Squalene (12.5, 50, and 200 μM; 24 h) impacts MCF10A epithelial cells in a way that depends on dose: decreasing the amounts of intracellular ROS, avoiding H2O2-induced oxidative damage, and guarding against H2O2-induced oxidative damage DNA oxidative damage[2].

Reactive oxygen species and antimicrobial malondialdehyde levels in lipoproteins are decreased by squalene (0.25–1 g/kg; given chow; diet for 11 weeks), which also encourages changes in HDL-cholesterol and paraoxonase 1 [3].

Animal/Disease Models: Male mouse model (wild type, Apoa1 and Apoe deficient) [3]
Doses: 0.25 g/kg, 1 g/kg
Route of Administration: Feeding; Diet results for 11 consecutive weeks: HDL in mice Protein cholesterol and paraoxonase 1 were increased, and oxidative stress was diminished.

Absorption, Distribution and Excretion
Squalene is used in the oil phase of certain emulsion vaccine adjuvants, but its fate as a vaccine component following intramuscular (IM) injection in humans is unknown. In this study, we constructed a physiologically-based pharmacokinetic (PBPK) model for intramuscularly injected squalene-in-water (SQ/W) emulsion, in order to make a quantitative estimation of the tissue distribution of squalene following a single IM injection in humans. The PBPK model incorporates relevant physicochemical properties of squalene; estimates of the time course of cracking of a SQ/W emulsion; anatomical and physiological parameters at the injection site and beyond; and local, preferential lymphatic transport. The model predicts that a single dose of SQ/W emulsion will be removed from human deltoid muscle within six days following IM injection. The major proportion of the injected squalene will be distributed to draining lymph nodes and adipose tissues. The model indicates slow decay from the latter compartment most likely due to partitioning into neutral lipids and a low rate of squalene biotransformation there. Parallel pharmacokinetic modeling for mouse muscle suggests that the kinetics of SQ/W emulsion correspond to the immunodynamic time course of a commercial squalene-containing adjuvant reported in that species. In conclusion, this study makes important pharmacokinetic predictions of the fate of asqualene-containing emulsion in humans. The results of this study may be relevant for understanding the immunodynamics of this new class of vaccine adjuvants and may be useful in future quantitative risk analyses that incorporate mode-of-action data.
Over 60% of ingested squalene is absorbed from the small intestine; from there it is carried in the lymph in the form of chylomicrons into the systemic circulation. In the blood, squalene is carried mainly in very-low-density lipoproteins and distributed to the various tissues of the body. A large percentage of squalene gets distributed to the skin.
Animal studies indicate Squalene is slowly absorbed through the skin, while both compounds /Squalane and Squalene/ are poorly absorbed from the gastrointestinal tract.

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Metabolism / Metabolites
A review of the oxidization of squalene, a specific human compound produced by the sebaceous gland, is proposed. Such chemical transformation induces important consequences at various levels. Squalene by-products, mostly under peroxidized forms, lead to comedogenesis, contribute to the development of inflammatory acne and possibly modify the skin relief (wrinkling). Experimental conditions of oxidation and/or photo-oxidation mechanisms are exposed, suggesting that they could possibly be bio-markers of atmospheric pollution upon skin. Ozone, long UVA rays, cigarette smoke ... are shown powerful oxidizing agents of squalene. Some in vitro, ex vivo and in vivo testings are proposed as examples, aiming at studying ingredients or products capable of boosting or counteracting such chemical changes that, globally, bring adverse effects to various cutaneous compartments.
This study has used proton transfer reaction-mass spectrometry (PTR-MS) for direct air analyses of volatile products resulting from the reactions of ozone with human skin lipids. An initial series of small-scale in vitro and in vivo experiments were followed by experiments conducted with human subjects in a simulated office. The latter were conducted using realistic ozone mixing ratios (approximately 15 ppb with occupants present). Detected products included mono- and bifunctional compounds that contain carbonyl, carboxyl, or alpha-hydroxy ketone groups. Among these, three previously unreported dicarbonyls have been identified, and two previously unreported alpha-hydroxy ketones have been tentatively identified. The compounds detected in this study (excepting acetone) have been overlooked in surveys of indoor pollutants, reflecting the limitations of the analytical methods routinely used to monitor indoor air. The results are fully consistent with the Criegee mechanism for ozone reacting with squalene, the single most abundant unsaturated constituent of skin lipids, and several unsaturated fatty acid moieties in their free or esterified forms. Quantitative product analysis confirms that squalene is the major scavenger of ozone at the interface between room air and the human envelope. Reactions between ozone and human skin lipids reduce the mixing ratio of ozone in indoor air, but concomitantly increase the mixing ratios of volatile products and, presumably, skin surface concentrations of less volatile products. Some of the volatile products, especially the dicarbonyls, may be respiratory irritants. Some of the less volatile products may be skin irritants.
Squalene is metabolized to cholesterol.

