Antioxidative Role of Synthetic and Natural Ascorbic Acid (Vitamin C) in Metabolic Pathways of A Biological System

2021 ◽  
Vol 15 (12) ◽  
pp. 3143-3143
Author(s):  
Naveed Shuja

The properties of a substance are determined by the structure of its component molecules. Ascorbic acid occurs abundantly in fresh fruit, especially blackcurrants, citrus fruit and strawberries, and in most fresh vegetables; good sources are broccoli and peppers. It is destroyed by heat and is not well stored in the body3. Ascorbic acid is a good reducing agent and facilitates many metabolic reaction and repair processes. In pharmaceutical preparations and fruit juices, ascorbic acid is readily separated from other compounds by TLC on silica gel and quantitated directly by absorption at 254nm. Serum and plasma may be deproteinized with twice the volume of methanol or ethanol.

Nutrients ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 615
Author(s):  
Martin Doseděl ◽  
Eduard Jirkovský ◽  
Kateřina Macáková ◽  
Lenka Krčmová ◽  
Lenka Javorská ◽  
...  

Vitamin C (L-ascorbic acid) has been known as an antioxidant for most people. However, its physiological role is much larger and encompasses very different processes ranging from facilitation of iron absorption through involvement in hormones and carnitine synthesis for important roles in epigenetic processes. Contrarily, high doses act as a pro-oxidant than an anti-oxidant. This may also be the reason why plasma levels are meticulously regulated on the level of absorption and excretion in the kidney. Interestingly, most cells contain vitamin C in millimolar concentrations, which is much higher than its plasma concentrations, and compared to other vitamins. The role of vitamin C is well demonstrated by miscellaneous symptoms of its absence—scurvy. The only clinically well-documented indication for vitamin C is scurvy. The effects of vitamin C administration on cancer, cardiovascular diseases, and infections are rather minor or even debatable in the general population. Vitamin C is relatively safe, but caution should be given to the administration of high doses, which can cause overt side effects in some susceptible patients (e.g., oxalate renal stones). Lastly, analytical methods for its determination with advantages and pitfalls are also discussed in this review.


Author(s):  
Arun Kumar ◽  
Reena V Saini ◽  
Adesh K Saini

Ascorbic acid (AA) or Vitamin C is an important antioxidant which participates in numerous cellular functions. Although in human plasma its concentration is in micromolars but it reaches millimolar concentrations in most of the human tissues. The high ascorbate cellular concentrations are generated and maintained by a specific sodium-dependent Vitamin C transporter type 2 (SVCT2, member of Slc23 family). Metabolic processes recycle Vitamin C from its oxidized forms (ascorbate) inside the cells. AA concentration is highest in the neurons of the central nervous system (CNS) of mammals, and deletion of its transporter affects mice brain and overall survival. In the CNS, intracellular ascorbate serves several functions including antioxidant protection, peptide amidation, myelin formation, synaptic potentiation, and protection against glutamate toxicity. SVCT2 maintains neuronal ascorbate content in CNS which has relevance for neurodegenerative diseases such as Alzheimer’s, Parkinson’s, and Huntington’s disease. As ascorbate supplements decrease infarct size in ischemia-reperfusion injury and protect neurons from oxidative damage, it is a vital dietary antioxidant. The aim of this review is to assess the role of the SVCT2 in regulating neuronal ascorbate homeostasis in CNS and the extent to which ascorbate affects brain function as an antioxidant.


2019 ◽  
Vol 39 (1) ◽  
Author(s):  
Wei Gao ◽  
Xianfeng Yu ◽  
Jindong Hao ◽  
Ling Wang ◽  
Minghui Qi ◽  
...  

