Table 2.
List of 32 principal approved synthetic low-molecular-weight antioxidants used as technological additives, dietary supplements or therapeutic agents (alphabetical order).
| Common Name/Alternative Names | IUPAC Name (PubChem) |
Applications/Regulatory | Description | Ref. |
|---|---|---|---|---|
| Acetylcarnitine | (R)-3-Acetoxy-4-(trimethylammonio)butyrate | Drug Dietary supplements Antioxidant in dietary supplements /ATC N06BX12 UNII NDW10MX58T |
Pharmacological properties: reduce oxidative stress in patients with Sickle Cell disease, positive effects on neurological disorders (psychostimulant, nootropic), neuropathies, potential antiviral (supportive and therapeutic option in patients with COVID-19 -clinical trial NCT04623619) | [21,28] |
| Antioxidant mechanism: decreases the generation of free radicals, prevents peroxidation of lipids, and oxidation of proteins through a tyrosine kinase A receptor-mediated mechanism; increases intracellular glutathione levels | [29,30] | |||
| Safety issues: LD50 (oral, rat) >5000 mg/kg; nonirritant to skin; nonmutagenic | [31] | |||
| Acetylcysteine (NAC) |
(R)-2-Acetamido-3-sulfanylpropanoic acid | Drug Antioxidant in cosmetics /Eur. Pharmacopoeia |
Pharmacological properties: antioxidant, mucolytic therapeutic agent, reduces the effects of acetaminophen overdose, prevents the contrast nephropathy; immune-modulating properties useful for the treatment and prevention of COVID-19 | [32,33,34,35] |
| Antioxidant mechanism: alteration of intracellular redox reactions, deacetylation to cysteine, which participates in the synthesis of the antioxidant glutathione (stimulates glutathione synthetase), scavenging different types of ROS | [36,37] | |||
| Safety issues: hypersensitivity reactions | [21] | |||
| Allopurinol (International Nonproprietary Name by WHO) |
4-Hydroxypyrazolo[3,4-d]pyrimidine | Therapeutic drug /Eur. and US Pharmacopoeia |
Pharmacological properties: antioxidant, antigout, anticancer (leukemia, lymphoma) | [12,21] |
| Antioxidant mechanism: inhibitor of xanthine oxidase, prevents O2∙− | [12] | |||
| Safety issues: rushes, lymphadenopathy, leucopenia or leukocytosis, eosinophilia, arthralgia, and vasculitis, hepatotoxic | [21] | |||
| Amiloxate (International Nonproprietary Name by WHO) |
3-Methylbutyl (E)-3-(4-methoxyphenyl)prop-2-enoate | Cosmetics /US Pharmacopeia |
Pharmacological properties: antioxidant, UV light absorber, anti-inflammatory, antimicrobial, antiedematous | [21] |
| Antioxidant mechanism of action: free radical scavenger | [38] | |||
| Safety issues: contact and photocontact allergen | [39] | |||
| Ascorbic acid (Vitamin C) | (2R)-2-[(1S)-1,2-Dihydroxyethyl]-3,4-dihydroxy-2H-furan-5-one | Dietary supplements Antioxidant in foods (E300; sodium ascorbate E301; calcium ascorbate E302), pharmaceuticals and cosmetics (ascorbyl palmitate) /FDA GRAS |
Pharmacological properties: antioxidant, scavenger of free radicals, protection of DNA damage, involved in collagen synthesis, increases the intestinal absorption of iron, antiviral/immune-modulating properties useful for treatment and prevention of COVID-19, positive effects in age-related macular degeneration, neurological disorders, atherosclerosis, cancer | [21,40] |
