Skin hyperpigmentation is a condition characterized by patches of skin that appear darker than the surrounding skin due to excessive melanin production in specific areas. Melanin, the primary pigment responsible for skin pigmentation, is synthesized through a biological process known as melanogenesis. An increase in melanin pigment within epithelial tissues is referred to as melanosis. Epidermal melanosis occurs when melanocytes remain normal in number but melanin content increases in the hyperpigmented skin, whereas dermal melanosis is characterized by the presence of melanin within the dermis, between collagen bundles.
Melanin synthesis and types of pigmentation
Melanocytes produce two major types of melanin: eumelanin, which is brown to black, and pheomelanin, which is yellow to reddish-brown. These pigments contribute to the coloration of human skin, hair, and eyes. Each melanocyte interacts with approximately 36 keratinocytes, facilitating the distribution of melanin within the epidermis. The major types of skin hyperpigmentation include melasma, post-inflammatory hyperpigmentation, and solar lentigines, commonly known as age spots or liver spots.
Causes and molecular mechanisms
Skin hyperpigmentation may result from several factors, including ultraviolet (UV) radiation exposure, Addison's disease, hormonal imbalances, and vitamin B12 abnormalities. At the cellular level, UV radiation induces the production of reactive oxygen species (ROS), which activate intracellular signaling pathways, including the mitogen-activated protein kinase (MAPK) pathway. These signaling mechanisms can influence melanogenesis and contribute to increased melanin production and subsequent skin pigmentation.
Type of skin hyperpigmentation
- Post-inflammatory hyperpigmentation
- Melasma
- Age spot
Manifestations of skin hyperpigmentation
(a): Post-inflammatory hyperpigmentation; (b): Acne produced PIH; (c): Melsama on face; (d): Melsama spot; (e): Age spots on face
Ayurvedic approaches
Ayurveda describes various medicinal approaches to skin care, including oil massage and the topical application of medicinal pastes, which are traditionally used to promote smooth, soft, and radiant skin. Bloodletting is also described as a therapeutic procedure in classical Ayurvedic literature.
Medicinal substances possessing Kusthaghna (skin disorder-relieving), Kandughna (anti-itching), Raktashodhaka (traditionally described as blood-purifying), Twak Prasadaka (skin-enhancing), and Varnyakara (complexion-enhancing) properties are traditionally considered beneficial in managing skin disorders. These formulations may be explored for their potential role in improving hyperpigmentation and reducing dark skin discoloration; however, their depigmenting efficacy and safety require validation through appropriate clinical studies.1
Herbs used for hyperpigmentation2,3
|
Herbs |
Part used |
Mechanism of action |
Phytoconstituents |
|
Glycyrrhiza glabra [Fabaceae] |
Root |
UVB protection; moisturising agent |
Glycyrrhizic acid, glycyrrhizin, glabridin |
|
Vitex negundo [Verbenaceae] |
Root |
Tyrosinase inhibition |
Negundin A, (+)-lyoniresinol-3α-O-β-D-glucoside |
|
Aloe barbadensis [Asphodelaceae] |
Leaf |
Moisturising agent; tyrosinase inhibition |
Aloesin, 2″-feruloylaloesin |
|
Morus alba [Moraceae] |
Fruit |
Tyrosinase inhibition; ROS scavenging |
Apigenin, umbelliferone, astragalin, moranoline, 1-deoxynojirimycin, resveratrol |
|
Panax ginseng [Araliaceae] |
Root |
Antioxidant activity; skin-whitening effect |
