The combination of 2% 4-hydroxyanisole (mequinol) and 0.01% tretinoin effectively improves the appearance of solar lentigines in ethnic groups

Natural Compounds and Biopolymers-Based Hydrogels Join Forces to Promote Wound Healing

Rapid and complete wound healing is a clinical emergency, mainly in pathological conditions such as Type 2 Diabetes mellitus. Many therapeutic tools are not resolutive, and the research for a more efficient remedial remains a challenge. Wound dressings play an essential role in diabetic wound healing. In particular, biocompatible hydrogels represent the most attractive wound dressings due to their ability to retain moisture as well as ability to act as a barrier against bacteria. In the last years, different functionalized hydrogels have been proposed as wound dressing materials, showing encouraging outcomes with great benefits in the healing of the diabetic wounds. Specifically, because of their excellent biocompatibility and biodegradability, natural bioactive compounds, as well as biomacromolecules such as polysaccharides and protein, are usually employed in the biomedical field. In this review, readers can find the main discoveries regarding the employment of naturally occurring compounds and biopolymers as wound healing promoters with antibacterial activity. The emerging approaches and engineered devices for effective wound care in diabetic patients are reported and deeply investigated.

Blue Laser (450 nm) Treatment of Solar Lentigines

This study tested a blue light source for the treatment of solar lentigines. A total of 14 patients with solar lentigines were treated with radiation from a novel, high-power 450 nm blue laser that was created for this project. The group contained eight patients with solar lentigines on the face, two patients with the lesions on the dorsal of the hands, and four patients with the lesions on the trunk and forearms. The best results (complete recovery) have been achieved for the lesions on the face and dorsal of the hands. The treatment of lesions on the trunk and forearms was not fully satisfying due to the occurrence of slight scarring. This study shows that, in some cases, the use of a blue laser may be an alternative to the use of longer wavelength sources.

A Randomized Controlled Trial on the Effectiveness of Epidermal Growth Factor-Containing Ointment on the Treatment of Solar Lentigines as Adjuvant Therapy

Background and Objective: Little is known about the anti-pigmentation effects of whitening agents on solar lentigines. Epidermal growth factor (EGF) has been used as a booster for wound healing in the skin, and it has been suggested to have anti-pigmentation effects. This study aimed to evaluate the effect and safety of EGF-containing ointment for treating solar lentigines with a Q-switched (QS) 532 nm neodymium-doped yttrium aluminum garnet (Nd:YAG) laser (Bluecore company, Seoul, Republic of Korea). Materials and Methods: Subjects who underwent QS 532 nm Nd:YAG laser treatment of solar lentigines were randomly assigned to treatment with an EGF ointment or petrolatum. After the laser procedure, the subjects were administered the test ointment twice a day for 4 weeks. The physician's assessment of the degree of pigment clearance and patient's satisfaction were assessed after 4 and 8 weeks. Additionally, the melanin index (MI), erythema index (EI), transepidermal water loss (TEWL), and post-inflammatory hyperpigmentation (PIH) were evaluated. This trial was registered with ClinicalTrials.gov (NCT04704245). Results: The blinded physician's assessment using 5-grade percentage improvement scale and patient's satisfaction were significantly higher in the study group than in the control group at the 4th and 8th weeks. The MI was significantly higher in the control group than in the study group at the 4th and 8th weeks. The EI and TEWL did not differ significantly between the two groups at either time point. The incidence of PIH was higher in the control group (37.5%) than in the EGF group (7.14%) at the 8th week. Conclusions: The application of EGF-containing ointment on facial solar lentigines with a QS 532 nm Nd:YAG laser showed efficient and safe therapeutic effects, with less PIH. Thus, EGF-containing ointment could be suggested as the promising adjuvant treatment strategy with a QS laser for solar lentigines.

Efficacy of D-pigment dermocosmetic lightening product for solar lentigo lesions of the hand: A randomized controlled trial

