Introduction:
Squalene is a natural chemical known for its pharmacological, cosmetic, and nutritional properties. It is a precursor to many hormones in animals and sterols in plants, making it a versatile chemical with many advantages. Squalene has been used to minimize UV-induced skin damage, lower LDL and cholesterol levels in the blood, prevent cardiovascular disease, and even have antitumor and anticancer effects against several forms of cancer. Squalene is found not only in the human body but also in plants such as olive oil, soybean oil, rice, wheat germ, grape seed oil, peanuts, corn, and amaranth. However, due to the shortage of natural sources and effective extraction methods, the inclusion of squalene in the human diet is limited. As a result, biotechnological advancements in developing synthetic approaches for squalene manufacturing have been made.
What Are the Characteristics of Squalene?
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Physicochemical Properties: Squalene is a triterpene-structured hydrocarbon chain produced by six isoprene molecules. It is prone to oxidation because it is a highly unsaturated lipid with six carbon double bonds (C=C). Conversely, squalene has antioxidant properties because it may trap oxygen singlets during oxidation processes. Squalene is essential for cell membranes in plants. It is found in the hydrophobic center of the lipid bilayer and contributes to membrane organization, biophysical characteristics, and protein function regulation. Squalene also forms insoluble compounds with other components, including saponins and phytosterols, which help stabilize the architecture of the lipid bilayer and contribute to cell membrane permeability.
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Bioactive Properties: Squalene is a valuable substance for cosmetic and medical uses since it has various bioactive characteristics. Controlling weight and lowering cholesterol are two of its major impacts. When taken orally, squalene can lower triglyceride, total cholesterol, and LDL cholesterol levels. Additionally, it has antioxidant properties that protect cells from oxidative damage brought on by UV radiation and other external factors. The ability of squalene to capture oxygen singlets and stop lipid peroxidation is thought to be responsible for its antioxidant effect. Along with its antioxidant characteristics, Squalene has emollient and moisturizing effects on the skin. It has a hydrating effect that prevents the appearance of burns and wrinkles by securing water molecules on the skin's surface. Squalene may remove xenobiotics and activate liver detoxification enzymes, making it known for its detoxifying effects. Squalene may also have an anticancer effect, one of its most important bioactive features. Squalene has been able to stop the growth of tumors in various cancers, including colon, skin, lung, and breast. This is accomplished by preventing the activity of 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase (HMG-CoA reductase), restricting the production of cholesterol, and limiting the growth and differentiation of active cells.
How Do the Biosynthesis and Method of Extraction of Plant-Based Squalene Occur?
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Biosynthesis: Squalene is generated in plants by the mevalonate or isoprenoids pathway, where it is formed from isopentenyl diphosphate (IPP) and dimethyl-allyl-diphosphate (DMAPP). The biosynthesis process starts with acetyl-CoA being converted to mevalonate, which is subsequently phosphorylated to create isopentenyl diphosphate (IPP). Isopentenyl diphosphate isomerase catalyzes the conversion of isopentenyl diphosphate (IPP) to dimethyl-allyl-diphosphate (DMAPP), and the condensation of two isopentenyl diphosphate (IPP) molecules results in geranyl diphosphate (GPP). Farnesyl diphosphate (FPP) is formed by condensing geranyl diphosphate (GPP) with another isopentenyl diphosphate (IPP) molecule. Finally, two Farnesyl diphosphate (FPP) molecules are reduced to produce squalene.
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Method of Extraction: Olive oil, amaranth, soybean oil, rice, and grape seed oil are a few examples of vegetable sources of squalene. Squalene can be extracted from vegetable sources using mechanical pressure techniques or organic solvents. However, these procedures frequently involve refinement procedures to eliminate unwanted molecules, which lowers the final amount of squalene. With its high yields and purity, supercritical fluid extraction (ScCO2) has become a successful technique for squalene extraction.
What Are the Applications of Plant-Based Squalene?
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Antioxidant: Squalene is a powerful antioxidant that prevents lipid peroxidation by scavenging oxygen. Additionally, it reduces superoxide anion, which can lessen skin irritation. Antioxidants can be applied topically to prevent UV-induced cancer and skin photoaging. Amaranth oil boosts sebum levels, exhibiting its special composition, which includes antioxidants like vitamin E, Coenzyme Q10, and squalene.
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Emollient: Squalene, a natural emollient used in penetrants and cosmetics for the skin, is present in amaranth oil. Without leaving a greasy residue, it absorbs into the skin effectively, restoring suppleness and flexibility. Squalene doesn't oxidize, produces emulsions with fixed oils and lipophilic compounds, and speeds up lipstick dye dispersion. It also functions as an ingredient in long-lasting fragrances.
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Natural Lubricant: The natural lubricant squalene moisturizes skin and lessens wrinkles and fine lines. Emulsions like oleogel can benefit from the special squalene concentration of amaranth oil. Vernix caseosa substitute replicates the composition of Vernix caseosa, is made of lipid fractions, and is available as a unique barrier cream for skin with poor barrier protection, such as psoriasis.
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Skin Protection: Acne and seborrheic dermatitis are common skin conditions. Correct sebum constituents are essential for optimal density, fluidity, and viscosity, especially linoleic acid. The fatty acid squalene helps lessen acne by lowering fat levels. Patients with atopic dermatitis can benefit from squalene and alkylglycerols, which protect their skin from bacterial and fungal infections. Cosmetics containing squalene can treat keratosis diseases, protect against skin irritations brought on by product oxidation, and limit bacteria in follicles by acting as bacteriostatic and antifungal agents.
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Topically Applied Vehicles: Squalene provides enhanced loading capacity, long-term stability, trigger release, and potential supersaturated formulations when used with topically applied vehicles like lipid emulsions and nanostructured lipid carriers (NLCs). Improved local drug activity and the introduction of new chemicals into various treatments are both possible with increased epidermal penetration rates.
Conclusion:
Squalene, derived from plants, has attracted attention for its potential in medicine, cosmetics, and nutrition. It has a range of bioactive characteristics, including anti-inflammatory, anti-cancer, emollient, moisturizing, and antioxidant properties. Squalene is in higher demand, notably in the cosmetics industry, which has driven researchers to look into new sources and extraction methods. Olive oil and amaranth are two examples of vegetable squalene sources that have the potential for commercial manufacturing. With its high yields and purity, supercritical fluid extraction has proven to be an effective technique for squalene extraction.
