Depigmenting and bleaching agents: coping with hyperpigmentation

Q-switched frequency-doubled Nd:YAG (532 nm) laser versus trichloroacetic acid 35% peeling in the treatment of dorsal hand solar lentigo: An assessor-blind split-hand randomized controlled trial

BACKGROUND

Solar lentigo (SL) is a benign hyperpigmented spot occurring due to ultraviolet exposure, most commonly in the elderly. We aimed to compare the safety and efficacy of trichloroacetic acid (TCA) peeling with Q-switched laser in the treatment of SLs.

METHODS

This assessor-blind split-hand randomized controlled trial included 45 patients with symmetric SLs on the back of their hands referred to the dermatology clinics from March 1 to June 24, 2021. TCA 35% was applied to the back of one hand, and the contralateral hand received Q-switched laser. The interventions were repeated for a total of three sessions 4 weeks apart. Eight weeks after the last treatment session, lesion lightening was graded from 1 to 4. Patient satisfaction with treatment was assessed using a visual analogue scale (VAS). Adverse events were also noted.

RESULTS

Of the 45 patients included in the current study with a mean age of 52.71 ± 9.73 years, 11 (24.4%) were male. The Fitzpatrick skin type was II in 11 patients (24.4%), III in 23 (51.1%), and IV in 11 (24.4%). Lesion lightening and patient satisfaction were both significantly better with Q-switched laser compared to TCA peeling (standardized mean difference [SMD] = -1.25, 95% confidence interval [CI] -1.69; -0.79, p < 0.001 and SMD = -1.12, 95% CI -1.56; -0.67, p < 0.001, respectively). Overall, post-inflammatory hyperpigmentation (PIH) occurred in one patient in the laser group and for in the TCA group. Also, erythema and pruritus were observed in all patients of both groups after intervention which were treated with topical repair cream.

CONCLUSIONS

Q-switched laser was superior to TCA peeling for the treatment of SLs in terms of lesion lightening and patient satisfaction with a large effect.

Laccase Mediator Cocktail System as a Sustainable Skin Whitening Agent for Deep Eumelanin Decolorization

The overproduction of eumelanin leads to a panel of unaesthetic hyper-pigmented skin diseases, including melasma and age spots. The treatment of these diseases often requires the use of tyrosinase inhibitors, which act as skin whitening agents by inhibiting the synthesis of eumelanin, with harmful side effects. We report here that laccase from Trametes versicolor in association with a cocktail of natural phenol redox mediators efficiently degraded eumelanin from Sepia officinalis, offering an alternative procedure to traditional whitening agents. Redox mediators showed a synergistic effect with respect to their single-mediator counterpart, highlighting the beneficial role of the cocktail system. The pro-oxidant DHICA sub-units of eumelanin were degraded better than the DHI counterpart, as monitored by the formation of pyrrole-2,3,5-tricarboxylic acid (PTCA) and pyrrole-2,3-dicarboxylic acid (PDCA) degradation products. The most effective laccase-mediated cocktail system was successively applied in a two-component prototype of a topical whitening cream, showing high degradative efficacy against eumelanin.

Additive Effect of a Combination of Artocarpus lakoocha and Glycyrrhiza glabra Extracts on Tyrosinase Inhibition in Melanoma B16 Cells

Artocarpus lakoocha (Al) and Glycyrrhiza glabra (Gg) extracts have been reported to show tyrosinase inhibitory activity and melanin pigment reduction. This is the first study to assess the combination of Al and Gg extracts in enhancing inhibition of tyrosinase and reduction of melanin pigments. Al and Gg extracted by maceration in 70% and 95% ethanol were analyzed for oxyresveratrol and glabridin using Ultra High Performance Liquid Chromatography. Extracts of Al and Gg singly and combinations of Al95 and Gg95 were tested for cytotoxicity, tyrosinase inhibitory activity, and reduction of melanin pigments in melanoma B16 cells. Al95 had higher antioxidant, tyrosinase inhibitory activity and reduced more melanin pigments in B16 cells compared to Al70, and exhibited higher levels of oxyresveratrol. Gg95 inhibited oxidative stress and mushroom tyrosinase better than Gg70, and exhibited higher levels of glabridin. Combinations of Al95 and Gg95 at various ratios (concentration of 0.1 mg/mL) were not cytotoxic to B16 cells. Interestingly, Al95 and Gg95 combined at a ratio 9:1 reduced melanin pigment up to 53% in B16 cells. This combination of Al95 and Gg95 extracts exhibited the additive effect of reducing melanin pigments by suppressing the expression of microphthalmia-associated transcription factor (MITF), tyrosinase (TYR) and tyrosinase-related protein-2 (TRP-2) in B16 cells. The combination of Al and Gg extracts could be developed as skin care products for hyperpigmentation treatment.