Solar lentigo, benign lesions which mostly appear on chronically, sun-exposed surfaces, are associated with ageing. Patients are increasingly requesting a more uniform skin texture, especially for hands. Treatment options include dermoabrasion, intense pulsed light, cryotherapy, peelings, and laser therapy. Topical compounds can be employed, in alternative or associated with dermatologic procedures. The current study was designed to evaluate solar lentigo hyperpigmentation, skin architecture and clinician and patient assessments comparing a dermocosmetic lightening product (active) with a moisturizing product (control) according to clinical, digital and subjective analyses in 72 lesions over 12-month follow up period. Statistically significant differences were observed between the lesions treated with the active compared to the control in terms of papillary brightness (p = 0.03) and contrast (p = 0.03), and in the limitation of dermal-epidermal junction destructuring (p = 0.03) according to dermal-epidermal junction destructuring score at Reflectance Confocal Microscopy. Luminance (p = 0.04) and redness (p = 0.03) were improved at color analysis, and physician and patient evaluations favored the active in efficacy and patient satisfaction investigations. The dermocosmetic lightening product utilized in the current study proved to be more effective, according to clinical, digital and subjective analyses in reducing lesion hyperpigmentation, stabilizing the lesion skin architecture and increasing patient satisfaction compared to the control in a cohort of 36 subjects, over a 12-month period. Beside demonstrating the efficacy of this topical lightening product, we propose a “destructuring score”, which improves the robustness of solar lentigo’s evaluation, and can be used in future studies to standardize the quantitative comparisons of different treatment options.

Discovery of new depigmenting compounds and their efficacy to treat hyperpigmentation: Evidence from in vitro study

Human skin pigmentation is a result of constitutive and facultative pigmentation. Facultative pigmentation is frequently stimulated by UV radiation, pharmacologic drugs, and hormones whereby leads to the development of abnormal skin hyperpigmentation. To date, many state-of-art depigmenting compounds have been studied using in vitro model to treat hyperpigmentation problems for cosmetic dermatological applications; little attention has been made to compare the effectiveness of these depigmenting compounds and their mode of actions. In this present article, new and recent depigmenting compounds, their melanogenic pathway targets, and modes of action are reviewed. This article compares the effectiveness of these new depigmenting compounds to modulate several melanogenesis-regulatory enzymes and proteins such as tyrosinase (TYR), TYR-related protein-1 (TRP1), TYR-related protein-2 (TRP2), microphthalmia-associated transcription factor (MITF), extracellular signal-regulated kinase (ERK) and N-terminal kinases (JNK) and mitogen-activated protein kinase p38 (p38 MAPK). Other evidences from in vitro assays such as inhibition on melanosomal transfer, proteasomes, nitric oxide, and inflammation-induced melanogenesis are also highlighted. This article also reviews analytical techniques in different assays performed using in vitro model as well as their advantages and limitations. This article also provides an insight on recent finding and re-examination of some protocols as well as their effectiveness and reliability in the evaluation of depigmenting compounds. Evidence and support from related patents are also incorporated in this present article to give an overview on current patented technology, latest trends, and intellectual values of some depigmenting compounds and protocols, which are rarely highlighted in the literatures.

Natural options for management of melasma, a review

A blemish free, even-toned skin is universally associated with healthy skin. This reasoning makes people desire to have a flawless skin. Melanin is a naturally occurring pigment in humans. This pigment is responsible for skin, hair, and eye color, therefore determines our race and phenotypic appearance. On darker skin types, it is common that melanin production processes malfunctions. These malfunctions often lead to overproduction and secretion of melanin. As a result, unwanted pigmentary problems such melasma occur. Due to unknown etiology and its recurrence in nature, melasma is challenging to treat. The current available melasma treatment options often produce undesired side effects and suboptimum results. First-line topical treatments usually involve hydroquinone or topical steroids. Apart from the irritant reactions, this treatment mode is not suitable for all skin types. Skin care specialists are in search of an effective long-term cosmetics and cosmeceuticals to address hypermelanosis problems. Understanding of naturally occurring depigmenting agents provides an opportunity for more effective ways to manage melasma in all skin types. This review considers the benefits of naturally occurring ingredients which could help address skin pigmentation problems and broaden the choice for skin-lightening treatments.

Postinflammatory hyperpigmentation: A comprehensive overview: Treatment options and prevention

Postinflammatory hyperpigmentation (PIH) occurs after various dermatoses, exogenous stimuli, and dermatologic procedures. The clinical course of PIH is chronic and unpredictable, although the probability of resolution of epidermal hyperpigmentation is better than those of dermal hyperpigmentation. PIH can be prevented or alleviated. When it does occur, the underlying inflammatory conditions should be sought and treated as the first step to reduce the progression of inflammation and PIH (which is an inflammatory consequence). If the inflammatory conditions subsides or there is no evidence of inflammation at the time of diagnosis, the treatments of PIH should be considered as the next step. Understanding the available treatment options helps the physician choose the appropriate treatment for each patient. Having a reproducible model for PIH is essential for the development of treatment modalities. The second article in this 2-part continuing medical education series on PIH specifically addresses the evidence that supports medical and procedural treatments of PIH and other forms of acquired hyperpigmentation. It also describes a PIH model and provides an algorithm for clinical practice along with discussion about the prevention of PIH.

