent developments of molecular genetics.
The mechanism of action of CPH
In early times, it was suggested that the DMAE moiety enters the choline synthesis cycle (and improves the acetylcholine supply of the brain); however, this explanation had been contradicted by others since that time. A strong argument against the original concept is that a choline-rich diet alone does not have the same effect as CPH.
When 14C-labelled DMAE or CPH was administered intravenously, much higher levels of DMAE were encountered in the brain after CPH treatment, than with DMAE alone, this is because the esterified form of DMAE with PCPA penetrates much better through blood-brain barrier.
CPH is hydrolyzed on both sides of this barrier in its two component parts. However, the DMAE moiety becomes phosphorylated in the brain to yield phosphoryl-DMAE, which is then converted to phosphatidyl-DMAE, seemingly the end-metabolite of DMAE in the brain.
Phosphatidyl-DMAE is incorporated in the nerve cell membranes, and remains in this form for a relatively long time on the place of choline, i.e., it forms a special class of phospholipids in the brain cell membranes. The PCPA moiety is excreted in the urine, apparently without any metabolic change. Although some fraction of DMAE administered either alone or in form of CPH, was found in acid soluble and lipid cholines in the brain; evidence is available that trimethylation of DMAE takes place only in the liver, but not in the brain. Therefore, the presence of DMAE in the nerve cell membrane had to be considered as the starting point of any approach to the mechanism of action of CPH.
Experiments have revealed the effects of DMAE on brain functions in terms of its local oxyradical protecting effect on the cell membrane components, such as;
(i) The protein cross-linking model and
(ii)Electron spin resonance spectroscopic demonstrations of hydroxyl free radical scavenger properties of DMAE in spin trapping experiments- this has confirmed the molecular basis for the biological effects of CPH.
Obviously, neither the presence of DMAE in the brain nerve cell membranes, nor the in vitro OH· radical scavenging ability of this compound prove directly that it acts as a OH· radical scavenger also in vivo. However, numerous animal experimental results demonstrate indirectly that the presence of DMAE in the cell membrane is of physiological significance, which can be attributed to their local OH· radical scavenger properties.
Aging causes an increase of microsviscosity of the membrane lipids in the synaptosomal membranes. Measured by fluorescence polarization techniques after diphenyl-hexatriene (DPH) labeling of brain cortical synaptosomal membranes, the membrane microviscosity decreased again significantly after treatment of old rats with CPH for 60 days. Synaptosomal membranes were protected considerably by CPH pretreatment against the toxic effect of in vivo acute Fe2+ overload in the cerebrospinal fluid of young rats. The molecular weight distribution of the proteins is considerably shifted toward the higher values in the synaptosomes of the rat brain cortex during aging. A treatment of 60 days with CPH reversed this tendency to a significant extent in old rats.
The fluorescence recovery after photobleaching (FRAP) technique measures the lateral mobility of membrane proteins and lipids. The lateral diffusion constant of hepatocyte membrane proteins (Dp) displayed a characteristic, negative, linear age correlation in Fischer 344, Wistar rats, in C57BL black mice, in wild mouse strains of considerably different longevity (Peromyscus leucopus, Mus musculus), BN/Bi rats, as well as the senescence accelerated mouse (SAM).
The same finding has been described for the Con-A-receptor proteins in the skeletal muscle cells of mice, and in the large brain cortical cells of rats. Although membrane lipid lateral mobility (Dl) is faster almost by an order of magnitude than of Dp, it showed a very similar age-dependence in hepatocyte membranes. The age-dependent decays of Dp and Dl of various tissues are inversely proportional to the life span of the given strain.
FRAP experiments on two-year-old Fischer 344 rats pretreated per os through gastric tube with aqueous solutions of 80 mg/kg CPH for 5 weeks, revealed a significantly higher value of Dp than in the controls. Fischer 344 male rats above the age of 2 years display a linear body weight loss until death. This loss was slightly inhibited by CPH. This fact indicates that the increase in Dp under the effect of CPH causes an overall improvement of the status of the animals. It is also noteworthy that caloric restriction experiments on mice also increased the Dp values to such an extent that it might correspond with the life prolonging effect of this intervention.
As explained by the MHA, the age-dependent decline of the passive potassium permeability in the nerve cells is an important, key issue in brain aging. CPH treatment of 60 days (80-100 mg/kg) in old rats re-increased the passive potassium permeability of the neuronal cell membrane, i.e., it decreased the intracellular potassium content and rehydrated significantly the cytoplasm of brain neurons. These findings indicate that CPH may be useful in the prevention or therapy of the age-dependent brain alterations.
The rates of synthesis of total- as well as mRNA, measured in vivo by means of radioisotope methods in rats, display an age-dependent decrease in the brain cortex between one and two years of age (to 40-50% of the young-adult value). In vivo treatments of 60 days with CPH improved these rates to 80-90%.
CPH treatment prolonged the medium life span of laboratory animals, especially if the treatment started at relatively young ages. It improved also the learning ability of several animal species. In some cases an increase of the medium life span up to 30% was seen in mice, but only if the CPH treatment started at the age of 6 months.
Human experiments with CPH
Fifty persons of 76 years of age with a male/female ratio of 1/1 were recruited in a double blind, randomized, human clinical trial. CPH treatment of 8 weeks improved the psychometric and behavioral performance in about 50% of patients with medium level dementia. The placebo group displayed improvement of only 27%.
A considerable rehydration of the intracellular mass was observed in the verum group at the expense of the extracellular liquid, meanwhile the body weight remained unchanged. These data are mentioned here to demonstrate that the nootropic CPH behaves in humans in the same predictable way as per the basis of the MHA.
My own experience
Several persons around the age of 40 years, including myself, started to take CPH (500 mg/day) in 1976, and we’ve maintained this experimental treatment up to the present day. Due to the relatively low number of these subjects, I appreciate that this cannot be considered as a scientific experiment; nevertheless, all the participants have agreed that they have maintained better physical and mental performance, than the untreated persons of similar age in their family. Apart from this observation, it is important to note that the treated persons have had no side effects even after these 35 years.
I myself can confirm the positive effects of taking CPH on my own performance and health status. I was working in this period very intensely in my research field and also as the Editor-in-Chief of the Elsevier journal ‘Archives of Gerontolgy and Geriatrics’. I stopped this latter activity only at the end of 2011, after 30 years, and even at that time I had no health-dependent reason for doing so.
My physical performance has all this time been in good shape. I could compare my state particularly well in September 2011, when we had the 50-year anniversary of our university class (being actually 74-76 years of age, having taking my medical degree in 1961). More than one third of our class had died by the time of this anniversary! Even the surviving classmates showed various types of chronic diseases, many of them in quite serious phases.
I want to stress again that such a comparison has no really strict scientific value, but may offer a subjective judgement. The decay of the activities in general is a good indicator of the age-dependent health state, and the appearance of chronic diseases is obviously not a good sign for the future of this age-group of persons.
Also, I want to tell you that whilst type-II diabetes has appeared in the last few years for me, it has been reacting quite well to the antidiabetic treatments so far, and caused no complications. In general, different authors agree that CPH does not alter the sugar-tolerance of the subjects. The same can be stated about the hypertensive phenomena. I have some trend for hypertension; however, it has been well controlled.
My main conclusion is that CPH is harmless in the given dose even after a contnuous taking as a preventive anti-aging compound, and on the other hand, it is helpful in the maintenance of the general health status of the human body.
I can recommend CPH with responsibility on the basis of my own experience.
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