Pulse Radiolysis Using Very-high-energy Ions for Optimizing Cancer Therapy.

Cancer therapy by means of high-energy ions is very efficient. As a consequence of the linear-energy-transfer effect only a negligible part of the produced free radicals can escape combination processes to form molecular products and to cause undesired side processes. Positrons (e⁺) and γ-rays, generated by the nuclear interaction of high-energy ions in the medium, serve in monitoring the radiation dose absorbed by the tumor.

Melatonin: Free Radicals and Metabolites Resulting by Emission and Consumption of Solvated Electrons (eaq-): Reaction Mechanisms.

Background/aim: Melatonin not only regulates circadian rhythm, but also induces apoptosis in tumor cells. Hence, elucidation of the basic reaction mechanisms of melatonin and its metabolites is a matter of interest.

Material And Methods: Melatonin dissolved in a mixture of water/ethanol=40/60 form associates (unstable complexes).

Fundamental biological importance of solvated electrons in humans.

Abstract In recent years, "solvated electrons" were shown to be emitted by various biological systems in humans such as hormones, enzymes, amino acids, etc., even by vitamins, dyes, and other organic compounds. Based on experimental results and data from the literature, it is hypothesized that most biological systems in humans are capable of emission.

Corticosterone metabolites originating as a consequence of solvated electron (e(-)aq) emission.

Corticosterone in water-ethanol solution can eject "solvated electrons" (eaq(-)) when excited into the singlet state by monochromatic UV-light (λ=254 nm). As a consequence of this process free radicals and H(+) ions were also generated. Hence, the objectives of this study were to determine the quantum yield, Q, at different corticosterone concentrations, and elucidate the fate of the generated free radicals and the involved reaction mechanisms.

Effect of cytochrome C and vitamin C on the survival of MCF-7 cancer cells under γ-ray treatment.

In the present study, the radiation-induced effect of cytochrome c (CytC) and vitamin C (VitC) is studied with respect to survival of MCF-7 cancer cells grown in aerated media. Both, CytC and VitC, were incubated with MCF-7 cancer cells under various concentrations individually, as well as in mixture and cells were subsequently treated with γ-ray in a dose range of 0 to 30 Gy. Generally, an increase of cell survival was observed under substance treatment up to a radiation dose of 5 Gy compared to the control group.

Significance of solvated electrons (e(aq)-) as promoters of life on earth.

Based on the present state of knowledge a new hypothesis concerning the origin of life on Earth is presented, and emphasizes the particular significance of solvated electrons (e(aq)(-)). Solvated electrons are produced in seawater, mainly by (40)K radiation and in atmospheric moisture by VUV light, electrical discharges and cosmic ray. Solvated electrons are involved in primary chemical processes and in biological processes.

Vitamin C: electron emission, free radicals and biological versatility.

The many-sided biological role of vitamin C (ascorbate) is briefly illustrated by specific examples. It is demonstrated that in aqueous solutions, vitamin C emits solvated electrons (e(aq)(-)), when excited in single state. Vitamin C can also react with e(aq)(-) as well as transfer them to other biological systems and thereby acts as efficient electron mediator.

Formation of sex hormone transients resulting from attack of free radicals.

Background: Transients of the sex hormones testosterone (TES) and estrone (E1) exhibit an impact on the carcinogenesis of most prostate and breast cancer types. For elucidation of involved reaction mechanisms, in vitro, experiments using γ-ray for generation of attacking hormone transients and UV-light (λ=254 nm) for excitation of hormone molecules were applied. Materials and Methods.

Vitamin-induced intracellular electrons are the mechanism for their well-known beneficial effects: a review.

A new conception of the action mechanisms of vitamins and some other compounds without a vitamin status is briefly presented. It is based on results obtained through pulse radiolysis, molecular radiation biological investigations, and in vitro studies. The data clearly show that antioxidant vitamins (C, E, β-carotene) and B vitamins and related compounds possess the capability to emit "solvated electrons" in aqueous solutions or polar media.

Hormones: electron emission, communication, mutual interaction, regeneration, metabolites, carcinogenesis and receptor action.

Abstract This review discusses the highlights of the recently made discovery about the ability of hormones to eject 'solvated electrons' (eaq-) in water containing media. The resulting consequences for communication with other biological systems by the electron-transfer process, formation of metabolites, the possible initiation of cancer, hormone regeneration and the action of hormone-receptor systems are briefly discussed. The molecular structure of the hormones and the environment are hereby found to be the most important determining factors for the yield of ejected eaq-.

New findings concerning the mutual action of hormones and receptors.

The actual mechanisms concerning the role of the hormone-receptor complex cannot satisfactorily explain the various hormone activities. Photobiological studies were performed in order to gain a deeper insight in this respect. 17β-estradiol (17βE(2)) was used as representative hormone and methionine-enkephaline (ME) was used as an adequate model for a receptor.

Cytochrome c: electron emission, photodegradation and mutual interaction with vitamin C.

Cytochrome c (Cytc) in airfree, aqueous media (pH ~7.4; 37°C) can emit e(-)(aq) when exited in single state by monochromatic UV light (λ=254 nm). The obtained Qi(e(-)(aq)) at lower Cytc concentrations is higher compared to the amount obtained at higher substrate concentrations because at >10(-8) mol l(-1) Cytc 'associates' (unstable complexes) are formed, which consume a part of the ejected e(-)(aq).

Dopamine: effect of concentration and pH on the electron emission. Reaction mechanisms.

