It is well known that women crave skin beauty, especially in Asia, which has led to the rapid development of whitening cosmetics research. Many whitening ingredients used in cosmetics have been well known, such as salicylic acid and its derivatives, vitamin C and its derivatives, arbutin, traminic acid, ellagic acid, kojic acid and so on. In recent years, with the pursuit of green natural consumption trend by consumers, whitening ingredients derived from some plant resources, such as licorice extract, chamomile extract, angelica extract, Rhodiola extract, etc., have once become the hot spot and focus of industry research. Here we will introduce the key point that the skin lighting cosmetics you bought and how they make you white and delicate? If you’re interested in trying botanical skin lighteners, read on to discover which one’s best.
Salicylic acid and its derivatives
The melanin in the skin is usually transported to the upper layer of the cuticle with the differentiation and maturity of keratinocytes. Salicylic acid can accelerate the exfoliation of keratinocytes on the surface, but also has the effect of promoting the infiltration of other ingredients, which is used to add to cosmetics and other whitening ingredients. Potassium methoxylsalicylate, a salicylic acid derivative, can inhibit melanin synthesis by blocking tyrosinase activity. It has also been reported that it can regulate the synthesis and differentiation of keratinocytes, which can adjust the keratinization process of the skin, so that melanin can shed off with the normal metabolism of the corneum, and reduce the skin dullness caused by the aggregation of melanin in the corneum. However, salicylic acid, as a small molecule acid, has strong permeability and can easily penetrate into the dermis and subcutaneous tissues, dissolve the cuticle and destroy the sebaceous membrane. Therefore, it is easy to stimulate the microvessels and nerves between the deep skin, resulting in a micro-irritant reaction.
Vitamin C and its derivatives
Vitamin C, also known as ascorbic acid, mainly reduces the melanin in the skin through reduction to reduce dark spots. The generation of melanin is a process of progressive oxidation, and vitamin C needs long-term use to maintain whitening because the environment continues to oxidize. Vitamin C has excellent reducibility, such as reducing o-quinone and inhibiting melanin production and inhibiting peroxidase action. However, due to the solubility of vitamin C in water, its water-oil distribution characteristics indicate that it is not easy to penetrate into the skin cuticle, and itself is easy to be oxidized and unstable, so its application is limited.
Vitamin C in cosmetics is often used in combination with metal ion-containing ingredients or in addition to its derivatives to reduce its own oxidation, a common vitamin C derivative is water-soluble magnesium phosphate salts.
Arbutin is a glucosylated hydroquinone derivative derived from rhododendron. It is reported that arbutin can reduce tyrosinase activity and inhibit the maturation of melanin bodies in the skin. Based on differences in chemical structure, arbutin can be divided into α -arbutin, β -arbutin and deoxyarbutin. The price of β -arbutin is lower than other isomers, but the whitening effect of α -arbutin and deoxyarbutin is superior to β -arbutin. Deoxyarbutin has the best effect on reducing melanin formation among the three types, and its whitening effect is 10 times that of hydroquinone, 38.5 times that of α -arbutin, and 350 times that of β -arbutin. The whitening effect is still lasting even after stopping use, and its safety is 4 times that of hydroquinone.
Studies have confirmed that arbutin extract can inhibit melanin formation by inhibiting melanin synthesis related genes. A 2009 study found that arbutin whitens skin by lowering levels of melanocyte-stimulating hormone (α-MSH) in melanocytes.
In recent years, arbutin hypersensitivity has been reported, and in vitro and in vivo tests have also shown that arbutin has certain cytotoxicity. The scientific Committee on Consumer Safety of the European Union has stated that there is no risk of α -arbutin addition in face cream and body lotion (2% and 0.5%, respectively), and β -arbutin addition in face cream is not more than 7% (hydroquinone less than 0.0001%). The risk found in β -arbutin is that it can be broken down under certain conditions to produce hydroquinone.
Nicotinamide, a B vitamin, is widely used in the treatment of skin problems such as photosensitive dermatitis. Studies have shown that nicotinamide powder has a good inhibitory effect on inflammation. According to modern scientific research, the whitening mechanism of nicotinamide is mainly: inhibiting the synthesis of melanin; Inhibiting melanin transport in keratinocyte layer and accelerating melanin exfoliation.
Studies have found that about 20% of people develop an intolerance once nicotinamide levels exceed 4%, such as skin redness, itching, edema, and tingling. Therefore, the concentration below 2% is relatively safe to use on the skin; But clinical trials have found that niacinamide has a significant effect at concentrations above 3%. Therefore, people with sensitive muscles, poor skin barrier function or dermatitis should be careful to use skin care products containing nicotinamide.
Skin lighteners are cosmetics that include benefits such as “reducing melanin deposition, inhibiting the formation of dark spots and freckles, reducing pigmentation in the skin, and helping to whiten the skin.” Licorice root contains kojic acid, which inhibits tyrosinase and reduces the appearance of hyperpigmentation. Kojic acid can chelate with copper complex on tyrosinase and reduce tyrosinase activity through competitive inhibition reaction. Kojic acid can also block the intermediates of melanin production and inhibit related proteins (TRP-2), so as to achieve the whitening effect of inhibiting melanin production. But kojic acid also has its disadvantages, such as poor stability of light and heat, easy oxidation and discoloration, easy chelation with metal ions, and poor skin absorption.
L-ergothioneine (EGT, ERGO)
Ergothionein is a new type of naturally occurring sulfur-containing amino acid, which is widely distributed in plants, animals and microorganisms in nature, was first discovered in Ergothionein fungi in 1909. It has strong antioxidant and cell protection and is widely used in sunscreen, repair, whitening, anti-aging and other fields. The results showed that the amount of ergothionein added to cosmetics up to 0.01% to 3% can prevent the formation of pigment and pigmentation. In a half-face double-blind test, a emulsion containing 0.5% ergothionein increased moisture content by 15% and elasticity by 20% after four weeks. All this proves that low concentration of ergothione has a certain effect on skincare.
At present, ergothione raw materials are mainly produced by chemical synthesis and biological fermentation, and the price ultimately depends on the different access, purity and quality. At present, the main synthetic technology is biological fermentation, that is, fungus mycelium fermentation technology. Ergothionein was produced by the combined fermentation of hericium ordosica and pine mushroom mycelium in most Chinese manufacturers.