Seeking The Perfect Complexion With Pigment Lightening Ingredients

By Ada S. Polla, CEO and Anne Pouillot, Director of Science, Alchimie Forever

Once upon a time, being tanned was a sign of wealth – tanned skin indicated that instead of slaving away in an office, one had the time and money to enjoy the world’s most beautiful beaches. At another point in time, being tanned was a sign of poverty, indicating that you worked in the fields as a peasant.

Today, we strive for the middle. More aware of the dangers of unprotected sun exposure, consumers understand the value of sunscreen, and strive for a complexion that is fair, even, yet shows a bit of sun.

Understanding the way melanin works, how to prevent it from forming, and how to even it out once it is visible is key to achieving this perfect complexion. In this review, we look at both the causes of pigmentation, and at some of the ingredients that aim to even out pigmentation and improve the evenness of complexion.

Pigmentation is a complex metabolic process that includes tyrosinase activity, melanosome formation, and a cascade of intermediate metabolites that result in the formation of melanin.

As with many things, however, melanin is in the gray, with both good and bad attributes. The most important positive role of melanin is to protect the skin against UV radiation. Melanocytes are thus important for the human body. However, when melanogenesis becomes hyperactive in melanocytes, the skin develops epidermal hyperpigmentation, including melasma, freckles, and senile lentigines. In lay terms, melanin hyperactivity leads to unsightly, pesky brown spots.

Let’s look more specifically at the three main causes of hyperactive melanin.

Ultraviolet radiation from the sun directly stimulates melanin synthesis and the proliferation of melanocytes, as well as the release of cytokines such as the alpha-melanocyte-stimulating hormones (MSH) from keratinocytes or melanocytes which up-regulate the tyrosinase level in melanocytes.¹

Hormones, specifically estrogen, are also involved in the synthesis of melanin. These are hyper-secreted during pregnancy. Melasma (also known as the pregnancy mask) appears at any time during a woman’s reproductive years and is often associated with pregnancy or oral contraceptive use. It is highly exacerbated by exposure to UV.

Various skin conditions, such as acne, eczema, and allergic responses, can lead to post-inflammatory hyperpigmentation. This is an excess of melanin pigments following cutaneous inflammation or injury such as acne, contact dermatitis, atopic dermatitis, or trauma. Darkly pigmented individuals are particularly prone to developing this form of hypermelanosis.²

The treatment of pigment disorders remains a challenge, as there are no standardized treatmentsfor melasma, post-inflammatory hyperpigmentation, or pigmentation due to photoaging. Typically, the use of dual or triple combination product as a first approach is recommended. The combination of various pharmacologic agents with chemical peels, microdermabrasion, and/or pigment-specific lasers can lead to accelerated healing times and a more rapid and significant improvement, and can reduce the occurrence of post-inflammatory hyperpigmentation.

The ideal depigmentating compound should have a potent, rapid, and selective bleaching effecton hyperactivated melanocytes,carry no short- or long-term side effects, and lead to a permanent removal of undesired pigment, acting at one or more steps of the pigmentation process.

• What is it?
  This hydroxyphenolic chemical inhibits tyrosinase by preventing the conversion of tyrosine to dihydroxyphenylalanine, a precursor of melanin. Hydroquinone may interfere with pigmentation even through alteration of melanosome formation and melanization ectent and selectively damaging melanosomes and melanocytes.
• Pros
  In the US, hydroquinone is readily available in concentrations up to 2% as an over-the-counter (OTC) drug and by prescription at higher concentrations.³It is considered the gold standard for treatment of hyperpigmentation, and has been for over 50 years.
• Cons
  The side effects of hydroquinone include allergic contact dermatitis, irritant contact dermatitis, and post-inflammatory hyperpigmentation and nail discoloration. Irritation, stinging, and/or burning were observed transiently during the first day of application and disappeared with use of the medication after a few days. For many of these reasons, hydroquinone is banned in the European Union for cosmetic use (prescription only).

• What is it?
  Kojic acid is a naturally occurring hydrophilic fungal product derived from certain species of acetobacter, aspergillus, and penicillium.
• Pros
  Kojic acid reduces hyperpigmentation by inhibiting the production of tyrosinase and is also a potent antioxidant.⁴
• Cons
  Kojic acid has the potential to cause contact dermatitis and erythema.⁵

• What is it?
  Arbutin is a derivative of hydroquinone and exists in the dried leaves of certain plant species such as bearberry or blueberry.
• Pros
  Arbutin inhibits tyrosinase activity, inhibits melanosome maturation, and is less toxic to melanocytes than hydroquinone. Arbutin is a safe and mild agent for treating cutaneous hyperpigmentation disorders, including melasma and UV-induced hyperpigmentation.
• Cons
  None.

• What is it?
  Ellagic acid is a natural polyphenol found in many plants such as strawberries, grapes, and green tea.
• Pros
  Ellagic acid can prevent pigmentation caused by sunburn, such as spots and freckles.
• Cons
  None.

• What is it?
  Paper mulberry extract comes from the root bark of the Morus alba tree and has been shown to have skin whitening properties.
• Pros
  Mulberry leaves have been shown to inhibit tyrosinase activity and melanin formation. No toxicity has been associated with this ingredient, as is shown by many human skin irritation tests.
• Cons
  None.

• What is it?
  Niacinamide is a biologically active form of vitamin B3 found in many root vegetables and yeasts.
• Pros
  Niacinamide inhibits the transfer of melanosomes from melanocytes to keratinocytes. Furthermore, topical niacinamide has also been shown to decrease collagen oxidation products and improve aging-induced yellowing or sallowness.
• Cons
  None.

• What is it?
  Vitamin C is an antioxidant that can scavenge free radicals such as peroxides, which contribute to tyrosinase activation and melanin formation.
• Pros
  Topical application of vitamins C and E decreases the tanning response inhibiting the UV-induced melanogenesis and proliferation of melanocytes.
• Cons
  Vitamin C can momentarily retard the melanin-biosynthesis pathway, but never eliminate it.

There are three main causes of uneven pigmentation: excessive sun exposure, hormones, and trauma leading to inflammatory hyperpigmentation.Identifying the cause of “brown spots” is key to optimal treatment. Combining therapies (such as laser treatment or chemical peels) with topical products will ensure optimal therapeutic results. And choosing topical products with a combination of ingredients, such as these mentioned above, is key.

This article was originally published in GCI Magazine, March 2015.

References

1. Imokawa G et al 267; 24675-24680 1992.
2. Chong M. Disorders of hyperpigmentation. In: Bolognia J, Jorizzo R, Rapini P, editors. Dermatology : Mosby ; 2008, p939-40 and Rivera AE. Acne scarring: a review and current treatment modalities, J Am Acad Dermatol. 2008; 59(4):659-76).
3. Engasser PG et al. Cosmetics and dermatology: bleaching creams 1981; Grimes PE Melasma. Etiologic and therapeutic consideration 1995.
4. Kahn V. Effect of kojic acid on the oxidation of DL-DOPA, norepinephrine, and dopamine by mushroom tyrosinase. Pigment Cell Res. 1995; 8:234-40.
5. Nakagawa M et al Contact allergy to kojic acid in skin care products 1995.