| Antioxidant mechanism: reducing agent, hydrogen donor forming a relatively stable ascorbyl-free radical Asc−∙ (efficient electron donor in biological redox reactions) and dehydroascorbic acid; efficiently recycles other antioxidants (e.g., α-tocopherol, glutathione); ascorbic acid regenerates itself from Asc−∙ with NADH or NADPH-reductases; in the presence of copper and iron becomes pro-oxidant | [41] | |||
| Safety issues: LD50 (oral, rat) 11,900 mg/kg, (IV, mouse) 518 mg/kg; large doses may result in hyperoxaluria and the formation of renal calcium oxalate calculi | [21,31] | |||
| Butylated hydroxyanisole (BHA) |
mixture of 2-t-Butyl-4-methoxyphenol and 3-t-Butyl-4-methoxyphenol |
Antioxidant in foods (E320), food packages, animal feed, pharmaceuticals and cosmetics /FDA (0.02% max. of fat/oil), GRAS |
Properties: high antioxidant activity; increases the levels of liver glutathione and glutathione-S-transferase; not preferred for pharmacological use, due to safety concerns. It acts synergistically with BHT, PG |
[42] |
| Antioxidant mechanism: prevents lipid peroxidation acting as hydrogen donor and interrupting the free radical autoxidative chain reactions (the resulting oxidized phenolic ion is stabilized by the inherent resonance of the benzene ring) | [43] | |||
| Safety issues: LD50 (oral, mouse) 2000 mg/kg; may cause rashes, hyperactivity; confirmed carcinogen (IARC group 2B) | [31,44] | |||
| Butylated hydroxytoluene (BHT) |
2,6-Di-t-butyl-4-methylphenol | Antioxidant in foods (E321), food packages, animal feed, pharmaceuticals and cosmetics /FDA (0.02% max. of fat/oil), GRAS |
Properties: high antioxidant activity; antiviral (inactivates lipid-containing viruses); not preferred for pharmacological use, due to safety concerns. It acts synergistically with BHA |
[42,45] |
| Antioxidant mechanism: prevents lipid peroxidation acting as hydrogen donor and interrupting the free radical autoxidative chain reactions (the resulting oxidized phenolic ion is stabilized by the inherent resonance of the benzene ring) | [43] | |||
| Safety issues: LD50 (oral, rat) 890 mg/kg, (IP, mouse) 138 mg/kg, (IV, mouse) 180 mg/kg; suspected carcinogen (IARC group 3); human skin irritant; eye irritant; may cause rashes, hyperactivity | [31,44] | |||
|
t-Butyl hydroquinone (TBHQ) |
2-t-Butylbenzene-1,4-diol | Antioxidant in foods (E319), pet foods, animal feed, pharmaceuticals and cosmetics /FDA (limitation 0.02% of oil, 0.003% in dry sausage, 0.01% in rendered animal fat, 0.02% in margarine, 0.01% on fat in poultry) |
Properties: antioxidant, antibacterial; not preferred for pharmacological use, due to safety concerns | [46] |
| Antioxidant mechanism: is a nuclear factor E2-related factor 2 (Nrf2) agonist, increases the levels of glutathione | [47] | |||
| Safety issues: LD50 (oral, rat) 700 mg/kg, (IP, rat) 300 mg/kg; tumorigenic and mutagen in experimental animals | [31,44] | |||
| β-Carotene (Provitamin A) |
1,3,3-Trimethyl-2-[(1E,3E,5E,7E,9E,11E,13E,15E,17E)-3,7,12,16-tetramethyl-18-(2,6,6-trimethylcyclohexen-1-yl)octadeca-1,3,5,7,9,11,13,15,17-nonaenyl]cyclohexene | Antioxidant in foods [E160a(i)], animal feed and cosmetics Dietary supplements /FDA GRAS |
Pharmacological properties: antioxidant, precursor of vitamin A, prevents age-related macular degeneration and ischemic heart disease, protects against cancer, antiviral; potential treatment option for COVID-19 with vitamin A | [21,48,49] |
