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1.
Front Pharmacol ; 13: 899198, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35571085

RESUMO

Oxidative stress is a pivotal point in the pathophysiology of COVID-19 and presumably also in Long-COVID. Inflammation and oxidative stress are mutually reinforcing each other, thus contributing to the systemic hyperinflammatory state and coagulopathy which are cardinal pathological mechanisms of severe stages. COVID-19 patients, like other critically ill patients e.g. with pneumonia, very often show severe deficiency of the antioxidant vitamin C. So far, it has not been investigated how long this deficiency lasts or whether patients with long COVID symptoms also suffer from deficiencies. A vitamin C deficit has serious pathological consequences because vitamin C is one of the most effective antioxidants, but also co-factor of many enzymatic processes that affect the immune and nervous system, blood circulation and energy metabolism. Because of its anti-oxidative, anti-inflammatory, endothelial-restoring, and immunomodulatory effects the supportive intravenous (iv) use of supraphysiological doses has been investigated so far in 12 controlled or observational studies with altogether 1578 inpatients with COVID-19. In these studies an improved oxygenation, a decrease in inflammatory markers and a faster recovery were observed. In addition, early treatment with iv high dose vitamin C seems to reduce the risks of severe courses of the disease such as pneumonia and also mortality. Persistent inflammation, thrombosis and a dysregulated immune response (auto-immune phenomena and/or persistent viral load) seem to be major contributors to Long-COVID. Oxidative stress and inflammation are involved in the development and progression of fatigue and neuro-psychiatric symptoms in various diseases by disrupting tissue (e.g. autoantibodies), blood flow (e.g. immune thrombosis) and neurotransmitter metabolism (e.g. excitotoxicity). In oncological diseases, other viral infections and autoimmune diseases, which are often associated with fatigue, cognitive disorders, pain and depression similar to Long-COVID, iv high dose vitamin C was shown to significantly relieve these symptoms. Supportive iv vitamin C in acute COVID-19 might therefore reduce the risk of severe courses and also the development of Long-COVID.

2.
Nutrients ; 13(7)2021 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-34371879

RESUMO

Sepsis is an extremely complex clinical syndrome, usually involving an excessive inflammatory response including an overshooting cytokine release that damages tissue and organs of the patient. Due to the severity of this condition, it is estimated that over 11 million people die from sepsis each year. Despite intensive research in the field, there is still no specific therapy for sepsis. Many sepsis patients show a marked deficiency of vitamin C. 9 out of 10 sepsis patients have a hypovitaminosis C, and every third patient even shows a clinical deficiency in the scurvy range. In addition, low vitamin C levels of intensive care sepsis patients correlate with a higher need for vasopressors, higher Sequential Organ Failure Assessment (SOFA) scores, and increased mortality. Based on this observation and the conducted clinical trials using vitamin C as sepsis therapy in intensive care patients, the aim of the present ex vivo study was to evaluate the effects of high-dose vitamin C alone and in a triple combination supplemented with vitamin B1 (thiamine) and hydrocortisone on the lipopolysaccharide (LPS)-induced cytokine response in peripheral blood mononuclear cells (PBMCs) from healthy human donors. We found that all corticosteroid combinations strongly reduced the cytokine response on RNA- and protein levels, while high-dose vitamin C alone significantly diminished the PBMC mediated secretion of the cytokines interleukin (IL)-10, IL-23, and monocyte chemo-attractant protein (MCP-1), which mediate the inflammatory response. However, vitamin C showed no enhancing effect on the secretion of further cytokines studied. This data provides important insights into the possible immunomodulatory function of vitamin C in an ex vivo setting of human PBMCs and the modulation of their cytokine profile in the context of sepsis. Since vitamin C is a vital micronutrient, the restoration of physiologically adequate concentrations should be integrated into routine sepsis therapy, and the therapeutic effects of supraphysiological concentrations of vitamin C in sepsis patients should be further investigated in clinical trials.


Assuntos
Anti-Inflamatórios/farmacologia , Ácido Ascórbico/farmacologia , Hidrocortisona/farmacologia , Leucócitos Mononucleares/efeitos dos fármacos , Sepse/tratamento farmacológico , Tiamina/farmacologia , Adulto , Células Cultivadas , Citocinas/genética , Citocinas/metabolismo , Quimioterapia Combinada , Feminino , Regulação da Expressão Gênica , Humanos , Mediadores da Inflamação/metabolismo , Leucócitos Mononucleares/metabolismo , Masculino , Pessoa de Meia-Idade , Sepse/metabolismo , Adulto Jovem
3.
Int J Oncol ; 58(6)2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33955499

