Metabolites resulting from the bacterial fermentation of dietary fibers, such as short-chain fatty acids, especially butyrate, play important roles in maintaining gut health and regulating various biological effects in the skin. However, butyrate is underutilized due to its unpleasant odor. To circumvent this organoleptic unfavorable property, phenylalanine butyramide (PBA), a butyrate precursor, has been synthesized and is currently available on the market. We evaluated the inhibition of mushroom tyrosinase by butyrate and PBA through in vitro assays, finding IC50 values of 34.7 mM and 120.3 mM, respectively. Docking calculations using a homology model of human tyrosinase identified a putative binding mode of PBA into the catalytic site. The anti-aging and anti-spot efficacy of topical PBA was evaluated in a randomized, double-blind, parallel-arm, placebo-controlled clinical trial involving 43 women affected by photo-damage. The results of this study showed that PBA significantly improved skin conditions compared to the placebo and was well tolerated. Specifically, PBA demonstrated strong skin depigmenting activity on both UV and brown spots (UV: -12.7% and -9.9%, Bs: -20.8% and -17.7% after 15 and 30 days, respectively, p < 0.001). Moreover, PBA brightened and lightened the skin (ITA°: +12% and 13% after 15 and 30 days, respectively, p < 0.001). Finally, PBA significantly improved skin elasticity (Ua/Uf: +12.4% and +32.3% after 15 and 30 days, respectively, p < 0.001) and firmness (Uf: -3.2% and -14.9% after 15 and 30 days, respectively, p < 0.01).

Prolonged exposure to environmental oxidative stress can result in visible signs of skin aging such as wrinkles, hyperpigmentation, and thinning of the skin. Oryza sativa variety Sang 5 CMU, an inbred rice cultivar from northern Thailand, contains phenolic and flavonoid compounds in its bran and husk portions that are known for their natural antioxidant properties. In this study, we evaluated the cosmetic properties of crude extracts from rice bran and husk of Sang 5 CMU, focusing on antioxidant, anti-inflammatory, anti-melanogenesis, and collagen-regulating properties. Our findings suggest that both extracts possess antioxidant potential against DPPH, ABTS radicals, and metal ions. Additionally, they could downregulate TBARS levels from 125% to 100% of the control, approximately, while increasing the expression of genes related to the NRF2-mediated antioxidant pathway, such as NRF2 and HO-1, in H2O2-induced human fibroblast cells. Notably, rice bran and husk extracts could increase mRNA levels of HO-1 more greatly than the standard L-ascorbic acid, by about 1.29 and 1.07 times, respectively. Furthermore, the crude extracts exhibited anti-inflammatory activity by suppressing nitric oxide production in both mouse macrophage and human fibroblast cells. Specifically, the bran and husk extracts inhibited the gene expression of the inflammatory cytokine IL-6 in LPS-induced inflammation in fibroblasts. Moreover, both extracts demonstrated potential for inhibiting melanin production and intracellular tyrosinase activity in human melanoma cells by decreasing the expression of the transcription factor MITF and the pigmentary genes TYR, TRP-1, and DCT. They also exhibit collagen-stimulating effects by reducing MMP-2 expression in H2O2-induced fibroblasts from 135% to 80% of the control, approximately, and increasing the gene associated with type I collagen production, COL1A1. Overall, the rice bran and husk extracts of Sang 5 CMU showed promise as effective natural ingredients for cosmetic applications.

We report a case series of two patients who had similar skin pigmentation but were caused by vitamin B12 deficiency and Addison\'s disease. We further discuss the pathophysiology of skin hyperpigmentation in both of these disorders and the response to treatment. Our case report highlights the importance of the identification of simple bedside clinical signs to diagnose reversible causes of skin pigmentation.

Description Atopic dermatitis is a chronic inflammatory skin disorder classically affecting flexural areas of the body. It is present in children and adults, including those with darker skin pigmentation. Chronic lesions are hyperpigmented plaques that are dry, cracked, and/or scaly often with lichenification. Differential diagnoses include psoriasis, seborrheic dermatitis, ichthyosis, and pityriasis rosea. This article will showcase clinical images with varying presentations of chronic atopic dermatitis in a range of age groups and skin colors according to the Fitzpatrick scale.

Hydroxychloroquine (HCQ) is a commonly used medication for its immunosuppressive and dermatologic effects. It has known ocular side effects, which include retinopathy, corneal deposits, and choroidal thinning. Herein, we report the first known case of HCQ-induced hyperpigmentation of the sclera. A 75-year-old female presented after 10 months of gradual progression of painless blue-gray discoloration of the bilateral sclera, fingernails, and lower extremities secondary to oral HCQ therapy. Cessation of the drug led to a partial reversal of the hyperpigmentation at 5 months, further supporting HCQ as the causative agent. Hyperpigmentation reactions can be distressing to patients and lead to decreased medication adherence; given the widespread use of HCQ, it is important to increase awareness of this potential drug reaction.

