ascorbic-acid and gallocatechol

In the United States, nearly 44,000 people are diagnosed with oral or pharyngeal cancer annually. The life expectancy for those who are diagnosed have a survival rate of 57% after five years. Among them, oral cancer can be classified as benign or malignant tumors and is diagnosed at several stages in the development: premalignant conditions, premalignant lesions, and malignant cancer. The early signs of oral cancer often go unnoticed by the individual and are often discovered during routine dental examinations. Early detection and treatment may help to increase patient survival rates. The most widely used treatments for oral cancer include surgery, radiation, and chemotherapy-alone or in combination. Preclinical and clinical evidence for the use of green tea, raspberry, asparagus, and cannabis extracts is discussed in this review. Diet changes, supplementation with antioxidants, high-dose vitamin C therapy, and cannabinoid use have been suggested to decrease cancer cell replication and increase chance of remission. Early detection and lifestyle changes, including the use of dietary supplements in at-risk populations, are critical steps in preventing and successfully treating oral cancer. The main evidence for supplement use is currently in cancer prevention rather than treatment. Further research, determination, and mechanism of action for bioactive compounds such as epigallocatechin, epicatechin-3-gallate, and Bowman-Birk inhibitor concentrate, through in vitro, in vivo, and clinical trials need to be completed to support the use of natural products and their effectiveness in preventative care and supporting therapeutic approaches.

Topics: Anthocyanins; Antioxidants; Ascorbic Acid; Asparagus Plant; Cannabinoids; Carotenoids; Catechin; Complementary Therapies; Dietary Supplements; Dose-Response Relationship, Drug; Glycine max; Humans; Lycopene; Mouth Neoplasms; Phytotherapy; Tea

Certain phenolic phytochemicals can kill cancer cells. Possible interference from antioxidants is a concern, and this issue has not been studied appreciably. Therefore, the effect of ascorbate and N-acetylcysteine on the ability of epigallocatechin gallate (EGCG) and curcumin to kill HCT116 colon cancer cells was examined. EGCG and curcumin each caused DNA damage in the cells. The DNA-damaging ability of EGCG, but not curcumin, was hindered by either ascorbate or NAC, which was also shown in HT29 and SW480 colon cancer cells. Also, iron chelators (deferoxamine and 2,2'-dipyridyl) inhibited the ability of EGCG, but not curcumin, to cause damage to the DNA in HCT116 cells. Interestingly, curcumin, but not EGCG, increased the expression of growth arrest and DNA damage-inducible gene 153 and also heme oxygenase-1, and this stress gene upregulation by curcumin was antioxidant-insensitive. With prolonged incubation of HCT116 cells with either EGCG or curcumin, cell shrinkage, membrane blebbing, apoptotic bodies, and chromatin condensation/fragmentation were observed. These morphological changes were not apparent in EGCG-treated cells that had been pretreated with either ascorbate or NAC. However, the ascorbate and NAC pretreatments did not prevent the occurrence of the morphological changes in curcumin-treated cells. Thus, these findings suggest that ascorbate and NAC interfere with the ability of EGCG, but not curcumin, to kill HCT116 cells. This basic knowledge may help to better plan and optimize strategies for chemoprevention or chemotherapy.

Topics: Acetylcysteine; Antioxidants; Apoptosis; Ascorbic Acid; Catechin; Cell Line, Tumor; Colonic Neoplasms; Curcumin; DNA Damage; Drug Interactions; Gene Expression; HCT116 Cells; Heme Oxygenase-1; HT29 Cells; Humans; Iron Chelating Agents

Experimental and clinical studies have revealed the effectiveness of a specific nutrient synergy (SNS) mixture composed of ascorbic acid (AA), lysine, proline, arginine, epigallocatechin gallate (EGCG) and other micronutrients in targeting crucial physiological mechanisms involved in cancer progression and metastasis. HTLV-1 causes adult T-cell leukemia (ATL). The spread and metastases of ATL as well as other tumors has been associated with matrix metalloproteinases, especially the gelatinases MMP-2 and MMP-9. The objective of this study was to investigate whether SNS, AA and EGCG affects the gelatinolytic activity of MMP-2 and its transcriptional and translational levels in HTLV-1-positive and -negative malignant T-cells. The results indicated that SNS and EGCG caused a dose-dependent decline in the activity, transcription and translation of MMP-2 after treatment with SNS and EGCG, while AA was only able to inhibit the activity at maximum doses tested and to some extent, the protein expression levels of MMP-2, without affecting their transcriptional levels. The highest activity was noted in the case of SNS which is likely to be due to a synergistic effect of the different constituents in the formulation. These results point towards the potential integration of SNS in the anti-invasive treatment of ATL and related diseases.

Topics: Ascorbic Acid; Catechin; Drug Synergism; Gene Expression Regulation, Neoplastic; HTLV-I Infections; Human T-lymphotropic virus 1; Humans; Leukemia, T-Cell; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Protein Biosynthesis; Transcription, Genetic

The effect of green tea formulated with vitamin C and xylitol on intestinal cell transport of gallated and nongallated catechin was studied. The transport of catechins from both apical to basolateral and basolateral to apical directions was measured. The effect of vitamin C (4, 10, 20 ppm), xylitol (11, 27.5, 55 ppm), and combinations of both on the intestinal transport rate of catechins was examined. The efflux value (Pb→a/Pa→b) of (-)-epigallocatechin (EGC), (-)-epigallocatechin gallate (EGCG), (-)-epicatechin (EC), and (-)-epicatechin gallate (ECG) was 0.26, 0.22, 1.22, and 0.17, respectively, indicating that EC appeared to be less absorbed compared with other catechins. The addition of xylitol (11, 27.5, 55 ppm) and vitamin C (4, 10, 20 ppm) and in combination enhanced transport rate of nongallated catechins such as EC and EGC. For EC, vitamin C was revealed to be the most effective on intestinal transport, implying the inhibition of the efflux transport mechanism of EC. Intestinal transport of gallated catechins significantly increased from catechins formulated with vitamin C and xylitol in a dose-dependent manner compared to the catechin-only formulation. Results provide a potential strategy to enhance the delivery and bioavailability of catechins in humans by modulating green tea formulation with vitamin C and xylitol.

