This time I’d like to write very interesting topic..skin lightening cosmetics. This just something people try to do for hundred years ago.. cover blemishes with cosmetics. The records of the fourth century physician Galen speaks of them in the previous millennium. Until about 1973, dangerous agents such as ammoniated mercury had been used. Since then, mercury derivatives had been banned from most countries.
Many people are concerned with the degree of pigmentation of their skin. In Asia, most women desire whiter skin because of traditional beliefs that white skin denotes nobility and aristocracy. An extreme case is in Japan where Geisha are known to paint their face white as a sign of social status, grace and beauty. Today the Geisha still paint their faces white but only as a ceremony of celebration of culture, history and background.
In other region within lower-class society such as in Nigeria, Saudi Arabia, Pakistan, Mexico when asked why women used skin-whitening creams, and in some cases even applied these creams to their children, one woman from an Arab-American family replied directly, “Oh, that’s simple. It is well known that in many Arab families the whiter looking children are the most preferred. People will often respond positively to the lighter-colored child and simply ignore the darker one.”
In an interview with one Latin American woman about identification and self-image, she told that “whiter-looking Spanish women are generally perceived as more attractive to many Latino men and vice versa.” The woman, a journalist, went on to say that during her childhood, her parents and her friends’ parents had always carefully screened the children invited to their parties “to be certain that they were light enough in color” and thus “of sufficient socioeconomic value to be included.”
So, the prevalent medical evidence of high levels of mercury poisoning among women of Saudi, African, Asian and Mexican backgrounds reflects a common and prevailing belief that whiter skin has greater currency and appeal. Apparently, the patients reporting to clinics with mercury-induced disease believe that the health risks associated with bleaching their skins are outweighed by the rewarding sociocultural return. In other words, they believe that removing the healthy melanin from their skin with toxic creams and soaps makes them more valuable in their own cultures and in European and Euro-American societies in general.
POISONOUS CREAM! Above is an example of a “skin-lightening” cream that contains poisonous levels of mercury.
The product contained 6,000 parts per million (ppm) of mercury, despite FDA regulations which limit mercury to 1 ppm. What is the effect if someone apply mercury-based beauty/lightening cream ? Mercury poisoning is known to cause neurological and kidney damage and may also lead to psychiatric disorders. Now, we can see the urgency to quickly invent novel skin lighteners and depigmenting agents with a proven eficacy and safety profile with reasonable price. They’re a prominent need.
– What is Hiperpigmentation ?
Hyperpigmentation or skin discoloration is condition of skin when some patches of skin become darker than the surrounding area or generalized, when all body is affected. Hyperpigmentation can be inherited or, more often, aquired by a number of causes including photoaging, hormonal changes (contraceptives pregnancy, menopause), repeated and prolonged exposure to the sun, and chronic skin irriations, inflammation or skin diseases. Many people are concerned with the degree of pigmentation of their skin. For example, people with age spots/melasma, chloasma/mask of pregnancy or freckles may wish such pigmented spots to be less pronounced.
Others may wish to reduce the skin darkening caused by exposure to sunlight or to lighten their natural skin color. Such skin pigmentation disorder occur because the body produces too much melanin, which is the pigment produced by melanocytes in the skin. In recent years, cosmetic compositions have been developed to reduce the amount of melanin in the skin and therefore, whiten the skin.
– Biosynthesis of melanin
schematic of melanin synthesis
Skin and follicular/hair pigmentation is the result of the exposure of melanin at the surface of the skin and of the the hair follicle. Melanogenesis/synthesis of melanin is carried out specifically by the melanocytes, dendritic cells present in the basal layer of the epidermis, which put out branches for contact with the keratinocytes. The newly synthesized melanin is transferred from the melanocyte dendrites to the keratinocytes, which ultimately expose the melanin at the surface of the epidermis, thus providing uniform coloration of the epidermis.
