Cytogerontological studies of biological activity of oregano essential oil

Babili F.E., Bouajila J., Souchard J.P., Bertrand C., Bellvert F., Fouraste I., Moulis C., Valentin A.

Burlakova E.B., Erokhin V.N., Misharina T.A., Fatkullina L.D., Krementsova A.V., Semenov V.A., Terenina M.B., Vorobyova A.K., Goloshchapov A.N.

The effect of savory essential oil added with drinking water (150 ng/ml) or with feed (2.5 μg/g) on the lifetime of AKR mice and the parameters of oxidative stress in animal blood were investigated. It was found for the first time that long-term administration of an essential oil in low doses increased the average lifetime of mice by 20–35% and was accompanied by a decrease in the hemolysis level and the content of lipid peroxidation products in erythrocytes of mice, as well as alteration in the structural state of their membranes and stabilization of polyunsaturated fatty acids level in mice liver cells.

Khokhlov A.N.

The history of gerontological experiments on cell cultures is reviewed. Cytogerontological studies and aging theories by Weismann, Carrel, Hayflick, and the author are compared. It is emphasized that the basic notion of aging mechanisms was deeply revised several times within the 20th century. It is concluded that at present the aging of multicellular organisms cannot be satisfactorily explained with the help of cytogerontological studie’s data. Experiments on cell cultures need to be combined with fundamental gerontological studies, including survival curve analysis for humans or experimental animals.

Khokhlov A.N.

According to author’s concept, the aging process is caused by cell proliferation restriction-induced accumulation of various macromolecular defects (mainly DNA damage) in cells of an organism or cell population. In case of cell cultures, this proliferation restriction is related to either so-called contact inhibition or Hayflick’s limit, and in case of multicellular organisms, to the appearance, in the process of differentiation, of organs and tissues consisting of postmitotic or very slowly dividing cells. Cell proliferation is absolutely incompatible with normal functioning of a macroorganism. Thus, the development program automatically leads to a situation inducing the aging process (martaliry rates increase with age). Therefore, any special program of aging simply becomes senseless. This, however, does not reject for some organisms the reasonability of programmed death, which makes possible the elimination of harmful, from the species’s point of view, individuals. It is also very important to understand that increase or decrease of organism’s life span under the action of various factors are not necessarily related to a modification of the aging process, even though the experimental results in this field are interpreted just in this way.

Can Baser K.

Oregano essential oils obtained from the genera Origanum, Thymus, Coridothymus, Thymbra, Satureja and Lippia are rich in carvacrol, a monoterpenic phenol isomeric with thymol. Turkey is the biggest exporter of oregano herb and oil to the world markets. Oregano is mainly used in food, spice and pharmaceutical industries. Carvacrol is responsible for the biological activities of oregano. Many diverse activities of carvacrol such as antimicrobial, antitumor, antimutagenic, antigenotoxic, analgesic, antispasmodic, antiinflammatory, angiogenic, antiparasitic, antiplatelet, AChe inhibitory, antielastase, insecticidal, antihepatotoxic and hepatoprotective activities and uses such as feed additive, in honeybee breeding and in gastrointestinal ailments have been shown. This paper highlights these activities and attempts to explain the possible in vivo mechanism of action of carvacrol.

Edris A.E.

Essential oils and their volatile constituents are used widely to prevent and treat human disease. The possible role and mode of action of these natural products is discussed with regard to the prevention and treatment of cancer, cardiovascular diseases including atherosclerosis and thrombosis, as well as their bioactivity as antibacterial, antiviral, antioxidants and antidiabetic agents. Their application as natural skin penetration enhancers for transdermal drug delivery and the therapeutic properties of essential oils in aroma and massage therapy will also be outlined. Copyright © 2007 John Wiley & Sons, Ltd.

Khokhlov A.N.