Abstract The TET (Ten-Eleven Translocation) proteins catalyze the oxidation of 5mC (5-methylcytosine) to 5hmC (5-hydroxymethylcytosine) and play crucial roles in embryonic development. Ascorbic acid (Vc, Vitamin C) stimulates the expression of TET proteins, whereas DMOG (dimethyloxallyl glycine) inhibits TET expression. To investigate the role of TET1, TET2, and TET3 in PA (parthenogenetic) embryonic development, Vc and DMOG treatments were administered during early embryonic development. The results showed that Vc treatment increased the blastocyst rate (20.73 ± 0.46 compared with 26.57 ± 0.53%). By contrast, DMOG reduced the blastocyst rate (20.73 ± 0.46 compared with 11.18 ± 0.13%) in PA embryos. qRT-PCR (quantitative real-time PCR) and IF (immunofluorescence) staining results revealed that TET1, TET2, and TET3 expressions were significantly lower in PA embryos compared with normal fertilized (Con) embryos. Our results revealed that Vc stimulated the expression of TET proteins in PA embryos. However, treatment with DMOG significantly inhibited the expression of TET proteins. In addition, 5hmC was increased following treatment with Vc and suppressed by DMOG in PA embryos. Taken together, these results indicate that the expression of TET proteins plays crucial roles mediated by 5hmC in PA embryonic development.


2009 ◽  
Vol 4 (5) ◽  
pp. 1934578X0900400 ◽  
Author(s):  
Nuria Martí ◽  
Pedro Mena ◽  
Jose Antonio Cánovas ◽  
Vicente Micol ◽  
Domingo Saura

The literature on the content and stability of vitamin C (ascorbic acid, AA) in citrus juices in relation to industrial practices is reviewed. The role of vitamin C from citrus juices in human diet is also reviewed. Citrus fruits and juices are rich in several types of bioactive compounds. Their antioxidant activity and related benefits derive not only from vitamin C but also from other phytochemicals, mainly flavonoids. During juice processing, temperature and oxygen are the main factors responsible for vitamin C losses. Nonthermal processed juices retain higher levels of vitamin C, but economic factors apparently delay the use of such methods in the citrus industry. Regarding packing material, vitamin C in fruit juice is quite stable when stored in metal or glass containers, whereas juice stored in plastic bottles has a much shorter shelf-life. The limiting step for vitamin C absorption in humans is transcellular active transport across the intestinal wall where AA may be oxidized to dehydroascorbic acid (DHAA), which is easily transported across the cell membrane and immediately reduced back to AA by two major pathways. AA bioavailability in the presence of flavonoids has yielded controversial results. Whereas flavonoids seem to inhibit intestinal absorption of AA, some studies have shown that AA in citrus extract was more available than synthetic ascorbic acid alone. DHAA is reported to possess equivalent biological activity to AA, so recent studies often consider the vitamin C activity in the diet as the sum of AA plus DHAA. However, this claimed equivalence should be carefully reexamined. Humans are one of the few species lacking the enzyme (L-gulonolactone oxidase, GLO) to convert glucose to vitamin C. It has been suggested that this is due to a mutation that provided a survival advantage to early primates, since GLO produces toxic H2O2. Furthermore, the high concentration of AA (and DHAA) in neural tissues could have been the key factor that caused primates (vertebrates with relative big brain) to lose the capacity to synthesize vitamin C. Oxidative damage has many pathological implications in human health, and AA may play a central role in maintaining the metabolic antioxidant response. The abundance of citrus juices in the Mediterranean diet may provide the main dietary source for natural vitamin C.


2010 ◽  
Vol 5 (2) ◽  
pp. 1934578X1000500 ◽  
Author(s):  
Gábor Janicsák ◽  
István Zupkó ◽  
Imre Máthé ◽  
Judit Hohmann

The lipid peroxidation-inhibiting activities of aqueous methanolic extracts of eleven Salvia species (Fam. Lamiaceae) were evaluated in an enzyme-independent biological system. The total polyphenol contents and the amounts of the most abundant phenoloids of the genus, caffeic and rosmarinic acids, were also determined. The EC50 values of the extracts displayed substantial differences. All of the investigated species except S. jurisicii (EC50 191.2 μg/mL) exhibited higher activities than that of ascorbic acid (EC50 123.8 μg/mL), the reference compound. Among the studied species, S. scabiosifolia (EC50 5.4 μg/mL) demonstrated the highest effect, followed in sequence by S. dumetorum, S. transsylvanica, S. officinalis l albiflora, S. nemorosa l albiflora and S. recognita (EC50 6.5 – 10.2 μg/mL). The close correlation was confirmed between the antioxidant activities and the total phenol contents of the extracts. For caffeic and rosmarinic acids, the correlation was much weaker, indicating the important role of other polyphenols in the antioxidant activity.