| Antioxidant mechanism: quenching of singlet oxygen 1O2, prevents lipid peroxidation by scavenging peroxide radicals | [50] | |||
| Safety issues: nontoxic on skin; massive doses may cause yellowing of the skin; increase in cancer incidence by administration of high doses; LD50 >5000 mg/kg | [21,31] | |||
| Cholecalciferol (Vitamin D3) |
(3S,5Z,7E)-9,10-Secocholesta-5,7,10-trien-3-ol | Dietary supplements Drug Pharmaceuticals /FDA GRAS |
Pharmacological properties: antioxidant (despite some studies showing controversy), therapeutic potential in diseases related to oxidative stress, anti-ricket, enhances absorption of calcium and phosphorus along the small intestine, anti-inflammatory, cardioprotective, potential in the treatment of COVID-19 (clinical trial phase 1, 2019, NCT04407286) | [51,52,53] |
| Antioxidant mechanism: reduces lipid peroxidation, induces antioxidant enzymes (SOD), stimulates the enzyme sirtuin 1 involved in reduction in oxidative stress and inflammatory response | [51] | |||
| Safety issues: LD50 (oral, rat) 42 mg/kg; experimental teratogen | [31] | |||
| Cysteine | (2R)-2-Amino-3-sulfanylpropanoic acid | Antioxidant in foods (E920), pharmaceuticals and cosmetics Dietary supplements /FDA GRAS, Eur. and US Pharmacopoeia |
Pharmacological properties: antioxidant, prevention of corneal ulceration after chemical burn, skin-whitening | [54] |
| Antioxidant mechanism of action: reducing agent, precursor of reduced glutathione (GSH), chain-breaking antioxidant mechanism; in foods (fruits), L-Cys inhibits the activity of polyphenol oxidase and reduces browning by combination with reactive electrophilic quinones | [55,56] | |||
| Safety issues: LD50 (IP, mouse) 1250 mg/kg, (IV, mouse) 771 mg/kg | [31] | |||
| Dioxybenzone | (2-Hydroxy-4-methoxyphenyl)-(2-hydroxyphenyl)methanone | Dermatological drug (sunscreen in cosmetics) /US Pharmacopeia |
Pharmacological properties: antioxidant, UV light absorber, skin cancer chemopreventive | [57] |
| Antioxidant mechanism: scavenging free radicals and relieving of oxidative stress related to cancer from UV exposure | [57] | |||
| Safety issues: LD50 (oral, rat) >10 g/kg; nontoxic in single oral doses; nonirritating to rabbit eye or skin; | [32] | |||
| Disodium EDTA (disodium edetate) |
Disodium 2-[2-[bis(carboxymethyl)amino]ethyl-(carboxymethyl)amino]acetate | Foods (calcium disodium EDTA E385; Disodium EDTA E386) Drug (Calcium disodium EDTA) Pharmaceuticals Cosmetics /FDA, Eur. and US Pharmacopoeia |
Pharmacological properties: antioxidant, metal chelating, for treatment of lead poisoning (Calcium disodium EDTA) or hypercalcemia (disodium EDTA), potential use in COVID-19 | [31,58] |
| Antioxidant mechanism: reduces metal-induced free radical production, protects against DNA damage and lipid oxidation | [59] | |||
| Safety issues: LD50 (oral, rat) 2 g/kg, (IV, mouse) 56 mg/kg, (IP, mouse) 260 mg/kg; experimental teratogen, reproductive effects; mutagenic data | [32,60] | |||
| Erythorbic acid (isoascorbic acid, isovitamin C) |
(2R)-2-[(1R)-1,2-Dihydroxyethyl]-3,4-dihydroxy-2H-furan-5-one | Antioxidant in foods (E315; sodium erythorbate E316) and pharmaceuticals /FDA GRAS for E315 |
Pharmacological properties: antioxidant, antimicrobial, enhance iron bioavailability, antitumor | [31,61,62,63] |