RESUMO

For glioblastoma, the treatment with standard of care therapy comprising resection, radiation, and temozolomide results in overall survival of approximately 14-18 months after initial diagnosis. Even though several new therapy approaches are under investigation, it is difficult to achieve life prolongation and/or improvement of patient's quality of life. The aggressiveness and progression of glioblastoma is initially orchestrated by the biological complexity of its genetic phenotype and ability to respond to cancer therapy via changing its molecular patterns, thereby developing resistance. Recent clinical studies of pharmacological ascorbate have demonstrated its safety and potential efficacy in different cancer entities regarding patient's quality of life and prolongation of survival. In this review article, the actual glioblastoma treatment possibilities are summarized, the evidence for pharmacological ascorbate in glioblastoma treatment is examined and questions are posed to identify current gaps of knowledge regarding accessibility of ascorbate to the tumor area. Experiments with glioblastoma cell lines and tumor xenografts have demonstrated that high­dose ascorbate induces cytotoxicity and oxidative stress largely selectively in malignant cells compared to normal cells suggesting ascorbate as a potential therapeutic agent. Further investigations in larger cohorts and randomized placebo­controlled trials should be performed to confirm these findings as well as to improve delivery strategies to the brain, through the inherent barriers and ultimately to the malignant cells.


Assuntos
Ácido Ascórbico/administração & dosagem , Neoplasias Encefálicas/tratamento farmacológico , Glioblastoma/tratamento farmacológico , Animais , Ácido Ascórbico/farmacocinética , Barreira Hematoencefálica/metabolismo , Barreira Hematoencefálica/patologia , Neoplasias Encefálicas/mortalidade , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral , Relação Dose-Resposta a Droga , Glioblastoma/mortalidade , Glioblastoma/patologia , Humanos , Infusões Intravenosas , Camundongos , Estresse Oxidativo/efeitos dos fármacos , Permeabilidade , Qualidade de Vida , Distribuição Tecidual , Resultado do Tratamento , Ensaios Antitumorais Modelo de Xenoenxerto
4.
Nutrients ; 13(4)2021 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-33807280

RESUMO

Fatigue is common not only in cancer patients but also after viral and other infections. Effective treatment options are still very rare. Therefore, the present knowledge on the pathophysiology of fatigue and the potential positive impact of treatment with vitamin C is illustrated. Additionally, the effectiveness of high-dose IV vitamin C in fatigue resulting from various diseases was assessed by a systematic literature review in order to assess the feasibility of vitamin C in post-viral, especially in long COVID, fatigue. Nine clinical studies with 720 participants were identified. Three of the four controlled trials observed a significant decrease in fatigue scores in the vitamin C group compared to the control group. Four of the five observational or before-and-after studies observed a significant reduction in pre-post levels of fatigue. Attendant symptoms of fatigue such as sleep disturbances, lack of concentration, depression, and pain were also frequently alleviated. Oxidative stress, inflammation, and circulatory disorders, which are important contributors to fatigue, are also discussed in long COVID fatigue. Thus, the antioxidant, anti-inflammatory, endothelial-restoring, and immunomodulatory effects of high-dose IV vitamin C might be a suitable treatment option.


Assuntos
Ácido Ascórbico/uso terapêutico , COVID-19/complicações , Fadiga/tratamento farmacológico , Fadiga/etiologia , SARS-CoV-2 , Ácido Ascórbico/administração & dosagem , COVID-19/patologia , Estudos de Viabilidade , Humanos , Injeções Intravenosas
6.
J Int Med Res ; 46(9): 3640-3655, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29950123

RESUMO

Objective Oxidative stress appears to be a key factor in the pathogenesis of allergic diseases and a potential therapeutic target in allergy treatment. Allergic diseases are reportedly associated with reduced plasma levels of ascorbate, which is a key physiological antioxidant. Ascorbate prevents excessive inflammation without reducing the defensive capacity of the immune system. Methods An interim analysis of a multicenter, prospective, observational study was conducted to investigate the change in disease-specific and nonspecific symptoms (fatigue, sleep disorders, depression, and lack of mental concentration) during adjuvant treatment with intravenous vitamin C (Pascorbin®; Pascoe, Giessen, Germany) in 71 patients with allergy-related respiratory or cutaneous indications. Results Between the start and end of treatment, the mean sum score of three disease-specific symptoms decreased significantly by 4.71 points and that of four nonspecific symptoms decreased significantly by 4.84 points. More than 50% of patients took no other allergy-related medication besides vitamin C. Conclusions Our observations suggest that treatment with intravenous high-dose vitamin C reduces allergy-related symptoms. Our observations form a basis for planning a randomized controlled clinical trial to obtain more definitive evidence of the clinical relevance of our findings. We also obtained evidence of ascorbate deficiency in allergy-related diseases. TRIAL REGISTRATION: Clinical Trials NCT02422901.


