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1.
Drug Res (Stuttg) ; 71(1): 4-9, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33128226

RESUMO

Drug repositioning is a strategy that identifies new uses of approved drugs to treat conditions different from their original purpose. Current efforts to treat Covid-19 are based on this strategy. The first drugs used in patients infected with SARS-CoV-2 were antimalarial drugs. It is their mechanism of action, i. e., rise in endosomal pH, which recommends them against the new coronavirus. Disregarding their side effects, the study of their antiviral activity provides valuable hints for the choice and design of drugs against SARS-CoV-2. One prominent drug candidate is thymoquinone, an antimalarial substance contained in Nigella sativa - most likely one of the first antimalarial drugs in human history. Since the outbreak of the pandemic, the number of articles relating thymoquinone to Covid-19 continuously increases. Here, we use it as an exemplary model drug, compare its antiviral mechanism with that of conventional antimalarial drugs and establish an irreducible parametric scheme for the identification of drugs with a potential in Covid-19.Translation into the laboratory is simple. Starting with the discovery of Nigella sativa seeds in the tomb of Pharaoh Tutankhamun, we establish a physicochemical model for the interaction of thymoquinone with both coronavirus and cells. Exploiting the predictive capability of the model, we provide a generalizable scheme for the systematic choice and design of drugs for Covid-19. An unexpected offshoot of our research is that Tutankhamun could not have died of malaria, a finding contrary to the mainstream theory.


Assuntos
Antimaláricos/uso terapêutico , Tratamento Farmacológico da COVID-19 , Nigella sativa/química , Antimaláricos/história , Antivirais/uso terapêutico , Benzoquinonas/farmacologia , Benzoquinonas/uso terapêutico , Reposicionamento de Medicamentos , Egito , Pessoas Famosas , História Antiga , Humanos
2.
Ann Transl Med ; 8(7): 440, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32395484

RESUMO

BACKGROUND: It is shown that despite exponential increase in the number of clinically exciting results in low level light therapy (LLLT), scientific progress in the field is retarded by a wrong fundamental model employed to explain the photon-cell interaction as well as by an inadequate terminology. This is reflected by a methodological stagnation in LLLT, persisting since 1985. The choice of the topics is, by necessity, somewhat arbitrary. Obviously, we are writing more about the fields we know more about. In some cases, there are obvious objective reasons for the choice. Progress in LLLT is currently realized by a trial and error process, as opposed to a systematic approach based on a valid photon-cell interaction model. METHODS: The strategy to overcome the current problem consists in a comprehensive analysis of the theoretical foundation of LLLT, and if necessary, by introducing new interaction models and checking their validity on the basis of the two pillars of scientific advance (I) agreement with experiment and (II) predictive capability. The list of references used in this work, does contain a representative part of what has been done in the photon-cell interaction theory in recent years, considered as ascertained by the scientific community. RESULTS: Despite the immense literature on the involvement of cytochrome c oxidase (COX) in LLLT, the assumption that COX is the main mitochondrial photoacceptor for R-NIR photons no longer can be counted as part of the theoretical framework proper, at least not after we have addressed the misleading points in the literature. Here, we report the discovery of a coupled system in mitochondria whose working principle corresponds to that of field-effect transistor (FET). The functional interplay of cytochrome c (emitter) and COX (drain) with a nanoscopic interfacial water layer (gate) between the two enzymes forms a biological FET in which the gate is controlled by R-NIR photons. By reducing the viscosity of the nanoscopic interfacial water layers within and around the mitochondrial rotary motor in oxidatively stressed cells R-NIR light promotes the synthesis of extra adenosine triphosphate (ATP). CONCLUSIONS: Based on the results of our own work and a review of the published literature, we present the effect of R-NIR photons on nanoscopic interfacial water layers in mitochondria and cells as a novel understanding of the biomedical effects R-NIR light. The novel paradigm is in radical contrast to the theory that COX is the main absorber for R-NIR photons and responsible for the increase in ATP synthesis, a dogma propagated for more than 20 years.