For the most part, research in the area of cytogerontology, i.e., investigation of the mechanisms of aging in the experiments on cultured cells, is carried out using the “Hayflick's model”. More than forty years have passed since the appearance of that model, and during this period of time, very much data were obtained on its basis. These data contributed significantly to our knowledge of the behavior of both animal and human cultured cells. Specifically, we already know of the mechanisms underlying the aging in vitro. On the other hand, in my opinion, little has changed in our knowledge of the aging of the whole organism. In all likelihood, this can be explained by that the Hayflick's model is, like many others used in the experimental gerontology, correlative, i.e. based on a number of detected correlations. In the case of Hayflick's model, these are correlations between the mitotic potential of cells (cell population doubling potential) and some “gerontological” parameters and indices: species life-span, donor age, evidence of progeroid syndromes, etc., as well as various changes of normal (diploid) cells during long-term cultivation and during aging of the organism. It is, however, well known that very frequently a good correlation has nothing to do with the essence (gist) of the phenomenon. For example, we do know that the amount of gray hair correlates quite well with the age of an individual but is in no way related to the mechanisms of his/her aging and probability of death. In this case, the absence of cause-effect relationships is evident, which are, at the same time, indispensable for the development of gist models. These models, as distinct from the correlative ones, are based on a certain concept of aging. In the case of Hayflick's model, such a concept is absent: we cannot explain, using the “Hayflick's limit,” why our organism ages. This conclusion was convincingly confirmed by the discovery of telomere mechanism which determines the aging of cellsin vitro. That discovery initiated the appearance of theories attempting to explain the process of aging in vivo also on its basis. However, it has become clear that the mechanisms of aging of the entire organism, located, apparently, in its postmitotic cells, such as neurons or cardiomyocytes, cannot be explained in the framework of this approach. Hence, we believe that it is essential to develop “gist” models of aging using cultured cells. The mechanisms of cell aging in such models should be similar to the mechanisms of cell aging in the entire organism. Our “stationary phase aging” model could be one of such models, which is based on the assumption of the leading role of cell proliferation restriction in the processes of aging. We assume that the accumulation of “senile” damage is caused by the restriction of cell proliferation either due to the formation of differentiated cell populations during development (in vivo) or to the existence of saturation density phenomenon (in vitro). Cell proliferation changes themselves do not induce aging, they only lead to the accumulation of macromolecular defects, which, in turn, lead to the deterioration of tissues, organs, and, eventually, of the entire organism, increasing the probability of its death. Within the framework of our model, we define cell aging as the accumulation in a cell population of various types of damage identical to the damage arising in senescing multicellular organism. And, finally, it is essential to determine how the cell is dying and what the death of the cell is. These definitions will help to draw real parallels between the “genuine” aging of cells (i.e., increasing probability of their death with “age”) and the aging of multicellular organisms.

Bauer K., Garbe D., Surburg H.

KHOKHLOV A.N.

Studies of cellular and molecular mechanisms of aging are currently often carried o u t on cells senescing not only in vivo but also in vitro (Hayflick’s model), that is, altering with increasing of population doubling level in culture. However, some data suggest that in some cases the results obtained with this model are not in accord with those of in vivo aging studies. Furthermore, such experiments, as a rule, are comparable in labor-consuming character with routine studies in laboratory animals. In fact, Hayflick himself suggests that cells in vivo never realize their proliferative potential and never reach phase 111. In other words, an organism never ages because of a cell’s limitation, called “Hayflick’s limit.” It ages, we believe,’ because of an accumulation of various kinds of damage in cells due to restriction of cell proliferation during the formation (the differentiation process) of populations of specialized resting cells or very slowly dividing cells. The rate of any type of damage accumulation in the cell population (not in a single cell!) has to depend on the ratio of the rates of three processes: (1) cell proliferation, ( 2 ) spontaneous appearance of damage, and (3) damage repair. Thus, during cell proliferation a “dilution” of the damage occurs. Our data2 demonstrating a direct relation between the average proliferative activity of a cell line or strain and the average DNA molecular weight support this hypothesis. With all this in mind we suppose that it is more advisable to study cellular aging mechanisms using the “stationary phase aging” model.‘ The model is based on the assumption that in cells of stationary cultures various changes similar to those in cells of aging organisms have to appear. Last year we and other investigators obtained many experimental results confirming this assumption. “Age” changes at different levels (accumulation of DNA breaks and DNA protein cross-links, DNA demethylation, changes in spontaneous sister chromatid exchange level, plasma membrane changes, nuclear structure modulations, and decreased rate of mitogenstimulated cell cycling and of cell colony-forming ability a.0.) were shown to occur in stationary cell cultures. These experiments can be carried out in nearly any type of cell including normal and transformed human and animal cells, plant cells, bacteria, mycoplasmas, yeasts, and the like. In particular, we now study the phenomenon of stationary phase aging and the possibility of modulating this kind of cell aging by geroprotectors (physical or chemical factors that retard aging) and geropromoters (factors that accelerate aging) in cyanobacteria cultures. ‘Thus, an evolutionary approach to analysis of the data is provided. Moreover, changes in stationary cell cultures become detectable very soon, as a rule in 2-3 weeks after beginning the experiment. All of these data suggest that the stationary phase aging model is a good alternative to the Hayflick model.