| Antioxidant mechanism: sodium erythorbate is a reducing agent acting similar to ascorbic acid despite it lacking vitamin C activity, and inhibits nitrite reaction in meat curing | [64] | |||
| Safety issues: Nontoxic; mutagenic; causes DNA damage; LD50 (oral, mouse) 8300 mg/kg and LD50 (oral, rats) 18 g/kg (erythorbic acid); LD50 (oral, rats) >5 g/kg (sodium erythorbate) | [31,62] | |||
| Etidronic acid | (1-Hydroxy-1-phosphonoethyl)phosphonic acid | Drug (etidronate disodium) Antioxidant in pharmaceuticals and cosmetics /FDA, Eur. and US Pharmacopeia |
Pharmacological properties: antioxidant, chelating agent for heavy metal ions, reduces osteoclastic activity (treatment of Paget’s disease, osteoporosis), increase the bone mineral density, inhibition of protein tyrosine phosphatase | [65,66] |
| Antioxidant mechanism: calcium, iron chelator inhibiting the chondrocyte lipid peroxidation, suppress radical formation | [67] | |||
| Safety issues: LD50 (oral, mouse) 1800 mg/kg; impairment of bone mineralization, hypercalcemia, esophageal cancer | [21,32] | |||
| 4-Hexylresorcinol | 4-Hexylbenzene-1,3-diol | Flavoring agent in food (E586) Topical antiseptic Cosmetics /Eur. and US Pharmacopeia |
Pharmacological properties: antioxidant, antiseptic, antihelmintic, local anesthetic, antiviral (against parainfluenza virus type 3) | [21,68] |
| Antioxidant mechanism: inhibits tyrosinase, increases glutathione levels preventing DNA damage, scavenging of peroxyl radicals and oxygen superoxide, reduces lipid and protein peroxidation | [69] | |||
| Safety issues: LD50 (oral, rat) 550 mg/kg; LDLo (IP, mouse) 50 mg/kg, (subcut., mouse) 750 mg/kg; may irritate eyes, skin, respiratory tract; experimental reproductive effects | [31] | |||
| Idebenone | 2-(10-Hydroxydecyl)-5,6-dimethoxy-3-methylcyclohexa-2,5-diene-1,4-dione | Drug (nootropic, antioxidant therapy) /EMA |
Pharmacological properties: antioxidant, stimulates ATP production, neuroprotective (dementia, Alzheimer’s disease), treatment of visual impairment in patients with Leber’s Hereditary Optic Neuropathy; adjuvant for secondary effects of viral infection | [21,70,71] |
| Antioxidant mechanism: scavenger of free radicals (superoxide) being recycled by mitochondrial and cytosolic reductase), inhibits lipid peroxidation in mitochondrial membrane; electron donor to mitochondrial electron transport chain | [70] | |||
| Safety issues: LD50 (oral, rat) 10 g/kg, LD50 (IP, rat) 757–886 mg/kg | [70] | |||
| Lipoic acid | 5-[(3R)-1,2-Dithiolan-3-yl]pentanoic acid | Drug (antioxidant therapy of diabetic neuropathy) Nutraceutical /Eur. and US Pharmacopeia |
Pharmacological properties: antioxidant, analgesic, treatment of diabetic neuropathy, detoxification of mercury in brain cells, treatment of multiple sclerosis (clinical trial 2021) and schizophrenia (clinical trial 2021), potential antiviral including COVID-19 | [21,72,73,74] |
| Antioxidant mechanism: iron, copper chelation, scavenging ROS, the reduced form (dihydrolipoic acid) regenerates endogenous antioxidants (vitamin C, vitamin E, glutathione) repairing oxidative damage | [75] | |||
| Safety issues: cholestatic hepatitis; LD50 (oral, rats) >2000 mg/kg; no mutagenic (Ames assay), not genotoxic (mouse micronucleus assay) | [21,76] | |||
| Melatonin | N-[2-(5-Methoxy-1H-indol-3-yl)ethyl]acetamide | Drug /US Pharmacopeia |