Evidence-based Review, Grade of Recommendation, and Suggested Treatment Recommendations for Melasma

Treatment of melasma is known to be less satisfactory, often incomplete, and relapse is frequent. Although many treatment options are available, they are either known to be unsafe on long-term use or their long-term safety profile is unknown. Patients often use various drugs, even topical steroid-based preparation without any medical supervision for long period of time, making the skin unsuitable for many of the drugs available. Thus, there has been gross disparity among the treating physician about what drugs and what regimen are best suitable for various categories of melasma patients and in different situations. With this background, numerous newer drugs, mostly combinations of some proprietary molecules or even unknown plant extracts, have flooded the market for the management of melasma. Information on efficacy or safety of these products are almost unknown. Studies on Asian people, especially Indian population, are far less commonly available. Therapeutic guideline for use on Indian patients with melasma is almost missing. Extrapolation of data from Caucasian people for use on Asian people may not be scientifically justifiable because Caucasian and Asian people are known to have inherent difference in their response as well as tolerance to the drugs used for melasma. With this background, we have extensively evaluated, following a strict, scientifically designed protocol, all the available studies on melasma management till May 2016 and prepared this document on level of evidence, grade of recommendation and suggested therapeutic guideline for melasma as per the method proposed by Oxford Centre of Evidence-Based Medicine. Various ethical, social, logical, regional, and economic issues in the context of Indian and similar populations were given due importance while preparing the suggested therapeutic recommendation.

Efficacy and Safety of Topical Pidobenzone 4% as Adjuvant Treatment for Solar Lentigines: Result of a Randomized, Controlled, Clinical Trial

BACKGROUND/OBJECTIVE

This study aims at the evaluation of the efficacy and safety of a combination therapy based on pidobenzone 4% and fractional CO2 laser or cryotherapy in the treatment of solar lentigines and the prevention of eventual posttreatment hyperchromia.

METHODS

Efficacy was clinically evaluated by grading the pigmentation level with the Skin Tone Color Scale (STCS), and by grading patients' impression through a Visual Analog Scale (VAS).

RESULTS

Our study shows that the associated treatment was safe and that it improves the therapeutic results on solar lentigines and prevents postiatrogenic hyperpigmentation compared with physical therapy alone.

CONCLUSION

The combination of cryotherapy and pidobenzone 4% has been found to be the most useful treatment.

[The specific features of the distribution of 4-metoxyhydroxybenzene in the organism of the warm-blooded animals suffering lethal intoxication]

This work was designed to study the distribution of 4-metoxyhydroxybenzene in the organism of the omnivorous warm-blooded animals (rats) after the intragastric administration of this poisonous compound at a dose three-fold greater than the LD50 value. The administered 4-metoxyhydroxybenzene was isolated from the organs and blood of the experimental animals by exposing the biological tissues to acetone with subsequent purification on a silica gel L 40/100 mcm using a hexane:dioxane:propanol-2 (20:5:1) as the mobile phase. The identification and quantitation of 4-metoxyhydroxybenzene were carried out with the use of TLC, GC-MS, and UF-spectrophotometry. It was shown that the administered 4-metoxyhydroxybenzene remained unmetabolized in the internal organs and blood of the poisoned experimental animals. The largest amounts of 4-metoxyhydroxybenzene were found in the stomach contents (2584,92±117,47), brain (59.49±6.05), contents of small intestines (28.21±3.77), and kidneys (26.13±1.64).

Tyrosol and its analogues inhibit alpha-melanocyte-stimulating hormone induced melanogenesis

