5. Natural hyperpigmentation treatment
Despite the wide range of therapies available, a growing number of people are choosing plants and natural items as alternatives. Plant-based and natural remedies have been used for treating skin issues for ages, and they are gaining popularity as a secure and efficient method to treat skin hyperpigmentation. [
111,
112,
113,
114,
115].
Vitamins A, B, C, and E can all be used to address skin pigmentation problems and are necessary for healthy skin. Each vitamin, which can be obtained in foods or supplements, has specific advantages. [
116,
117]
Niacin, Pantothenic acid, and biotin are the B vitamins most frequently found in skincare products. Niacin, also known as niacinamide, is a vitamin that is used in face creams and masks to minimize the appearance of enlarged pores, fine lines, and dullness. Pantothenic acid is also applied to dry, flaky skin as a moisturizer. Numerous hair, nail, and skin care products include biotin [
118,
119]. Ascorbic acid (vitamin C), an antioxidant, inhibits tyrosinase by binding to copper and suppressing the oxidative polymerization of melanin precursors, which prevents melanin synthesis in the melanogenesis pathway [
120,
121]. A statistically significant decrease from baseline to Week 16 was observed in a trial on 39 patients using 25% L-ascorbic acid dissolved in Nmethyl-2-pyrrolidone and dimethyl isosorbide, as indicated by MASI values and mexameter data. [
122,
123]. A particular kind of vitamin E is alpha-tocopheryl acetate. When fat is subjected to oxidation and during the spread of free radical reactions, vitamin E, a powerful chain-breaking antioxidant, prevents the synthesis of reactive oxygen species molecules. [
124,
125,
126]
Artocarpus lakoocha and
Glycyrrhiza glabra extracts have been reported to exhibit tyrosinase inhibitory effects and melanin pigment reduction. For the treatment of hyperpigmentation, the combination of 9:1 Artocarpus lakoocha and Glycyrrhiza glabra decreased melanin pigment by up to 53% in B16 cells by lowering the production of tyrosinase (TYR), microphthalmia-associated transcription factor (MITF), and tyrosinase-related protein-2 (TRP-2). [
127,
128,
129]
Antioxidants and fatty acids included in oils like rosehip, jojoba, and argan oil aid in reducing inflammation and brightening the skin. Natural oils can also shield the skin from the effects of the environment, preventing further discoloration. Aloe vera also includes aloin (compound 19 in
Figure 9), which has been demonstrated to lighten skin and function well as a nontoxic hyperpigmentation therapy. Sharique described aloe vera as a natural depigmenting ingredient. [
130,
131,
132]
When used as an emollient, jojoba oil exhibits first-rate lubricity without having an oily or greasy texture in single-segment and emulsion structures. It can also contribute to the skin's effective water regulation during transpiration, reducing evaporation without obstructing the passage of gases or water vapor [
133,
134,
135,
136]. According to a study, jojoba oil (or its ozonized or hydrogenated derivatives) has emollient properties. The study discovered that a significant increase in skin surface flexibility developed within 5 minutes and persisted for hours, suggesting a potential application in solutions for dry skin [
137]. Jojoba liquid wax was found to be just as effective at treating diaper rash as triamcinolone acetonide, nystatin, neomycin, and gramicidin. Jojoba oil is also an anti-inflammatory. Due to the absence of systemic adverse effects, jojoba had the benefit of being safer [
138]. Additionally, it has anti-acne and anti-psoriasis qualities, which allow the dissolution of sebum deposits through the hair follicles due to its capacity to infiltrate the follicles, eliminate the comedones, and clear the skin [
139].
In a research, ten women used argan oil as a bandage on their skin for 28 days. None of the women experienced itching or noticed any skin irritation or redness, demonstrating the oil's efficacy in reducing the amount of pigmentation. These women did observe a minor decrease in melanin content in the vicinity of the bandage, though, which lends credence to the idea that the oil lessens pigmentation. [
140,
141,
142]. Licorice root extract, turmeric extract, and green tea extract are other herbal extracts high in antioxidants that help to reduce inflammation and brighten the skin.