Topics: Antioxidants; Ascorbic Acid; Biological Availability; Caco-2 Cells; Catechin; Chemistry, Pharmaceutical; Chromatography, High Pressure Liquid; Humans; Intestinal Absorption; Intestinal Mucosa; Intestines; Mass Spectrometry; Plant Extracts; Tea; Xylitol

Topics: Ascorbic Acid; Catalysis; Catechin; Copper; Gold; Stereoisomerism; Thiourea

The replacement of established evidence-based cancer therapy protocols (mainstream therapy) by unevaluated complementary and alternative medicine (CAM) is a challenge in pediatric oncology. We tested the hypothesis that oral application of L-lysine and ascorbic acid (Lysin C Drink) in combination with epigallocatechin-gallate (EGCG) and amino-acids (Epican forte) is effective in a preclinical model of neuroblastoma.. Primary tumors and spontaneous metastases were induced in A/J mice by injection of NXS2 neuroblastoma cells. Mice were treated by daily oral gavage with L-lysine and ascorbic acid (Lysin C Drink) (equivalent to 150 mg ascorbic acid/day/mouse) (treatment A) or with EGCG plus ascorbic- and amino-acids (Epican forte) (9.2 mg/mouse) (treatment B). Treatment A was started in the prophylactic setting (7 days before tumor cell injection) as well as in the therapeutic setting (1 day after tumor cell inoculation). Finally, treatment B was evaluated alone and in combination with treatment A in the therapeutic setting. The effect on primary tumor growth and the development of spontaneous liver metastases was evaluated.. L-lysine and ascorbic acid (Lysin C Drink) and EGCG plus ascorbic- and amino-acids (Epican forte) are ineffective in reduction of primary tumor growth and prevention of spontaneous liver metastases in this model.. Neither a formal clinical development nor the use of these substances can be recommended for neuroblastoma.

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Ascorbic Acid; Catechin; Dietary Supplements; Disease Models, Animal; Female; Liver Neoplasms, Experimental; Lysine; Mice; Mice, Inbred A; Neuroblastoma; Proline

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Ascorbic Acid; Catechin; Cell Growth Processes; Dietary Supplements; Liver Neoplasms, Experimental; Lysine; Mice; Neuroblastoma; Proline; Research Design

Seven kinds of green tea leaves were manufactured with far-infrared (FIR) irradiation, and the physicochemical characteristics of the green tea were determined. Appropriate FIR irradiation during the manufacturing process significantly increased the polyphenolic content of green tea. FIR irradiation at 90 degrees C for 10 min, replacing the roasting step, and of the fully processed green tea leaves (GTP3) increased the total phenol content of green tea from 475.6 to 811.1 mg/g and the total flavanol content from 175.7 to 208.7 mg/g, as compared to the control. Epigallocatechin and epigallocatechin gallate increased from 57.68 and 9.60 mg/g in a nonirradiated control to 89.88 and 16.33 mg/g in GTP3, respectively. Ascorbic acid, caffeine, and nitrite scavenging activities were also increased in GTP3. However, the overall color change of GTP3 was negligible. These results indicate that the chemical properties of green tea are significantly affected by FIR irradiation at specific stages of the manufacturing process of green tea leaves and that this FIR irradiation results in high-quality green tea.

Topics: Ascorbic Acid; Caffeine; Camellia sinensis; Catechin; Flavonols; Food Handling; Free Radical Scavengers; Infrared Rays; Phenols; Plant Leaves; Tea

Blood plasma was incubated with 50 mM AAPH [2, 2'-azobis-(2-amidinopropane) hydrochloride] in the absence or presence of catechins (5-100 microM). Lipid oxidation was evaluated by measuring the formation of 2-thiobarbituric acid reactive substances (TBARS). The concentration of alpha-tocopherol (AT), beta-carotene (BC), ascorbic acid (AA), and catechins was determined by reverse phase high performance liquid chromatography (HPLC) with electrochemical detection. All the assayed catechins inhibited plasma TBARS formation. Based on the calculated IC50, the order of effectiveness was: epicatechin gallate (ECG) > epigallocatechin gallate (EGCG) > epigallocatechin (EGC) > epicatechin (EC) > catechin (C). Catechins protected plasma AT and BC from AAPH-mediated oxidation. The order of effectiveness for AT protection was ECG > EGCG > EC = C > EGC; and for BC protection, the order was EGCG > ECG > EGC > > EC > C. The addition of catechins modified the kinetics of TBARS formation and AT depletion, but the rate of AA depletion was not affected. Catechin oxidation did not start until the complete depletion of AA, and it preceded AT depletion. These results indicate that catechins are effective antioxidants in human blood plasma, delaying the lipid oxidation and depletion of endogenous lipid-soluble antioxidants (AT and BC).

Topics: Ascorbic Acid; beta Carotene; Catechin; Chromatography, High Pressure Liquid; Dose-Response Relationship, Drug; Flavonoids; Humans; Kinetics; Lipid Peroxidation; Thiobarbituric Acid Reactive Substances; Vitamin E