In vitro Dermal Absorption of Hydroquinone: Protocol Validation and Applicability on Illegal Skin-Whitening Cosmetics

In Europe, hydroquinone is a forbidden cosmetic ingredient. It is, however, still abundantly used because of its effective skin-whitening properties. The question arises as to whether the quantities of hydroquinone used become systemically available and may cause damage to human health. Dermal absorption studies can provide this information. In the EU, dermal absorption has to be assessed in vitro since the Cosmetic Regulation 1223/2009/EC forbids the use of animals. To obtain human-relevant data, a Franz diffusion cell protocol was validated using human skin. The results obtained were comparable to those from a multicentre validation study. The protocol was applied to hydroquinone and the dermal absorption ranged between 31 and 44%, which is within the range of published in vivo human values. This shows that a well-validated in vitro dermal absorption study using human skin provides relevant human data. The validated protocol was used to determine the dermal absorption of illegal skin-whitening cosmetics containing hydroquinone. All samples gave high dermal absorption values, rendering them all unsafe for human health. These results add to our knowledge of illegal cosmetics on the EU market, namely that they exhibit a negative toxicological profile and are likely to induce health problems.

Synthesis and Antimicrobial Activity of Nitrobenzyl-oxy-phenol Derivatives

Two hydroquinone derivatives were prepared and their antimicrobial activity evaluated. Their minimum inhibitory concentrations (MICs) were determined using a broth dilution method. Gentamycin and ciprofloxacin were used as reference antibiotics. The antimicrobial activity of 4-(benzyloxy)phenol (monobenzone) was also evaluated based on its structural similarity to the new compounds; activity was comparable to that of 3,5-dimethyl-4-((4-nitrobenzyl)oxy)phenol (4a). 2,3,5-Trimethyl-4-((4-nitrobenzyl)oxy)phenol (4b) exhibited the best antibacterial activity against both clinical isolates and type strain of Moraxella catarrhalis (M. catarrhalis), with a MIC value of 11 µM, comparable to ciprofloxacin 9 µM.

Foreign Body Granulomas

A large list of foreign substances may penetrate the skin and induce a foreign body granulomatous reaction. These particles can enter the skin by voluntary reasons or be caused by accidental inclusion of external substances secondary to cutaneous trauma. In these cases, foreign body granulomas are formed around such disparate substances as starch, cactus bristles, wood splinters, suture material, pencil lead, artificial hair, or insect mouthparts. The purpose of this article is to update dermatologists, pathologists, and other physicians on the most recent etiopathogenesis, clinical presentations, systemic associations, evaluation, and evidence-based management concerning foreign body granulomatous reactions of skin.

Discovery of Potent Cysteine-Containing Dipeptide Inhibitors against Tyrosinase: A Comprehensive Investigation of 20 × 20 Dipeptides in Inhibiting Dopachrome Formation

Tyrosinase is an essential copper-containing enzyme required for melanin synthesis. The overproduction and abnormal accumulation of melanin cause hyperpigmentation and neurodegenerative diseases. Thus, tyrosinase is promising for use in medicine and cosmetics. Our previous study identified a natural product, A5, resembling the structure of the dipeptide WY and apparently inhibiting tyrosinase. Here, we comprehensively estimated the inhibitory capability of 20 × 20 dipeptides against mushroom tyrosinase. We found that cysteine-containing dipeptides, directly blocking the active site of tyrosinase, are highly potent in inhibition; in particular, N-terminal cysteine-containing dipeptides markedly outperform the C-terminal-containing ones. The cysteine-containing dipeptides, CE, CS, CY, and CW, show comparative bioactivities, and tyrosine-containing dipeptides are substrate-like inhibitors. The dipeptide PD attenuates 16.5% melanin content without any significant cytotoxicity. This study reveals the functional role of cysteine residue positional preference and the selectivity of specific amino acids in cysteine-containing dipeptides against tyrosinase, aiding in developing skin-whitening products.

Critical review of Ayurvedic Varṇya herbs and their tyrosinase inhibition effect

INTRODUCTION

The aspiration for light skin (fair complexion) is becoming pronounced in a greater number of people in the present times with natural products being more in demand than their synthetic counterparts. Research in the area of skin-lightening agents is an expanding field with the knowledge being updated regularly. In Ayurveda, varṇya, raktaprasādana, tvacya are few terms specifying skin lightening with respect to its modern counterpart i.e., Tyrosinase inhibition, the most commonly reported method of skin lightening.