Assuntos
Antioxidantes/administração & dosagem , Ácido Ascórbico/administração & dosagem , Hipersensibilidade/tratamento farmacológico , Administração Intravenosa , Adolescente , Adulto , Idoso , Criança , Feminino , Humanos , Hipersensibilidade/etiologia , Inflamação/etiologia , Inflamação/prevenção & controle , Masculino , Pessoa de Meia-Idade , Estresse Oxidativo/efeitos dos fármacos , Estudos Prospectivos , Adulto Jovem
7.
Antioxid Redox Signal ; 23(14): 1130-43, 2015 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-26154592

RESUMO

SIGNIFICANCE: It is generally accepted that reactive oxygen species (ROS) scavenging molecules or antioxidants exert health-promoting effects and thus their consumption as food additives and nutraceuticals has been greatly encouraged. Antioxidants may be beneficial in situations of subclinical deficiency and increased demand or acutely upon high-dose infusion. However, to date, there is little clinical evidence for the long-term benefit of most antioxidants. Alarmingly, recent evidence points even to health risks, in particular for supplements of lipophilic antioxidants. RECENT ADVANCES: The biological impact of ROS depends not only on their quantities but also on their chemical nature, (sub)cellular and tissue location, and the rates of their formation and degradation. Moreover, ROS serve important physiological functions; thus, inappropriate removal of ROS may cause paradoxical reductive stress and thereby induce or promote disease. CRITICAL ISSUES: Any recommendation on antioxidants must be based on solid clinical evidence and patient-relevant outcomes rather than surrogate parameters. FUTURE DIRECTIONS: Such evidence-based use may include site-directed application, time-limited high dosing, (functional) pharmacological repair of oxidized biomolecules, and triggers of endogenous antioxidant response systems. Ideally, these approaches need guidance by patient stratification through predictive biomarkers and possibly imaging modalities.


Assuntos
Antioxidantes/farmacologia , Estilbenos/farmacologia , Animais , Antioxidantes/uso terapêutico , Humanos , Oxirredução , Estresse Oxidativo , Espécies Reativas de Oxigênio/metabolismo , Resveratrol , Estilbenos/uso terapêutico , Pesquisa Translacional Biomédica
8.
Med Sci Monit ; 18(4): CR215-24, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22460093

RESUMO

BACKGROUND: Vitamin C is an immune-relevant micronutrient, which is depleted in viral infections and this deficiency seems to play a critical role in the pathogenesis of herpes infections and in the development of postherpetic neuralgia. The objective of this observational multicenter study was to evaluate the utilization, safety and efficacy of intravenously administrated vitamin C in patients with shingles. MATERIAL/METHODS: Between April 2009 and December 2010 16 general practitioners recorded data of 67 participants with symptomatic herpes zoster who received vitamin C intravenously (Pascorbin® 7.5 g/50 ml) for approximately 2 weeks in addition to standard treatment. The assessment of pain (VAS) and the dermatologic symptoms of shingles such as hemorrhagic lesions and the number of efflorescences were investigated in a follow-up observation phase of up to 12 weeks. RESULTS: Mean declines of pain scores (VAS), number of affected dermatomes and efflorescences, and the presence of hemorrhagic vesicles between the baseline and follow-up assessments at 2 and 12 weeks were statistically significant. Overall, 6.4% of the participants experienced post-herpetic neuralgia. Common complaints such as general fatigue and impaired concentration also improved during the study. The effects and the tolerability of the treatment were evaluated positively by the physicians. The risk of developing PHN was reduced. CONCLUSIONS: The data presented here provide evidence that concomitant use of intravenously administered ascorbic acid may have beneficial effects on herpes zoster-associated pain, dermatologic findings and accompanying common complaints. To confirm our findings, randomized, placebo-controlled clinical studies are necessary.


Assuntos
Ácido Ascórbico/uso terapêutico , Herpes Zoster/tratamento farmacológico , Ácido Ascórbico/administração & dosagem , Ácido Ascórbico/efeitos adversos , Ácido Ascórbico/farmacologia , Atenção/efeitos dos fármacos , Fadiga/etiologia , Feminino , Hemorragia/etiologia , Herpes Zoster/complicações , Herpes Zoster/virologia , Herpesvirus Humano 3/efeitos dos fármacos , Herpesvirus Humano 3/fisiologia , Humanos , Injeções Intravenosas , Masculino , Pessoa de Meia-Idade , Medição da Dor , Estudos Prospectivos , Resultado do Tratamento
9.
In Vivo ; 25(6): 983-90, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22021693

