The Use of Botanical Extracts as Topical Skin-Lightening Agents for the Improvement of Skin Pigmentation Disorders

Abstract

Both physicians and dermatology patients are searching for long-term topical skin care solutions (both cosmetic and cosmeceutical) to address problems presented by skin hyperpigmentation. Specifically, some women often express a desire to "lighten" skin tone by achieving improved visible tone, reduction in yellowness (or sallow tone), and reduction in the appearance of hyperpigmented spots ("age" or "sun" spots). Traditional depigmenting agents, such as hydroquinone, corticosteroids, and kojic acid, although highly effective, can raise several safety concerns (for example, ochronosis, atrophy, carcinogenesis, and other local or systemic side effects) with long-term exposure. An understanding of the benefits of natural and botanical extracts provides opportunities to develop new products to address pigmentation problems. Active compounds isolated from plants, such as arbutin, aloesin, gentisic acid, flavonoids, hesperidin, licorice, niacinamide, yeast derivatives, and polyphenols, inhibit melanogenesis without melanocytotoxicity by different mechanisms. This review presents an overview of trends in the application of plant extracts as topical treatments for hyperpigmentation disorders. It highlights some of the most relevant natural extracts, providing in vitro screening results and relevant available clinical study trial findings supporting their efficacy.