AIM

The present review is undertaken for screening twenty herbs from Varṇya Mahākaṣāya, Lodhrādi varṇya gaṇa, Elādi varṇa prasādana gaṇa and few varṇya formulations to evaluate their probable modes of action through which the skin lightening is effected as per both Ayurveda and biomedical concepts.

MATERIALS AND METHODS

Critical review of herbs to show varṇya property is compiled from various Ayurvedic texts as well as from multiple articles on the internet to justify their skin lightening property on the basis of data collected.

RESULT AND CONCLUSION

All the twenty herbs reviewed are found to act as varṇya directly (citation as varṇya) or indirectly (alleviation of pitta and rakta) as per Ayurveda and to interfere in melanogenesis pathway through tyrosinase inhibition as per biomedicine. This shows their potential to act as good skin whitening agents. Śuṇṭhi being a part of many varṇya formulations, is the only herb among all reviewed in the present study found to exhibit tyrosinase inhibition without any Ayurvedic citation of varṇya property.

Local treatment of chloasma in pregnant women

Goal. To assess the efficacy and safety of Azelic (15% gel of azelaic acid for topical administration) for the treatment of chloasma in pregnant women. Materials and methods. The study involved 28 pregnant women aged 18-36 (mean age: 24.7) with a normal course of pregnancy. The patients consulted a doctor in the spring, summer or fall complaining of focal skin hyperpigmentation on the face, chin and chest area. Ten patients (35.7%) developed hyperpigmentation prior to their pregnancy and 18 women (64.3%) - during the pregnancy. As of the consultation date, the pregnancy terms in all of the patients were 18-20 weeks. Chloasma was diagnosed by using dermatoscopy and skin examination with the Wood’s lamp. The patients were informed about the content and procedure of the study and gave their consent to take part in the study. Thin layers of Azelic (15% gel of azelaic acid for topical administration) were applied to the hyperpigmented skin of the patients and gently rubbed twice a day (in the morning and evening) as topical treatment for four months. The treatment results were assessed taking into consideration the patient’s subjective assessment, study group structure depending on the clinical efficacy, percentage of adverse events, and survey results based on the Dermatology Life Quality Index questionnaire. To reveal any potential general toxicological effects of the treatment, hepatic samples, total blood count and coagulogram results were analyzed as a part of obstetrical and gynecologic care for pregnant women. Key findings. Positive dynamics of the following characteristics was revealed: subjective assessment of treatment results by the patients, clinical efficacy of treatment and life quality index. Therapeutic results were observed as early as after one month but not later than three months after the treatment began. The therapeutic efficacy was recorded in 92.9-96.4% of all cases after four months of treatment: pigment spots disappeared or became paler, and their dimensions and their contrast as compared to the healthy skin reduced, the skin texture and life quality improved (the Dermatology Life Quality Index reduced from 15.5 ± 1.8 to 6.7 ± 0.5 points against the background of the treatment efficacy: from severe to moderate impact of the disease on the patient’s life, respectively). Five women (17.9%) developed erythema and burning sensations in the drug application site within the first two weeks immediately after the gel application (one of the patients had the same symptoms for six weeks of the treatment); the symptoms were weak and transient and did not require any additional treatment. Hepatic samples, total blood count and coagulogram results were within physiological standards during the treatment. Conclusion. Topical application of Azelic (15% gel of azelaic acid for topical administration) twice a day for four months is an efficient and safe method to treat chloasma in pregnant women.

Evidence-based treatment for melasma: expert opinion and a review

Introduction

Melasma is one of the most common pigmentary disorders seen by dermatologists and often occurs among women with darker complexion (Fitzpatrick skin type IV–VI). Even though melasma is a widely recognized cause of significant cosmetic disfigurement worldwide and in India, there is a lack of systematic and clinically usable treatment algorithms and guidelines for melasma management. The present article outlines the epidemiology of melasma, reviews the various treatment options along with their mode of action, underscores the diagnostic dilemmas and quantification of illness, and weighs the evidence of currently available therapies.

Methods

A panel of eminent dermatologists was created and their expert opinion was sought to address lacunae in information to arrive at a working algorithm for optimizing outcome in Indian patients. A thorough literature search from recognized medical databases preceded the panel discussions. The discussions and consensus from the panel discussions were drafted and refined as evidence-based treatment for melasma. The deployment of this algorithm is expected to act as a basis for guiding and refining therapy in the future.

