Melasma and thyroid disorders: a systematic review and meta-analysis

Components analysis of San-Bai decoction, and its pharmacodynamics and mechanism on preventing and treating melasma

ETHNOPHARMACOLOGICAL RELEVANCE

San-Bai Decoction (SBD) is a classic whitening prescription originally recorded in the 'Introduction to Medicine' of the Ming Dynasty. SBD has been known for invigorating Qi and blood, promoting spleen and stomach, whitening skin, and fading melasma. However, its pharmacodynamic material basis and specific mechanism remain unclear.

AIM OF THE STUDY

The aim of this study is to clarify the pharmacodynamic material basis of SBD and its mechanism of removing melasma.

MATERIALS AND METHODS

The positive and negative ion mass spectrum data of SBD extract were collected by UHPLC-Q-Exactive Orbitrap MS/MS, imported into Compound Discoverer (CD) 3.1 software, matched through the online database, and manually checked. Finally, the in vitro chemical components of SBD were classified. Similarly, the mass spectrum data of SBD in the serum of normal rats and melasma model rats were also analyzed by CD 3.1 software. The in vitro identified Compound file of SBD was imported into the Expected Compounds and the Generate Expected Compounds project was selected. The SBD compounds were then chosen under the Compound Section. All phase I and II reaction types related to SBD components were selected, and the metabolic platform of CD 3.1 software was utilized to process the results and obtain possible metabolites. The metabolites were scored and products with high scores were subsequently screened. According to literature comparison, the final metabolites of SBD in both normal rats and melasma model rats were determined and comprehensively analyzed. The Melasma model rats were constructed through intramuscular injection of progesterone and ultraviolet radiation B (UVB) irradiation. The preventing and treating effect of SBD on melasma were evaluated by regulating inflammation, epidermal collagen content, and oxidative stress. Additionally, the effect of SBD on the Phosphatidylinositol 3-kinase (PI3K)/Protein kinase B (Akt)/Glycogen synthase kinase 3β (GSK3β) pathway was investigated through Western blot (WB) to explore its underlying mechanism on whitening and removing melasma efficacy.

RESULTS

Ultimately, 94 components were identified in SBD, including 41 flavonoids, 27 organic acids, and 9 glycosides, 3 terpenoids, 2 amides, 2 aldehydes, 1 phenylpropanoid and 9 other compounds. In the blood of normal rat group, a total of 24 prototype components and 61 metabolites were identified. Similarly, there were19 prototype components and 44 metabolites identified from the blood of melasma model rats. Pharmacodynamic experiment results indicated that SBD effectively reduced the incidence of melasma, prevent the loss of epidermal collagen, and elevate the activity of superoxide dismutase and decrease the malondialdehyde content in both liver and skin. Interestingly, the WB results demonstrated that SBD effectively activated PI3K/Akt/GSK3β pathway, and down-regulated the expression of melanin-related proteins.

CONCLUSIONS

For the first time, the components of SBD extracts, and its prototype components and metabolites in the blood of normal rats and melasma model rats were successfully identified by high-resolution liquid chromatography-mass spectrometry with CD software. Additionally, the differences of in vivo components of SBD between normal rats and melasma model rats were analyzed. The preventive and therapeutic effect of SBD on melasma was verified in the melasma model rats induced by progesterone and UVB irradiation, and its mechanism was related to activating PI3K/Akt/GSK3β pathway and downregulating the expression of melanin-related proteins. These results provide an experimental foundation for further research on the pharmacodynamic substance basis and pharmacodynamic mechanism of SBD, as well as developing new anti-melasma formula with SBD.

Optimizing diagnostic and therapeutic measures for different types of melasma based on the biophysical characteristics of facial skin

The goal was to determine ways to optimize diagnostic and therapeutic measures for various types of melasma in the outpatient setting of the dermatovenerological ambulatory clinic. The study involved 112 women with a confirmed diagnosis of facial melasma whose disease lasted for at least 2 years. The severity of patient pigmentation was evaluated using the Melasma Area Severity Index and the Melasma Severity Scale. There was a significant increase in melanin levels across all melasma types, an increase in erythema in the dermal type, and an increase in sebum production in the epidermal type.

