Current Evidence is Inadequate in Proving the Benefits of Herbal Remedies on Melasma

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A novel scoping review analyzed the efficacy and safety benefits when using herbal remedies to treat melasma.¹ Although the initial evidence is inadequate, it’s a solid first step in recognizing the potential effects of herbal therapies for patients with melasma

Articles were obtained from PubMed, Scopus, Web of Science, Google Scholar, Cochrane, SID, and Magiran databases and included any piece published up to August 2024. Researchers extracted data related to the type of clinical trial, the kind of plant used, its application method, participant characteristics, results and outcomes, and any adverse effects. Two authors summarized the articles, charted the data, and synthesized the results. In total, 19 literatures were used.

The review explored over 15 types of plant remedies. However, rhubarb, chickpea and melon seed, parsley, sorrel, licorice, lentil, almond, and fig, tomatoes, and pine bark, had more statistically significant results.

Rhubarb has been proven to have several anti-inflammatory, anti-scarring, and antioxidant effects, which can have a positive impact on sunlight-induced melasma. One study found that patients who took a liquid form of rhubarb twice a day had a 79.31% satisfaction rate versus the placebo at 24.14%.

Another study analyzed chickpea, a skin-lightening plant with anti-tyrosinase and antioxidant activities, when combined with melon seed. Although research on the plant’s ability to reduce pigmentation remains limited, the patients saw significant improvement in melasma-induced spots after 12 weeks with no serious adverse effects.

Several studies confirmed the anti-pigmentation effect of parsley. In fact, 1 study demonstrated that it had a treatment effect that was equal to hydroquinone 4%. Similar results of a decreased Melasma Area Severity Index (MASI) score were observed in 3% sorrel cream, specifically after 8 weeks of treatment when compared to hydroquinone, due to its inhibition of tyrosinase.

Licorice was one of the most extensively studied plants. Its lightening and antioxidant effects have been confirmed by numerous studies, with 2 noting that its effectiveness was higher than a placebo. Due to the flavonoid compound of glabridin, licorice can reduce melanocyte activity and melanin production, thus reducing pigmentation. Another study showed that using a topical combination of licorice and 5% ascorbic acid significantly increased recovery rates.

Tomatoes also showed some promising results, specifically when used as a combination treatment. Patients who took tomato supplements (lycopene extract) along with their standard melasma treatment of hydroquinone 4% saw a greater disease improvement. Another study found that using it with 3.45% topical rice-bran improved melasma-induced blur and reduced MASI score.

When used as an oral supplement along with standard topical drug treatment, pycnogenol, extracted from pine bark, improved patients’ quality of life and positively impacted melasma severity. This could be due to the plant extract’s proven antioxidant properties. A mixture of lentil, bitter almond, and fig, known as Tila-e-Kalf, had the same effect as 4% hydroquinone, according to 1 study.

Only 7 patients had mild adverse reactions to some of the medications, including parsley, licorice, and rhubarb. In the Tila-e-Kalf study, 1 patient experienced mild itching, which was less than what was reported in the corresponding hydroquinone group.

In summary, plants with tyrosinase inhibitors, retinoids, and anti-inflammatory compounds, can potentially reduce pigmentation in patients with melasma. However, limitations such as the low number of studies and lack of risk assessment bias may have impacted results.

The current first line of melasma treatment is a topical combination cream that includes 4% hydroquinone, 0.05% tretinoin, and 0.01% fluocinolone acetonide ointment.² Due to the potential side effects of these chemical drugs, herbal therapies have been a supplemental option for some patients around the world.

“Even though there are various therapies available for melasma, none of them guarantee a satisfactory result, and the management of this condition remains a challenge,” the authors wrote.

Nonetheless, this review is the first of its kind in examining published literature on the effectiveness of these natural products for melasma. Although a good start, more research is necessary to fully assess the efficacy and safety of herbal remedies. The investigators recommend larger studies that confirm each plant’s mechanisms of action using various doses, shapes, formulations, and concentrations of each plant.

References

1. Parvizi MM, Hekmat M, Yousefi N, Javaheri R, Mehrzadeh A, Saki N. Clinical Trials Conducted on Herbal Remedies for the Treatment of Melasma: A Scoping Review. J Cosmet Dermatol. Published online December 22, 2024. doi:10.1111/jocd.16741

2. Sehgal VN, Verma P, Srivastava G, Aggarwal AK, Verma S. Melasma: treatment strategy. J Cosmet Laser Ther. 2011;13(6):265-279. doi:10.3109/14764172.2011.630088