• Journal of the Society of Cosmetic Scientists of Korea
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• v.30 no.2
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• pp.167-172
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• 2004

In the human skin, vitamin C (L -ascorbic acid) that is well known as the activated materials has effects that is skin anti-aging and wrinkle repair by giving impetus to collagen biosynthesis and anti-oxidation, and that is the sun screen, a wound recovering, inhibition melanogenesis and so on. In spite of its effects, vitamin C has the defects of the skin stimulation and easily oxidized instability by water, air, heat and light. For solving their matters, many investigation is advanced and its results are synthesized the various vitamin C derivatives. And yet they have not solved the unstable property of vitamin C and were still insufficient for the comparing with the effect of the pure vitamin C itself. In this study, in order to prepare vitamin C derivative of being improved the stability and to apply vitamin C effect in the skin, we prepared new vitamin C derivative, phytosphingosine ascorbate, by using phytosphingosine, one of sphingolipids, which have a distinguished skin affinity. Phytosphingosine ascorbate can be prepared as the ionic bond between amine group (-NH$_2$) of phytosphingosine and hydroxy group (-OH) of vitamin C by way of the relatively simple reaction. So the structure and properties of the synthesized phytosphingosine ascorbate was confirmed the use of elemental analysis (C 58.3 : H 9.3 : N 2.8 : O 29.5), MALDI TOF-MS (Mw=492.58), Ultraviolet spectra (268.5nm), lH NMR, FT-IR spectra, thermal analysis (m.p=l54$^{\circ}C$), HPLC and so on. And we could confirm the anti-bacterial and anti-oxidation effects. Based on these results, we could confirm to prepare a new material that was expected of both effects of vitamin C and phytosphingosine and that is improved properties of vitamin C.

• IMMUNE NETWORK
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• v.9 no.5
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• pp.147-152
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• 2009

Ascorbate (vitamin C) is a cofactor for a number of metabolic enzymes and is an indisputable essential vitamin C for humans. However, the potential of ascorbate as an anticancer agent has been a topic of controversy. A number of previous reports have addressed both positive aspects and limitations of ascorbate in cancer therapy. In this review, we briefly summarize the potential antitumor effects of ascorbate and its prospects for clinical use.

• Journal of Ginseng Research
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• v.13 no.2
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• pp.242-247
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• 1989

The effect of ginseng extract and sodium ascorbate (vitamin C) administered separately or in combination on the some cancer cells cultured in vitro have been examined. Mouse leukemic cells (L1210 and P388), human rectal cancer cells (HRT-18) and human colon cancer cells (HCT-48) were used for the experiment. When given separately, the growth rate for each kind of cancer cell was inhibited In proportion to the concentration of ginseng extract or vitamin C. The inhibitory effect on the growth rate of the cancer cells was stronger in ginseng extract than in vitamin C except for the HCT-48 cells. Based on the cytotoxic activity, combined administration of ginseng extract and vitamin C demonstrated a synergistic inhibition of cancer cell growth. The cytotoxic activities of ginseng extract and vitamin C on the mouse leukemic cells were more sensitive than on human colon cancer cells. And the sensitivity of cytotoxic activity was somewhat different in different cancer cell lines.

• Journal of Nutrition and Health
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• v.42 no.2
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• pp.107-118
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• 2009

In patients with type 2 diabetes, oxidative stress could be increased by their metabolic changes. Elevated plasma homocysteine is considered as one of markers of enhanced oxidative stress. Due to oxidative stress, some complications like cardiovascular or renal diseases may develop in type 2 diabetes patients. Plasma homocysteine concentration may be increased if folate status were inadequate. Protective effects against oxidative stress may be diminished if the status of anti-oxidative nutrient as vitamin C was poor. It is, therefore, important to maintain adequate status of folate and vitamin C in type 2 diabetes patients. Thus, this study was performed to determine the effects of supplementation of folate and/or ascorbate on blood glycated hemoglobin ($HbA_{1c}$) level, serum concentrations of homocysteine and cholesterol, plasma oxidized low density-lipoprotein (LDL), concentration and plasma glutathione peroxidase (GSH-Px) activity in the patients with type 2 diabetes. A total of 92 type 2 diabetes patients participated voluntarily with written consents. They were divided into one of the four experimental groups; Control (C), Folate-supplemented (F), Ascorbate-supplemented (A), and Folate plus ascorbate-supplemented (FA). The subjects in C were taken placebo, those in F were supplemented 1 mg of folate, those in A received 1,000 mg of ascorbate, and those in FA were given 1 mg of folate plus 1,000 mg of ascorbate daily for 4 weeks. Supplementation of folate or ascorbate resulted to increase serum folate level or plasma ascorbate concentration apparently, respectively. Folate supplementation not ascorbate seemed to decrease plasma concentrations of homocysteine and oxidized LDL and reduce plasma GSH-Px activity. There might not be synergic effect of the supplementation of folate plus ascorbate. The results indicate that oxidative stress in the patients with type 2 diabetes may lower mainly by folate supplementation.

