**7. Discussion**

Our experiments demonstrated that the interaction of carotenoids with lipids could result in the formation of their complexes, which were thermodynamically

#### *Carotenoids in Thermal Adaptation of Plants and Animals DOI: http://dx.doi.org/10.5772/intechopen.104537*

more favourable than when these two groups of molecules were separate. As a result of this, carotenoids were better able to absorb the light energy in the longer wavelength of the red part of the spectrum.

The physical properties of lipids in these complexes were also changed due to a possible reduction in their cohesiveness between these molecules. For oil droplets or fat globules, this resulted in a reduction of their surface tension and, consequently, facilitated their fusion or enlargement. The larger the lipid droplets are, the less energy they have. Therefore, carotenoids can create complexes with lipids, which trigger their transition into a thermodynamically more favourable and stable phase. The fact that a single molecule of the carotenoid can affect the behaviour of 10,000 or 100,000 molecules of lipids may imply the possibility that the released energy, after formation of this type of complex, can dissipate beyond its physical location and cause a long-range transition of the lipid matrix, with consequent physical changes of its properties.

Lipid droplets with increased size would have less friction between each other, and the oils and fats became less viscous. Whether the reduction in the viscosity was a result of blending carotenoids in existing oil or fat products, or their incorporation into *de novo* assembled lipid structures, the effect in principle was the same. This was confirmed in the clinical trial, when the increase in lycopene concentration in the skin sebum resulted in the reduction of the viscosity of its droplets (**Figure 2**). These changes in sebum quality were similar to the observations on the supplementation of volunteers with other carotenoids such as lutein (results not presented here) and astaxanthin [6].

A significantly higher response in changes of the viscosity of plant lipids, over animal ones, could probably be either a result of their stronger interaction with carotenoids or easier spreadability of conformational changes in the plant lipids than in the animal fats. Or this can be a combination of both of these factors. Animals cannot synthesise carotenoids but plants can, and this is probably why the affinity to these molecules to other plant molecules, lipids, is higher than to animal ones.

The increased surface area of enlarged oil droplets or fat globules would have more surface-to-surface contacts with each other, which would facilitate the transfer of changing temperature between these particles. Whether there is a thawing of frozen liquid hydrocarbons, or melting of solid lipids, or their heating, the incorporation of carotenoids into these molecules accelerated temperature energy transfer within them.

Since one molecule of a carotenoid was able to facilitate temperature changes in 10,000, or 100,000 or more molecules of lipids, it is unclear whether this was due to changes in lipid molecule thermoconductivity, or carotenoids, in their complex with lipids, may work as 'thermal antennas', which could dissipate and distribute thermal radiation/energy far beyond the physical location of carotenoid-lipid complex.

The ability of carotenoids to increase the accumulation of thermal energy and its distribution was significantly higher for the plant lipids than for the fish oil, which, in turn, responded better than the mammalian fats. The reason for this effect of carotenoids on heat absorption gradient in different lipids could be the fact that plants are exposed to much broader variations in environmental temperature changes than ectotherms/poikilotherms like fish, when the body temperature of endotherms like mammals is constant.

The viscosity of lipids is the essential parameter, which controls cellular membrane permeability to electrolytes and nutrients, energy synthesis, cell growth and proliferation. One of the main factors determining the viscosity of lipids, and their ability to conduct the heat or the cool, is a lipid composition, a ratio of triglyceride saturated and unsaturated fatty acids, their length, other incorporated lipids, etc.

Our experiments indicate that carotenoids could have a new biological role not only to control viscosity of lipids but their thermal energy absorption, retention and conductivity too. If this is the case, this could be a much more efficient pathway to control these parameters. For a plant cell, to synthesise one molecule of a carotenoid, which can change the viscosity of 10,000 or even 100,000 molecules of lipids, would be much faster and more economic than to activate a lipid replacement process, which would involve a few hundred or thousand more new lipid molecules to be synthesised.

This possible new role of carotenoids as a factor facilitating adaptation to environmental, and in particular, temperature variation stresses, may explain a number of observations, which do not have clear explanations. What is the role of carotenoids, which are not involved in photosynthesis whether in a plant or in a light harvesting microorganism? What is the role of these molecules in parts of the plant where photosynthesis is not happening at all, like fruits or roots?

