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| Citric acid is the acid form, and citrate is the salt or conjugate base form. The two terms are often used interchangeably in casual conversation, but chemically they refer to different states depending on the pH of the environment. Citrate is a naturally occurring compound found in various forms in nature. It is a conjugate base of citric acid, a weak organic acid that is commonly found in citrus fruits, such as lemons and oranges. Citrate plays a crucial role in the production of energy in cells. It is a key intermediate in the citric acid cycle (also known as the Krebs cycle or tricarboxylic acid cycle), which is a series of chemical reactions that occur in the mitochondria of cells. Naturally found in citrus fruits and many other plants. Citric acid is a key metabolic intermediate in the tricarboxylic acid (TCA) cycle. • Citric acid is central to cellular energy metabolism as part of the TCA cycle. Changes in its concentration can affect the flux through the cycle and the overall cellular redox state. • Enhanced TCA activity may lead to increased production of reducing equivalents (NADH, FADH₂) and subsequent electron transport chain (ETC) activity. If the ETC becomes overloaded or dysfunctional, it can lead to electron leakage and increased ROS production. • Although citric acid itself is not a classical antioxidant, it can act as a chelating agent for certain metal ions. By binding transition metals (such as iron and copper), citrate can potentially reduce metal-catalyzed ROS formation. • This chelating property can indirectly protect cells from oxidative damage, especially under conditions where free metal ions might otherwise catalyze ROS-generating reactions. -Crucial role of citrate to supply the acetyl-CoA pool for fatty acid synthesis and histone acetylation in tumors -Citrate is a major product of mitochondria, the engine of the cell. -The more Citrate builds up in the cell, the more the cell will think it has enough of what it needs and will reduce or even shut down the glycolisis process. Citrate is produced inside the mitochondria within the Krebs cycle. When the cell has excess energy, citrate is transported out of the mitochondrial matrix across the inner membrane via the mitochondrial citrate transport protein (CTP). In the cytoplasm, is then broken down by the ACLY (ACL) enzyme into acetyl-CoA: for fatty acid synthesis and cholesterol production oxaloacetate: to be converted back to pyruvate and enter mitochondria again (might be desirable to inhibit ACYL with HCA) and maybe Statins. -May also synergize with Metformin? Sodium citrate is the sodium salt of citric acid, used as a buffer and food additive, while citric acid is a weak organic acid, naturally found in citrus fruits. Summary: -Citrate is considered to play a crucial role in cancer metabolism by virtue of its production in the reverse Krebs cycle from glutamine -Chelation of Ca2+ by sodium citrate resulted in inactivation of CAMKK2 and AMPK (inhibited the Ca2+/CAMKK2/AKT/mTOR signaling) -”promoter of cell proliferation (at lower concentrations) and as an anticancer agent (at higher concentrations)” -”ACLY, which has been found to be overexpressed in many cancers, converts citrate into acetyl-CoA and OAA.“ -”administration of citrate at high level mimics a strong inhibition of ACLY” (HCA is a known natural ACLY inhibitor) -Citrate is a well-known physiological inhibitor of PFK1. -Some reduction in Mcl-1 expression -May low ROS by decreasing oxygen consumption (ie not compatible with proxidant treatment?) -Deactivation of the NF-κB signaling ? -Lemons: 5–8% citric acid by weight -Limes: 4–7% citric acid. -Grapefruits: 2–5% in the juice -Oranges (and Tangerines/Mandarins): 1–2% in the juice Many commercially prepared beverages (like some soft drinks, citrus-based jams, and preserves) and sour candies have citric acid added as a flavoring agent or preservative. In these products, the citric acid concentration can sometimes be higher than that in the unprocessed fruit juice. Acid Reflux & Dental Health: Increasing citric acid, especially from highly concentrated sources (like pure citric acid or very sour juices), may exacerbate symptoms in individuals with acid reflux or cause enamel erosion on teeth. Drinking water after consuming citrus products or using a straw (when drinking acidic beverages) can help reduce the direct contact of acid with your