• Analytical Science and Technology
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• v.29 no.4
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• pp.162-169
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• 2016

The purpose of this study was to compare the relative bioavailability of synthetic Vitamin C and Nutra-C^® (calcium ascorbate) using a randomized parallel pharmacokinetics study design. Under fasting conditions, 20 healthy volunteers were randomly allocated to receive a single oral dose (500 mg of ascorbic acid) of either synthetic Vitamin C or Nutra-C^®. Fasting blood was collected pre-dose and 1, 2, 3, 4, 7 and 10 hr post-dose. The ascorbic acid content of human serum was determined using HPLC with ultraviolet detection. The fasting serum ascorbic acid concentrations of synthetic Vitamin C and Nutra-C^® were 6.734 ± 2.09 ng/mL (n = 10) and 7.542 ± 2.96 ng/mL (n = 10), respectively. The bioavailability of Nutra-C^® was significantly greater (128 %, p < 0.05) than that of the synthetic Vitamin C.

• Radiation Oncology Journal
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• v.11 no.2
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• pp.227-231
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• 1993

The role of ascorbate as an antioxidant in the prevention and cure of disease that result from free radicals has been of considerable interest and controversy lately. As an antioxidant, we can expect it to protect against radiation damage caused by free radicals that are produced when radiation, especially sparsely ionizing radiation, interacts with living tissues. The plasma and whole blood concentration of ascorbate was analyzed before and just after the radiation therapy for the purpose of estimating the consumption amount of ascorbate during radiotherapy. Whole blood ascorbate was decreased from 1.82 mg/dl to 1.58 mg/dl, plasma ascorbate was decreased from 1.13 mg/dl to 1.08 mg/dl, and urine ascorbate was decreased from 9.33 mg/dl to 6.96 mg/dl after radiotherapy. Although the difference was not significant statistically, further human study should be followed to define the role of ascorbate as a radioprotector.

• Archives of Pharmacal Research
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• v.27 no.12
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• pp.1245-1252
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• 2004

Although ascorbate (vitamin C) has been shown to have anti-cancer actions, its effect on human hepatoma cells has not yet been investigated, and thus, the exact mechanism of this action is not fully understood. In this study, the mechanism by which ascorbate induces apoptosis using HepG2 human hepatoblastoma cells is investigated. Ascorbate induced apoptotic cell death in a dose-dependent manner in the cells, was assessed through flow cytometric analysis. Contrary to expectation, ascorbate did not alter the cellular redox status, and treatment with antioxidants (N-acetyl cysteine and N,N-diphenyl-p-phenylenediamine) had no influence on the ascorbate-induced apoptosis. However, ascorbate induced a rapid and sustained increase in intracellular $Ca^{2+}$ concentration. EGTA, an extracellular $Ca^{2+}$ chelator did not significantly alter the ascorbate-induced intracellular $Ca^{2+}$ increase and apoptosis, whereas dantrolene, an intracellular $Ca^{2+}$ release blocker, completely blocked these actions of ascorbate. In addition, phospholipase C (PLC) inhibitors (U-73122 and manoalide) significantly suppressed the intracellular $Ca^{2+}$ release and apoptosis induced by ascorbate. Collectively, these results suggest that ascorbate induced apoptosis without changes in the cellular redox status in HepG2 cells, and that the PLC-coupled intracellular $Ca^{2+}$ release mechanism may mediate ascorbate-induced apoptosis.

• BMB Reports
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• v.32 no.5
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• pp.451-455
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• 1999

The concentrations of L-ascorbic acid (AsA, ascorbate, vitamin C) and its biosynthetic and metabolically-related enzymes such as L-galactono-1,4-lactone dehydrogenase (GLDase), ascorbate peroxidase (APX), and ascorbate oxidase (ASO) were investigated in suspension cultures of Scutellaria baicalensis. Cells growing from 4 days after subculture (DAS) to 9 DAS and from 16 DAS to 19 DAS showed a diauxic growth, and then growth rapidly decreased with further culturing. The AsA content slowly increased to 19 DAS, reached a maximum at 21 DAS (ca $120\;{\mu}g/g$ dry cell wt), and then rapidly decreased with further culturing. GLDase and ASO activity were well correlated with the cell growth curve, showing a maximum at 19 DAS, whereas APX activity showed a good correlation with the changes in AsA content, showing a maximum at 21 DAS. The total ascorbate contents (reduced form, AsA, and oxidized form, dehydroascorbate, DHA) were markedly enhanced at 10 DAS when L-galactose and L-galactono-1,4-lactone (25 mM) were added to SH medium supplemented with 20 g/l sucrose at 9 DAS, by 5.5 and 6.8 times, respectively. DHA composed more than 90% of the total ascorbate contents in suspension cultures of S. baicalensis, even though the ratio of reduced to oxidized form slightly varied with cell growth stage. The results indicate that L-galactose and L-galactono-1,4-lactone are effective precursors of AsA in cell cultures of S. baicalensis, and that in vitro cultured cells provide suitable biomaterials for the study of biosynthesis and metabolism of AsA.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2010.10a
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• pp.14-14
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• 2010