Koroch A.R., Rodolfo Juliani H., Zygadlo J.A.

The present review demonstrates that EOs and their components have many functional properties and exert their action in mammals as well as in other organisms (insects, fungi, bacteria and viruses). The synergistic effect of EO components is a promising field that could lead to the optimisation of a given bioactivity. This phenomenon has been observed in many activities, such as those of antimicrobials, antioxidants, analgesics and semiochemicals. EOs are complex mixtures of components that show higher activities than their isolated components; their final activities are due to the combine effects of several minor components. Thus, EOs contain multifunctional components that exert their activities through different mechanisms. EOs and their components may have new applications against various diseases of different origins (cancer, fungal, bacterial or viral), because some of these complex diseases require multiple components and multifunctional therapies. The natural product industry is actively seeking natural therapeutics, preservatives, repellents and other agents that can replace synthetic compounds. The scientific literature has identified new applications and uses of both traditional and exotic EOs. These applications can ultimately assist growers and rural communities in the developing world to increase interest in their products.

Vârban D., Zăhan M., Crișan I., Pop C.R., Gál E., Ștefan R., Rotar A.M., Muscă A.S., Meseșan Ș.D., Horga V., Ladoși I., Olar L., Stoie A., Vârban R.

Oregano and tarragon are widely cultivated culinary herbs used for food seasoning, having familiar characteristic aromas appreciated by the wide public. The aim of this research was to characterize essential oils (EOs) from locally sourced organic oregano and tarragon (Cluj, Romania) and study their bioactivity potential. Results showed that oregano EO had a sesquiterpene dominant profile responsible for strong bands between 2800 and 3000 cm−1 on the Fourier transform infrared spectroscopy (FT-IR) spectrum and a composition consistent with reports from similar climatic regions. The tarragon EO profile was defined by phenylpropanoids responsible for the strong sharp peaks between 1000 and 1600 cm−1 on the FT-IR spectrum. In oregano EO, 22 compounds were identified with β-caryophyllene as a major constituent. In tarragon EO, 20 compounds were identified with eugenol as a major constituent. Oregano EO had a stronger antibacterial effect against both Gram-negative and Gram-positive bacterial strains, while tarragon EO had a slightly stronger cytotoxic effect on three types of cancer cell lines tested (skin melanoma, prostate carcinoma, and colorectal adenocarcinoma). It was concluded that, given the fact that a sufficient supply of high-quality plant material can be available for EO extraction, culinary herbs can become reliable candidates for many industries without the risk of discontinued supply. Therefore, research aiming to widen their potential applications is welcome and worth pursuing.

Morgunova G.V., Karmushakov A.F., Klebanov A.A., Khokhlov A.N.

Partial uncoupling of the processes of oxidative phosphorylation and energy storage in the form of ATP (“mild” uncoupling) helps reduce the production of reactive oxygen species and can also mimic the effect of calorie restriction. A number of studies have shown that uncouplers, such as 2,4-dinitrophenol (DNP), affect the lifespan of Drosophila, yeast, mice, and rats as well as the manifestation of “age-related” changes in cultures of mammalian and human cells undergoing replicative senescence. This paper is devoted to studying the effect of DNP on the growth and subsequent dying out of “stationary phase aging” Chinese hamster cells. Using the method for evaluating the colony-forming efficiency of cells, the maximum permissible concentration was selected, 5 ×10–5 M, in which the substance presumably induces “mild” uncoupling and does not inhibit cell proliferation. At higher concentrations, DNP has a cytotoxic effect on the studied cell culture. Under the influence of DNP in the potentially “mild” uncoupling concentration (5.6 × 10–7 M), the kinetics of cell growth and dying out does not change, and the lifespan of the cell culture does not increase. This effect may be due to the type of cells studied. In addition, there is a probability that the optimal concentration lies in the range from 5 ×10–7 to 5 × 10–5 M or even lower than 5 × 10–7 M.