Dopamine (DA) in airfree, aqueous solution (pH 7.4; 37°C) is able to emit e(-)(aq) when electronically excited in its singlet state by monochromatic UV light (λ=254 nm; 4.85 eV/hν).

Method for regeneration of hormones: 17β-estradiol, 21α-hydroxyprogesterone and corticosterone. A pathway for a possible medical application.

The hormones 17β-estradiol (17βE2), 21α-hydroxyprogesterone (21α-HOPRG) and corticosterone (CORT) were used as representative models for the study. As a source for hormone excitation in singlet state serviced monochromatic UV-light (λ=254 nm), it was stated that the transients resulting by e-aq emission in air-free mixture water/ethanol 40/60, as long as they are in "status nascendi", can be regenerated by electron transfer from a potent electron donor, e.g.

Photo-induced regeneration of hormones by electron transfer processes: Potential biological and medical consequences.

Based on the previous results concerning electron transfer processes in biological substances, it was of interest to investigate if hormone transients resulting by e.g. electron emission can be regenerated.

The effect of progesterone on the electron emission and degradation of testosterone.

Based on recent findings that hormones can emit electrons () from their excited singlet state in polar media, it was of importance to study a possible mutual interaction of progesterone (PRG) and testosterone (TES) in this respect. Hormones of highest purity were dissolved in an air-free mixture of 40% triply distilled water and 60% ethanol, because the hormones are unsoluble in water. As energy source for substrate excitation in singlet state served a monochromatic UV-light (254 nm), the emitted electrons were scavenged by chloroethanol, whereby the quantum yield of produced Cl⁻ ions, Q (Cl⁻), is equal to Q(e⁻(aq)).

Adrenaline: communication by electron emission. Effect of concentration and temperature. Product analysis.

BACKGROUND: Based on the recent findings about the ability of sexual hormones to emit electrons (e(aq) (-)) and to act as electron mediator, it was of interest to investigate adrenaline as an important neurotransmitter. MATERIALS AND METHODS: Highest purity adrenaline (ADR) and chemicals were used for preparation of aqueous solutions (pH ~7.4).

Metabolite formation of 17alpha-hydroxyprogesterone as a consequence of e⁻(aq)-emission and progesterone effect regarding cancer.

Based on previous investigations on several hormones, 17α-hydroxyprogesterone (17α-HOPRG) was studied in respect to cancer initiation by its metabolites resulting from electron emission. The emission of electrons (e⁻(aq)) from its singlet excited state of 17α-HOPRG and HPLC-analysis of products were studied. Possible carcinogenicity of metabolites originating from 17α-HOPRG and the effect of progesterone (PRG) in this respect were studied in vitro.

Mutual interaction of 17beta-estradiol and progesterone: electron emission. Free radical effect studied by experiments in vitro.

Background: Based on the different behaviour of 17beta-estradiol (17betaE(2)) and progesterone (PRG), it was of interest to investigate the interaction of both hormones in respect of their electron emission and cytotoxicity by experiments in vitro.

Materials And Methods: The studies include determination of emitted electrons (e(-)(aq)) by the individual hormones as well as by their mixtures, all complexed with cyclodextrin (HBC). Experiments in vitro (Escherichia coli bacteria) were performed for a better understanding of the mechanisms involved.

Electron emission and product analysis of estrone: progesterone interactions studied by experiments in vitro.

Recent studies showed that hormones like progesterone, testosterone, etc. can eject [Formula: see text] (solvated electrons). By means of electron transfer processes via the brain, the hormones communicate with other biological systems in the organism.

17beta-estradiol acting as an electron mediator: experiments in vitro.

Background: The present work reports on the effect of oxidizing (OH, O(2)(*-)) and reducing free radicals (e(-)(aq), H) on 17beta-estradiol (17betaE2) in respect to breast cancer initiation. The objectives of the study were based on the following premise: the ability of 17betaE2 to emit electrons (e(-)(aq)) as well as to transfer them to other biological systems. Thereby, the resulting transient hormone products are leading to the formation of metabolites, some of which may initiate the neoplastic process.

The 4-hydroxyestrone: Electron emission, formation of secondary metabolites and mechanisms of carcinogenesis.

4-Hydroxyestrone (4-OHE(1)), a typical cancer-inducing metabolite, originating from 17beta-estradiol (17beta-E2), was chosen as a model for the studies. The aim was to get a deeper insight in the mechanisms of its ability to initiate cancer. It was found, that 4-OHE(1) can eject electrons (e(aq)(-)), when excited in the singlet state by monochromatic UV-light (lambda=254 nm) in polar media (water:ethanol=40:60 vol.

Effect of free radicals on the biological action of genistein in vitro and synergism with mitomycin C.

Background: The effect of oxidizing and reducing free radicals on the biological properties of genistein (GEN) were investigated in vitro.

Materials And Methods: MCF-7 cells were treated with GEN (5 micromol or 40 micromol) and/or mitomycin C (MMC; 2.5 micromol).

Vitamin free radicals and their anticancer action. Review.

The antimumor effect of antioxidant vitamins (C, E and beta-carotene) as well as of the vitamins B1 up to B6 and B11 under the action of oxidizing (OH, O(2)(*-)) and reducing free radicals (e(aq)(-), H) is discussed. In addition, the synergistic action of vitamins on cytostatic agents under the influence of free radicals and the involved reaction mechanisms are briefly discussed. The very fast kinetics of electron transfer taking place within a biological molecule (vitamin B11) is shown for demonstration of the complicated free radical processes in the organism.