Vitamin C (ascorbic acid) is an essential component for collagen biosynthesis and also for the proper functioning of the cardiovascular system in humans. Unlike most of the animals, humans lack the ability to synthesize ascorbic acid on their own due to a mutation in the gene encoding the last enzyme of ascorbate biosynthesis. As a result, vitamin C must be obtained from dietary sources like plants. In this study, we have developed two different kinds of transgenic potato plants (Solanumtuberosum L. cv. Taedong Valley) overexpressing strawberry GalUR and mouse GLoase gene under the control of CaMV 35S promoter with increased ascorbic acid levels. Integration of the these genes in the plant genome was confirmed by PCR and Southern blotting. Ascorbic acid(AsA) levels in transgenic tubers were determined by high-performance liquid chromatography(HPLC). The over-expression of these genes resulted in 2-4 folds increase in AsA intransgenic potato and the levels of AsA were positively correlated with increased geneactivity. The transgenic lines with enhanced vitamin C content showed enhanced tolerance to abiotic stresses induced by methyl viologen(MV), NaCl or mannitol as compared to untransformed control plants. The leaf disc senescence assay showed better tolerance in transgenic lines by retaining higher chlorophyll as compared to the untransformed control plants. Present study demonstrated that the over-expression of these gene enhanced the level of AsA in potato tubers and these transgenics performed better under different abiotic stresses as compared to untransformed control. We have also investigated the mechanism of the abiotic stress tolerance upon enhancing the level of the ascorbate in transgenic potato. The transgenic potato plants overexpressing GalUR gene with enhanced accumulation of ascorbate were investigated to analyze the antioxidants activity of enzymes involved in the ascorbate-glutathione cycle and their tolerance mechanism against different abiotic stresses under invitro conditions. Transformed potato tubers subjected to various abiotic stresses induced by methyl viologen, sodium chloride and zinc chloride showed significant increase in the activities of superoxide dismutase(SOD, EC 1.15.1.1), catalase, enzymes of ascorbate-glutathione cycle enzymes such as ascorbate peroxidase(APX, EC 1.11.1.11), dehydroascorbate reductase(DHAR, EC 1.8.5.1), and glutathione reductase(GR, EC 1.8.1.7) as well as the levels of ascorbate, GSH and proline when compared to the untransformed tubers. The increased enzyme activities correlated with their mRNA transcript accumulation in the stressed transgenic tubers. Pronounced differences in redox status were also observed in stressed transgenic potato tubers that showed more tolerance to abiotic stresses when compared to untransformed tubers. From the present study, it is evident that improved to lerance against abiotic stresses in transgenic tubers is due to the increased activity of enzymes involved in the antioxidant system together with enhanced ascorbate accumulated in transformed tubers when compared to untransformed tubers. At moment we also investigating the role of enhanced reduced glutathione level for the maintenance of the methylglyoxal level as it is evident that methylglyoxal is a potent cytotoxic compound produced under the abiotic stress and the maintenance of the methylglyoxal level is important to survive the plant under stress conditions.

• Korean Journal of Community Nutrition
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• v.13 no.2
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• pp.263-275
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• 2008

Impaired fasting glucose (IFG) is one of significant risk factors of developing diabetes. The persons with IFG are, thus, an important target group for primary prevention of diabetes. It is well known that plasma homocysteine concentration may be increased in poor folate nutritional status. Elevated level of plasma homocysteine is considered as a marker of enhanced oxidative stress. In addition, the protective effect against oxidative stress may be diminished in poor antioxidative nutrient status as vitamin C. It is, therefore, important to maintain adequate nutritional status of folate and vitamin C in the patients with type 2 diabetes or IFG. This study was performed to determine the effects of supplementation of folic acid or vitamin C on plasma concentrations of homocysteine, oxidized LDL, and lipids and on the activity of plasma anti-oxidative enzyme in patients with IFG. A total of 97 patients with IFG were participated voluntarily with written consents. They were divided into one of the four experimental groups; Control (C), Folatesupplemented (F), Ascorbate-supplemented (A), and Folate plus ascorbate-supplemented (FA). The subjects in C were taken placebo, those in F were supplemented 1 mg of folate, those in A were received 1,000 mg of vitamin C, and those in FA were given 1 mg of folate plus 1,000 mg of vitamin C daily for 4 weeks. No change in plasma concentrations of vitamin C, lipids, and oxidized LDL and the activity of GSH-Px were observed in vitamin C-supplemented group (A + FA) and folate-supplemented group (F + FA) compared to the placebo group (C + A). Only the folate-supplemented group (F + FA) had significantly increased average serum folate concentration and lowered plasma homocysteine concentration compared to the placebo group (C + A). Thus, it should be recommended the patients with IFG to increase folate intake through diets and, if it is not sufficient, to take folic acid supplements to prevent the development of complications induced by hyperhomocysteinemia as well as oxidative stress.