Skip to main content

Home/ Dr. Goodyear/ Group items tagged acidic pH

Rss Feed Group items tagged

Filter: All | Bookmarks | Topics Simple Middle
Nathan Goodyear

The Potential Role of Systemic Buffers in Reducing Intratumoral Extracellular pH and Ac... - 0 views

cancerres.aacrjournals.org/...2677.long

pH acid tumor cancer alkaline NaHCO3

shared by Nathan Goodyear on 19 Nov 18 - No Cached
  • Nathan Goodyear on 19 Nov 18
     
    Great diagram of the pH in/around solid tumors. Cancer exists in an obvious hypoxic environment which favors the HIF-1alpha which favors lactate production which drops the pH in the tumor extracellular environment effecting chemoresistance, radioresistance, angiogenesis, invasion, aggressiveness, metastasis, immune evasion...
Nathan Goodyear

Enhancement of chemotherapy by manipulation of tumour pH | British Journal of Cancer - 0 views

www.nature.com/6690455

Cancer pH acid tumor cancer chemotherapy

shared by Nathan Goodyear on 19 Nov 18 - No Cached
  • Nathan Goodyear on 19 Nov 18
     
    Study from 1999 confirms the extracellular acid pH increases resistance to chemotherapy in in vivo study
Nathan Goodyear

Cancer acidity: An ultimate frontier of tumor immune escape and a novel target of immun... - 0 views

www.sciencedirect.com/...S1044579X17300366

TME cancer tumor microenvironment acid tumor cancer acidic pH

shared by Nathan Goodyear on 19 Apr 20 - No Cached
  • Nathan Goodyear on 19 Apr 20
     
    Acidic pH in TME favors cancer growth and spread immunologically.
Nathan Goodyear

Frontiers | Importance of Iron Complexation for Fenton-Mediated Hydroxyl Radical Produc... - 0 views

www.frontiersin.org/...full

Fenton reaction

shared by Nathan Goodyear on 07 Jul 19 - No Cached
  • Nathan Goodyear on 07 Jul 19
     
    Acidic pH required for OH and Fe+3 production. Higher ph, more basic, likely results in other products.
Nathan Goodyear

Acidity promotes tumour progression by altering macrophage phenotype in prostate cancer... - 0 views

www.nature.com/...s41416-019-0542-2

prostate cancer tumor microenvironment TME M2 macrophages acidic pH

shared by Nathan Goodyear on 19 Apr 20 - No Cached
  • Nathan Goodyear on 19 Apr 20
     
    The acidic pH of the TME induces M2 polarization.
Nathan Goodyear

Bicarbonate and dichloroacetate: Evaluating pH altering therapies in a mouse model for ... - 0 views

www.ncbi.nlm.nih.gov/...PMC3125283

DCA dichloracetic acid dichloroacetate cancer "pH and cancer" acid alkaline

shared by Nathan Goodyear on 16 Nov 18 - No Cached
  • Nathan Goodyear on 16 Nov 18
     
    Tumor Microenvironment is hypoxia and acid which negates effects of therapies such as DCA. Alkalinization of the tumor micronenvironment is a means to open the tumor to the effects of therapies such as DCA.
Nathan Goodyear

Lipid Peroxidation: Production, Metabolism, and Signaling Mechanisms of Malondialdehyde... - 0 views