Toxicity Summary
IDENTIFICATION AND USE: Squalene is a liquid. The source of squalene is usually from shark liver and sometimes from olive oil. It is used as traditional medicine, experimental medication, and dietary supplement. Squalene is a component of some adjuvants that are added to vaccines to enhance the immune response. MF59, an adjuvant added to the FLUAD flu vaccine, is such an example. Squalene by itself is not an adjuvant, but emulsions of squalene with surfactants do enhance the immune response. Squalene is also found in a variety of foods, cosmetics. HUMAN EXPOSURE AND TOXICITY: Squalene is not a significant human skin irritant or sensitizer. Limited contact sensitization tests indicate squalene is not a significant contact allergen or irritant. Twenty two million doses of the influenza vaccine FLUAD have been administered safely since 1997. This vaccine contains about 10 mg of squalene per dose. No severe adverse events have been associated with the vaccine. Some mild local reactions have been observed. Clinical studies on squalene-containing vaccines have been done in infants and neonates without evidence of safety concerns. One of the many possible exposures suspected of causing chronic multisymptom illnesses of Gulf War veterans is squalene, thought to be present in anthrax vaccine. However further studies found no association between squalene antibody status and chronic multisymptom illness. Most adults, whether or not they have received vaccines containing squalene, have antibodies against squalene. The genotoxic potential of the vaccine adjuvant squalene was assessed by the chromosomal aberrations (CAs), sister chromatid exchanges (SCEs) and micronucleus (MNs) tests in human lymphocytes and comet assay in human lymphocytes. Squalene did not affect the CAs and MN frequency, in all treatments in vitro. A significant increase in SCEs was observed in almost all concentrations at 24 hr treatment. Squalene did not affect significantly the comet tail length (CTL) (except 2500 ug/mL) and comet tail intensity (CTI) at all treatments in vitro. Therefore, squalene cannot be regarded as genotoxic in human lymphocytes. ANIMAL STUDIES: The acute animal toxicity of squalene by all routes is low. Squalene was nonirritant to rabbit skin and eye at 100% concentration. Dietary squalene promotes changes in HDL- cholesterol and paraoxonase 1 and decreases reactive oxygen species in lipoproteins and plasma malondialdehyde levels in mice. Squalene emulsion showed increased inflammation at 20% and 10% emulsions and the inflammatory response was mild at a concentration of 5% oil emulsion after intra-peritoneal vaccination of olive flounder. In rat lymphocytes genotoxicity assays squalene significantly increased and decreased CTL and CTI in some doses.