Since ancient times, licorice root extract has been utilized for its medical benefits, particularly for skin care. It has glycyrrhizin, which has been shown to have antioxidant and anti-inflammatory properties. [
143]. Given that it is thought to help enhance skin look and treat some skin disorders, these qualities make it a popular ingredient in skin care products [
144]. Several research have been done to determine whether licorice root extract is effective for treating skin conditions. According to a study, licorice root extract is useful for reducing hyperpigmentation and lightening the skin [
145]. Atopic dermatitis symptoms may be lessened by licorice root extract, according to a different study [
146]. James M. Spencer also demonstrated in his research that licorice root extract was efficient in lessening the severity of rosacea, melasma, and acne [
147]. Additionally, licorice root extract reduced the appearance of black spots and redness, as was discovered in a 2019 study by Maria Yusuf Dhariwala. [
148]
Since ancient times, turmeric extract has been valued for its therapeutic benefits. It has a yellow tint and various health advantages due to the presence of the active component curcumin. when it comes to pigmentation and skin conditions. Strong anti-inflammatory qualities found in curcumin can help lessen skin inflammation brought on by a variety of skin conditions, including psoriasis and eczema [
149,
150,
151,
152]. Antioxidants included in turmeric extract reduce oxidative damage that can cause skin aging and pigmentation disorders like melasma by neutralizing free radicals [
153]. Curcumin also has skin-lightening qualities. By preventing the formation of the melanin-producing enzyme tyrosinase, it can lessen hyperpigmentation and make the skin lighter. [
154] Curcuminoids, which are found in turmeric, have exfoliating qualities that aid to gently remove dead skin cells and encourage skin regeneration, minimizing the appearance of hyperpigmentation and dark patches [
155]. Using turmeric extract to treat skin issues was the subject of a 2018 study by Alexandra R. Vaughn. In psoriasis, eczema, and acne patients, the study found that turmeric extract was beneficial in lowering skin inflammation and enhancing skin health [
156]. A topical cream with turmeric extract proved successful in lowering the severity of acne in patients after four weeks of treatment, according to a 2018 study by Penelope J. Kallis.[
157]
Another organic component that has been investigated for its therapeutic advantages for the skin is green tea extract. It has a lot of polyphenols and antioxidants, as well as anti-inflammatory and skin-protective qualities [
158,
159,
160]. Green tea extract works in a variety of ways to treat pigmentation issues and skin problems. Catechins and epigallocatechin gallate (EGCG), two antioxidants found in green tea, work to combat free radicals that can damage skin and speed up the aging process [
161]. Green tea extract also has strong anti-inflammatory qualities that can help lessen skin irritation brought on by a variety of skin diseases such acne, eczema, and rosacea [
162]. EGCG in green tea extract can help inhibit tyrosinase activity, reducing the production of melanin and thus lightening the skin [
163]. Furthermore, green tea extract has been shown to offer some protection against UV radiation, which can cause skin damage and contribute to pigmentation disorders [
164]. A clinical study has been conducted for 11 patients on the use of green tea extract for treating acne; this study found that green tea extract was effective in reducing the number of acne lesions and improving overall skin health [
165]. Another published in 2017 found that green tea extract effectively reduced the appearance of fine lines and wrinkles in the skin [
166].
Kojic acid (Enshine® cream 2%, compound 20 in
Figure 9) has been found to be effective in treating various skin disorders and pigmentation issues due to its mechanism of action. It works by inhibiting the activity of tyrosine, which reduces the production of melanin, which can help to fade dark spots and hyperpigmentation [
167,
168,
169]. In addition to its tyrosinase-inhibiting properties, kojic acid has antioxidant and anti-inflammatory properties; these can be particularly beneficial for individuals with acne, rosacea, and other inflammatory skin conditions [
170,
171,
172,
173]. One study published in 2016 by Peter J. Gust evaluated the efficacy of a cream containing 2% kojic acid, 10% glycolic acid, and 2% hydroquinone for treating melasma. The study involved 40 participants who applied the cream twice daily for 12 weeks. The results showed a significant reduction in the severity of melasma in the treated group compared to the control group, with no reported adverse effects [
174]. In another study, Tamara Searle investigated using a cream containing 2% kojic acid, 1% arbutin, and 5% vitamin C to treat age spots. The study involved 60 participants who applied the cream twice daily for 12 weeks. The results showed a significant reduction in the number and severity of age spots in the treated group compared to the control group, with no reported adverse effects [
175]. Several herbs and naturally occurring substances commonly used in skincare products for their ability to lighten skin and reduce hyperpigmentation are listed in
Table 2.