www.hindawi.com/...360438

MDA malondialdehyde peroxidation oxidative stress free radicals

shared by Nathan Goodyear on 05 Dec 17 - No Cached
  • Hydroxyl radicals cause oxidative damage to cells because they unspecifically attack biomolecules [22] located less than a few nanometres from its site of generation and are involved in cellular disorders such as neurodegeneration [23, 24], cardiovascular disease [25], and cancer [26, 27].
  • It is generally assumed that in biological systems is formed through redox cycling by Fenton reaction, where free iron (Fe2+) reacts with hydrogen peroxide (H2O2) and the Haber-Weiss reaction that results in the production of Fe2+ when superoxide reacts with ferric iron (Fe3+)
  • other transition-metal including Cu, Ni, Co, and V can be responsible for formation in living cells
  • ...20 more annotations...
  • The hydroperoxyl radical () plays an important role in the chemistry of lipid peroxidation
  • The is a much stronger oxidant than superoxide anion-radical
  • Lipid peroxidation can be described generally as a process under which oxidants such as free radicals or nonradical species attack lipids containing carbon-carbon double bond(s), especially polyunsaturated fatty acids (PUFAs) that involve hydrogen abstraction from a carbon, with oxygen insertion resulting in lipid peroxyl radicals and hydroperoxides as described previously
  • under medium or high lipid peroxidation rates (toxic conditions) the extent of oxidative damage overwhelms repair capacity, and the cells induce apoptosis or necrosis programmed cell death
  • The overall process of lipid peroxidation consists of three steps: initiation, propagation, and termination
  • Once lipid peroxidation is initiated, a propagation of chain reactions will take place until termination products are produced.
  • The main primary products of lipid peroxidation are lipid hydroperoxides (LOOH)
  • Among the many different aldehydes which can be formed as secondary products during lipid peroxidation, malondialdehyde (MDA), propanal, hexanal, and 4-hydroxynonenal (4-HNE) have been extensively studied
  • MDA has been widely used for many years as a convenient biomarker for lipid peroxidation of omega-3 and omega-6 fatty acids because of its facile reaction with thiobarbituric acid (TBA)
  • MDA is one of the most popular and reliable markers that determine oxidative stress in clinical situations [53], and due to MDA’s high reactivity and toxicity underlying the fact that this molecule is very relevant to biomedical research community
  • 4-HNE is considered as “second toxic messengers of free radicals,” and also as “one of the most physiologically active lipid peroxides,” “one of major generators of oxidative stress,” “a chemotactic aldehydic end-product of lipid peroxidation,” and a “major lipid peroxidation product”
  • MDA is an end-product generated by decomposition of arachidonic acid and larger PUFAs
  • Identifying in vivo MDA production and its role in biology is important as indicated by the extensive literature on the compound (over 15 800 articles in the PubMed database using the keyword “malondialdehyde lipid peroxidation” in December 2013)
  • MDA reactivity is pH-dependent
  • When pH decreases MDA exists as beta-hydroxyacrolein and its reactivity increases
  • MAA adducts are shown to be highly immunogenic [177–181]. MDA adducts are biologically important because they can participate in secondary deleterious reactions (e.g., crosslinking) by promoting intramolecular or intermolecular protein/DNA crosslinking that may induce profound alteration in the biochemical properties of biomolecules and accumulate during aging and in chronic diseases
  • MDA is an important contributor to DNA damage and mutation
  • This MDA-induced DNA alteration may contribute significantly to cancer and other genetic diseases.
  • Dietary intake of certain antioxidants such as vitamins was associated with reduced levels of markers of DNA oxidation (M1dG and 8-oxodG) measured in peripheral white blood cells of healthy subjects, which could contribute to the protective role of vitamins on cancer risk
  • 4-HNE is an extraordinarily reactive compound
  • Nathan Goodyear on 05 Dec 17
     
    Great review of lipid peroxidation
Nathan Goodyear

Cellular pH Gradient in Tumor versus Normal Tissue: Potential Exploitation for the Trea... - 0 views

cancerres.aacrjournals.org/...1194.long

Cancer acid alkaline "pH and cancer"

shared by Nathan Goodyear on 16 Nov 18 - No Cached
  • Nathan Goodyear on 16 Nov 18
     
    Cancer has an acid bed compared to alkaline in health cell environment.
Nathan Goodyear

Modulated Electro-Hyperthermia-Induced Tumor Damage Mechanisms Revealed in Cancer Models - 0 views

www.ncbi.nlm.nih.gov/...PMC7504298

acid tumor cancer cancer acidic pH hypoxia apoptosis hyperthermia

shared by Nathan Goodyear on 14 Mar 21 - No Cached
  • Nathan Goodyear on 14 Mar 21
     
    "Cells are more responsive and sensitive to heat under oxygen-deprived and highly acidic conditions, which are common in cancer tissue due to aggressive growth and enhanced glycolysis"
Nathan Goodyear

Manipulating tumor acidification as a cancer treatment strategy. - 0 views

archive.foundationalmedicinereview.com/...264.pdf

Cancer "pH and cancer" acid alkaline

shared by Nathan Goodyear on 16 Nov 18 - No Cached
  • Nathan Goodyear on 16 Nov 18
     