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Interactions
The study aimed to identify endogenous lipid mediators of metabolic and inflammatory responses of human keratinocytes to solar UV irradiation. Physiologically relevant doses of solar simulated UVA+UVB were applied to human skin surface lipids (SSL) or to primary cultures of normal human epidermal keratinocytes (NHEK). The decay of photo-sensitive lipid-soluble components, alpha-tocopherol, squalene (Sq), and cholesterol in SSL was analysed and products of squalene photo-oxidation (SqPx) were quantitatively isolated from irradiated SSL. When administered directly to NHEK, low-dose solar UVA+UVB induced time-dependent inflammatory and metabolic responses. To mimic UVA+UVB action, NHEK were exposed to intact or photo-oxidised SSL, Sq or SqPx, 4-hydroxy-2-nonenal (4-HNE), and the product of tryptophan photo-oxidation 6-formylindolo[3,2-b]carbazole (FICZ). FICZ activated exclusively metabolic responses characteristic for UV, i.e. the aryl hydrocarbon receptor (AhR) machinery and downstream CYP1A1/CYP1B1 gene expression, while 4-HNE slightly stimulated inflammatory UV markers IL-6, COX-2, and iNOS genes. On contrast, SqPx induced the majority of metabolic and inflammatory responses characteristic for UVA+UVB, acting via AhR, EGFR, and G-protein-coupled arachidonic acid receptor (G2A). /These/ findings indicate that Sq could be a primary sensor of solar UV irradiation in human SSL, and products of its photo-oxidation mediate/induce metabolic and inflammatory responses of keratinocytes to UVA+UVB, which could be relevant for skin inflammation in the sun-exposed oily skin.
Active oxygen has been implicated in the pathogenesis of Parkinson's disease (PD); therefore, antioxidants have attracted attention as a potential way to prevent this disease. Squalene, a natural triterpene and an intermediate in the biosynthesis of cholesterol, is known to have active oxygen scavenging activities. Squalane, synthesized by complete hydrogenation of squalene, does not have active oxygen scavenging activities. We examined the effects of oral administration of squalene or squalane on a PD mouse model, which was developed by intracerebroventricular injection of 6-hydroxydopamine (6-OHDA). Squalene administration 7 days before and 7 days after one 6-OHDA injection prevented a reduction in striatal dopamine (DA) levels, while the same administration of squalane enhanced the levels. Neither squalene nor squalane administration for 7 days changed the levels of catalase, glutathione peroxidase, or superoxide dismutase activities in the striatum. Squalane increased thiobarbituric acid reactive substances, a marker of lipid peroxidation, in the striatum. Both squalane and squalene increased the ratio of linoleic acid/linolenic acid in the striatum. These results suggest that the administration of squalene or squalane induces similar changes in the composition of fatty acids and has no effect on the activities of active oxygen scavenging enzymes in the striatum. However, squalane increases oxidative damage in the striatum and exacerbates the toxicity of 6-OHDA, while squalene prevents it. The effects of squalene or squalane treatment in this model suggest their possible uses and risks in the treatment of PD.
A mouse study showed squalene to confer radioprotection against lethal whole-body radiation.
The present study aims to evaluate the protective effect of squalene against the genotoxicity of the chemotherapeutic agent doxorubicin (Dox) using two genotoxicity assays, the micronucleus assay and the comet assay. Different groups of mice were fed squalene at the doses of 1 and 4 mmol/g body weight (100 or 400 uL as squalene oil) either at 4 hr before or 1 hr after Dox (20 mg/kg) treatment. 24 hr after the Dox treatment, bone marrow erythrocytes were evaluated for the incidence of micronuclei, and the induced DNA strand breaks were examined in heart tissue by the alkaline comet assay. As expected, Dox significantly induced micronuclei in polychromatic (immature) erythrocytes, as well as in total erythrocytes. The frequency of Dox-induced micronucleated erythrocytes was significantly reduced in the mice treated with squalene both before and after Dox administration. Squalene itself obviously did not induce any micronuclei in bone marrow erythrocytes. The comet assay also demonstrated a significant increase in DNA damage, especially DNA single strand breaks in the Dox-treated group of mice as compared to the control. The Dox-induced DNA damage was also effectively reduced by squalene when it was administered either before or after the Dox treatment. Squalene did not induce any significant DNA damage by itself. Compared to the pre-treatment of squalene, post treatment gave rise to more effective prevention against Dox-induced DNA damage. The data suggest that the complimentary use ofsqualene with Dox will be beneficial to reduce the adverse effect of Dox in cancer chemotherapy, such as the increased incidence of undesirable mutagenic side effects.
For more Interactions (Complete) data for Squalene (9 total), please visit the HSDB record page.