Clinico-epidemiological profile and long term follow up in melasma

Melasma is a disorder of hyperpigmentation that is frustratingly resistant to therapy with a high recurrence rate on treatment discontinuation. With the scarcity of melasma epidemiological studies from India, we conducted this study to see clinico-epidemiological trends and therapeutic response. Totally 957 melasma patients were studied during the 5-year period between October 2014 and September 2019. A female preponderance was seen. Patients were classified as early, moderate, and late responders if they had more than 80% clinical improvement within 8, 8-12, and 12-16 weeks rest classified as nonresponders. Six hundred and forty-eight patients with mMASI of ≤5 had been prescribed non-hydroquinone-based therapies who had overall response rate of 40.9% by end of 16 weeks, 309 with mMASI >5 received hydroquinone based triple combination with a response rate of 33.6% at end of 16 weeks. A total of 33.65% responded to triple combination compared to 40.1% in the non-hydroquinone group. All nonresponders received oral tranexamic acid 250 mg twice daily. Most patients on oral tranexamic acid group developed recurrence by 6 weeks post discontinuation, compared with triple combination therapy group who had relapsed by 2 months post discontinuation and 4 months to relapse with non-hydroquinone-based therapies. Side effects experienced were 0.83% in hydroquinone group reporting erythema and burning. 0.57% in non-hydroquinone group perceived stinging sensation and none from tranexamic acid group. The longest follow up available in our study was for 18 months. The emergent need of the hour is a long, safe, and effective therapy for melasma.

Evaluation of Modified Melasma Area and Severity Index in Hyperthyroid Patients Receiving Anti-thyroid Drugs

BACKGROUND: Melasma is a common hyperpigmentation disorder, which causes brownish discoloration of the face. Despite unclear mechanisms, thyroid hormones were thought to play a role in melasma. AIM: This study aims to determine and compare the clinical improvement of melasma in hyperthyroid patients receiving anti-thyroid drugs. METHODS: An interventional study with a quasi-experimental design (pre-post-intervention study) was conducted at the Internal Medicine Outpatient Clinic and Dermatology and Venereology Outpatient Clinic, Cipto Mangunkusumo Hospital, Jakarta, Indonesia, from July 2019 to March 2020. A comparative analysis was done to compare the modified melasma area and severity index (mMASI) in hyperthyroid patients before and after 12 weeks of anti-thyroid drugs. All subjects did not receive any additional topical therapies for their melasma. The clinical features were evaluated objectively at baseline and 12th-week visit, by mMASI score on different areas of the face (forehead, left-right malar, and chin) and Wood’s lamp examination. RESULTS: All areas showed a decline in mMASI score components (e.g., involvement areas and darkness degree) after 12 weeks of treatment. However, only the malar area showed a significant decline (p < 0.05). Wood’s lamp examination at baseline revealed dermal type melasma on 17 subjects, mixed type on six subjects, and epidermal type on one subject. All types remained unchanged after 12 weeks of treatment. CONCLUSIONS: Our study demonstrated that mMASI score in malar area improved significantly, this might be because malar area included this study were comprised of epidermal, dermal, and mixed type. On the other hand, based on Wood’s lamp examination, all types of melasma remained unchanged after 12 weeks of treatment.

[Treatment of pigmentation disorders in association with systemic diseases]

Pigmentation disorders are a frequent skin problem and incorporate a broad spectrum of diseases, caused by an abnormal melanin pigmentation or also non-melanin pigmentation of the skin. Both hypermelanosis and hypomelanosis can be hereditary or acquired. This article summarizes the treatment approaches that are used in the majority of acquired pigmentation disorders of the skin. The following forms of hypermelanosis are addressed: lentiginosis, hyperpigmentation due to endocrine disorders or other systemic diseases, drug-induced hyperpigmentation. Acquired hypomelanoses include postinflammatory hypomelanosis, chemical depigmentation, idiopathic guttate hypomelanosis and punctate leucoderma. With reference to non-melanin pigmentation, the exogenous pigmentation due to chemicals, metals and drug exposure are discussed. The treatment is primarily based on finding the cause of the alterations to the pigment. The affected area, age and ethnic origin are also important factors. The spectrum of therapeutic options is broad: topical agents, chemical peeling, systemic agents, laser and light-based treatment. As some of these treatment procedures can have side effects, the availability of a protocol that contains information on the drug concentration, dose, parameters for laser treatment and the number of sessions is important. For every disorder the specific dermatological treatment is presented even when some pigmentation alterations that occur in association with systemic diseases, are cured by the treatment of the primary disease. Most diseases are exacerbated by exposure to UV light. Therefore, sun protection is recommended and a cosmetic coverage is indicated.