Since plants, or microorganisms such as algae, have exposure to much higher day-night, seasonal or other environmental temperature variability than animals, it is not surprising that the level of carotenoids in their tissue is 103 –106 higher than in animals [8, 9]. Within animals, ectotherms, which do not have their own mechanism to control their temperature, rely more on the accumulation of ingested carotenoids than endotherms, which can maintain their thermal homeostasis. It is not surprising that in tissues of fish or reptiles, carotenoid concentration could be from 10- to 100 fold higher than in mammalians [10, 11].

The ability of carotenoids to work as antennas facilitating transmission and distribution of the thermal energy within lipid matrixes may find its practical applications in different industries. This carotenoid property may improve the performance of lipids, and possibly other hydrocarbons, when they are used for the production of greases, lubricants, liquid crystal devices, nanotubes, thermal energy storage, biodiesel and some other products, oils and fuels.

For example, carotenoids can accelerate the heating of oil or lipid-in-oil emulsions in general (**Figure 4f**), or when they used for cooking purposes in particular. This can shorten the time of the cooking process, save fuel, which is used to generate heating energy, and preserve more thermo-sensitive vitamins and micronutrients in the finished cooked meal (**Figure 5**). The correlation between the rate of acceleration of the heating of the cooking meal, in oils with different carotenoids, and the level of preserved thermo-sensitive vitamins was not always observed. This was probably due to additional antioxidant properties of carotenoids, which could contribute to preservation of these vitamins in the cooking process.

Another useful application of the ability of carotenoids to disrupt lipid folding would be to increase the size and reduce the viscosity of oil droplets and fat globules in food products. We demonstrated that the ingestion of dairy butter, vegetable oils and chocolate with enlarged lipid particles resulted not only in the reduction of the postprandial lipidaemia but also, if these products were regularly consumed, in the reduction of elevated fasting blood lipids. This means than carotenoids can be used to convert edible oils and fats into lipid lowering and weight management food products.

Perhaps, the culinary practice of cooking in oils/fats with lycopene-rich tomato sauce is a contributing factor as to why Italians are one of the slimiest nations in Europe and the USA [12, 13].

In our *in vitro* and *ex vivo* experiments, on the effect of lycopene and lutein of formation and dissolution of cholesterol crystals, we used a range of the ratio *Carotenoids in Thermal Adaptation of Plants and Animals DOI: http://dx.doi.org/10.5772/intechopen.104537*

between these molecules the same as is present in humans from 1:4000 to 1:1000. The observed ability of carotenoids to interact with cholesterol molecules, to reduce the rate of its crystallisation, may be used for the prevention or control of the growth of cholesterol crystals and/or for the treatment by facilitating the disassembly of the already formed crystals, which are responsible for the rupture of atherosclerotic plaques leading to heart attack or ischaemic stroke [14, 15].

To assess the industrial, nutritional and medical applicability of using carotenoids to affect lipid properties, to create new materials, food and health care products would require more work and expertise in different fields.

In conclusion, it should be said that the main objective of the presentation of the data in this paper is to illustrate the new phenomenon, its potential biological role and practical applicability. The main body of the backing/supporting experiments on different carotenoids, lipids, doses, conditions, products, clinical trial participants, etc., would be a subject of future separate publications.

## **Acknowledgements**

The author is grateful to his colleagues for conducting experiments results of which are presented in this paper: Dr Alexandre Loktionov Jr., Dr Alexey Petyaev, Professor, Pavel Dovgalevsky, Professor Viktor Klochkov, Dr Natalya Chalyk, Dr Dmitry Pristenskiy, Dr Marina Chernyshova, Dr Alexandre Loktionov, Dr Tatyana Bandaletova, Nigel Kyle, Marina Lozbiakova. A special thank you to Mr. William George for his personal supporting this project, Professor Yuriy Bashmakov for stimulating discussions in the filed, and Mrs. Anne George for editing this manuscript.

## **Conflict of interest**

The author is a founder and director of Lycotec Ltd, the company that research and develop carotenoid based technologies.

*Carotenoids - New Perspectives and Application*


**1. Introduction**

Classic Hodgkin lymphoma (CHL) stands out among malignant tumors, by the relative paucity of the tumor cells in the involved lymph nodes. These Hodgkin and Reed-Sternberg (H/RS) cells (**Figure 1**) are distributed unevenly within the majority of inflammatory cells, fibrosis and necrosis [1]. It is understood that, independent of the proportion of H/RS cells in CHL, the outcome of the malignancy will be favorable, with a cure rate of 75–90% [2, 3]. Such a therapeutic success is unusual for cancer at large.