    Manipulation of the tumor pH bed is possible.
Nathan Goodyear

Bicarbonate Increases Tumor pH and Inhibits Spontaneous Metastases - 0 views

www.ncbi.nlm.nih.gov/...PMC2834485

Cancer "pH and cancer" pH alkaline acid

shared by Nathan Goodyear on 21 May 18 - No Cached
  • Nathan Goodyear on 21 May 18
     
    NaHCO3 inhibits metastasis of solid tumor.
Nathan Goodyear

Comparisons of normal saline and lactated Ringer's resuscitation on hemodynamics, metab... - 0 views

www.ncbi.nlm.nih.gov/...PMC4029282

IV fluids lactated ringers normal saline LR NS

shared by Nathan Goodyear on 03 Jul 18 - No Cached
  • NS contains 154 mM Na+ and Cl-, with an average pH of 5.0 and osmolarity of 308 mOsm/L.
  • LR solution has an average pH of 6.5, is hypo-osmolar (272 mOsm/L), and has similar electrolytes (130 mM Na+, 109 mM Cl-, 28 mM lactate, etc.) to plasma
  • hyperchloremic acidosis
  • ...26 more annotations...
  • LR’s acid base balance is superior to that of NS’s
  • There were no significant differences between LR and NS groups in fibrinogen concentrations or platelet count
  • Total protein dropped
  • no significant differences in Hct (Table  1) or total protein between LR and NS groups
  • Bicarbonate HCO3- levels were decreased by hemorrhage but returned to pre-hemorrhage values by 3 h after LR resuscitation, whereas no return was observed with NS resuscitation
  • Na+ was increased after NS resuscitation
  • No changes in Na+ or K+ were observed
  • K+ did not change initially after NS resuscitation but was elevated at 6 h afterwards
  • Ca++ was similarly decreased
  • Cl- was elevated for 6 h after NS resuscitation, with no changes shown after LR resuscitation
  • PT was similarly prolonged by resuscitation with LR (from 11.2 ± 0.2 sec at baseline to 12.1 ± 0.2 sec at 6 h) and NS
  • Plasma aPTT was also similarly prolonged by resuscitation with LR (from 17.1 ± 0.5 sec baseline to 20.1 ± 1.2 sec at 6 h) or NS
  • NS resuscitation resulted in better oxygen delivery and oxygen delivery-to-oxygen demand ratio as an index of oxygen debt
  • NS had better tissue perfusion and oxygen metabolism than LR
  • LR resuscitation returned BE and bicarbonate to pre-hemorrhage levels within 3 h, but no return of BE or bicarbonate was observed for 6 hr with NS resuscitation
  • current blood bank guidelines state that LR should not be mixed with blood to prevent the risk of clot formation from calcium included in LR
  • LR resuscitation should not be given with blood through the same iv-line and crystalloids should be avoided in patients with blood transfusion
  • PT and aPTT were prolonged for 6 h after hemorrhage and resuscitation, suggesting a hypocoagulable states
  • potential thrombotic risk from LR resuscitation is unlikely.
  • we suspected that the blood pressure after NS resuscitation would be lower than that of LR due to its vasodilator effects
  • NS required a larger resuscitation volume and was associated with poor acid base status and elevated serum potassium in this model
  • NS required 50% more volume and was associated with a higher cardiac output and lower peripheral resistance, as compared to LR resuscitation
  • These differences are possibly due to the vasodilator effects from NS
  • an elevation of K+ was observed at 6 h post NS resuscitation, while no change of K+ was observed after LR resuscitation
  • The mechanism for the increase of K+ from NS is not fully known
  • NS is associated with vasodilator effects and the risks of metabolic acidosis and hyperkalemia
  • Nathan Goodyear on 03 Jul 18
     
    LR vs NS crystalloid.
fitspresso

LeanBiome™ (Official) | Get Save UpTo $540 Today Only! - 0 views

usleanbiome.com

leanbiome us lean biome usa uk buy get does work discount 2022 australia legit weight loss bioma customer reviews review canada website ireland product