3.
Photobiomodul Photomed Laser Surg ; 37(6): 336-341, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31107170

RESUMO

Objective: Several reports claim that the enzyme cytochrome c oxidase (CCO) is the primary absorber for red-to-near-infrared (R-NIR) light in cells and causal for mitochondrial adenosine triphosphate (ATP) upregulation, and that pulsed R-NIR light has frequent therapeutic effects, which are superior to those of the continuous wave (CW) mode used in low-level light therapy (LLLT). Background data: Convincing evidence that the absorption of R-NIR photons by CCO is involved in mitochondrial ATP upregulations as well as a coherent explanation for the superiority of the pulsed irradiation mode is presently lacking in the literature. Methods: A comprehensive literature search and rigorous analysis of the data published on the idea that CCO is the primary absorber for R-NIR light, and of the claim that the effectivity of the pulsed irradiation mode can be derived from the absorption of R-NIR photons by CCO, reveal a number of severe inconsistencies. Results: A systematical analysis covering both the theory that CCO is the primary acceptor for R-NIR light and of its use to interpret differences between the biological effect of pulsed light and CW casts doubt on the general validity of the CCO-based hypothesis. Instead, we are offered a simple and conflict-free model accounting for both ATP upregulation and superiority of the pulsed mode in LLLT, which is in agreement with the results of recent laboratory experiments. Conclusions: CCO is not the primary acceptor for R-NIR light.


Assuntos
Trifosfato de Adenosina/metabolismo , Comunicação Celular/efeitos da radiação , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Terapia com Luz de Baixa Intensidade , Mitocôndrias/metabolismo , Fótons , Regulação para Cima
5.
Photomed Laser Surg ; 36(5): 284-286, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29570422

RESUMO

OBJECTIVE: The objective of this work is to put forward a mechanism by which low-level light [red-to near infrared (NIR) laser or light emitting diodes (LED)] is instrumental in the process of accelerating the healing of wounds. BACKGROUND DATA: Interaction modalities of low-level light with oxidatively stressed cells and tissues are the focus of intense research efforts. Several models of the light/cell-interaction mechanism have been proposed. In the most popular model, cytochrome c oxidase is believed to play the role of the principal acceptor for red-to NIR photons. METHODS: Using as an illustrative example the successful LED treatment of an edematous limb ulcer, the results of recent in vitro tests and complementary laboratory experiments are presented and discussed. RESULTS: The most plausible mechanism of biostimulatory effect of red-to NIR light consists of its impact on the nanoscopic interfacial water layers in mitochondria and the extracellular matrix (ECM) where mitochondrial reactive oxygen species (ROS) induce an increase in the viscosity of the water layers bound to the predominantly hydrophilic surfaces in the intramitochondrial space as well as the ECM, where the process progressively propagates with age. The biostimulatory effect of red-to NIR light consists of counteracting the ROS-induced elevation of interfacial water viscosities, thereby instantly restoring the normal mitochondrial function, including the synthesis of adenosine triphosphate (ATP) by the rotary motor (ATP synthase). CONCLUSIONS: An understanding of the mechanism of interaction of red-to NIR light with mitochondria, cells, and tissues safeguards progress in the field of low-level light therapy (LLLT) and puts us in the position to design better therapies.


Assuntos
Envelhecimento/fisiologia , Lasers Semicondutores/uso terapêutico , Úlcera da Perna/radioterapia , Terapia com Luz de Baixa Intensidade/métodos , Espécies Reativas de Oxigênio/metabolismo , Humanos , Mitocôndrias/metabolismo , Mitocôndrias/efeitos da radiação , Estresse Oxidativo/efeitos da radiação , Sensibilidade e Especificidade , Cicatrização/fisiologia , Cicatrização/efeitos da radiação
6.
Photomed Laser Surg ; 30(1): 54-60, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22029866