Khokhlov A.N.

This is a brief overview of the ideas of the possibility of using the cell kinetic model developed by the author in the 1980s to test, in experiments on cell cultures, potential geroprotectors and geropromoters that slow down or accelerate, respectively, the aging process in animals and humans. The history of the evolution of this model—from estimation of only the cell reproduction rate and saturation density in a non-subcultured cell culture to constructing survival curves in the stationary phase of growth and to a further analysis of the possible interrelation between all parts of the curve of cells’ growth and subsequent dying out—is considered. Possible approaches to mathematical and statistical analysis of the data obtained within the framework of this model system are analyzed. It is emphasized that such studies can be carried out on cells of a very different nature (normal and transformed human and animal cells, plant cells, yeast, mycoplasmas, bacteria, etc.), which makes possible an evolutionary approach to the interpretation of the results obtained. At the same time, in the author’s opinion, the most promising experiments are those carried out on immortalized cells of humans and animals, since they are not cancerous on the one hand and have an unlimited mitotic potential on the other hand and, therefore, do not “age” in the process of numerous divisions, as, for example, normal human diploid fibroblasts do. It is assumed that the appropriate mathematical analysis of the entire growth and dying out curve of a non-subcultured cell culture (from seeding into a culture flask to the complete death of all cells) may allow the clarification of certain relationships between the development and aging of a multicellular organism and to increase the reliability of identifying promising geroprotectors.

Morgunova G.V., Kolesnikov A.V., Klebanov A.A., Khokhlov A.N.

The most popular biomarker of cellular senescence (BCS) is the activity of senescence-associated β-galactosidase (SA-β-Gal). Today, this is the prevailing BCS in the studies based on the definition of cell senescence (which we do not accept) understood primarily as accumulation in the cells (most often—those not prone to replicative senescence) of certain BCS under the impact of various external factors causing DNA damage. However, some papers provide evidence that SA-β-Gal activity in the cells is not a good BCS, because it often depends not so much on age (in vitro or in vivo) as on the method of research, the presence of certain pathologies, and, what is most important, on the proliferative status of the cells studied. Apparently, the restriction of cell proliferation under certain conditions (due to differentiation, contact inhibition, DNA damage, some diseases, etc.) is itself the factor that stimulates SA-β-Gal expression. In other words, SA-β-Gal appears even in “young” cells if their proliferation is suppressed. Such data, in our opinion, are additional evidence for the validity of our concept of aging, which postulates the leading role of cell proliferation restriction in the age-related accumulation of various macromolecular defects (primarily DNA damage) in cells.

Khokhlov A.N., Morgunova G.V.

A brief comparative analysis of different approaches to cell viability testing in cytogerontological experiments is performed with a focus on problems in constructing survival curves for cultured cells in the “stationary phase aging” model. It is emphasized that the choice of methods to this end depends mainly on the researchers’ ideas about molecular and cellular mechanisms of aging. A note is made that the evaluation of colonyforming efficiency, though optimal for cell viability assessment, is unfortunately not applicable to postmitotic or very slowly propagating cells. Consideration is also given to some problems encountered when using the most popular molecular probes designed for live/dead cell viability assays.

Khokhlov A.N., Morgunova G.V., Ryndina T.S., Coll F.

The effect of isotonic Quinton Marine Plasma (QMP) solution on the growth and “stationary phase aging” (accumulation of “age”-related changes in cultured cells during cell proliferation slowing down within a single passage and subsequent “aging” in the stationary phase of growth) of transformed Chinese hamster cells was studied. No positive effects of QMP on the studied viability indexes of the cultured cells were found in any of the experiments. It is assumed that QMP, like many other potential anti-aging agents the authors studied recently (2,4-dinitrophenol in concentrations that provide mild uncoupling, the essential oil of oregano, hydrated C60-fullerene, etc.), can demonstrate its beneficial effect only at the level of the whole organism, triggering neurohumoral mechanisms that are not present in cytological model systems.

