Alpha-tocopherol ((+)-alpha-tocopherol) functions as a scavenger of peroxyl radicals. This action is crucial because it keeps long-chain polyunsaturated fatty acids in cell membranes intact, which preserves the biological activity of the fatty acids [1]. It has been reported that alpha-vitamin E ((+)-alpha-tocopherol) inhibits PKC in a variety of cell types, which in turn inhibits the formation of superoxide, nitric oxide by endothelial cells, and platelet aggregation in neutrophils and macrophages. The activation of the MAP kinase and PI3 kinase (PI3K) pathways was enhanced by exposure to α-tocopherol ((+)-α-tocopherol), suggesting that oxidative stress upregulates both the kinase pathway and the antioxidant effect of α-. Fatty acids in cell membranes are shielded by tocopherol [1]. It has been shown that alpha-vitamin E, also known as (+)-alpha-tocopherol, is protective against influenza A virus infection and may also be effective against hepatitis B and C. Proviral effects of α-tocopherol are observed, particularly in HEK293T/17 cells [3].

Alpha-vitamin E ((+)-alpha-tocopherol) inhibits development of proinflammatory cytokines IL-1, IL-6, and IFN-γ mRNA and protein compared with ischemia-reperfused myocardium of untreated pigs Increase undamaged area[1]. Treatment with alpha-vitamin E (D-alpha-tocopherol; intraperitoneally or orally) improves diabetic nephropathy in mice by activating diacylglycerol kinase alpha (DGKα) and reducing podocyte loss [2].

Absorption, Distribution and Excretion
The absorption of tocopherol in the digestive tract requires the presence of fat. The bioavailability of tocopherols is highly dependent on the type of isomer that is administered where the alpha-tocopherol can present a bioavailability of 36%. This isomer specificity also determines the intestinal permeability in which the gamma-tocopherol presents a very low permeability. After oral administration, the Cmax was 1353.79 ng/ml for δ-tocopherol, 547.45 ng/ml for γ-tocopherol, 704.16 ng/ml for β-tocopherol, and 2754.36 ng/ml for α-tocopherol. The Tmax is three to four hours for δ-tocopherol, γ-tocopherol, and β-tocopherol and about six hours for α-tocopherol.
The pharmacokinetic profile of tocopherol indicates a longer time of excretion for tocopherols when compared to tocotrienols. The different conjugated metabolites are excreted in the urine or feces depending on the length of their side-chain. Due to their polarity, intermediate-chain metabolites and short-chain metabolites are excreted via urine as glucoside conjugates. A mixture of all the metabolites and precursors can be found in feces. The long-chain metabolites correspond to >60% of the total metabolites in feces. It is estimated that the fecal excretion accounts for even 80% of the administered dose.
The apparent volume of distribution was 0.284 ± 0.021 mL for δ-tocopherol, 0.799 ± 0.047 mL for γ-tocopherol, and 0.556 ± 0.046 mL for β-tocopherol.
Clearance ranged from 0.081 to 0.190 L/h for δ-tocopherol, γ-tocopherol, and β-tocopherol.

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Metabolism / Metabolites
Excess tocopherol is converted into their corresponding carboxyethylhydroxychroman (CEHC), based on the isomer of tocopherol. More deeply, the metabolism of tocopherol begins with the hepatic metabolism which is led by a CYP4F2/CYP3A4-dependent ω-hydroxylation of the side chains which leads to the formation of 13'-carboxychromanol. The metabolic pathway is followed by five cycles of β-oxidation. The β-oxidation cycles function by shortening the side chains, the first cycle results in the formation of carboxydimethyldecylhydroxychromanol followed by carboxymethyloctylhydroxychromanol. These two metabolites are categorized as long-chain metabolites and they are not excreted in the urine. Some intermediate-chain metabolites that are products of two rounds of β-oxidation are carboxymethylhexylhydroxychromanol and carboxymethylbutylhydroxychromanol. These intermediate-chain metabolites can be found in human feces and urine. The catabolic end-product of tocopherols, as stated before, is CEHC which can be largely found in urine and feces. Two new metabolites have been detected in human and mice feces. These new metabolites are 12'-hydroxychromanol and 11'-hydroxychromanol. Because of their chemistry, it is thought that these metabolites can be the evidence for a ω-1 and ω-2 hydroxylation which leads to an impaired oxidation of 12'-OH followed side-chain truncation.
Hepatic.