Pharmacological properties: antioxidant, increases GABA and serotonin, efficient in sleep and autistic disorders, anticancer, sunburn prevention, potential positive effect on COVID-19 (clinical trial 2021) | [21,77,78] |
| Antioxidant mechanism: direct free radical scavenging, stimulation of antioxidant enzymes, lowering of free radical generation by increasing oxidative phosphorylation in mitochondria and reducing electron leakage, protects against DNA damage | [79,80] | |||
| Safety issues: LD50 (oral, mouse) 1250 mg/kg | [81] | |||
| Methionine | (2S)-2-Amino-4-methylsulfanylbutanoic acid | Dietary supplements Food and pharmaceutical flavoring agent Feed additive /FDA, Eur. and US, Pharmacopeia, FEMA GRAS |
Pharmacological properties: antioxidant, antihepatotoxic, alternative to acetylcysteine in the treatment of acetaminophen overdose, metal chelating, precursor of cysteine; anticancer (clinical trial phase 2, 2021) | [21,82] |
| Antioxidant mechanism: reduces ROS levels due to Met-sulfoxide reductase, activation of endogenous antioxidant enzymes, stimulating glutathione synthesis, heavy metal chelator | [83] | |||
| Safety issues: LD50 (oral, rat) 36 g/kg, (IP, rat) 4328 mg/kg; as precursor of homocysteine, high doses may result in susceptibility of cardiovascular disease, type-2 diabetes, brain alterations | [31,84,85] | |||
| Niacinamide (Nicotinamide) |
Pyridine-3-carboxylic acid amide | Dietary supplements Food fortification Feed additive (nutritional) Pharmaceutical intermediate Cosmetics /FDA GRAS, Eur., US Pharmacopeia |
Pharmacological properties: antioxidant, prevents pellagra, precursor of coenzymes (NAD) involved in electron transfer reactions in the respiratory chain, skin stimulant, anticancer, reduces LDL, improves HDL, early Alzheimer’s disease treatment (clinical trial phase 2, 2021) | [21,31,32,86] |
| Antioxidant mechanism: scavenging •OH, 1O2 and superoxide O2•−, inhibits the initiation step of lipid peroxidation, increases glutathione levels, protects against both lipid and protein oxidation in brain | [86] | |||
| Safety issues: LD50 (oral, rat) 3500 mg/kg, (IP, mouse) 2050 mg/kg, (subcut., rat) 1680 mg/kg | [31] | |||
| Pentoxifylline (International Nonproprietary Name by WHO) |
3,7-Dimethyl-1-(5-oxohexyl)purine-2,6-dione | Drug /FDA, Eur. and US Pharmacopeia |
Pharmacological properties: antioxidant, anti-inflammatory, immunomodulatory, treatment of peripheral vascular disorders, inhibits the production of the cytokine TNFα, treatment of Diabetic Kidney Disease (clinical trial phase 4, 2021); antiviral potential adjuvant in treatment of COVID-19 (clinical trial) | [21,87,88] |
| Antioxidant mechanism: scavenges free radicals (∙OH), decreases lipid peroxidation | [89] | |||
| Safety issues: LD50 (oral, rat) 1385 mg/kg | [90] | |||
| Probucol (International Nonproprietary Name by WHO) |
2,6-Di-t-butyl-4-[2-(3,5-ditert-butyl-4-hydroxyphenyl)sulfanylpropan-2-ylsulfanyl]phenol | Drug US Pharmacopeia |
Pharmacological properties: antioxidant, anticholesterolemic | [21] |
| Antioxidant mechanism: inhibits lipid peroxidation | [91] | |||
| Safety issues: LD50 (oral, mouse, rat) >5000 mg/kg | [92] | |||
| Propyl gallate (PG) |
Propyl 3,4,5-trihydroxybenzoate | Antioxidant in food (E310), food packages, food-contact coatings, feed, pharmaceuticals and cosmetics /FDA (0.005% migrating from food pkg., 0.02% max. of fat or oil, GRAS, Eur. Pharmacopeia |