Khokhlov A.N.

The long history of ideas about the most famous “immortal” (non-aging) organism, freshwater hydra, is shortly reviewed. Over the years this polyp has attracted the attention of naturalists interested in problems of aging and longevity. In recent years, this interest has abruptly increased with the accent on fine mechanisms providing an almost complete lack of aging in hydra. It is emphasized that hydra immortality is based on indefinite self-renewal capacity of its stem cells. It is this fact that allows the polyp to continuously replace the “outworn” cells of the organism, keeping all its characteristics unchanged for an almost unlimited time. It is concluded that the applicability of the data obtained in gerontological experiments on hydra to human being is, unfortunately, very limited because normal functioning of many important organs and tissues in highly developed organisms is determined by the presence of postmitotic cells (neurons, cardiomyocytes, etc.), which actually cannot be replaced.

Kirpichnikov M.P., Khokhlov A.N.

The paper considers the history of how the scientific journal Moscow University Biological Sciences Bulletin (MUBSB) evolved during the last 7 years. It is the English edition of the Russian scientific peer-reviewed journal of the School of Biology of Lomonosov Moscow State University MSU Vestnik (Herald). Series 16. Biology. MUBSB is published by Allerton Press, a member of the Nauka/Interperiodica International Academic Publishing Company since 2007. The rapid progress of MUBSB in recent years is apparently due to the journal having been distributed since 2007 by the internationally renowned Springer publishing consortium that places electronic versions of all articles on its website, which has, to all appearances, led to a manifold increase in the number of journal subscribers. As a result, the number of downloads of MUBSB papers from the publishing company website also raised by an order of magnitude from 2007 to 2013. The growing popularity of the journal is noted to have lead to its inclusion in a number of international databases, and this, in turn, has increased its attractiveness for a large number of authors, including Russian nonmembers of Moscow State University, as well as scientists from research institutes and universities of other countries. The main features of the spectrum of the papers published in MUBSB are briefly considered.

Khokhlov A.N.

Today, gerontologists usually employ certain molecular or cellular biomarkers of aging to evaluate the effects of various interventions in this process, since this approach is much more time-efficient than the construction of survival curves. However, arguments for the expediency of using such biomarkers are often based on the results of studies on what is called cell/cellular senescence. Unfortunately, the usage of this term has recently evolved so that it has largely lost its initial meaning, which is that normal cultured cells are subject to replicative senescence (according to the Hayflick phenomenon) and undergo changes similar to those in the cells of an aging organism. Most of recent studies in this field deal with the induction of relevant changes in cultured (usually transformed) cells by various DNA-damaging factors. Such an approach is important for defining the strategy of cancer control but, yet again, leads away from the study of actual mechanisms of organismal aging. Moreover, there are grounds to consider that biomarkers of aging identified in these studies (in particular, senescence-associated beta-galactosidase activity, the most popular among them) are basically linked to cell proliferative status. At the organismal level, this status is generally determined by the program of development and differentiation of tissues and organs, which in a definitive state are composed of postmitotic or very slowly propagating cells. Therefore, it appears that canceling the aging program will not cause any significant changes in the age-dependent dynamics of the above biomarkers. This conclusion brings us back to the necessity of constructing the survival curves for test groups of animals or humans as the only reliable (though expensive and time-inefficient) approach to evaluating the efficiency of means to modify the aging process.

Khokhlov A.N., Klebanov A.A., Karmushakov A.F., Shilovsky G.A., Nasonov M.M., Morgunova G.V.

We believe that cytogerontological models, such as the Hayflick model, though very useful for experimental gerontology, are based only on certain correlations and do not directly apply to the gist of the aging process. Thus, the Hayflick limit concept cannot explain why we age, whereas our “stationary phase aging” model appears to be a “gist model,” since it is based on the hypothesis that the main cause of both various “age-related” changes in stationary cell cultures and similar changes in the cells of aging multicellular organism is the restriction of cell proliferation. The model is applicable to experiments on a wide variety of cultured cells, including normal and transformed animal and human cells, plant cells, bacteria, yeasts, mycoplasmas, etc. The results of relevant studies show that cells in this model die out in accordance with the Gompertz law, which describes exponential increase of the death probability with time. Therefore, the “stationary phase aging” model may prove effective in testing of various geroprotectors (anti-aging factors) and geropromoters (pro-aging factors) in cytogerontological experiments. It should be emphasized, however, that even the results of such experiments do not always agree with the data obtained in vivo and therefore cannot be regarded as final but should be verified in studies on laboratory animals and in clinical trials (provided this complies with ethical principles of human subject research).

