2-Mercaptonicotinoyl glycine prevents UV-induced skin darkening and delayed tanning in healthy subjects: A randomized controlled clinical study

BACKGROUND

Chronic nonextreme sun exposure induces two mechanisms of skin pigmentation, causing immediate darkening and delayed tanning. A new molecule, 2-mercaptonicotinoyl glycine (2-MNG), has been shown in vitro to inhibit both immediate darkening and new melanin synthesis via covalent conjugation of the thiol group of 2-MNG to melanin precursors.

OBJECTIVE

To evaluate 2-MNG in preventing both mechanisms in vivo.

METHODS

In a randomized, intra-individual and controlled study, 33 subjects with melanin-rich skin were exposed to UV daylight on designated areas on the back and treated with a cosmetic formula containing 0.5% or 1% 2-MNG alone or 0.5% 2-MNG in association with lipohydroxy acid (LHA, 0.3%) plus Mexoryl-SX (MSX, 1.5%). The respective vehicles were used as controls and 4-n-butyl-resorcinol (4-n-BR, 2.5%) as a positive reference.

RESULTS

2-MNG alone significantly reduced immediate darkening and inhibited new melanin production when compared with vehicle, with higher performance at 1% than at 0.5%. 2-MNG at 0.5% in association with LHA and MSX showed significantly higher performance than 2-MNG 0.5% alone. 2-MNG at 0.5% and 1% showed significantly better performance than 4-n-BR.

CONCLUSIONS

2-MNG inhibited both UV-induced skin pigmentation mechanisms in vivo. The association of 2-MNG with LHA plus MSX showed the highest efficacy on melanin-rich skin with pigmentation induced by UV exposure.

A Bayesian network meta-analysis of 14 molecules inhibiting UV daylight-induced pigmentation

INTRODUCTION

Hyperpigmentation disorders are very frequent, affect the quality of life and may become a psychological burden for afflicted patients. Many anti-pigmenting or depigmenting agents are available with various efficacy and almost no comparative data. 2-mercaptonicotinoyl glycine (2-MNG) was recently proposed as a viable candidate showing safe and effective results on hyperpigmentation control in vitro and in vivo.

OBJECTIVES

A Bayesian network meta-analysis (BNMA) was conducted to map and rank the anti-pigmenting and depigmenting efficacy of 2-MNG 0.5% on UV daylight (UVDL)-induced pigmentation together with 13 other reference molecules. A comparison in the kinetics of 2-MNG 0.5% was also performed.

METHODOLOGY

Fourteen studies were conducted, for each, on 15-30 women of skin phototype III in Shanghai, China and Paris, France. The products were applied on mini zone, in randomized and blinded protocol, on the back, 5 days a week during 6 weeks, at a dose of 4 mg/cm2 . During the second week, volunteers were exposed under to varying minimum erythemal dose of UVDL during 4 consecutive days-adapted to obtain a similar induction of skin pigmentation regardless of the population. Assessments were performed instrumentally using Chromameter®. Ascorbic acid 7% was used as a positive control for all experiments. A Bayesian network meta-analysis was then established to map and follow the kinetics of 2-MNG 0.5% performance with 13 reference molecules (glutathione 2%, kojic acid 1%, hydroquinone 4%, ascorbyl glucoside 2%, niacinamide 4%, etc.).

RESULTS

2-MNG 0.5% dominated the ranking at all time points with a significant high probability of strong efficacy against UVDL-induced pigmentation. Ascorbic acid 7% ranks second after 4 days of irradiations (D12 ) whereas hydroquinone 4% ranks second 1 month after irradiations (D40 ). In the kinetics, 2-MNG at 0.5% was effective as from the end of irradiations (D12 ) to the study endpoint (D40 ). This suggested an immediate and persistent efficacy across all timepoints evaluated.