Results

It is recommended that photoprotection and modified Kligman’s formula can be used as a first-line therapy for up to 12 weeks. In most patients, maintenance therapy will be necessary with non-hydroquinone (HQ) products or fixed triple combination intermittently, twice a week or less often. Concomitant camouflage should be offered to the patient at any stage during therapy. Monthly follow-ups are recommended to assess the compliance, tolerance, and efficacy of therapy.

Conclusion

The key therapy recommended is fluorinated steroid containing 2–4% HQ-based triple combination for first line, with additional selective peels if required in second line. Lasers are a last resort.

Electronic supplementary material

The online version of this article (doi:10.1007/s13555-014-0064-z) contains supplementary material, which is available to authorized users.

Uniaxially aligned electrospun cellulose acetate nanofibers for thin layer chromatographic screening of hydroquinone and retinoic acid adulterated in cosmetics

Uniaxially aligned cellulose acetate (CA) nanofibers were successfully fabricated by electrospinning and applied to use as stationary phase for thin layer chromatography. The control of alignment was achieved by using a drum collector rotating at a high speed of 6000 rpm. Spin time of 6h was used to produce the fiber thickness of about 10 μm which was adequate for good separation. Without any chemical modification after the electrospinning process, CA nanofibers could be readily devised for screening hydroquinone (HQ) and retinoic acid (RA) adulterated in cosmetics using the mobile phase consisting of 65:35:2.5 methanol/water/acetic acid. It was found that the separation run on the aligned nanofibers over a distance of 5 cm took less than 15 min which was two to three times faster than that on the non-aligned ones. On the aligned nanofibers, the masses of HQ and RA which could be visualized were 10 and 25 ng, respectively, which were two times lower than those on the non-aligned CA fibers and five times lower than those on conventional silica plates due to the appearance of darker and sharper of spots on the aligned nanofibers. Furthermore, the proposed method efficiently resolved HQ from RA and ingredients commonly found in cosmetic creams. Due to the satisfactory analytical performance, facile and inexpensive production process, uniaxially aligned electrospun CA nanofibers are promising alternative media for planar chromatography.

Cutaneous deposits

: The cutaneous deposition disorders are a group of unrelated conditions characterized by the accumulation of either endogenous or exogenous substances within the skin. These cutaneous deposits are substances that are not normal constituents of the skin and are laid down usually in the dermis, but also in the subcutis, in a variety of different circumstances. There are 5 broad categories of cutaneous deposits. The first group includes calcium salts, bone, and cartilage. The second category includes the hyaline deposits that may be seen in the dermis in several metabolic disorders, such as amyloidosis, gout, porphyria, and lipoid proteinosis. The third category includes various pigments, heavy metals, and complex drug pigments. The fourth category, cutaneous implants, includes substances that are inserted into the skin for cosmetic purposes. The fifth category includes miscellaneous substances, such as oxalate crystals and fiberglass. In this article, the authors review the clinicopathologic characteristics of cutaneous deposition diseases, classify the different types of cutaneous deposits, and identify all the histopathologic features that may assist in diagnosing the origin of a cutaneous deposit.

Effect of combination of 1064 nm Q-switched Nd:YAG and fractional carbon dioxide lasers for treating exogenous ochronosis

We describe three cases of exogenous ochronosis of the malar areas due to long-term application of skin-lightening agents for melasma, effectively treated by combination of Q-switched Nd:YAG and the fractional carbon dioxide lasers. None of these lasers has been reported to be used to effectively treat ochronosis before. The Q-switched Nd:YAG laser is capable of disintegrating dermal ochronotic fibers, thereby facilitating their phagocytosis and elimination via lymphatics. The fractional carbon dioxide laser is believed to assist transepidermal elimination of the onchronotic material. We believe successful treatment of ochronosis is possible when both mechanisms are applied.

Aplicação da dermatoscopia no auxílio diagnóstico da ocronose exógena

A ocronose exógena consiste em hiperpigmentação crônica de áreas previamente tratadas com agentes tópicos como: a hidroquinona, a resorcina, os antimaláricos e o fenol. O diagnóstico precoce permite suspender prontamente o agente causador, uma vez que as opções terapêuticas disponíveis são escassas e com resultados insatisfatórios. Reportam-se três casos de ocronose exógena na face, diagnosticados pela dermatoscopia. O estudo dermatoscópico evidenciou estruturas amorfas de coloração cinza-enegrecido, algumas obliterando as aberturas foliculares. O exame histopatológico corroborou o diagnóstico