Misharina T.A., Fatkullina L.D., Alinkina E.S., Kozachenko A.I., Nagler L.G., Medvedeva I.B., Goloshchapov A.N., Burlakova E.B.

We studied the effects of essential oils from oregano and clove and a mixture of lemon essential oil and a ginger extract on the antioxidant state of organs in intact and three experimental groups of Balb/c mice. We found that in vivo essential oils were efficient bioantioxidants when mice were treated with it for 6 months even at very low doses, such as 300 ng/day. All studied essential oils inhibited lipid peroxidation (LPO) in the membranes of erythrocytes that resulted in increasing membrane resistance to spontaneous hemolysis, decreasing membrane microviscosity, maintenance of their integrity, and functional activity. The essential oil significantly decreased the LPO intensity in the liver and the brain of mice and increased the resistance of liver and brain lipids to oxidation and the activity of antioxidant enzymes in the liver. The most expressed bioantioxidant effect on erythrocytes was observed after clove oil treatment, whereas on the liver and brain, after treatment with a mixture of lemon essential oil and a ginger extract.

Khokhlov A.N.

There is a standpoint according to which the suppression of the ability of cells in a multicellular organism to proliferate, taking place during aging, as well as the corresponding decline in the regenerative capacities of tissues and organs, is caused by the specialized mechanisms having emerged in the evolution that decrease the risk of malignant transformation and, thereby, provide for protection against cancer. At the same time, various macromolecular defects start to accumulate in senescent cells of the body, which, on the contrary, elevate the probability for malignant transformation of these cells. Thus, according to the mentioned concept, the restriction of cell proliferation is a double-edged sword, which, on the one hand, decreases the probability for malignant tumor development in young age and, on the other hand, limits the lifespan due to accumulation of “spoiled” cells in old age. However, it remains unclear why normal human cells placed under in vitro conditions and thus having no mentioned “anticancer” barriers, which function at the body level only, NEVER undergo spontaneous malignant transformation. In addition, it is unclear how the freshwater hydra escapes both aging and cancer, as it under certain conditions contains no postmitotic and senescent cells at all and under these conditions (excluding the need for sexual reproduction) can live almost indefinitely, possessing a tremendous regenerative potential (a new organism can emerge from even 1/100 part of the old one). Presumably, the restriction of cell proliferation in an aging multicellular organism is not the result of a certain special program. Apparently, there is no program of aging at all, the aging being a “byproduct” of the program of development, whose implementation in higher organisms necessarily requires emergence of cell populations with a very low and even zero proliferative activity, which actually determines the limited ability of the corresponding organs and tissues to regenerate. On the other hand, the populations of highly differentiated cells incapable or poorly capable of reproduction (e.g., neurons, cardiomyocytes, and hepatocytes) are the particular factor that determines the normal functioning of higher animals and humans. Even regeneration of such organs with the help of stem cells may interfere with the necessary links in elaborate systems. The reductionism (“everything is determined by adverse changes in individual cells”), which has recently become widespread in experimental gerontological research, has brought about several model systems for studying the aging mechanisms in isolated cells (Hayflick phenomenon, stationary phase aging model, cellular kinetic model for testing of geroprotectors and geropromoters, etc.). However, it currently seems that data obtained using such models are inappropriate for an automatic extrapolation to the situation in the whole body. Presumably, impairments in regulatory processes functioning at the neurohumoral level are the major players in the mechanisms underlying aging of multicellular organisms rather than a mere accumulation of macromolecular damage in individual cells. It cannot be excluded that a disturbance of such regulation is the particular reason for the abnormal INCREASE in proliferation intensity of some cell populations that are frequently observed in old age and that lead to senile acromegaly and development of numerous benign tumors. It looks like the quality of CONTROL over cells, organs, and tissues becomes poorer with age rather than the quality of the cells themselves, which leads to an increase in the death rate.

Khokhlov A.N.