The synthesis of melanins (pheomelanins, rich in sulfur, giving an orange color; eumelanins, conferring a brown color) is carried out in the melanosomes, which are melanocyte-specific lyosome-like organelles, by a complex enzymatic process. Three enzymes located on the internal face of the melanosomal membrane are successively involved in melanogenesis : tyrosinase, TRP-2 (tyrosinase-related protein-2) and TRP-1 (tyrosinase-related protein-1).
Tyrosine, a precursor for melanin synthesis, is hydroxylated to Dopa (dihydroxyphenylalanine) and then oxidized to dopaquinone, these two conversions being due to the action of tyrosinase. At this stage, the melanin synthesis canbe oriented toward pheomelanin (orange-yellow melanin) which is encountered in blond individuals/ redheads, or toward eumelanin (darkbrown melanin) which is encountered in individuals with dark pigmentation.
Eumelanin results from the polymerization of dopaquinone so as to give leukodopachrome and then dopachrome. The latter is in turn converted either to 5,6-dihydroxyindole (DHI) or to 5,6-dihydroxyindole-2-carboxylic acid (DHICA) under the action of TRP-2. At this level, the synthesis of eumelanin can be carried out according to two pathways. DHI is oxidized, under the action of tyrosinase or of a peroxidase, to indole-5,6-quinone, while DHICA, under the action of TRP-1, gives 5,6-dihydroindole-2-carboxylic acid. The indole-5,6-quinone and the 5,6-dihydroindole-2-carboxylic acid polymerize so as to form melanochromes and then eumelanin.
The synthesis of pheomelanin involves the formation of sulfur compounds (cysteinyl-DOPA) subsequent to the action on dopaquinone of glutathione and of cysteine. The cysteinyl-DOPA is converted to alanylhydroxybenzothiazine and then to pheomelanin.
Under the effect of solar radiation of UVB type, human keratinocytes produce and secrete endothelin peptide hormone which exerts a paracrine effect on the melanocytes. Endothelin activates a G protein-coupled membrane receptor (ETR) inducing melanocytes proliferation, and transcription of the genes encoding tyrosinase and the ETR. Similarly, in response to UV radiation, keratinocytes and melanocytes secrete the α-MSH peptide ( melanocortin-stimulating hormone ) which regulates melanocytes pigmentation activity. To do this, α-MSH binds to MC-R ( melanocortin receptor ), inducing activation of the cAMP/PKA transduction pathway, or even of the ser/thr kinase PKC, resulting in de novo synthesis of tyrosinase and in eumelanin synthesis. PKC-β appears to directly activate tyrosinase by phosphorylation of the cytoplasmic domain thereof. α-MSH also appears to facilitate the trasnsfer of melanin to keratinocytes by stimulating melanocyte dendricity.
– Treatment for hyperpigmentation
The substances known for their depigmenting properties can act according to one of the following mechanisms :
1. On the viability of the epidermal and/or follicular melanocytes where melanogenesis takes place. This substance ( also called MC1-R receptor antagonist ) capable of binding to the melanotropin cellular receptors ( MC1-R ) present on the melanocyte membrane, of blocking the binding of α-MSH (melanocortin stimulating hormone ), a ligand specific for MC1-R, and of inhibiting the activation of MC1-R by α-MSH which will specifically and reversibly inhibits melanogenesis by decreasing the synthesis and the excessive production of melanin pigments.
Among the MC1-R receptor antagonists known are : Melanostatine®5 ( INCI name : nonapeptide-1 ), an oligopeptide discovered by the Institut Europeen de Biologie cellulaire/European Cell Biology Institute, sold by the company Unipex and Sepiwhite MSH® ( INCI name : undecylenoyl phenylalanine ), lipoamino acid sold by the company Seppic.