shared by fitspresso on 27 Sep 23 - No Cached
  • fitspresso on 27 Sep 23
     
    LeanBiome™ (Official) | Get Save UpTo $540 Today Only! usleanbiome.com LeanBiome™ Hurry Up! Offer Expires in: 00 HOUR 29 MINUTE 59 SECOND LeanBiome Attention! Get Special 84% Discount Today Faster fat burning and weight loss Healthy cholesterol and sugar levels Higher energy levels Regular price: $129 Only for: 39$ What Is LeanBiome? LeanBiome Lean for Good is a weight loss dietary supplement derived from scientifically researched ingredients and comprehensively developed to help people achieve sustainable weight control. The formula comes in a capsule format that is easy to take and is made with natural ingredients from plants and other sources to achieve its goals. The main ingredient in LeanBiome is piperine, which has been found to affect the body's ability to absorb micronutrients and other compounds more effectively. LeanBiome is a dietary supplement that claims to help weight management. It contains 100% natural ingredients that support healthy weight loss. It does not interfere with any natural process making it safe for use. It ranks among the top weight loss supplements that claim to provide a permanent solution. LeanBiome is made by a company named Lean for Good. It is made with natural and research-backed ingredients that help you lose excess fat without hassles. It is sold in capsule form. The company assures the composition is GMO, gluten, and soy-free. As for manufacturing standards, you need not fret. The company makes the supplement in a facility certified by the FDA. How Does LeanBiome Work? The starting period of the LeanBiome program includes a detoxification process that effectively removes any accumulated ree radicals, toxins, fand oxidative stress. This cleansing enables improved blood circulation, setting the stage for the body to initiate its own fat-burning mechanisms. To enhance metabolic activity, introducing the lean bacteria contained in LeanBiome to your gut microbiome is a beneficial approach. This activation triggers r
Nathan Goodyear

The Ketogenic Diet and Sport: A Possible Marriage? : Exercise and Sport Sciences Reviews - 0 views

journals.lww.com/..._and_Sport___A_Possible.8.aspx

nutrition diet ketogenic ketogenic diet sports athletes exercise sports medicine

shared by Nathan Goodyear on 16 Nov 16 - No Cached
  • It is important to note that, although the blood level of glucose drops, it still remains at a physiological level (23), which is maintained through gluconeogenesis involving glucogenic amino acids and also glycerol released from triglycerides
  • “physiological ketosis” where KB levels may rise to 7 to 8 mmol L-1 (but without any pH change). In “pathological diabetic ketoacidosis,” on the other hand, ketonemia can exceed 20 mmol L-1 and also cause lowering of blood pH
  • in the initial phase of KD, about 16% of glucose comes from glycerol (released from triglyceride hydrolysis) and the bulk (60–65 g) from proteins via gluconeogenesis (proteins may be of either dietary or endogenous origin
  • ...5 more annotations...
  • the protein supply consumed during a KD “preserves,” as demonstrated, lean body mass
  • The importance of glycerol as a glucose source increases progressively during ketosis; in fact, glycerol passes from supplying 16% of total glucose to an average of 60% after many days (>7 d) of complete fasting (from 38% in lean individual to 79% in the obese).
  • The possible reasons for the effectiveness of KD for weight loss may be listed as follows, in order of evidence, strongest first: Figure 3Image Tools 1. Appetite reduction: protein satiety, effects on appetite-related hormones such as ghrelin, and possibly a sort of direct appetite-blocking effect of KB 2. Reduced lipogenesis and increased fat oxidation 3. A reduction in respiratory quotient may indicate a greater metabolic efficiency in fat oxidation 4. A thermic effect of proteins and increased energy usage by gluconeogenesis
  • all data regarding biochemical and molecular mechanisms suggest that it is very difficult to increase muscle mass during a KD; use of which really should be limited to the few days immediately before competition in bodybuilding.
  • a long-term KD can interfere with some muscle hypertrophy mechanisms and this could be counterproductive if the aim of the athlete is to gain muscle mass
  • Nathan Goodyear on 16 Nov 16
     
    Great read on the ketogenic  and its application to sports/training...
Nathan Goodyear

BMC Cancer | Full text | A lactate shuttle system between tumour and stromal cells is a... - 0 views

www.biomedcentral.com/...352

cancer prostate cancer CAFs cancer associated fibroblasts mono-carboxylate transporters