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Biological Half-Life
The elimination half-life ranged from 2.44 to 3.02 hours for δ-tocopherol, γ-tocopherol, and β-tocopherol.

Toxicity Summary
Although all forms of Vitamin E exhibit antioxidant activity, it is known that the antioxidant activity of vitamin E is not sufficient to explain the vitamin's biological activity.
Vitamin E's anti-atherogenic activity involves the inhibition of the oxidation of LDL and the accumulation of oxLDL in the arterial wall. It also appears to reduce oxLDL-induced apoptosis in human endothelial cells. Oxidation of LDL is a key early step in atherogenesis as it triggers a number of events which lead to the formation of atherosclerotic plaque. In addition, vitamin E inhibits protein kinase C (PKC) activity. PKC plays a role in smooth muscle cell proliferation, and, thus, the inhibition of PKC results in inhibition of smooth muscle cell proliferation, which is involved in atherogenesis.
Vitamin E's antithrombotic and anticoagulant activities involves the downregulation of the expression of intracellular cell adhesion molecule(ICAM)-1 and vascular cell adhesion molecule(VCAM)-1 which lowers the adhesion of blood components to the endothelium. In addition, vitamin E upregulates the expression of cytosolic phospholipase A2 and cyclooxygenase (COX)-1 which in turn enhances the release of prostacyclin. Prostacyclin is a vasodilating factor and inhibitor of platelet aggregation and platelet release. It is also known that platelet aggregation is mediated by a mechanism involving the binding of fibrinogen to the glycoprotein IIb/IIIa (GPIIb/IIIa) complex of platelets. GPIIb/IIIa is the major membrane receptor protein that is key to the role of the platelet aggregation response. GPIIb is the alpha-subunit of this platelet membrane protein. Alpha-tocopherol downregulates GPIIb promoter activity which results in reduction of GPIIb protein expression and decreased platelet aggregation. Vitamin E has also been found in culture to decrease plasma production of thrombin, a protein which binds to platelets and induces aggregation. A metabolite of vitamin E called vitamin E quinone or alpha-tocopheryl quinone (TQ) is a potent anticoagulant. This metabolite inhibits vitamin K-dependent carboxylase, which is a major enzyme in the coagulation cascade.
The neuroprotective effects of vitamin E are explained by its antioxidant effects. Many disorders of the nervous system are caused by oxidative stress. Vitamin E protects against this stress, thereby protecting the nervouse system.
The immunomodulatory effects of Vitamin E have been demonstrated in vitro, where alpha-tocopherol increases mitogenic response of T lymphocytes from aged mice. The mechanism of this response by vitamin E is not well understood, however it has been suggested that vitamin E itself may have mitogenic activity independent of its antioxidant activity.
Lastly, the mechanism of action of vitamin E's antiviral effects (primarily against HIV-1) involves its antioxidant activity. Vitamin E reduces oxidative stress, which is thought to contribute to HIV-1 pathogenesis, as well as to the pathogenesis of other viral infections. Vitamin E also affects membrane integrity and fluidity and, since HIV-1 is a membraned virus, altering membrane fluidity of HIV-1 may interfere with its ability to bind to cell-receptor sites, thus decreasing its infectivity.

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Effects During Pregnancy and Lactation
◉ Summary of Use during Lactation
Vitamin E is a normal component of human milk. Maternal obesity, smoking and possibly preterm birth (<37 weeks gestational age) are associated with lower milk vitamin E levels. Lactating mothers may need to supplement their dietary intake of vitamin E to achieve the recommended daily intake of 19 mg. Daily maternal vitamin E supplementation from prenatal multivitamins can safely and modestly increase milk vitamin E levels and improve the vitamin E status of the breastfed infant compared to no supplementation. Higher daily dosages have not been studied.
◉ Effects in Breastfed Infants
Relevant published information was not found as of the revision date.
◉ Effects on Lactation and Breastmilk
Relevant published information was not found as of the revision date.