2. By interfering with one of the stages of melanin biosynthesis, or by inhibiting one of the enzymes involves in the melanogenesis or by intercalating as a structural analogue of one of the chemical compounds of the melanin synthesis chain. These substances are widely used. Most skin whiteners currently on the market contain ingredients (hydroquinone, ascorbic acid, kojic acid,arbutin, azealic acid, glycyrrhetinic acid (licorice extract), cortex mori, and many others) that act as direct inhibitors of tyrosinase, the enzyme in the skin pigment cells (melanocytes) that make melanin.
Hydroquinone, however, exhibit considerable cytotoxicity capable of causing irreversible depigmentation and irritates the skin strongly, furthermore hydroquinone has recently been recognized as a carcinogen and thus the use of hydroquinone in cosmetic products has been prohibited by European regulatory. Just recently the FDA also announced its plans to possibly remove hydroquinone based products from store shelves (OTC) and limit its use to only prescription based medications.
3. By interfering in the transfer of melanin from melanocytes to keratinocytes such as Nicotinamide ( INCI name : niacinamide ).
4. Inhibit UV-induced melanin synthesis. These ingredients block UVA rays, the tanning rays, and therefore prevent skin darkening, ex. inorganic sunscreens such as Titanium Dioxide and Zinc Oxide. In case of darker skin, the usage of UV sunscreen ( with >SPF 30 ) become the entire imperative as it offers protection to skin from early ageing and wrinkling.
5. Removal of pigmented skin cells with exfoliants such as alpha-hydroxy acids ( glycolic acid, salicylic acid, lactic acid ).
The ideal depigmenting compound should have a potent, rapid and selective bleaching effect on hyperactivated melanocytes, carry no short- or long-term side-effects and lead to a permanent removal of undesired pigment.
– Recent Skin-Lightening Patents
Recent patents related to skin lightening include :
1. Pomegranate melanin reduction, the pomegranate extract may be standardized to about 20% punicalagins, which are large polyphenol tannin compounds.
2. Reducing retinoid irritation in skin lightening. Effective skin lightening is achieved by combining a polymeric microparticle-entrapped retinoid with a second skin lightening agent such as kojic acid or a derivative thereof ( kojic acid dipalmitate ) in an emulsion composition.
3. Dopa oxidase inhibitor. By inhibiting dopa oxidase activity, thereby suppressing melanin production.
– Tips for finding a good skin lightening cream
1. Never buy creams that contain steroids.
2. Avoid buying creams which contain hydroquinone.
3. Mitracarpus extract, bearberry extract and mulberry extract are good alternatives to hydroquinone.
4. Creams containing Kojic Acid in combination with glycolic acid show good results.
5. Azelic acid in 15-20% concentration is very effective and causes less irritation than hydroquinone.
6. Look for skin lightening creams that contain plant extracts too.
7. Creams having Vitamin C are extremely good in inhibiting melanin production.
8. Avoid creams which contain mercury as an active ingredient.
So..that’s all for now. If you’re already read it and have something in mind, just write comment below.
andriantoangkadirjo85 bottom line
– Do not use products or imported products if there are no ingredients, registration number, manufacturer address, expired date and batch code on the label.
– Perhaps we must make an equally strong effort to convince women and men of color that they are beautiful as they are. This task may be as challenging as trying to convince people with light skin that it is unnecessary and hazardous to lie out in the sun or go to a salon in pursuit of a tan.
– “Skin-whitening” cream, one product say, “lightens your complexion and eliminates ugly spots and accumulated impurities, leaving the skin with an even glow.” Other products suggest its use for” any discoloration due to age, wrinkles, freckles or sun spots”
– A number of skin-lightening compounds have been partially or completely banned because of toxicity and environmental concerns. For example : mercury, hormonal preparations and oxidizing agents have been banned as skin-lightening agents.
– The trend is to find natural extracts that can synergistically provide inhibition of the tyrosinase enzyme.
– Combining skin-lightening agents is possible, specifically the combinations of niacinamide with an ascorbyl derivatives or with mulberry and bearberry extract, and arbutin and ascorbyl derivatives with kojic dipalmitate.