When considering the many prognostics and risk factors regarding CHL, the stage of the tumor, as expected, is the most relevant. Evidence of systemic symptoms: fever higher than 38°C for at least a month; weight loss of more than 10% of body weight, lasting 6 months or more, and/or drenching night sweats, singly or collectively, worsen the prognosis [1]. A difference is described between genders, as females fare as a rule better than males, no consideration being given to a higher incidence of nodular sclerosis CHL in females. Indeed, children and older adult males with mixed cellularity CHL, especially in developing countries, get on worse with the disease [2, 4]. In contrast, females would be included in the bulk of CHL patients, aged 15–36, with a favorable outcome [5].

#### **Figure 1.**

*Section of lymph node from a patient with classic HL. Off center is a Hodgkin/Reed-Sternberg giant tumor cell (H&E × 360).*

Some 15-20% of human cancers are thought to arise by mechanisms which concern viruses, bacteria, or parasites [6, 7]. Evidence for their involvement comes partly from the detection of the microorganism in biopsies and partly from epidemiological and animal studies. Viruses might modify cellular genes directly, as with RNA tumor viruses, or may affect cell proliferation, as with DNA tumor viruses, and thus contribute to neoplasm formation [6, 7]. As a rule, the virus is responsible for only a limited number of steps in the promotion or progression of cancer. In most cases, the precise role of cancer-associated virus is hard to decipher, due to the long delay from the initial viral infection [6]. In any case, the number of human beings infected with the above viruses is much larger by far from that of patients who develop cancer. Therefore, tumor viruses probably act in conjunction with additional factors [7].

Chronic inflammation may play an important role in the above processes as well as in other pathologic events which may lead to cancer [8]. In some cases of unresolved chronic inflammation, the immune response becomes maladaptive, hence promoting tumorigenesis [8]. A regenerative process supported by an array of bioactive mediators, promote cell survival, tissue remodeling, and angiogenesis. The mediators will also cause genomic stress and mutations [9].

A correlation between CHL and the Epstein-Barr virus (EBV) has been demonstrated many years ago [10, 11], with a causal relationship being established as soon as 2001 [12]. The incidence of EBV infection in CHL has shown a wide geographic variation, from 17 to 30% in industrialized countries, to as high as 100% in some developing countries [13, 14]. Several more years elapsed before the distribution of EBV infection by gender, age, and CHL type was determined (**Figure 2**) [13, 14]. Thus, EBV is expressed more frequently in males, notably in children from developing countries, as well as in older adults all over the globe, these two groups showing as a rule mixed cellularity CHL. Female CHL patients stand out, in general, by showing nodular sclerosis CHL with a markedly lower level of EBV expression and a young adult age (15–36) [15]. A small subset of young adult males will develop CHL after recovering from infectious mononucleosis [16]. The EBV is recognized as oncogenic. Specifically, its transforming potential, with cell proliferation, inflammation, and apoptosis arrest, has been related to the nuclear factor-κB (NF-κB) and the EBV/LMP1 will further contribute to the inhibition of the H/RS cell apoptosis [15–19]. As noted, EBV does not play a significant role in the largest subset of CHL that affect young adults and most of the female CHL patients.

**139**

**Figure 2.**

recalled to various extents of those of CHL.

but it may be long lasting [12].

*A Role for the Measles Virus in Oncology DOI: http://dx.doi.org/10.5772/intechopen.84342*

The above subset of young adult female patients corresponds to that defined in the hallmark epidemiological studies in the early 1980s as patients with the "late host response model" [15–19]. These patients are considered to be submitted to the late exposure to a common infectious agent, the term "late" meaning that instead of coming across the common infectious agent for the first time in early childhood, this occurs at adolescence or young adulthood. The epidemiological thesis further suggests that these individuals had a late encounter with the agent, since they had few and late contacts with other children (single child, individual family house, and child who skipped the kindergarten) [15]. To account for the late host response model, it is suggested that a common agent, probably a virus, reaches the organism for the first time at a stage in which the metabolism and/or the hormonal balance is markedly different from that of a toddler, the age at which the encounter regularly takes place. At this point, the internal environment has varied deeply and probably, so has the immune system [15–19]. Thus, it seems that the EBV plays a relatively minor role, in the largest subset of the CHL that is most prevalent in industrialized countries [18]. When looking for a substitute for the EBV in CHL, it was observed that none of the additional viruses, HHV-6, -7, -8, polyoma JC virus, SV40, HTLV-1 and -2, and human retrovirus 5, once considered as possible candidates, have been detected in CHL tissues [20–26]. The only virus to be incompletely excluded at that time was the HCMV. However, one distinct virus showed qualities and associations which