The rising global popularity of cosmetic and corrective tattoos has concurrently led to an increased demand for their removal. While in the past, methods like surgical excision, chemical destruction, and dermabrasion were employed, lasers have emerged as a reliable and effective tool for tattoo removal. Increasing technological options and combination treatment strategies have raised the importance of understanding the various approaches to laser tattoo removal along with their respective clinical impact. This CME aims to describe the multifaceted aspects of laser tattoo removal, including the method selection, application principles, and safety considerations. Furthermore, it addresses the factors considered when selecting the most suitable laser to achieve optimal treatment outcomes.

OBJECTIVE: To determine the effectiveness of picosecond KTP in reducing peri-ocular dark circles caused mainly by excessive pigmentation and to compare Picosecond KTP with Thulium laser ability in reducing the intensity and extent of peri-ocular dark circles.
METHODS: This split-face prospective study included twelve women with periorbital dark circles (pigmented or mixed-pigmented type). The left lower eyelid was treated using the PicoHi machine (HIRONIC Ltd), a full beam Q-switched Nd-YAG provided by KTP crystal (523 nm) at settings of 0.3 J/cm2, 5 mm, 5 Hz, and 300 Ps. Whereas the right lower eyelid was treated using the Lavieen machine (WON TECH Co., Ltd), a fractional Thulium laser (1927 nm) at setting 1320 mJ/cm2, 30 × 15 mm, 1500 microseconds. Patients received a series of 3 treatment sessions, given at 4-week intervals.
RESULTS: The 532-nm full beam Q-switched KTP and fractional Thulium lasers were more likely to induce post-inflammatory hyperpigmentation rather than decrease the pigmentation. The risk is higher with a Q-switched KTP laser, which may be attributed to the skin tone of the participants. Nonetheless, some improvement in the pigmented type of PDCs, although not detected clinically, was documented by the VISIA software.
CONCLUSIONS: No solid conclusion can be drawn from the results of the study. Picosecond KTP and Thulium lasers may have a role in reducing PDCs yet more studies should be performed in order to determine the exact impact these lasers have.

BACKGROUND: The SLC29A3 gene, which encodes a nucleoside transporter protein, is primarily located in intracellular membranes. The mutations in this gene can give rise to various clinical manifestations, including H syndrome, dysosteosclerosis, Faisalabad histiocytosis, and pigmented hypertrichosis with insulin-dependent diabetes. The aim of this study is to present two Iranian patients with H syndrome and to describe a novel start-loss mutation in SLC29A3 gene.
METHODS: In this study, we employed whole-exome sequencing (WES) as a method to identify genetic variations that contribute to the development of H syndrome in a 16-year-old girl and her 8-year-old brother. These siblings were part of an Iranian family with consanguineous parents. To confirmed the pathogenicity of the identified variant, we utilized in-silico tools and cross-referenced various databases to confirm its novelty. Additionally, we conducted a co-segregation study and verified the presence of the variant in the parents of the affected patients through Sanger sequencing.
RESULTS: In our study, we identified a novel start-loss mutation (c.2T > A, p.Met1Lys) in the SLC29A3 gene, which was found in both of two patients. Co-segregation analysis using Sanger sequencing confirmed that this variant was inherited from the parents. To evaluate the potential pathogenicity and novelty of this mutation, we consulted various databases. Additionally, we employed bioinformatics tools to predict the three-dimensional structure of the mutant SLC29A3 protein. These analyses were conducted with the aim of providing valuable insights into the functional implications of the identified mutation on the structure and function of the SLC29A3 protein.
CONCLUSIONS: Our study contributes to the expanding body of evidence supporting the association between mutations in the SLC29A3 gene and H syndrome. The molecular analysis of diseases related to SLC29A3 is crucial in understanding the range of variability and raising awareness of H syndrome, with the ultimate goal of facilitating early diagnosis and appropriate treatment. The discovery of this novel biallelic variant in the probands further underscores the significance of utilizing genetic testing approaches, such as WES, as dependable diagnostic tools for individuals with this particular condition.

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We present a case of a patient with a 10-year history of blue-black macules and patches on the face and an associated history of skin-lightening cream usage. The skin lightening cream contained hydroquinone, which is often associated with exogenous ochronosis (EO). Interestingly, the biopsy did not show characteristic findings of ochronosis, confusing the final diagnosis, however discontinuing the skin-lightening creams halted the progression of the patient\'s skin lesions supporting a diagnosis of EO. EO presents as asymptomatic hyperpigmentation after using products containing hydroquinone. This condition is most common in Black populations, likely due to the increased use of skin care products and bleaching cream containing hydroquinone in these populations. Topical hydroquinone is FDA-approved to treat melasma, chloasma, freckles, senile lentigines, and hyperpigmentation and is available by prescription only in the US and Canada. However, with the increased use of skin-lightening creams in certain populations, it is important for dermatologists to accurately recognize the clinical features of exogenous ochronosis to differentiate it from similar dermatoses. An earlier diagnosis can prevent the progression to severe presentations with papules and nodules. We summarize the clinical presentations diagnostic features, and treatment pearls, concluding with a discussion of the differential diagnoses.  J Drugs Dermatol. 2024;23(7):567-568.     doi:10.36849/JDD.8248.