RESUMO

OBJECTIVE: The aim of the present study is to present the results of in vitro experiments with possible relevance in the treatment of Alzheimer's disease (AD). BACKGROUND DATA: Despite intensive research efforts, there is no treatment for AD. One root cause of AD is the extra- and intracellular deposition of amyloid-beta (Aß) fibrils in the brain. Recently, it was shown that extracellular Aß can enter brain cells, resulting in neurotoxicity. METHODS: After internalization of Aß(42) into human neuroblastoma (SH-EP) cells, they were irradiated with moderately intense 670-nm laser light (1000 Wm(-2)) and/or treated with epigallocatechin gallate (EGCG). RESULTS: In irradiated cells, Aß(42) aggregate amounts were significantly lower than in nonirradiated cells. Likewise, in EGCG-treated cells, Aß(42) aggregate amounts were significantly lower than in non-EGCG-treated cells. Except for the cells simultaneously laden with Aß(42) and EGCG, there was a significant increase in cell numbers in response to laser irradiation. EGCG alone had no effect on cell proliferation. Laser irradiation significantly increased ATP levels in Aß(42)-free cells, when compared to nonirradiated cells. Laser-induced clearance of Aß(42) aggregates occurred at the expense of cellular ATP. CONCLUSIONS: Irradiation with moderate levels of 670-nm light and EGCG supplementation complementarily reduces Aß aggregates in SH-EP cells. Transcranial penetration of moderate levels of red to near-infrared (NIR) light has already been amply exploited in the treatment of patients with acute stroke; the blood-brain barrier (BBB) penetration of EGCG has been demonstrated in animals. We hope that our approach will inspire a practical therapy for AD.


Assuntos
Doença de Alzheimer/radioterapia , Amiloide/ultraestrutura , Antineoplásicos/uso terapêutico , Neoplasias Encefálicas/diagnóstico por imagem , Catequina/análogos & derivados , Terapia com Luz de Baixa Intensidade , Neuroblastoma/ultraestrutura , Trifosfato de Adenosina/metabolismo , Amiloide/efeitos dos fármacos , Amiloide/efeitos da radiação , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/radioterapia , Catequina/uso terapêutico , Humanos , Microscopia de Fluorescência , Neuroblastoma/tratamento farmacológico , Neuroblastoma/metabolismo , Neuroblastoma/radioterapia , Células Tumorais Cultivadas , Ultrassonografia
8.
Artigo em Inglês | MEDLINE | ID: mdl-20849242

RESUMO

Anticancer drugs executing their function intracellularly enter cancer cells via diffusive processes. Complementary to these slow processes, cells can be forced to incorporate drugs by convection - a more efficient transport process. Transmembrane convection is induced by moderately intense pulsed laser light (or light emitting diodes) changing the structure of nanoscopic water layers in cells. This is a fundamental difference with the method of photodynamic therapy. In a model system we demonstrate that a total irradiation time of one minute is sufficient to completely inhibit proliferation of cancer cells. Transmembrane convection protects healthy cells from extended chemotherapy exposure, could be exploited to overcome multidrug resistance, and is a promising new tool in a variety of therapies as well as in skin rejuvenation.


Assuntos
Antineoplásicos/farmacocinética , Sistemas de Liberação de Medicamentos , Terapia com Luz de Baixa Intensidade , Neoplasias/tratamento farmacológico , Neoplasias/radioterapia , Transporte Biológico/efeitos da radiação , Processos de Crescimento Celular/efeitos da radiação , Permeabilidade da Membrana Celular/efeitos da radiação , Células HeLa , Humanos , Nanomedicina/tendências , Água/metabolismo
9.
J Control Release ; 148(2): 131-4, 2010 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-20934473

RESUMO

Transmembrane diffusion imposes fundamental limits to the uptake of cytostatic drugs executing their function intracellularly. Here, we report that transmembrane convection-a mechanism exploiting the effect of moderately intense 670nm laser light on the density and viscosity of nanoscopic interfacial water layers (IWL) in the cell-forces cancer cells to uptake high doses of cytostatic drugs in a short time. Transmembrane convection is a viable alternative to established uptake forms (i.e., it works complementary to diffusive processes) and breaks the limits imposed by diffusion. We demonstrate the potency of the method in human cervical cancer cells, HeLa, using the anticancer compounds doxorubicin (DOX), methotrexate (MTX) and epigallocatechin gallate (EGCG). The method is applicable to virtually the entire chemotherapeutic arsenal and is expected to help overcome multidrug resistance in cancer cells.