Ginsenosides, p-coumaric acid |
|
Ginkgo [Ginkgoaceae] |
Flower |
Tyrosinase inhibition |
Ginkgolide A, bilobalide |
|
Azadirachta indica [Meliaceae] |
Leaf, bark |
Antioxidant; antibacterial activity |
Oleic acid, azadirachtin, isomeldenin, nimbin, nimbinene, 6-desacetylnimbinene, nimbandiol |
|
Santalum album [Santalaceae] |
Wood |
Antioxidant activity; skin-whitening effect |
α-Santalol, β-santalol |
|
Muntingia calabura [Muntingiaceae] |
Flower, leaf, fruit |
Antityrosinase and antioxidant activities |
Stigmasterol, triglycerides, α-linolenic acid |
|
Blumea balsamifera [Asteraceae] |
Leaves |
Antityrosinase activity; inhibition of lipid peroxidation; hepatoprotective activity |
3-O-7″-biluteolin (as supplied) |
|
Magnolia officinalis [Magnoliaceae] |
Bark |
Inhibition of melanogenesis |
Magnoloside Ia, crassifolioside, magnoloside Va |
|
Pueraria thunbergiana [Leguminosae] |
Root |
Inhibition of melanogenesis |
Schaftoside, puerarin, genistin |
|
Emblica officinalis [Phyllanthaceae] |
Fruit |
Antioxidant activity; skin-whitening effect |
Quercetin, kaempferol, gallic acid, methyl gallate, ellagic acid, trigalloyl glucose, phyllanthine, phyllembein |
|
Curcuma longa [Zingiberaceae] |
Root |
Antioxidant activity; skin-whitening effect |
Curcuminoids |
|
Camellia sinensis [Theaceae] |
Leaves |
Antioxidant activity |
Epigallocatechin gallate, epicatechin, gallocatechin |
|
Nelumbo nucifera Gaertn. [Nelumbonaceae] |
Flower |
Antioxidant activity; tyrosinase inhibition |
Pronuciferine, armepavine, kaempferol-3-O-glucoside, luteolin glucoside |
|
Crocus sativus L. [Iridaceae] |
Dried stigmas |
Tyrosinase inhibition |
Crocin, picrocrocin, β-carotene, safranal |
|
Hemidesmus indicus [Asclepiadaceae] |
Root |
Antioxidant activity; tyrosinase inhibition |
Hemidesminine, lupeol, vanillin |
|
Vitis vinifera [Vitaceae] |
Seed, leaf |
Tyrosinase inhibition |
Gallic acid, protocatechuic acid, vanillic acid, syringic acid, ellagic acid |
|
Euphorbia supina [Euphorbiaceae] |
Leaf, flowers, tubers |
Antioxidant activity; skin-lightening effect |
Protocatechuic acid, nodakenin, 3-O-glucoside |
|
Brillantaisia cicatricosa Lindau [Acanthaceae] |
Leaves |
Traditional uses include hyperpigmentation, leprosy, vermifuge, emetic, eczema, snakebite, and lactogenic applications |
Alkaloids, glycosides, terpenoids, steroids, flavonoids, tannins, saponins |
|
Chenopodium uganda [Chenopodiaceae] |
Stem, leaves, flower |
Tyrosinase inhibition |
Phenolics, flavonoids, saponins, triterpenoids |
|
Sesamum angolense Welw. [Pedaliaceae] |
Leaves |
Traditional uses include hyperpigmentation and dysentery |
Terpenoids, steroids |
|
Protea madiensis Oliv. [Proteaceae] |
Root, bark |
Traditional use in skin diseases and hyperpigmentation |
Terpenoids, steroids |
|
Carica papaya L. [Caricaceae] |
Leaves |
Moisturising agent; antioxidant activity |
Papain, chymopapain A and B |
|
Acacia catechu [Mimosaceae] |
Bark |
Antioxidant activity; skin-whitening effect |
Catechin, catechutannic acid |
|
Arnica montana [Asteraceae] |
Flower |
Inhibitory activity in B16 melanoma cells |
Triterpenes, essential oils, fatty acids, thymol, pseudoguaianolide sesquiterpene lactones |
|
Artemisia dracunculus [Asteraceae] |
Leaves |
Inhibition of melanocyte-stimulating hormone activity (as supplied) |
Isobutyl and piperidiyl compounds (as supplied) |
|
Glycine max [Fabaceae] |
Seed |
Antioxidant activity; tyrosinase inhibition |
Kunitz-type trypsin inhibitor, Bowman–Birk protease inhibitor |