Melanin is responsible for skin color and plays a major role in defending against harmful external factors such as ultraviolet (UV) irradiation. Tyrosinase is responsible for the critical steps of melanogenesis, including the rate-limiting step of tyrosine hydroxylation. The mechanisms of action of skin hypopigmenting agents are thought to be based on the ability of a given agent to inhibit the activity of tyrosinase and, hence, down regulate melanin synthesis. Tyrosol and its glycoside, salidroside, are active components of Rhodiola rosea, and in our preliminary study we found that Rhodiola rosea extract inhibited melanogenesis. In this study, we examined the effects of tyrosol and its analogues on melanin synthesis. We found that treatment of B16F0 cells to tyrosol (1), 4-hydroxyphenylacetic acid (5), 3-hydroxyphenylacetic acid (6), 2-hydroxyphenylacetic acid (7), or salidroside (11) resulted in a reduction in melanin content and inhibition of tyrosinase activity as well as its expression. Tyrosol (1), 4-hydroxyphenylacetic acid (5) and 2-hydroxyphenylacetic acid (7) suppressed MC1R expression. Tyrosol (1), 4-hydroxyphenylacetic acid (5), 3-hydroxyphenylacetic acid (6), and 2-hydroxyphenylacetic acid (7) inhibited α-MSH induced TRP-1 expression, but salidroside (11) did not. All the compounds did not affect MITF and TRP-2 expression. Furthermore, we found that the cell viability of tyrosol (1), 4-hydroxyphenylacetic acid (5), 3-hydroxyphenylacetic acid (6), and 2-hydroxyphenylacetic acid (7) at concentrations below 4 mM and salidroside (11) at concentrations below 0.5 mM were higher than 90%. The compounds exhibited metal-coordinating interactions with copper ion in molecular docking with tyrosinase. Our results suggest that tyrosol, 4-hydroxyphenylacetic acid, 3-hydroxyphenylacetic acid, 2-hydroxyphenylacetic acid, and salidroside are potential hypopigmenting agents.

Biphasic pro-melanogenic and pro-apoptotic effects of all-trans-retinoic acid (ATRA) on human melanocytes: time-course study

BACKGROUND

The effects of retinoids on melanogenesis and their mechanism as depigmenting agents in topical therapy have not been fully elucidated. Conflicting data about their impact on melanogenic pathways have been reported.

OBJECTIVE

To investigate the effects of all-trans-retinoic acid (ATRA) on normal human melanocytes from Caucasian subjects.

METHODS

We assessed ATRA's cytotoxicity by measuring viability with a cell proliferation assay, and apoptotic effects using Annexin V and γ-H2AX markers. ATRA's melanogenic activity was investigated based on spectrophotometric measurement of melanin content and tyrosinase enzymatic activity. Tyrosinase expression was assessed by Western blotting. We tested the antioxidant activity of superoxide dismutase (SOD) and catalase (CAT) in melanocytes using a spectrophotometric assay.

RESULTS

Of the concentrations tested in this 72h time-course study, the 1.0μM ATRA had a well-defined two-stage pro-melanogenic and pro-apoptotic effect on melanocytes. In the first 6h, treated cells showed significant increase (p≤0.01) of melanin content, tyrosinase, SOD, and CAT activities compared to the controls. While overall tyrosinase expression was not affected by ATRA, all other tested parameters decreased progressively beyond the short-term point of 6h. ATRA treatment of over 6h induced melanocyte apoptosis, as shown by the time-dependent decrease in cell viability, coupled with significant increase in Annexin V positive cells and nuclear accumulation of γ-H2AX foci.

CONCLUSION

The results obtained using this testing platform show a biphasic ATRA action: immediate pro-melanogenic effect and longer-term exposure pro-apoptotic activity. These data qualify ATRA as a potent tool to better understand the mechanisms that regulate the pigmentary system.

A randomized controlled study to evaluate the depigmenting activity of L-ascorbic acid plus phytic acid-serum vs. placebo on solar lentigines

BACKGROUND

Solar lentigines (SL) are benign signs of sun damage that many people find distressing.

AIM

To assess the efficacy and safety of L-ascorbic acid 10% + phytic acid 2% for treating SL.

PATIENTS/METHODS

A double-blind, vehicle-controlled trial in 30 healthy subjects with ≥2 SL. Subjects were randomly assigned to apply product to one side of the body and vehicle to the other twice daily for 3 months with follow-up of 2 months.

RESULTS

  The pigmentation index for product-treated SL was reduced (maximum reduction 1.3 at 3 months [M3]), while that for vehicle-treated lesions remained stable. These differences were statistically significant for M1-M4 (P ≤ 0.003). Dermoscopy detected significant intergroup differences in pigmentation at M5 (P=0.011). Colorimetry results indicated a statistically significant improvement in brightness (L*) between study drug and vehicle at M5. Fifteen subjects experienced 23 adverse events; six (mostly halo depigmentation) were judged possibly related to the study drug. There were six instances of mild-to-moderate intolerance in the study drug group and five in the vehicle-treated group.

CONCLUSIONS

Study treatment was significantly more efficacious than vehicle in many respects and was well tolerated. Future, larger studies are needed to confirm these results and to compare the product with gold standard treatments.