There is a viewpoint that suppression of the proliferative capacity of cells and impairment of the regeneration of tissues and organs in aging are a consequence of specially arisen during evolution mechanisms that reduce the risk of malignant transformation and, thus, protect against cancer. We believe that the restriction of cell proliferation in an aging multicellular organism is not a consequence of implementing a special program of aging. Apparently, such a program does not exist at all and aging is only a "byproduct" of the program of development, implementation of which in higher organisms suggests the need for the emergence of cell populations with very low or even zero proliferative activity, which determines the limited capacity of relevant organs and tissues to regenerate. At the same time, it is the presence of highly differentiated cell populations, barely able or completely unable to reproduce (neurons, cardiomyocytes, hepatocytes), that ensures the normal functioning of the higher animals and humans. Apparently, the impairment of regulatory processes, realized at the neurohumoral level, still plays the main role in the mechanisms of aging of multicellular organisms, not just the accumulation of macromolecular defects in individual cells. It seems that the quality of the cells themselves does not worsen with age as much as reliability of the organism control over cells, organs and tissues, which leads to an increase in the probability of death.

Khokhlov A.N.

The term “cellular/cell senescence” was first introduced by Leonard Hayflick to describe the “age-related” changes in normal eukaryotic cells during aging in vitro, i.e., over the exhaustion of their mitotic potential. In the “classic” variant, it was assumed that cells “grow old” with the help of some internal mechanism, which leads to accumulation of various macromolecular defects (DNA damage in the first place). Currently, as a rule, “cellular senescence” means accumulation/appearance of particular “biomarkers of aging” in cells (they are most often transformed cells that do not demonstrate any replicative senescence) under the influence of various external factors (oxidative stress, H2O2, mitomycin C, ethanol, ionizing radiation, doxorubicin, etc.) that cause DNA damage. This phenomenon has been called DDR (DNA Damage Response). Among the said biomarkers, there are senescence-associated beta-galactosidase activity, expression of p53 and p21 proteins as well as of proteins involved in the regulation of inflammation, such as IL-6 or IL-8, activation of oncogenes, etc. Thus, “aging/senescence” of cells does not occur simply by itself—it takes place because of the influence of DNA-damaging agents. This approach, in my opinion, despite being very important to define a strategy to fight cancer, distracts us, yet again, from the study of the real mechanisms of aging. It should be emphasized that the “stationary phase aging” model developed in my laboratory also allows registering the occurrence of certain biomarkers of aging in cultured cells, but in this case they arise due to the restriction of their proliferation by contact inhibition, i.e., due to a rather physiological impact, which does not cause any damage to cells by itself (the situation is similar to what we observe in a whole multicellular organism).

Yablonskaya O.I., Ryndina T.S., Voeikov V.L., Khokhlov A.N.

The effect of an aqueous solution of hydrated C60-fullerene (HyFn) on the growth and “stationary phase aging” (accumulation of “age-related” changes in cultured cells during the slowing down of their proliferation within a single passage and the subsequent “aging” in the stationary phase of growth) of transformed B11-dii FAF28 Chinese hamster cells was studied. The final calculated concentration of HyFn in the growth medium was 10−19 M. A paradoxical result contrasting the available data on the absence of HyFn cytotoxicity at higher concentrations was obtained in our experiments: namely, HyFn decelerated cell proliferation (estimated by the growth of mass culture, as well as by the efficiency of colony formation) and accelerated the “stationary phase aging” of the cell culture. Moreover, repeated addition of an aqueous solution of HyFn (to the final calculated concentration of 10−19 M) to the cells that had already reached the stationary phase of growth caused a rapid (within no more than 24 h) death of a significant part of the cell population. The observed effect of HyFn at ultralow concentration is supposed to arise from the alterations in the properties of the water surrounding the fullerene molecule: namely, water becomes a donor and acceptor of electrons and regulates redox processes (especially those involving oxygen) in aqueous systems. This effect of HyFn at an ultralow concentration may be specific for transformed cells, and, therefore, experiments on normal fibroblasts with limited mitotic potential are planned as a continuation of the present study. It is also possible that the reported antiaging effect of HyFn in experimental animals is due to its anticancer, immunostimulatory, antiviral, and antibacterial properties manifested only at the whole-organism level.