Pharmacological properties: antioxidant, hepatoprotector, limited antibacterial and antifungal activity | [21,31] |
| Antioxidant mechanism: hydrogen donor interrupting the free radical autoxidative chain reactions | [43] | |||
| Safety issues: LD50 (oral, rat) 3.8 g/kg, (IP, rat) 0.38 g/kg; skin irritant; questionable carcinogen; experimental tumorigenic, teratogen, reproductive effects | [21,31,44] | |||
| Propylene glycol (PEG) |
Propane-1,2-diol | Food emulsifier (E1520) Pet foods Agent for pharmaceuticals and cosmetics (viscosity control) /FDA GRAS, US and Eur. Pharmacopeia |
Properties: antiseptic, humectant, efficient solvent and extractant of active ingredients including antioxidants | [31] |
| Antioxidant mechanism: propylene glycol mannate sulfate induces the antioxidant enzymes (superoxide dismutase, glutathione peroxidase, catalase) eliminating the oxygen free radicals (study on hyperlipidemic rats) | [93] | |||
| Safety issues: LD50 (oral, rat) 21 g/kg; ocular and skin irritant; no reproductive toxicity; not mutagenic, not carcinogenic | [31,94] | |||
| Retinol (vitamin A) |
(2E,4E,6E,8E)-3,7-Dimethyl-9-(2,6,6-trimethylcyclohexen-1-yl)nona-2,4,6,8-tetraen-1-ol | Dietary supplements Cosmetics /FDA GRAS, Eur. and US Pharmacopeia |
Pharmacological properties: antioxidant, role in vision, epithelial differentiation, growth, bone development, immunity, anticancer, anti-inflammatory, potential immunomodulator in COVID-19 | [95,96] |
| Antioxidant mechanism: scavenges lipid peroxyl radicals (LOO∙) by forming a stable trans-retinol radical intermediate, reduces DNA damage (studies in cancer therapy), stimulates endogenous antioxidant enzymes | [97] | |||
| Safety issues: daily intakes of Vitamin A >50,000 IU in adults and 20,000 IU in infants and young children may cause toxic manifestations; LD50 (oral, rat, 10 day) 7910 mg/kg, (oral, mouse) 6060 mg/kg; experimental reproductive effects; hepatomegaly, visual disturbances | [98,99] | |||
| Selenious acid | Selenous acid | Pharmaceuticals Supplements /US Pharmacopeia |
Pharmacological properties: antioxidant, enzymatic cofactor (glutathione peroxidase), anticancer, stimulates hemoglobin synthesis in erythroleukemia cell lines, immunomodulatory, prevention of atherosclerosis | [21,100] |
| Antioxidant mechanism: selenium is a Cu+ chelator, inhibits DNA damage from •OH radical, maintains the enzymatic activity of glutathione peroxidase | [16] | |||
| Safety issues: LD50 7 mg Se/kg for sodium selenite, 138 mg Se/kg for selenium sulfides (as formulated for anti-dandruff shampoos), and 6700 mg Se/kg for elemental selenium | [101] | |||
| Sitosterol | (3S,8S,9S,10R,13R,14S,17R)-17-[(2R,5R)-5-Ethyl-6-methylheptan-2-yl]-10,13-dimethyl-2,3,4,7,8,9,11,12,14,15,16,17-dodecahydro-1H-cyclopenta[a]phenanthren-3-ol | Dietary supplements Stabilizer in pharmaceuticals, cosmetics /Canadian Provisional DSL |
Pharmacological properties: antioxidant, hypolipidemic, treatment of diaper rash, anti-inflammatory, antiapoptotic, anticancer, potential role as immunostimulant and inhibitor of SARS-CoV-2 spike glycoprotein | [21,31,32,102] |
| Antioxidant mechanism: reduces liver lipid peroxidation in induced cancer colon, maintains the level of antioxidant enzymes (catalase, superoxide dismutase, glutathione peroxidase, glutathione reductase, glutathione S-transferase, reduced glutathione) | [103] | |||