shared by Nathan Goodyear on 12 Nov 14 - No Cached
  • Under hypoxic conditions, tumour cells primarily use glycolysis for energy, producing lactate, which is expelled to the tumour microenvironment, allowing tumours to continue their glycolytic activity
  • Sonveaux et al. showed that lactate, which is generally considered a waste product, is preferred over glucose by oxidative tumour cells as their primary energy source
  • MCT4 is a low-affinity transporter, which is abundant in highly glycolytic muscle cells and is one of the many target genes of hypoxia-inducible factor 1 alpha (HIF-1α)
  • ...8 more annotations...
  • Other targets of HIF-1α include glucose transporter-1 (GLUT-1), the main transporter involved in glucose uptake [9,10]; lactate dehydrogenase V (LDHV), which is responsible for the conversion of pyruvate into lactate; pyruvate dehydrogenase kinase isozyme 1 (PDK1), which is responsible for the phosphorylation and consequent inactivation of pyruvate dehydrogenase (PDH); and carbonic anhydrase IX (CAIX), a hypoxia-related protein involved in pH regulation [11]. Alpha-methylacyl-CoA racemase (AMACR), pristanoyl-CoA oxidase (ACOX-3) and D-bifunctional protein (DBP), are also important fatty acid oxidation-related proteins in prostate cancer
  • the essential role played by the cross-talk between stroma and epithelium in carcinogenesis and prostate cancer progression has been increasingly recognised
  • strong membranous expression of MCT1 was consistently observed in cancer cells, suggesting a role for MCT1 in the transport of lactate into tumour cells from the acidic extracellular matrix, suggesting that lactate might be used as a fuel by oxidative cancer cells.
  • Our hypothesis is in agreement with those of Fiaschi et al.[17], who describe the metabolic reprogramming of CAFs towards the Warburg phenotype as a result of contact with prostate cancer cells
  • Using in vitro studies, they showed lactate production and efflux by de novo expressed MCT4 in CAFs and also demonstrated that, upon contact with CAFs, prostate cancer cells were reprogrammed towards aerobic metabolism, with an increase in lactate uptake via the lactate transporter MCT1.
  • pharmacological inhibition of MCT1-mediated lactate uptake dramatically affected PCa cell survival and tumour outgrowth
  • In this model, “energy transfer” or “metabolic coupling” between the tumour stroma and epithelial cancer cells fuels tumour growth and metastasis via oxidative mitochondrial metabolism in anabolic cancer cells
  • the concomitant expression of MCT1 in tumour cells and MCT4 in fibroblasts in the same tissue is clinically significant, and associated with poor prognosis.
  • Nathan Goodyear on 12 Nov 14
     
    Study confirms the importance of the crosstalk between cancer cells and CAFs via MCTs in prostate cancer.
Nathan Goodyear

Long-term stabilization of stage 4 colon cancer using sodium dichloroacetate therapy - 1 views

www.ncbi.nlm.nih.gov/...PMC5067498

DCA dichloroacetate dichloracetic acid cancer colon cancer

shared by Nathan Goodyear on 18 Jan 18 - No Cached
  • inhibition of mitochondrial pyruvate dehydrogenase kinase
  • inhibition of aerobic glycolysis (the Warburg effect) and activation of mitochondrial potassium ion channels
  • angiogenesis blockade
  • ...5 more annotations...
  • changes in expression of HIF1-α
  • alteration of pH regulators V-ATPase and MCT1, and other cell survival regulators such as PUMA, GLUT1, Bcl2 and p53
  • DCA as a cancer stabilizing agent
  • A protocol of natural medications was developed to address the dose-limiting neurologic toxicity, in collaboration with a naturopathic physician (Andrews). The oral DCA regimen that was developed included three natural medications acetyl L-carnitine[29-31], R-alpha lipoic acid[32-34] and benfotiamine[35-37], for the primary purpose of neuropathy prevention
  • measurable benefits from DCA therapy in 60%-70% of cases
  • Nathan Goodyear on 18 Jan 18
     
    Good review of dichloracetate or DCA in antitumor activity.  DCA has been shown to have numerous anticancer properties.
Nathan Goodyear

Clinical review: Specific aspects of acute renal failure in cancer patients - 0 views