RESUMO

AIM: The aim of the study was to evaluate under praxis conditions the safety and efficacy of intravenous (i.v.) vitamin C administration in the first postoperative year of women with breast cancer. PATIENTS AND METHODS: Epidemiological multicentre cohort study, including 15 gynaecologists and general practitioners representatively distributed in Germany. Data from 125 breast cancer patients in UICC stages IIa to IIIb were selected for the study. A total of 53 of these patients were treated with i.v. vitamin C (supplied as Pascorbin® 7.5 g) additional to standard tumour therapy for at least 4 weeks (study group) and 72 without this additional therapy (control group). Main outcome measures were efficacy in regard to outcome and severity of disease- or therapy-induced complaints during adjuvant chemo- and radiotherapy and aftercare. RESULTS: Comparison of control and study groups revealed that i.v. vitamin C administration resulted in a significant reduction of complaints induced by the disease and chemo-/radiotherapy, in particular of nausea, loss of appetite, fatigue, depression, sleep disorders, dizziness and haemorrhagic diathesis. After adjustment for age and baseline conditions (intensity score before adjuvant therapy, chemotherapy, radiotherapy), the overall intensity score of symptoms during adjuvant therapy and aftercare was nearly twice as high in the control group compared to the study group. No side-effects of the i.v. vitamin C administration were documented. DISCUSSION: Oxidative stress and vitamin C deficiency play an important role in the etiology of adverse effects of guideline-based adjuvant chemo-/radiotherapy. Restoring antioxidative capacity by complementary i.v. vitamin C administration helps to prevent or reduce disease-, or therapy-induced complaints in breast cancer patients. CONCLUSION: Complementary treatment of breast cancer patients with i.v. vitamin C was shown to be a well tolerated optimization of standard tumour-destructive therapies, reducing quality of life-related side-effects.


Assuntos
Assistência ao Convalescente , Ácido Ascórbico/administração & dosagem , Neoplasias da Mama/fisiopatologia , Qualidade de Vida , Ácido Ascórbico/efeitos adversos , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/radioterapia , Terapia Combinada , Feminino , Alemanha , Humanos , Pessoa de Meia-Idade , Estudos Retrospectivos
10.
Cancer Chemother Pharmacol ; 67(5): 1157-66, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-20694726

RESUMO

PURPOSE: While the benefits of ascorbic acid (vitamin C, ascorbate) as an essential nutrient are well established, its effects on tumor cells and in tumor treatment are controversial. In particular, conflicting data exist whether ascorbate may increase the cytotoxic effects of antineoplastic drugs or may rather exert adverse effects on drug sensitivity during cancer treatment. Findings are further obscured regarding the distinction between ascorbate and dehydroascorbate (DHA). Thus, the purpose of this study was to evaluate and directly compare the cytotoxic efficacy of ascorbate compared to DHA, and to analyse if ascorbate at pharmacological concentrations affects the efficacy of antineoplastic agents in prostate carcinoma cells. METHODS: We directly compare the effects of ascorbate (supplied as 'Pascorbin solution for injection') and DHA on tumor cell viability, and determine IC(50) values for various cell lines. At concentrations well below the IC(50), ascorbate effects on cell proliferation and cell cycle are analysed. We furthermore determine changes in cellular sensitivity towards various cytostatic drugs upon pre-treatment of cells with ascorbate. RESULTS: We demonstrate higher therapeutic efficacy of ascorbate over DHA in various cell lines, independent of cell line-specific differences in ascorbate sensitivity, and identify the extracellular generation of H(2)O(2) as critical mechanism of ascorbate action. We furthermore show that, in addition to pro-apoptotic effects described previously, ascorbate treatment already at concentrations well below the IC(50) exerts anti-proliferative effects on tumor cells. Those are based on interference with the cell cycle, namely by inducing a G(0)/G(1) arrest. Pre-treatment of tumor cells with ascorbate leads to increased cellular sensitivity towards Docetaxel, Epirubicin, Irinotecan and 5-FU, but not towards Oxaliplatin and Vinorelbin. For Docetaxel and 5-FU, a linear correlation between this sensitizing effect and the ascorbate dosage is observed. CONCLUSIONS: The redox-active form of vitamin C, ascorbate, shows therapeutic efficacy in tumor cells. These antitumor effects of ascorbate are mainly based on its extracellular action and, in addition to the induction of apoptosis, also include an anti-proliferative effect by inducing cell cycle arrest. Furthermore, ascorbate treatment specifically enhances the cytostatic potency of certain chemotherapeutics, which implicates therapeutic benefit during tumor treatment.


Assuntos
Antineoplásicos/farmacologia , Ácido Ascórbico/farmacologia , Apoptose/efeitos dos fármacos , Camptotecina/análogos & derivados , Camptotecina/farmacologia , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Ácido Desidroascórbico/farmacologia , Docetaxel , Sinergismo Farmacológico , Epirubicina/farmacologia , Humanos , Irinotecano , Masculino , Compostos Organoplatínicos/farmacologia , Oxaliplatina , Neoplasias da Próstata , Taxoides/farmacologia , Vimblastina/análogos & derivados , Vimblastina/farmacologia , Vinorelbina
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