Assuntos
Antineoplásicos/metabolismo , Permeabilidade da Membrana Celular/efeitos da radiação , Membrana Celular/efeitos da radiação , Lasers , Neoplasias do Colo do Útero/metabolismo , Transporte Biológico , Catequina/análogos & derivados , Catequina/metabolismo , Contagem de Células , Membrana Celular/metabolismo , Difusão , Doxorrubicina/metabolismo , Resistencia a Medicamentos Antineoplásicos , Feminino , Células HeLa , Humanos , Metotrexato/metabolismo , Modelos Biológicos , Fatores de Tempo , Viscosidade
10.
Photomed Laser Surg ; 28(3): 429-30, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20438353

RESUMO

OBJECTIVE: Increasing observational evidence suggests that epigallocatechin gallate--the major polyphenolic component of green tea--is instrumental in suppressing the growth of cancer cells. Therefore, methods that promise to enhance the suppressive potential of green tea have the highest clinical relevance. BACKGROUND DATA: Human cervical cancer cells, HeLa, the first continuous cancer cell line, represent a mainstay model in cancer research. Green tea inhibited their growth, whereas their exposure to moderate levels of laser light resulted in an opposite effect. Both effects are individually documented in the literature. METHODS: HeLa cells were supplemented with green tea, irradiated with moderately intense laser light (670 nm) for 1 min, and incubated for 52 h. RESULTS: We found an extraordinary inhibition of HeLa cells by a combination of green tea and red light. We achieved an inhibition of 1,460%, compared with non-irradiated samples. CONCLUSION: Our result receives clinical relevance from a recent study in which epigallocatechin gallate suppressed the growth of melanoma in vivo.


Assuntos
Anticarcinógenos/farmacologia , Catequina/análogos & derivados , Terapia a Laser , Catequina/farmacologia , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/efeitos da radiação , Relação Dose-Resposta a Droga , Células HeLa/efeitos dos fármacos , Células HeLa/efeitos da radiação , Humanos
11.
Photomed Laser Surg ; 27(6): 969-71, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19817517

RESUMO

OBJECTIVE: Juvenile skin has been the subject of intense research efforts since ancient times. This article reports on synergistic complementarities in the biological actions of green tea and red light, which inspired the design of a green tea-assisted facial rejuvenation program. BACKGROUND DATA: The approach is based on previous laboratory experiments providing insight into a mechanism by which visible light interacts with cells and their microenvironment. METHODS: After 2 months of extreme oxidative stress, green tea-filled cotton pads were placed once per day for 20 minutes onto the skin before treatment with an array of light-emitting diodes (central wavelength 670 nm, dermal dose 4 J/cm2). RESULTS: Rejuvenated skin, reduced wrinkle levels, and juvenile complexion, previously realized in 10 months of light treatment alone were realized in 1 month. CONCLUSION: The accelerated skin rejuvenation based on the interplay of the physicochemical and biological effects of light with the reactive oxygen species scavenging capacity of green tea extends the action spectrum of phototherapy. The duo opens the gate to a multitude of possible biomedical light applications and cosmetic formulas, including reversal of topical deterioration related to excess reactive oxygen species, such as graying of hair.