Postinflammatory hyperpigmentation: etiologic and therapeutic considerations

Postinflammatory hyperpigmentation (PIH) is a reactive hypermelanosis and sequela of a variety of inflammatory skin conditions. PIH can have a negative impact on a patient's quality of life, particularly for darker-skinned patients. Studies show that dyschromias, including PIH, are one of the most common presenting complaints of darker-skinned racial ethnic groups when visiting a dermatologist. This is likely due to an increased production or deposition of melanin into the epidermis or dermis by labile melanocytes. A variety of endogenous or exogenous inflammatory conditions can culminate in PIH and typically most epidermal lesions will appear tan, brown, or dark brown while dermal hypermelanosis has a blue-gray discoloration. Depigmenting agents target different steps in the production of melanin, most commonly inhibiting tyrosinase. These agents include hydroquinone, azelaic acid, kojic acid, arbutin, and certain licorice (glycyrrhiza) extracts. Other agents include retinoids, mequinol, ascorbic acid (vitamin C), niacinamide, N-acetyl glucosamine, and soy, and these products depigment by different mechanisms. Certain procedures can also be effective in the treatment of PIH including chemical peeling and laser therapy. It is important to note that these same therapeutic modalities may also play a role in causing PIH. Lastly, those lesions that are not amenable to medical or surgical therapy may experience some improvement with cosmetic camouflage.

Whitening efficacy of plant extracts including orchid extracts on Japanese female skin with melasma and lentigo senilis

The purpose of this study was to assess the in vivo efficacy of a cosmetic formulation containing plant extracts including orchid extracts, compared to 3% vitamin C derivative formulated with the same excipient, in Japanese female adult volunteers with melasma and/or lentigo senilis. The ethics committee of Osaka National Hospital approved the protocol of the study. Before recruitment, selection and inclusion of a volunteer in this study, signed informed consent was obtained from each volunteer after she was given clear and precise information on the study, enabling her to appreciate the aim of the study and the consequences of her consent. Forty-eight female volunteers aged 30-60 years applied the plant extracts and vitamin C derivative to one side of the face. After repeated application for 8 weeks, efficacy was evaluated clinically by colorimetric measurements and subjectively using a questionnaire. After 8 weeks of treatment, both the clinical evaluations by a dermatologist and the questionnaire surveys by volunteers indicated that the cosmetic formulation containing plant extracts was significantly effective in improving the size, brightness, color intensity, clarity, visibility and global appearance of the pigmented spots, and also the luminosity complexion and skin clarity of the face. The good agreement between the results of clinical evaluations and those of questionnaire surveys showed that the orchid-rich plant extracts possess efficacy similar to vitamin C derivative in whitening the skin as well as melasma and lentigo senilis on the face of Japanese women.

The role of topical retinoids in the treatment of pigmentary disorders: an evidence-based review

Topical retinoids have been used in the treatment of pigmentary disorders such as melasma, actinic lentigines, and postinflammatory hyperpigmentation. This article evaluates the clinical efficacy and tolerability of retinoid treatment for pigmentary disorders through an evidence-based approach. We searched the MEDLINE and The Cochrane Library databases using the keywords 'retinoid' combined with 'melasma,' 'lentigines,' or 'postinflammatory hyperpigmentation.' For each study, the methodology and outcomes were assessed according to specific criteria. There is fair evidence to support the use of topical tretinoin as a monotherapy in the treatment of melasma as well as in the treatment of lentigines (grade B). Adverse effects of topical retinoids are quite frequent, and include local skin irritation, erythema, and peeling, and their severity is mild to moderate. There is evidence to support the use of topical tretinoin in a fixed, triple-combination therapy (hydroquinone 4%/tretinoin 0.05%/fluocinolone acetonide 0.01%) for the treatment of melasma (grade B). There is poor evidence (grade C) to support the use of combination formulations for the treatment of lentigines, and large, randomized, double-blind, controlled trials are needed to further evaluate their use for this indication. In conclusion, there is evidence to support the use of topical retinoids as monotherapy or in combination with other topical agents in the treatment of pigmentary disorders.

New and experimental treatments of cloasma and other hypermelanoses

In clinical practice, acquired hyperpigmentations represent the most common disorders of pigmentation the dermatologist has to treat. Despite the large number of depigmenting agents available, the treatment of hyperpigmentations is often unsuccessful and disappointing and is still a challenge for dermatologists. This article focuses on the chemical compounds reported to be in depigmenting or skin lightening agents, their proposed mechanism of action, and their clinical efficacy in the treatment of melasma and hypermelanoses, mainly based on randomized clinical trials. It also reviews chemical peels and their indications, together with the possible uses of laser and intense pulsed light.