|
Thymelaea hirsuta [Thymelaeaceae] |
Leaves, stem, flower |
Antioxidant activity; antimelanogenic effect |
Genkwadaphnin, gnidicin |
|
Betula pendula [Betulaceae] |
Bark, leaves |
Tyrosinase inhibition |
Phenolics, flavonoids, tannins, saponins, glycosides, sterols, terpene derivatives |
|
Caesalpinia sappan [Fabaceae] |
Wood |
Inhibition of melanogenesis and cellular tyrosinase activity |
Homoisoflavanone, sappanone A |
|
Callicarpa longissima [Lamiaceae] |
Leaves |
Inhibition of melanin production |
Not specified |
|
Carthamus tinctorius L. [Asteraceae] |
Seeds |
Inhibition of melanogenesis |
Essential oils containing palmitic acid, palmitoleic acid, margaric acid, margaroleic acid |
|
Coccoloba uvifera [Polygonaceae] |
Not specified |
Antioxidant and antityrosinase activities; inhibition of IL-1α, TNF-α, and α-MSH production in melanocytes |
Titratable acids, ascorbic acid |
|
Colocasia antiquorum [Araceae] |
Root, bark |
Inhibition of melanogenesis |
Colocasinol A |
|
Crataegus azarolus L. [Rosaceae] |
Leaves |
Effects on B16F10 melanoma cells |
Vitexin-2″-O-rhamnoside |
|
Juniperus chinensis L. [Cupressaceae] |
Fruit |
Inhibition of tyrosinase and melanogenesis |
Amentoflavone-7-O-D-glucoside |
|
Glechoma hederacea L. [Lamiaceae] |
Stem |
Reduction in cellular melanin content and tyrosinase activity |
Germacrene D, ursolic acid, oleanolic acid |
|
Garcinia livingstonei [Clusiaceae] |
Bark |
Inhibition of melanin production |
Amentoflavone, 3β-hydroxyeupha-5,22-diene, O-methylfukugetin, morelloflavone, volkensiflavone |
|
Viola odorata [Violaceae] |
Leaves |
Antimelanogenic activity |
Vitamin C, methyl salicylate |
|
Passiflora edulis [Passifloraceae] |
Seed |
Inhibition of melanogenesis |
Piceatannol |
|
Stewartia pseudocamellia [Theaceae] |
Bark, fruit |
Antimelanogenic activity |
Deoxystewartianol-4′-O-arabinoglucoside, stewartianol-3-O-glucoside |
|
Cyperus rotundus [Cyperaceae] |
Rhizomes |
TRPV1 channel inhibition; ORAI1 channel inhibition |
Valencene, camphene |
|
Cudrania tricuspidata [Moraceae] |
Fruit |
Inhibition of L-DOPA auto-oxidation |
Flaviostatin (as supplied) |
Conclusion
Skin hyperpigmentation involves complex mechanisms of melanogenesis influenced by UV exposure, oxidative stress, hormonal factors, and inflammation. Ayurvedic practices and medicinal herbs offer potential avenues for skin care, with several plant-derived phytoconstituents demonstrating antioxidant, tyrosinase-inhibitory, and antimelanogenic activities. However, further well-designed clinical studies are needed to establish their efficacy, safety, and role in evidence-based hyperpigmentation management.
References:
- Angadi SS, Gowda ST. Management of Vyanga (facial melanosis) with Arjuna Twak Lepa and Panchanimba Churna. Ayu. 2014;35(1):50-53. doi:10.4103/0974-8520.141924. https://pmc.ncbi.nlm.nih.gov/articles/PMC4213969/
- Rathee P, Kumar S, Kumar D, Kumari B, Yadav SS. Skin hyperpigmentation and its treatment with herbs: An alternative method. Future Journal of Pharmaceutical Sciences. 2021 Jul 2;7(1):132. https://link.springer.com/content/pdf/10.1186/s43094-021-00284-6.pdf
- Popaniya HS, Vaja PN, Tank CJ. Tyrosinase inhibition: A potent mechanism of action of plants used in treatment of Melasma. Asian Journal of Pharmaceutical Research. 2024;14(3):289-94. https://www.researchgate.net/profile/Hiral-Popaniya/publication/385536869_A_Concise_Review_on_Herbal_Immunity_Booster/links/6815ed68bfbe974b23c2bbcf/A-Concise-Review-on-Herbal-Immunity-Booster.pdf