Author(s):  
Mary K Walingo ◽  

Vitamin C, also known as ascorbic acid, abounds in nature and is highly labile. It is a water-soluble vitamin that is lost in large amounts during food processing. It is a vitamin whose prescribed requirement across cultures is not uniform. For example , the prescribed requirement of vitamin C in Great Britain is 30mg/day, while in the U.S.A., it is 60mg/day and 100mg/day in Japan. These variations are unusual and point to the need for further research to establish the acceptable RDAs for diverse populations. The RDA for vitamin C should be more than the amount needed to prevent the occurrence of disease. Vitamin C plays significant functions in the body that enhance its role in the health status of the human body. The biochemical functions of vitamin C include: stimulation of certain enzymes, collagen biosynthesis, hormonal activation, antioxidant, detoxification of histamine, phagocytic functions of leukocytes, formation of nitrosamine, and proline hydroxylation amongst others. These functions are related to the health effects of vitamin C status in an individual. In human health, vitamin C has been associated with reduction of incidence of cancer, blood pressure, immunity, and drug metabolism and urinary hydroxyproline excretion, tissue regeneration. This vitamin is needed for the proper metabolism of drugs in the body through adequate hepatic mixed function oxidase system. Epidemiological data have revealed the preventive and curative role of vitamin C on certain disease conditions in the body though controversies still persist. Vitamin C is effective in protecting against oxidative damage in tissues and also suppresses formation of carcinogens like nitrosamines. There is an inverse relationship with blood pressure and both plasma vitamin C and Vitamin C. Vitamin C has a lowering effect on blood pressure, especially on systolic pressure more than a diastolic pressure. Low levels of plasma vitamin C are associated with stroke and with an increased risk of all cause mortality. Increased consumption of ascorbic acid raises serum ascorbic levels and could decrease the risk of death.


Vestnik ◽  
2021 ◽  
pp. 86-91
Author(s):  
Г. Муханқызы ◽  
Т.А. Алимова ◽  
Б.Б. Таубаева ◽  
Г.А. Байжанова

Известно, что в детском возрасте происходят интенсивный рост и напряженные обменные процессы, что и определяет высокую потребность организма ребенка как в витаминах, так и в минеральных веществах. Несмотря на отсутствие дефицита свежих овощей и фруктов, у 80-90% населения Казакстана обнаруживается дефицит витамина С, у 40-60% - снижены уровни витаминов А, В, В, у 30-40% детей наблюдается дефицит железа и кальция, у 70-80% - дефицит йода. Многочисленные исследования, проводимые в различных регионах совместно с Институтом питания, показали, что за последние годы обеспеченность витаминами населения Казакстана существенно ухудшилась. Также отмечено, что у Казахстанских детей дефицит витаминов имеет характер полигиповитаминоза и является круглогодичным, т. е. без улучшения в летние месяцы. Нарушая обмен веществ, дефицит витаминов способствует снижению иммунитета, отрицательно сказывается на физическом и психическом развитии ребенка, повышает частоту и усугубляет тяжесть хронических заболеваний. It is known that in childhood there is intense growth and intense metabolic processes, which determines the high need of the child's body for both vitamins and minerals. Despite the absence of a shortage of fresh vegetables and fruits, 80-90% of the population of Kazakstan is found to be deficient in vitamin C, 40-60% - reduced levels of vitamins A, B1, B2, 30-40% of children are deficient in iron and calcium, 70-80% - iodine deficiency. Numerous studies conducted in various regions together with the Institute of Nutrition have shown that in recent years, the vitamin supply of the population of Kazakstan has significantly deteriorated. It is also noted that in Kazakstan children, vitamin deficiency has the character of polyhypovitaminosis and is year-round, i.e. without improvement in the summer months. By disrupting the metabolism, vitamin deficiency contributes to a decrease in immunity, negatively affects the physical and mental development of the child, increases the frequency and exacerbates the severity of chronic diseases [1-7].


1943 ◽  
Vol 29 (4) ◽  
pp. 535-574 ◽  
Author(s):  
J. S. FRIEDENWALD ◽  
W. BUSCHKE ◽  
H. O. MICHEL

Sign in / Sign up

Export Citation Format

Share Document