teeth. • Low/Moderate Doses: In some models, low to moderate citrate supplementation can actually help cells maintain redox balance. • High Doses: At higher concentrations, citrate can overload certain metabolic pathways. An excess supply of citrate may drive the TCA cycle at a rate that overwhelms the electron transport chain, potentially increasing the leakage of electrons and therefore raising ROS production. • Cancer vs. Non-Cancer Cells: Cancer cells frequently have reprogrammed metabolism. In some cases, citrate supplementation in cancer cells can have different effects compared to healthy cells. For instance, due to the metabolic alterations in cancer cells, a high dose of citrate might exacerbate mitochondrial dysfunction, leading to higher ROS levels. Conversely, in a non-cancer context or cells with robust metabolic flexibility, the same dose might be better tolerated or even beneficial for redox balance. ROS: Antioxidant Role: • In some contexts, citrate can act as an antioxidant. It has the capacity to chelate metal ions (like iron and copper), which can catalyze ROS formation via reactions such as the Fenton reaction. • Moreover, as a key intermediate in the tricarboxylic acid (TCA) cycle, citrate contributes to cellular energy metabolism, which, when properly balanced, may help maintain homeostasis and limit excessive ROS production. Potential Pro-Oxidant Effects: • At high doses or under certain conditions, an overload of citrate might alter normal cellular metabolic pathways. For example, excess citrate can affect mitochondrial function and the TCA cycle’s balance, potentially leading to metabolic disturbances that contribute to increased ROS formation in some in vitro models or under pathological conditions. • In certain experimental settings, drastic changes in cellular intermediate concentrations can trigger compensatory mechanisms that might inadvertently lead to oxidative stress. Context Matters: • The net effect of high-dose citrate on ROS largely depends on the experimental model and the presence of additional factors (such as the concentration of available metal ions, the oxidative state of the cell, and the cell’s overall metabolic status). • In a well-regulated physiological environment, moderate levels of citrate may support antioxidant defenses, whereas in stress or disease states, high doses might tip the balance toward increased ROS production. -High doses of citric acid/citrate in cancer cells are generally associated with an increase in ROS due to metabolic and mitochondrial stress. However, because the effect is highly context-specific, the overall outcome may depend on multiple factors related to the cancer cell type and its existing metabolic state. (Note this statement might not be supported by research papers-but rather chat ai) DoseCitric acid: 4g-30g/day. 4g-8g/day most common? split 3-4 times/day? with meals
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| Reactive oxygen species (ROS) are highly reactive molecules that contain oxygen and can lead to oxidative stress in cells. They play a dual role in cancer biology, acting as both promoters and suppressors of cancer. ROS can cause oxidative damage to DNA, leading to mutations that may contribute to cancer initiation and progression. So normally you want to inhibit ROS to prevent cell mutations. However excessive ROS can induce apoptosis (programmed cell death) in cancer cells, potentially limiting tumor growth. Chemotherapy typically raises ROS. -mitochondria is the main source of reactive oxygen species (ROS) (and the ETC is heavily related) "Reactive oxygen species (ROS) are two electron reduction products of oxygen, including superoxide anion, hydrogen peroxide, hydroxyl radical, lipid peroxides, protein peroxides and peroxides formed in nucleic acids 1. They are maintained in a dynamic balance by a series of reduction-oxidation (redox) reactions in biological systems and act as signaling molecules to drive cellular regulatory pathways." "During different stages of cancer formation, abnormal ROS levels play paradoxical roles in cell growth and death 8. A physiological concentration of ROS that maintained in equilibrium is necessary for normal cell survival. Ectopic ROS accumulation promotes cell proliferation and consequently induces malignant transformation of normal cells by initiating pathological conversion of physiological signaling networks. Excessive ROS levels lead to cell death by