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Protein Binding
There has not been described a specific plasma transport protein for tocopherol but it is thought that it is highly bound to lipoproteins such as VLDL, HDL and chylomicrons.

[1]. Vitamin E, antioxidant and nothing more. Free Radic Biol Med. 2007 Jul 1;43(1):4-15.

[2]. Amelioration of diabetic nephropathy by oral administration of d-α-tocopherol and its mechanisms. Biosci Biotechnol Biochem. 2018 Jan;82(1):65-73.

[3]. Screening of melatonin, α-tocopherol, folic acid, acetyl-L-carnitine and resveratrol for anti-dengue 2 virus activity. BMC Res Notes. 2018 May 16;11(1):307.

Pharmacodynamics
The antioxidant effects of tocopherol can be translated into different changes at the pharmacodynamic level. In vitro studies have shown that this antioxidant activity can produce modification in protein kinase C (PKC) which will later be translated into an inhibition of cell death. Some other derivate effects are the anti-inflammatory properties of tocopherol which can be related to the modulation of cytokines or prostaglandins, prostanoids and thromboxanes.

C29H50O2

430.7061

430.381

59-02-9

59-02-9 (vitamin E);58-95-7 (acetate);17407-37-3 (Hemisuccinate);9002-96-4 (PEG 1000 succinate);

14985

Colorless to light yellow liquid

0.9±0.1 g/cm3

485.9±0.0 °C at 760 mmHg

2.5-3.5ºC

210.2±24.4 °C

0.0±1.2 mmHg at 25°C

1.495

11.9

1

2

12

31

503

3

O1C2C(C([H])([H])[H])=C(C([H])([H])[H])C(=C(C([H])([H])[H])C=2C([H])([H])C([H])([H])[C@@]1(C([H])([H])[H])C([H])([H])C([H])([H])C([H])([H])[C@]([H])(C([H])([H])[H])C([H])([H])C([H])([H])C([H])([H])[C@]([H])(C([H])([H])[H])C([H])([H])C([H])([H])C([H])([H])C([H])(C([H])([H])[H])C([H])([H])[H])O[H]

GVJHHUAWPYXKBD-IEOSBIPESA-N

InChI=1S/C29H50O2/c1-20(2)12-9-13-21(3)14-10-15-22(4)16-11-18-29(8)19-17-26-25(7)27(30)23(5)24(6)28(26)31-29/h20-22,30H,9-19H2,1-8H3/t21-,22-,29-/m1/s1

(2R)-2,5,7,8-tetramethyl-2-[(4R,8R)-4,8,12-trimethyltridecyl]-3,4-dihydrochromen-6-ol

Vitamin E

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Note: (1). This product requires protection from light (avoid light exposure) during transportation and storage.  (2). Please store this product in a sealed and protected environment (e.g. under nitrogen), avoid exposure to moisture.

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Ethanol : ~100 mg/mL (~232.17 mM)
DMSO : ~100 mg/mL (~232.17 mM)
H2O : < 0.1 mg/mL

Solubility in Formulation 1: ≥ 11.25 mg/mL (26.12 mM) (saturation unknown) in 10% EtOH + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 112.5 mg/mL clear EtOH stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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Solubility in Formulation 2: 11.25 mg/mL (26.12 mM) (saturation unknown) in 10% EtOH + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), suspension solution; with ultrasonication.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 112.5 mg/mL clear EtOH stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly.
Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.

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Solubility in Formulation 3: ≥ 11.25 mg/mL (26.12 mM) (saturation unknown) in 10% EtOH + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 112.5 mg/mL clear EtOH stock solution to 900 μL of corn oil and mix evenly.

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Solubility in Formulation 4: ≥ 2.5 mg/mL (5.80 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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Solubility in Formulation 5: 2.5 mg/mL (5.80 mM) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), suspension solution; with ultrasonication.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly.
Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.

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Solubility in Formulation 6: ≥ 2.5 mg/mL (5.80 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

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Solubility in Formulation 7: 10 mg/mL (23.22 mM) in 0.5% CMC-Na/saline water (add these co-solvents sequentially from left to right, and one by one), suspension solution; with ultrasonication.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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 (Please use freshly prepared in vivo formulations for optimal results.)