*Association between age, gender, EBV expression, and classic Hodgkin lymphoma, including the types thereof.*

The "candidate" proposed by us is the measles virus (MV). It penetrates the organism through the oropharynx. But, since it is lymphotropic, it enters the adjacent lymphoid tissues. This may account for the vast majority of CHL starting in cervical and/or in mediastinal lymph nodes [12, 27]. Histologically, it elaborates multinucleated cells—the Warthin-Finkeldey polykaryons. Of note, these polykaryons differ largely from the H/RS cells of CHL, mainly by the number of nuclei (up to 70) as well as by their phenotype (they are T-lymphocytes) [28]. An acute measles infection is soon followed, on the one hand by a life-long specific immunity, but also, paradoxically a transient cellular immune deficiency systematically develops. This deficiency lasts about 6 months, but at times, may last longer. The cellular immune deficiency which affects CHL patients is not different in principle,

*A Role for the Measles Virus in Oncology DOI: http://dx.doi.org/10.5772/intechopen.84342*

#### **Figure 2.**

*Viruses and Viral Infections in Developing Countries*

Some 15-20% of human cancers are thought to arise by mechanisms which concern viruses, bacteria, or parasites [6, 7]. Evidence for their involvement comes partly from the detection of the microorganism in biopsies and partly from epidemiological and animal studies. Viruses might modify cellular genes directly, as with RNA tumor viruses, or may affect cell proliferation, as with DNA tumor viruses, and thus contribute to neoplasm formation [6, 7]. As a rule, the virus is responsible for only a limited number of steps in the promotion or progression of cancer. In most cases, the precise role of cancer-associated virus is hard to decipher, due to the long delay from the initial viral infection [6]. In any case, the number of human beings infected with the above viruses is much larger by far from that of patients who develop cancer. Therefore, tumor viruses probably act in conjunction with additional factors [7]. Chronic inflammation may play an important role in the above processes as well as in other pathologic events which may lead to cancer [8]. In some cases of unresolved chronic inflammation, the immune response becomes maladaptive, hence promoting tumorigenesis [8]. A regenerative process supported by an array of bioactive mediators, promote cell survival, tissue remodeling, and angiogenesis.

*Section of lymph node from a patient with classic HL. Off center is a Hodgkin/Reed-Sternberg giant tumor cell*

The mediators will also cause genomic stress and mutations [9].

CHL that affect young adults and most of the female CHL patients.

A correlation between CHL and the Epstein-Barr virus (EBV) has been demonstrated many years ago [10, 11], with a causal relationship being established as soon as 2001 [12]. The incidence of EBV infection in CHL has shown a wide geographic variation, from 17 to 30% in industrialized countries, to as high as 100% in some developing countries [13, 14]. Several more years elapsed before the distribution of EBV infection by gender, age, and CHL type was determined (**Figure 2**) [13, 14]. Thus, EBV is expressed more frequently in males, notably in children from developing countries, as well as in older adults all over the globe, these two groups showing as a rule mixed cellularity CHL. Female CHL patients stand out, in general, by showing nodular sclerosis CHL with a markedly lower level of EBV expression and a young adult age (15–36) [15]. A small subset of young adult males will develop CHL after recovering from infectious mononucleosis [16]. The EBV is recognized as oncogenic. Specifically, its transforming potential, with cell proliferation, inflammation, and apoptosis arrest, has been related to the nuclear factor-κB (NF-κB) and the EBV/LMP1 will further contribute to the inhibition of the H/RS cell apoptosis [15–19]. As noted, EBV does not play a significant role in the largest subset of

**138**

**Figure 1.**

*(H&E × 360).*

*Association between age, gender, EBV expression, and classic Hodgkin lymphoma, including the types thereof.*

The above subset of young adult female patients corresponds to that defined in the hallmark epidemiological studies in the early 1980s as patients with the "late host response model" [15–19]. These patients are considered to be submitted to the late exposure to a common infectious agent, the term "late" meaning that instead of coming across the common infectious agent for the first time in early childhood, this occurs at adolescence or young adulthood. The epidemiological thesis further suggests that these individuals had a late encounter with the agent, since they had few and late contacts with other children (single child, individual family house, and child who skipped the kindergarten) [15]. To account for the late host response model, it is suggested that a common agent, probably a virus, reaches the organism for the first time at a stage in which the metabolism and/or the hormonal balance is markedly different from that of a toddler, the age at which the encounter regularly takes place. At this point, the internal environment has varied deeply and probably, so has the immune system [15–19]. Thus, it seems that the EBV plays a relatively minor role, in the largest subset of the CHL that is most prevalent in industrialized countries [18].