Highly sensitive spectrometric method for determination of hydroquinone in skin lightening creams: application in cosmetics

A highly sensitive, simpler, faster and economical UV/visible spectrophotometric method has been established for the estimation of hydroquinone (HQ) in dilute organic matrices. The method is based on using ammonium meta-vanadate as an oxidizing catalyst for conversion of HQ to p-benzoquinone (BQ) in the presence of oxygen. As a result of higher absorption of UV light by BQ than by HQ, its signal has been utilized for determining HQ at the trace level. The effect of various parameters such as amount of oxidizing agent, stability time, temperature, acids and bases, solvents and interference by various compounds has been studied upon the absorption of BQ as HQ. Under optimized conditions, Beer's Law was obeyed in the range of 0.025-2.00 μg ml(-1) HQ at 245.5 nm using 1 : 1 (V/V) 2-propanol/water system with a lower detection limit of 7 ng ml(-1) and linear regression coefficient of 0.9998. Relative standard deviation of 1.5% was observed for 0.5 μg ml(-1) HQ solution (n = 11). The newly developed method has been successfully applied to diluted samples of various skin lightening creams for free HQ determination at the trace level. Comparison of the results obtained by the proposed method with those by a previously reported method proved its validity.

Hyperpigmentation and melasma

Facial and neck pigmentations are significant cosmetic problems. They are common in middle-aged women, related to endogenous (hormones) and exogenous factors (cosmetics, perfumes, sun exposure), and often represent paramount causes of emotional distress. Although melasma is the most common cause of facial pigmentation, there are many other forms including drug-induced and postinflammatory hyperpigmentation. We review pathogenesis, clinical and histopathological data, effect on quality of life, and treatment options in facial hyperpigmentation disorders.

Physiological and biological skin changes in pregnancy

Pregnancy affects all organ systems in the body, including the skin. Some skin changes are physiological, whereas others such as the dermatoses of pregnancy are pathological. Dermatologists regularly encounter pregnant patients, and the identification of normal skin changes and their differentiation from disease states are essential to insure the well-being of both mother and fetus. This review discusses the physiological skin changes in pregnancy, including alterations in pigmentation, hair, nail, and connective tissue, as well as vascular and hematologic changes and modulation of glandular function.

Melanin pigmentary disorders: treatment update

Most of the melanin pigmentary disorders are cosmetically important and have a strong impact on the quality of life of affected individuals. This article examines recent advances in the treatment of melanin pigmentary disorder including hypermelanosis and hypomelanosis. The development of laser technologies has completed the use of the increasing number of bleaching agents in treating hyperpigmented lesions. The treatment of hypomelanotic disorders is still often disappointing, but new therapeutic options provide encouraging results.

Optimal management of recalcitrant disorders of hyperpigmentation in dark-skinned patients

Alterations in skin pigmentation may often have a dramatic expression in individuals with a dark skin complexion and can be a source of significant emotional distress in these individuals. Hyperpigmented disorders such as melanosis (melasma), post-inflammatory hyperpigmentation, drug-induced hyperpigmentation, and erythema dyschromicum perstans tend to have a prolonged course and, in many cases, are refractory to treatment, further contributing to the psychological impairment of the affected patients. Melanosis, is a common form of facial pigmentation attributable to sunlight and hormonal factors. A range of treatment modalities, such as depigmenting agents, topical retinoids, and chemical peels in conjunction with rigorous sun protection, can improve the melanosis but the condition usually recurs. Combination regimens, including frequent applications of superficial- and medium-depth chemical peels, appear to be particularly effective and well tolerated in dark-skinned patients with melanosis. Post-inflammatory hyperpigmentation is the result of excess pigment deposition following an inflammatory skin disorder. Topical tretinoin, hydroquinone, azelaic acid, kojic acid, and glycolic acid peels have been employed with variable degrees of success. Drug-induced pigmentation is a frequent cause of acquired hypermelanosis, its clinical expression depending on the triggering molecule and the underlying pathogenetic mechanism. Identifying and discontinuing the offending agent is the main approach in this condition, although, recent reports have demonstrated the efficacy of Q-switched lasers in accelerating the pigment removal. Erythema dischromicum perstans is a characteristic dermal pigmentation occurring mainly in dark-skinned individuals. Immunomodulating agents, such as clofazimine and dapsone have been shown to lighten this disorder, although, the exact mode of action is not clear.

Pigmentary disorders in ethnic skin

Pigmentary disorders are commonly seen in ethnic skin. They are psychologically problematic in darker skin. Treatment of many of these disorders remains difficult.