www.ncbi.nlm.nih.gov/...PMC1550893

cancer renal failure

shared by Nathan Goodyear on 13 Aug 18 - No Cached
  • uric acid crystal formation in the renal tubules secondary to hyperuricaemia
  • calcium phosphate deposition related to hyperphosphataemia
  • usually develops shortly after the initiation of cytotoxic chemotherapy
  • ...18 more annotations...
  • Non-recombinant urate oxidase (Uricozyme®)
  • recombinant urate oxidase (Rasburicase®)
  • urine alkalisation may induce calcium phosphate deposition
  • renal replacement therapy should be started on an emergency basis when hydration fails to produce a prompt metabolic improvement or when ARF develops
  • Up to 50% of patients with newly diagnosed multiple myeloma have renal failure and up to 10% require dialysis
  • renal ultrasonography remains the method of choice for investigating extra-renal obstruction
  • The relief of the obstruction, either by percutaneous nephrostomy or through a ureteral stent, is the cornerstone of treatment
  • TMA may be associated with the cancer itself, with cancer chemotherapy, or with allogeneic BMT
  • thrombotic microangiopathy (TMA)
  • it may be as high as 5%
  • Most of the cases occur in patients with solid tumours, the most common type being adenocarcinoma (stomach, breast and lung)
  • The pathophysiology of the TMA-malignancy association remains controversial, although many studies suggest an insult to the vascular endothelium
  • mitomycin C. Subsequently, TMA has been reported with many anti-cancer agents, including gemcita-bine, bleomycin, cisplatin, CCNU, cytosine arabinoside, daunorubicin, deoxycoformycin, 5-FU, azathioprine and interferon α
  • Plasma exchanges have been shown to improve prognosis in the general population of patients with TMA
  • Causative factors should be looked for and antihypertensive treatment given. Lastly, in the absence of guidelines, we believe that plasma exchange should be proposed in patients with severe cancer treatment-associated TMA
  • The most widely used protective measure is saline infusion to induce solute diuresis
  • During methotrexate infusion and elimination, fluids should be given to maintain a high urinary output and urinary alkalisation should be performed to keep the urinary pH above 7.5. Rescue with folinic acid (50 mg four times a day) should be started 24 hours after each high-dose metho-trexate infusion and serum methotrexate concentrations should be measured every day
  • cyclophosphamide and ifosfamide
  • Nathan Goodyear on 13 Aug 18
     
    cancer and renal failure
Nathan Goodyear

Ascorbic acid: Chemistry, biology and the treatment of cancer - 0 views

www.ncbi.nlm.nih.gov/...PMC3608474

Fenton reaction ferritin vitamin C Fe cancer

shared by Nathan Goodyear on 07 Jul 19 - No Cached
  • iron and ascorbate has long been used as an oxidizing system; the combination of these two reagents is referred to as the Udenfriend system
  • ascorbate serves as a reducing cofactor for many enzymes
  • uptake of ascorbate from the intestinal tract is very tightly controlled
  • ...11 more annotations...
  • pharmacokinetic data indicate that intravenous administration of ascorbate can bypass this tight control resulting in highly elevated plasma levels
  • ascorbate readily oxidizes to produce H2O2, pharmacological ascorbate has been proposed as a prodrug for the delivery of H2O2 to tumors
  • Ascorbate is an excellent reducing agent and readily undergoes two consecutive, one-electron oxidations to form ascorbate radical (Asc•−) and dehydroascorbic acid (DHA)
  • Ascorbate oxidizes readily. The rate of oxidation is dependent on pH and is accelerated by catalytic metals
  • In near-neutral buffers with contaminating metals, the oxidation and subsequent loss of ascorbate can be very rapid
  • Ascorbate is required for maintaining iron in the ferrous state
  • In the presence of catalytic metal ions, ascorbate can also exert pro-oxidant effects
  • Ascorbate is an excellent one-electron reducing agent that can reduce ferric (Fe3+) to ferrous (Fe2+) iron, while being oxidized to ascorbate radical
  • In a classic Fenton reaction, Fe2+ reacts with H2O2 to generate Fe3+ and the very oxidizing hydroxyl radical
  • e presence of ascorbate can allow the recycling of Fe3+ back to Fe2+, which in turn will catalyze the formation of highly reactive oxidants from H2O2
  • Depending on concentrations, the effects of ascorbate on models of lipid peroxidation can be pro- or antioxidant
  • Nathan Goodyear on 07 Jul 19
     
    ferritin released enhanced pharmacologic ascorbate induced-cytotoxicity, indicating that ferritin with high iron-saturation could be a source of catalytic iron. Consistent with this, ascorbate has also been shown to be capable of releasing iron from cellular ferritin
Nathan Goodyear