| Safety issues: LD50 (oral, mouse) >25,000 mg/kg; skin and eye irritant; nontoxic | [31] | |||
| Thiodipropionate | 3-(2-Carboxylatoethylsulfanyl)propanoate | Foods (0.02% of fat or oil content of food) Food packages Pharmaceuticals Cosmetics (0.1% and rarely exceed 0.2%) /FDA |
Properties: antioxidant, skin lightening. Acts synergistically with phenols |
[104] |
| Antioxidant mechanism: chain-breaking, decomposes hydrogen peroxide | [105] | |||
|
Safety issues: Dilauryl thiodipropionate: LD50 (oral, rat) >10.3 g/kg; no known toxicity; eye irritant Distearyl thiodipropionate: LD50 (oral, rat) >2500 mg/kg, (IP, rat) >2 g/kg; |
[31] | |||
| α-Tocopherol (vitamin E) |
(2R)-2,5,7,8-Tetramethyl-2-[(4R,8R)-4,8,12-trimethyltridecyl]-3,4-dihydrochromen-6-ol | Dietary supplements Antioxidant in food (E306; α-tocopherol E307; γ-tocopherol E308; δ-tocopherol E309), food packages, animal feed, pharmaceuticals and cosmetics /FDA GRAS |
Pharmacological properties: high antioxidant activity, anticancer, prevents atherosclerosis, cardiovascular diseases and age-related macular degeneration | [106,107] |
| Antioxidant mechanism: directly reacts and neutralizes •OH, alkoxyl and lipid peroxyl (ROO∙) radicals stopping the ROS-induced damage; may be regenerated with vitamin C | [16] | |||
| Safety issues: TDLo (oral, rat) 7500 mg/kg | [31] | |||
| Ubiquinone (ubidecarenona, coenzyme Q 10) |
2-[(2E,6E,10E,14E,18E,22E,26E,30E,34E)-3,7,11,15,19,23,27,31,35,39-decamethyltetraconta-2,6,10,14,18,22,26,30,34,38-decaenyl]-5,6-dimethoxy-3-methylcyclohexa-2,5-diene-1,4-dione | Dietary supplements Antioxidant in pharmaceuticals and cosmetics /US Pharmacopoeia |
Pharmacological properties: antioxidant, cofactor in the mitochondrial electron transport chain, useful in the treatment of cardiovascular diseases, Parkinson’s, fibromyalgia, migraine, diabetes, adjuvant in COVID-19 (clinical trial phase 2, 2021, NCT04960215, 2020-005961-16) | [31,108,109] |
| Antioxidant mechanism: reduces lipid peroxidation, increases antioxidant enzymes (catalase, superoxide dismutase, glutathione peroxidase) | [110] | |||
| Safety issues: lethal dose >2000 mg/kg (oral, rat) | [111] | |||
| Zinc | Zinc | Dietary supplements Antioxidant in pharmaceuticals (zinc glycinate) Cosmetics /FDA FDA GRAS (zinc gluconate) |
Pharmacological properties: antioxidant, enzyme activator, antimicrobial, antidiarrheic, anti-inflammatory, antitumor (clinical trial NCT04488783), antiviral including protection against COVID-19 | [31,112,113] |
| Antioxidant mechanism: induces antioxidant glutathione and enzymes (SOD, glutathione S-transferase, hemeoxygenase-1); protection of protein –SH groups; gene regulation (p53, NF-kB, AP-1) | [114] | |||
|
Safety issues: Zinc acetate: LD50 (oral, rat) 2510 mg/kg Zinc carbonate: TDLo (oral, mouse) 2800 mg/kg; experimental teratogen Zinc chloride: LD50 (oral, rat) 350 mg/kg; irritant, questionable carcinogen; experimental tumorigenic, teratogen, reproductive effects Zinc citrate: LD50 (oral, rat) >5000 mg/kg; experimental reproductive effects Zinc gluconate: LD50 (oral, mouse) 1290 mg/kg; experimental reproductive effects Zinc sulfate: LD50 (oral, rat) 2949 mg/kg; irritant, questionable carcinogen; experimental tumorigenic, teratogen, reproductive effects |
[31] |