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Non-Human Toxicity Values
LD50 Mice iv 1800 mg/kg
LD50 Mice oral 5 g/kg

[1]. SQUALENE: PHYSIOLOGICAL AND PHARMACOLOGICAL PROPERTIES. Eksp Klin Farmakol. 2015;78(6):30-6.

[2]. Squalene protects against oxidative DNA damage in MCF10A human mammary epithelial cells but not in MCF7 and MDA-MB-231 human breast cancer cells. Food Chem Toxicol. 2010 Apr;48(4):1092-100.

[3]. Dietary squalene increases high density lipoprotein-cholesterol and paraoxonase 1 and decreases oxidative stress in mice. PLoS One. 2014 Aug 12;9(8):e104224.

Trans-squalene is a clear, slightly yellow liquid with a faint odor. Density 0.858 g / cm3.
Squalene is a triterpene consisting of 2,6,10,15,19,23-hexamethyltetracosane having six double bonds at the 2-, 6-, 10-, 14-, 18- and 22-positions with (all-E)-configuration. It has a role as a human metabolite, a plant metabolite, a Saccharomyces cerevisiae metabolite and a mouse metabolite.
Squalene is originally obtained from shark liver oil. It is a natural 30-carbon isoprenoid compound and intermediate metabolite in the synthesis of cholesterol. It is not susceptible to lipid peroxidation and provides skin protection. It is ubiquitously distributed in human tissues where it is transported in serum generally in association with very low density lipoproteins. Squalene is investigated as an adjunctive cancer therapy.
Squalene has been reported in Erythrophleum fordii, Amaranthus hybridus, and other organisms with data available.
squalene is a metabolite found in or produced by Saccharomyces cerevisiae.
A natural 30-carbon triterpene.
See also: Olive Oil (part of); Shark Liver Oil (part of).

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Mechanism of Action
Squalene, an isoprenoid compound structurally similar to beta-carotene, is an intermediate metabolite in the synthesis of cholesterol. In humans, about 60 percent of dietary squalene is absorbed. It is transported in serum generally in association with very low density lipoproteins and is distributed ubiquitously in human tissues, with the greatest concentration in the skin, where it is one of the major components of skin surface lipids. Squalene is not very susceptible to peroxidation and appears to function in the skin as a quencher of singlet oxygen, protecting human skin surface from lipid peroxidation due to exposure to UV and other sources of ionizing radiation. Supplementation of squalene to mice has resulted in marked increases in cellular and non-specific immune functions in a dose-dependent manner. Squalene may also act as a "sink" for highly lipophilic xenobiotics. Since it is a nonpolar substance, it has a higher affinity for un-ionized drugs. In animals, supplementation of the diet with squalene can reduce cholesterol and triglyceride levels. In humans, squalene might be a useful addition to potentiate the effects of some cholesterol-lowering drugs. The primary therapeutic use of squalene currently is as an adjunctive therapy in a variety of cancers. Although epidemiological, experimental and animal evidence suggests anti-cancer properties, to date no human trials have been conducted to verify the role this nutrient might have in cancer therapy regimens.
Based on previous finding of singlet oxygen generation from coproporphyrin excreted on the skin surface from Propionibacterium acnes, we hypothesized that singlet oxygen formed in this way under UV exposure would promote peroxidation of skin surface lipids. We found that squalene was oxidized efficiently by singlet oxygen derived from coproporphyrin under UV exposure, and that the rate constant of squalene peroxidation by singlet oxygen was ten-fold higher than that of other skin surface lipids examined. The reaction was promoted more efficiently by UVA than by UVB. Furthermore, we found that topical application of squalene peroxide induced skin hyperpigmentation through increasing prostaglandin E(2) release from keratinocytes in guinea pigs. These results suggest that squalene peroxide formation by singlet oxygen plays a key role in photo-induced skin damage.