High-Dose Vitamin C for Cancer Therapy - PMC - 0 views

www.ncbi.nlm.nih.gov/...PMC9231292

vitamin C cancer

shared by Nathan Goodyear on 27 Jul 22 - No Cached
  • diabetes [8], atherosclerosis [9], the common cold [10], cataracts [11], glaucoma [12], macular degeneration [13], stroke [14], heart disease [15], COVID-19 [16], and cancer.
  • 1–5% of the Vit-C inside the human cells
  • interaction between Fe(II) and H2O2 produces OH− through the Fenton reaction
  • ...35 more annotations...
  • metabolic activity, oxygen transport, and DNA synthesis
  • Iron is found in the human body in the form of haemoglobin in red blood cells and growing erythroid cells.
  • macrophages contain considerable quantities of iron
  • iron is taken up by the majority of cells in the form of a transferrin (Tf)-Fe(III) complex that binds to the cell surface receptor transferrin receptor 1 (TfR1)
  • excess iron is retained in the liver cells
  • the endosomal six transmembrane epithelial antigen of the prostate 3 (STEAP3) reduces Fe(III) (ferric ion) to Fe(II) (ferrous ion), which is subsequently transferred across the endosomal membrane by divalent metal transporter 1 (DMT1)
  • labile iron pool (LIP)
  • LIP is toxic to the cells owing to the production of massive amounts of ROS.
  • DHA is quickly converted to Vit-C within the cell, by interacting with reduced glutathione (GSH) [45,46,47]. NADPH then recycles the oxidized glutathione (glutathione disulfide (GSSG)) and converts it back into GSH
  • Fe(II) catalyzes the formation of OH• and OH− during the interaction between H2O2 and O2•− (Haber–Weiss reaction)
  • Ascorbate can efficiently reduce free iron, thus recycling the cellular Fe(II)/Fe(III) to produce more OH• from H2O2 than can be generated during the Fenton reaction, which ultimately leads to lipid, protein, and DNA oxidation
  • Vit-C-stimulated iron absorption
  • reduce cellular iron efflux
  • high-dose Vit-C may elevate cellular LIP concentrations
  • ascorbate enhanced cancer cell LIP specifically by generating H2O2
  • Vit-C produces H2O2 extracellularly, which in turn inhibits tumor cells immediately
  • tumor cells have a need for readily available Fe(II) to survive and proliferate.
  • Tf has been recognized to sequester most labile Fe(II) in vivo
  • Asc•− and H2O2 were generated in vivo upon i.v Vit-C administration of around 0.5 g/kg of body weight and that the generation was Vit-C-dose reliant
  • free irons, especially Fe(II), increase Vit-C autoxidation, leading to H2O2 production
  • iron metabolism is altered in malignancies
  • increase in the expression of various iron-intake pathways or the downregulation of iron exporter proteins and storage pathways
  • Fe(II) ion in breast cancer cells is almost double that in normal breast tissues
  • macrophages in the cancer microenvironment have been revealed to increase iron shedding
  • Advanced breast tumor patients had substantially greater Fe(II) levels in their blood than the control groups without the disease
  • increased the amount of LIP inside the cells through transferrin receptor (TfR)
  • Warburg effect, or metabolic reprogramming,
  • Warburg effect is aided by KRAS or BRAF mutations
  • Vit-C is supplied, it oxidizes to DHA, and then is readily transported by GLUT-1 in mutant cells of KRAS or BRAF competing with glucose [46]. DHA is quickly converted into ascorbate inside the cell by NADPH and GSH [46,107]. This decrease reduces the concentration of cytosolic antioxidants and raises the intracellular ROS amounts
  • increased ROS inactivates glyceraldehyde 3-phosphate dehydrogenase (GAPDH)
  • ROS activates poly (ADP-ribose) polymerase (PARP), which depletes NAD+ (a critical co-factor of GAPDH); thus, further reducing the GAPDH associated with a multifaceted metabolic rewiring
  • Hindering GAPDH can result in an “energy crisis”, due to the decrease in ATP production
  • high-dose Vit-C recruited metabolites and increased the enzymatic activity in the pentose phosphate pathway (PPP), blocked the tri-carboxylic acid (TCA) cycle, and increased oxygen uptake, disrupting the intracellular metabolic balance and resulting in irreversible cell death, due to an energy crisis
  • mega-dose Vit-C influences energy metabolism by producing tremendous amounts of H2O2
  • Due to its great volatility at neutral pH [76], bolus therapy with mega-dose DHA has only transitory effects on tumor cells, both in vitro and in vivo.
1 - 19 of 19
Showing 20▼ items per page