damaging cellular components, including proteins, lipid bilayers, and chromosomes. Therefore, both scavenging abnormally elevated ROS to prevent early neoplasia and facilitating ROS production to specifically kill cancer cells are promising anticancer therapeutic strategies, in spite of their contradictoriness and complexity." "ROS are the collection of derivatives of molecular oxygen that occur in biology, which can be categorized into two types, free radicals and non-radical species. The non-radical species are hydrogen peroxide (H 2O 2 ), organic hydroperoxides (ROOH), singlet molecular oxygen ( 1 O 2 ), electronically excited carbonyl, ozone (O3 ), hypochlorous acid (HOCl, and hypobromous acid HOBr). Free radical species are super-oxide anion radical (O 2•−), hydroxyl radical (•OH), peroxyl radical (ROO•) and alkoxyl radical (RO•) [130]. Any imbalance of ROS can lead to adverse effects. H2 O 2 and O 2 •− are the main redox signalling agents. The cellular concentration of H2 O 2 is about 10−8 M, which is almost a thousand times more than that of O2 •−". "Radicals are molecules with an odd number of electrons in the outer shell [393,394]. A pair of radicals can be formed by breaking a chemical bond or electron transfer between two molecules." Recent investigations have documented that polyphenols with good antioxidant activity may exhibit pro-oxidant activity in the presence of copper ions, which can induce apoptosis in various cancer cell lines but not in normal cells. "We have shown that such cell growth inhibition by polyphenols in cancer cells is reversed by copper-specific sequestering agent neocuproine to a significant extent whereas iron and zinc chelators are relatively ineffective, thus confirming the role of endogenous copper in the cytotoxic action of polyphenols against cancer cells. Therefore, this mechanism of mobilization of endogenous copper." > Ions could be one of the important mechanisms for the cytotoxic action of plant polyphenols against cancer cells and is possibly a common mechanism for all plant polyphenols. In fact, similar results obtained with four different polyphenolic compounds in this study, namely apigenin, luteolin, EGCG, and resveratrol, strengthen this idea. Interestingly, the normal breast epithelial MCF10A cells have earlier been shown to possess no detectable copper as opposed to breast cancer cells [24], which may explain their resistance to polyphenols apigenin- and luteolin-induced growth inhibition as observed here (Fig. 1). We have earlier proposed [25] that this preferential cytotoxicity of plant polyphenols toward cancer cells is explained by the observation made several years earlier, which showed that copper levels in cancer cells are significantly elevated in various malignancies. Thus, because of higher intracellular copper levels in cancer cells, it may be predicted that the cytotoxic concentrations of polyphenols required would be lower in these cells as compared to normal cells." Majority of ROS are produced as a by-product of oxidative phosphorylation, high levels of ROS are detected in almost all cancers. -It is well established that during ER stress, cytosolic calcium released from the ER is taken up by the mitochondrion to stimulate ROS overgeneration and the release of cytochrome c, both of which lead to apoptosis. Note: Products that may raise ROS can be found using this database, by: Filtering on the target of ROS, and selecting the Effect Direction of ↑ Targets to raise ROS (to kill cancer cells): • NADPH oxidases (NOX): NOX enzymes are involved in the production of ROS. -Targeting NOX enzymes can increase ROS levels and induce cancer cell death. -eNOX2 inhibition leads to a high NADH/NAD⁺ ratio which can lead to increased ROS • Mitochondrial complex I: Inhibiting can increase ROS production • P53: Activating p53 can increase ROS levels(by inducing the expression of pro-oxidant genes) • Nrf2 inhibition: regulates the expression of antioxidant genes. Inhibiting Nrf2 can increase ROS levels • Glutathione (GSH): an antioxidant. Depleting GSH can increase ROS levels • Catalase: Catalase converts H2O2 into H2O+O. Inhibiting catalase can increase ROS levels • SOD1: converts superoxide into hydrogen peroxide. Inhibiting SOD1 can increase ROS levels • PI3K/AKT pathway: regulates cell survival and metabolism. Inhibiting can increase ROS levels • HIF-1α inhibition: regulates genes involved in metabolism and angiogenesis. Inhibiting