When looking for a substitute for the EBV in CHL, it was observed that none of the additional viruses, HHV-6, -7, -8, polyoma JC virus, SV40, HTLV-1 and -2, and human retrovirus 5, once considered as possible candidates, have been detected in CHL tissues [20–26]. The only virus to be incompletely excluded at that time was the HCMV. However, one distinct virus showed qualities and associations which recalled to various extents of those of CHL.

The "candidate" proposed by us is the measles virus (MV). It penetrates the organism through the oropharynx. But, since it is lymphotropic, it enters the adjacent lymphoid tissues. This may account for the vast majority of CHL starting in cervical and/or in mediastinal lymph nodes [12, 27]. Histologically, it elaborates multinucleated cells—the Warthin-Finkeldey polykaryons. Of note, these polykaryons differ largely from the H/RS cells of CHL, mainly by the number of nuclei (up to 70) as well as by their phenotype (they are T-lymphocytes) [28]. An acute measles infection is soon followed, on the one hand by a life-long specific immunity, but also, paradoxically a transient cellular immune deficiency systematically develops. This deficiency lasts about 6 months, but at times, may last longer. The cellular immune deficiency which affects CHL patients is not different in principle, but it may be long lasting [12].

At the time our thesis was formulated, the type of MV neural infection known as subacute sclerosing panencephalitis (SSPE) was considered one of the very few persistent MV infections, most being CNS slow viral infections. However, it was difficult to grasp a possible association between MV and cancer, which would not account for the long lapse of time necessary for the malignant transformation. In that context, the absence of a persistent MV infection might be counterproductive. The alternative being that against all odds, MV may be oncogenic, and the MV is not among the consensually recognized oncogenic viruses! An additional clue to MV causing a persistent infection beyond the CNS is the absence of membrane expression of hemagglutinin MV antigens, although this lack of expression might be due also to the lymph node mode of fixation [29].


**3.3. Bacteria in soil**

Soil-associated bacteria are highly influenced by soil moisture. For most plant pathogenic bacteria, high humidity favors disease onset and development. Incidentally, bacterial wilt (*Ralstonia solanacearum*) was first known as the "moisture disease" of potatoes, before the causal agent was identified [71]. In fact, the disease is prevalent during the wet summers, when high temperatures and high humidity are combined in a perfect condition for bacterial multiplication.

When comparing irrigation methods on bacterial wilt, Marouelli et al. [7] found that disease was significantly higher when processing tomato in Central Brazil was drip-irrigated, with an average of 42.5% wilted plants, 65 days after seedling transplant, in comparison with 5.0% incidence with sprinkle irrigation. Frequency of drip irrigation did not affect bacterial wilt incidence. It is believed that drip irrigation maintains the plant rhizosphere close to field capacity, thus favoring the disease, contrasting with the sprinkle irrigation, which provides periods of dry and wet conditions. Furrow irrigation was not studied, but it would most probably have an effect similar to the drip irrigation, or even more pronounced, if dispersion of the pathogen in the furrow is taken into account.

Contrasting with bacterial wilt, potatoes are affected by common scab, induced by *Streptomyces* spp. In this case, however, low soil humidity during tuber growth phase favors scab formation, what makes irrigation management recognized as one of the most efficient scab control measures. According to Wharton et al. [72], keeping soil moisture near field capacity for a few weeks at the beginning of tuberization substantially inhibits pathogen infection and disease development. The most likely explanation for this phenomenon is that the maintenance of high soil moisture is a condition that favors a more varied and competitive microbiota in the host rhizosphere, to the detriment of *Streptomyces* species.

Overall, because plant pathogenic bacteria may be viable in water for long periods of time, irrigation deserves special attention for two important epidemiological processes: survival and dispersal [73].