Assuntos
Face , Raios Infravermelhos/uso terapêutico , Fototerapia/métodos , Rejuvenescimento , Envelhecimento da Pele/efeitos da radiação , Chá , Técnicas Cosméticas , Humanos , Espécies Reativas de Oxigênio/metabolismo
13.
Environ Sci Technol ; 42(9): 3324-8, 2008 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-18522113

RESUMO

Earlier we introduced a biosensor for the identification of nanobacteria in water drops. Here, we generalize its principle and apply it to identify nanobacteria in synovial fluid from a patient with osteoarthritis. Results indicate the prevalence of nanobacteria in the synovial fluid. The identification method is applicable to body fluids such as unfiltered human blood and urine, is independent of culturing procedures, and permits for a rapid detection of nanoparticles in liquid drops. In view of increasing clinical evidence on a contribution of nanobacteria in disease, their reported detection in HIV-infected people in South Africa, laboratory experiments indicating the excretion of viable (i.e., propagating) nanobacteria from humans via urine, the use of human excreta in agricultural irrigation, models predicting an injection of nanoaerosols contained in irrigation water enriched with human excreta into the atmosphere, and the identification of nanobacteria in the terrestrial atmosphere, promote the identification method described in this work to an important tool to monitor nanobacteria in body fluids and environmental samples.


Assuntos
Bactérias/metabolismo , Sangue/microbiologia , Monitoramento Ambiental/métodos , Nanopartículas/química , Líquido Sinovial/microbiologia , Urina/microbiologia , Agricultura/métodos , Cálcio/química , Humanos , Técnicas Microbiológicas , Microscopia Eletrônica de Varredura , Modelos Biológicos , Nanotecnologia/métodos , Fósforo/química , Poliestirenos
14.
Photomed Laser Surg ; 25(3): 150-8, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17603854

RESUMO

OBJECTIVE: The purpose of this study was to identify synergistic effects in the interaction of light with biosystems in the presence of chemical agents. Their systematic analysis promises therapeutic strategies. BACKGROUND DATA: Light intensities around 1000 Wm(2) potentially induce density variations in nanoscopic water layers adhering to surfaces in air or subaquatically. In permeable nanoscopic compartments in the interior of biosystems, this could result in powerful flow processes and bidirectional flows for repetitive applications of light. Consequently, external stimulation with light will force microorganisms and cells to incorporate a suitable antiinfective. Nanoscale biosystems, which respond to both light stimulation and antibiotics, are nanobacteria. Responses include growth, inhibition, and slime secretion. Slime secretion was provoked in vitro by gentamycin, an agent proposed for in vivo eradication, and blocked by light. Depending on the field of action, co-operative effects between light and an antiinfective can be exploited by considering two properties of the drug: transmission of light and resorption by the tissue. Antiinfectives can be administered in an active form or via drug delivery systems. In the latter case, a double action of the light could be exploited: stimulated release from the carrier and subsequent uptake by the targeted biosystem. METHODS: The attenuation of laser light (670 nm) by antiinfectives was measured in films of different thickness of a vaginal suppository. The effect of 670-nm laser light - not absorbed by water - on nanoscopic water layers was examined by comparing the evaporation time of irradiated drops of water-based nanosuspensions with non-irradiated controls. RESULTS: The 6-microm-thick suppository films were virtually transparent to the laser light, and the 1-mm-thick films totally attenuated it. Nanosuspension drops irradiated with 670-nm light needed more time to evaporate than controls. CONCLUSION: Low-level light (LLL) therapy is compatible with antiinfectives, and even capable of boosting effects of superficially applied and/or absorbed antiinfectives. Temporal coordination between light treatment and drug administration maximizes drug effects and minimizes possible adverse effects. Irradiation should start when the drug concentration has reached its maximum in the desired field of action. Light-induced flow in nanoscale cavities could represent one mechanism of LLL therapy.


Assuntos
Anti-Infecciosos/uso terapêutico , Terapia com Luz de Baixa Intensidade , Cicatrização , Fenômenos Biofísicos , Biofísica , Terapia Combinada , Neuropatias Diabéticas/terapia , Feminino , Humanos , Linfócitos/efeitos da radiação , Nanomedicina , Vaginose Bacteriana/terapia , Cicatrização/efeitos da radiação
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