HIF-1α can increase ROS • Glycolysis: Inhibiting glycolysis can increase ROS levels • Fatty acid oxidation: Cancer cells often rely on fatty acid oxidation for energy production. -Inhibiting fatty acid oxidation can increase ROS levels • ER stress: Endoplasmic reticulum (ER) stress can increase ROS levels • Autophagy: process by which cells recycle damaged organelles and proteins. -Inhibiting autophagy can increase ROS levels and induce cancer cell death. • KEAP1/Nrf2 pathway: regulates the expression of antioxidant genes. -Inhibiting KEAP1 or activating Nrf2 can increase ROS levels and induce cancer cell death. • DJ-1: regulates the expression of antioxidant genes. Inhibiting DJ-1 can increase ROS levels • PARK2: regulates the expression of antioxidant genes. Inhibiting PARK2 can increase ROS levels • SIRT1 inhibition:regulates the expression of antioxidant genes. Inhibiting SIRT1 can increase ROS levels • AMPK activation: regulates energy metabolism and can increase ROS levels when activated. • mTOR inhibition: regulates cell growth and metabolism. Inhibiting mTOR can increase ROS levels • HSP90 inhibition: regulates protein folding and can increase ROS levels when inhibited. • Proteasome: degrades damaged proteins. Inhibiting the proteasome can increase ROS levels • Lipid peroxidation: a process by which lipids are oxidized, leading to the production of ROS. -Increasing lipid peroxidation can increase ROS levels • Ferroptosis: form of cell death that is regulated by iron and lipid peroxidation. -Increasing ferroptosis can increase ROS levels • Mitochondrial permeability transition pore (mPTP): regulates mitochondrial permeability. -Opening the mPTP can increase ROS levels • BCL-2 family proteins: regulate apoptosis and can increase ROS levels when inhibited. • Caspase-independent cell death: a form of cell death that is regulated by ROS. -Increasing caspase-independent cell death can increase ROS levels • DNA damage response: regulates the repair of DNA damage. Increasing DNA damage can increase ROS • Epigenetic regulation: process by which gene expression is regulated. -Increasing epigenetic regulation can increase ROS levels -PKM2, but not PKM1, can be inhibited by direct oxidation of cysteine 358 as an adaptive response to increased intracellular reactive oxygen species (ROS) ProOxidant Strategy:(inhibit the Mevalonate Pathway (likely will also inhibit GPx) -HydroxyCitrate (HCA) found as supplement online and typically used in a dose of about 1.5g/day or more -Atorvastatin typically 40-80mg/day, -Dipyridamole typically 200mg 2x/day Combined effect research -Lycopene typically 100mg/day range (note debatable as it mainly lowers NRF2) Dual Role of Reactive Oxygen Species and their Application in Cancer Therapy ROS-Inducing Interventions in Cancer — Canonical + Mechanistic Reference -generated from AI and Cancer database ROS rating: +++ strong | ++ moderate | + weak | ± mixed | 0 none NRF2: ↓ suppressed | ↑ activated | ± mixed | 0 none Conditions: [D] dose [Fe] metal [M] metabolic [O₂] oxygen [L] light [F] formulation [T] tumor-type [C] combination
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| 2315- | Citrate, | Why and how citrate may sensitize malignant tumors to immunotherapy |
| - | Review, | Var, | NA |
| 1593- | Citrate, | Citrate Induces Apoptotic Cell Death: A Promising Way to Treat Gastric Carcinoma? |
| - | in-vitro, | GC, | BGC-823 | - | in-vitro, | GC, | SGC-7901 |
| 1585- | Citrate, | Sodium citrate targeting Ca2+/CAMKK2 pathway exhibits anti-tumor activity through inducing apoptosis and ferroptosis in ovarian cancer |
| - | in-vitro, | Ovarian, | SKOV3 | - | in-vitro, | Ovarian, | A2780S | - | in-vitro, | Nor, | HEK293 |
| 1576- | Citrate, | Targeting citrate as a novel therapeutic strategy in cancer treatment |
| - | Review, | Var, | NA |
| 1574- | Citrate, | Citrate Suppresses Tumor Growth in Multiple Models through Inhibition of Glycolysis, the Tricarboxylic Acid Cycle and the IGF-1R Pathway |
| - | in-vitro, | Lung, | A549 | - | in-vitro, | Melanoma, | WM983B | - | in-vivo, | NA, | NA |
| - | in-vitro, | NSCLC, | A549 |
Query results interpretion may depend on "conditions" listed in the research papers. Such Conditions may include : -low or high Dose -format for product, such as nano of lipid formations -different cell line effects -synergies with other products -if effect was for normal or cancerous cells
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