Phlorotannins (compound 21 in
Figure 9) from the brown algae (brown seaweed) play a crucial role in the reduction of hyperpigmented effects and the prevention of premature skin aging. They protect the skin from the sun's infrared and blue rays.
Moreover, it encourages the production of cellular energy, increasing the skin’s oxygenation. This process enhances cell innovation and decreases pigmentation and the skin’s general look. Their antioxidant activity stops the deterioration of the collagen that firms the skin [
176,
177,
178]. Clinical trials and meta-analyses have investigated the effects of phlorotannins on skin disorders and pigmentation. A randomized, double-blind, placebo-controlled study published in 2022 found that a phlorotannin-rich Ecklonia cava (Phaeophyceae) extract improved skin hydration, elasticity, and wrinkle formation in women with dry skin. Another randomized, double-blind, placebo-controlled study found that a phlorotannin-rich extract of Ascophyllum nodosum reduced facial pigmentation and improved skin elasticity in women with age spots. [
179,
180]
Marine-derived chemicals from
Undaria pinnatifida, Octopus vulgaris, and
Sargassum polycystum, have all been investigated for their ability to enhance skin pigmentation and have antioxidant, anti-inflammatory, and immunomodulatory properties. These compounds include octaphlorethol A, fucoidan, and fucoxanthin (compounds 22-24 in
Figure 9) [
181,
182,
183,
184,
185,
186]. Several studies have investigated the effects of octaphlorethol A on skin disorders and pigmentation. A study found that octaphlorethol A inhibited melanin production and reduced skin pigmentation in human melanoma cells. Another study found that octaphlorethol A reduced inflammation and improved skin barrier function in mice with atopic dermatitis. [
187,
188]. In addition, a randomized, double-blind, placebo-controlled study found that a cream containing fucoidan and marine collagen improved skin hydration, elasticity, and wrinkle formation in women with dry skin [
189]. In addition, a randomized, double-blind, placebo-controlled study found that a cream containing fucoidan and marine collagen improved skin hydration, elasticity, and wrinkle formation in women with dry skin [
190]. A survey of 11 randomized controlled trials found that the carotenoid pigment, fucoxanthin, supplementation was associated with a significant reduction in the severity of melasma. However, the authors noted that the quality of the inclusive studies was generally low, and more research is needed to confirm these findings [
191,
192,
193].
6. Conclusion
Skin pigmentation refers to the color of an individual's skin, which is determined by the amount of melanin in the skin produced by melanocytes. Eumelanin and pheomelanin are the two primary forms of melanin. Dark skin tones are caused by eumelanin, which protects against skin cancer and sun damage. While pheomelanin produces lighter skin tones, which can control body temperature and offers protection from skin cancer. Some causes of skin pigmentation include genetics, sun exposure, hormonal changes, skin trauma, and certain medications. In addition, some skin pigmentation disorders, such as melasma, albinism, and vitiligo, which caused by genetic mutations.
There are two primary types of skin pigmentation; hyperpigmentation occurs when there is an overproduction of melanin, leading to areas of darker skin. This can be caused by sun exposure, hormonal changes, and certain medications. Or hypopigmentation occurs when there is a loss of melanin, leading to lighter skin areas. This can be caused by genetic conditions, skin trauma, and certain medications.
Clinical trials and meta-analysis show that oral medication by tranexamic acid and isotretinoin tablets could treat various skin illnesses, including eczema, melasma, and other related conditions. In addition, clinical trials indicate that the topical forms of betamethasone, clobetasol, silver sulfadiazine, triamcinolone, dimethicone, fluocinolone, hydroquinone, clotrimazole, ruxolitinib, salicylic acid, and tretinoin are effective in treating skin disorders. Furthermore, Natural extracts like rosehip, jojoba, argan oil, Aloe vera, Licorice root, curcumin, green tea, Kojic acid, phlorotannin,s and vitamins A, B, C, and E have potent anti-inflammatory properties that can help reduce inflammation in the skin caused by various skin conditions such as acne, eczema, and rosacea, which can be classified as a treatment for hyperpigmentation along with octaphlorethol A, fucoidan, and fucoxanthin marine extracts.