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Therapeutic Uses
EXPL THER Cardiovascular alterations and periodontal disease have been associated, although cardiovascular disease treatments have not yet been tested against periodontal alterations. We investigated effects of squalene, hydroxytyrosol and coenzyme Q(10) on gingival tissues of rabbits fed on an atherosclerotic diet. Forty-eight rabbits were distributed in six groups. Control group was fed on standard chow for 80 days. The rest were fed with an atherogenic diet for 50 days. After that, a group was sacrificed and the rest were subjected for another extra 30 days on commercial chow alone or supplemented with coenzyme Q(10), squalene or hydroxytyrosol. Atherosclerotic rabbits had higher fibrosis and endothelial activation and lower cellularity in gingival mucosa than controls (P<0.05). Hydroxytyrosol reduced endothelial activation (P<0.05) and squalene additionally decreased fibrosis (P<0.05). Results suggest that gingival vascular changes after the atherosclerotic diet have been reversed by hydroxytyrosol and squalene, natural products from the minor fraction of virgin olive oil.
EXPL THER Squalene has demonstrated /anti-/proliferative activity in animal cancer studies ... Squalene may have some radioprotective effects ... Animal work suggests that squalene may also have a cholesterol-lowering effect ...
EXPL THER Squalene is being investigated as an adjunctive therapy in some cancers. In animal models, it has proved effective in inhibiting lung tumors. It has also demonstrated chemopreventive effects against colon cancer in animal models.
EXPL THER Supplementation of squalene in mice has produced enhanced immune function...
For more Therapeutic Uses (Complete) data for Squalene (8 total), please visit the HSDB record page.

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Drug Warnings
Squalene supplementation should be avoided in infants, children, pregnant women and nursing mothers.
Those taking squalene supplements may have mild gastrointestinal symptoms such as diarrhea.
Squalene should not be confused with squalamine, which is an unusual steroid found in the dogfish shark and which has antibiotic properties.
It is not indicated for gastritis, joint pain and inflammation or to improve lung function.

C30H50

410.7180

410.391

111-02-4

638072

Colorless to light yellow liquid

0.8±0.1 g/cm3

429.3±0.0 °C at 760 mmHg

−75 °C(lit.)

254.1±22.2 °C

0.0±0.5 mmHg at 25°C

1.492

13.09

0

0

15

30

578

0

C([H])([H])(/C(/C([H])([H])[H])=C(\[H])/C([H])([H])C([H])([H])/C(/[H])=C(\C([H])([H])[H])/C([H])([H])C([H])([H])/C(/[H])=C(\C([H])([H])[H])/C([H])([H])C([H])([H])/C(/[H])=C(\C([H])([H])[H])/C([H])([H])[H])C([H])([H])/C(/[H])=C(\C([H])([H])[H])/C([H])([H])C([H])([H])/C(/[H])=C(\C([H])([H])[H])/C([H])([H])[H]

YYGNTYWPHWGJRM-AAJYLUCBSA-N

InChI=1S/C30H50/c1-25(2)15-11-19-29(7)23-13-21-27(5)17-9-10-18-28(6)22-14-24-30(8)20-12-16-26(3)4/h15-18,23-24H,9-14,19-22H2,1-8H3/b27-17+,28-18+,29-23+,30-24+

(6E,10E,14E,18E)-2,6,10,15,19,23-hexamethyltetracosa-2,6,10,14,18,22-hexaene

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

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

DMSO : ~16.67 mg/mL (~40.59 mM)

Solubility in Formulation 1: ≥ 1.67 mg/mL (4.07 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 16.7 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 2: 1.67 mg/mL (4.07 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 16.7 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 3: ≥ 1.67 mg/mL (4.07 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 16.7 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

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