CONCLUSION

The BNMA revealed a rapid and lasting efficacy of 2-MNG 0.5% on the anti-pigmenting and depigmenting phases of the clinical protocol. 2-MNG 0.5% ranked first, with immediate and lasting effect compared to 13 other references. This study is the first allowing comparison between reference anti-pigmenting and depigmenting agents and will help clinicians for proposing the most effective approach for their patients.

Efficacy of a multitargeted, salicylic acid-based dermocosmetic cream compared to benzoyl peroxide 5% in Acne vulgaris: Results from a randomized study

INTRODUCTION

Acne vulgaris (acne) is characterized by both inflammatory and non-inflammatory lesions. Benzoyl peroxide (BPO) 5% is approved to treat acne but may cause skin irritation and/or contact allergy.

OBJECTIVES

To compare the benefit in acne of a multitargeted dermocosmetic cream containing salicylic acid, lipohydroxy acid, niacinamide, 2-oleamido-1,3-octadecanediol, piroctone olamine, zinc, Aqua posae filiformis, and thermal spring water (DC-Eff) to BPO 5% gel.

MATERIALS AND METHODS

150 Caucasian subjects (50% female) aged between 18 and 40 years, with mild to moderate acne according to the GEA (Global Evaluation of Acne) grading system were randomized into two parallel groups (DC-Eff or BPO to be applied twice daily for 56 days). IGA (investigator global assessment), GEA, lesion count, clinical signs and symptoms, and subject assessment were evaluated at baseline, and after 28 and 56 days (D28 and D56) of treatment.

RESULTS

The responder analyses of the IGA and GEA scores showed that 62.2% and 47.3%, respectively, in the DC-Eff, compared with 50.0% and 36.5%, respectively, in the BPO, had improved by at least one point at D56. Inflammatory, non-inflammatory, and total lesion counts significantly (p < 0.0001) decreased with both products from baseline, with no between-group difference. Subjects considered that their skin was smoother and that DC-Eff was easy to apply. DC-Eff was better tolerated than BPO.

CONCLUSIONS

DC-Eff applied twice daily is as beneficial as BPO in improving mild-to-moderate acne. DC-Eff was better tolerated than BPO and highly appreciated.

Predicting the evolution of clinical skin aging in a multi-ethnic population: Developing causal Bayesian networks using dermatological expertise

INTRODUCTION

Software to predict the impact of aging on physical appearance is increasingly popular. But it does not consider the complex interplay of factors that contribute to skin aging.

OBJECTIVES

To predict the +15-year progression of clinical signs of skin aging by developing Causal Bayesian Belief Networks (CBBNs) using expert knowledge from dermatologists.

MATERIAL AND METHODS

Structures and conditional probability distributions were elicited worldwide from dermatologists with experience of at least 15 years in aesthetics. CBBN models were built for all phototypes and for ages ranging from 18 to 65 years, focusing on wrinkles, pigmentary heterogeneity and facial ptosis. Models were also evaluated by a group of independent dermatologists ensuring the quality of prediction of the cumulative effects of extrinsic and intrinsic skin aging factors, especially the distribution of scores for clinical signs 15 years after the initial assessment.

RESULTS

For easiness, only models on African skins are presented in this paper. The forehead wrinkle evolution model has been detailed. Specific atlas and extrinsic factors of facial aging were used for this skin type. But the prediction method has been validated for all phototypes, and for all clinical signs of facial aging.

CONCLUSION

This method proposes a skin aging model that predicts the aging process for each clinical sign, considering endogenous and exogenous factors. It simulates aging curves according to lifestyle. It can be used as a preventive tool and could be coupled with a generative AI algorithm to visualize aging and, potentially, other skin conditions, using appropriate images.

A precise analysis of the relative contribution of UVA1 and visible light colour domains in solar light-induced skin pigmentation

BACKGROUND

Solar light induces or aggravates hyperpigmentation issues. The contribution of UVA1, as well as visible light (VL), especially high-energy blue-violet visible (HEV) light, is now clearly established.

OBJECTIVES

This work aimed at determining the relative contribution of UVA1, HEV and VL wavelength bands and their sub-domains in pigmentation induction.

METHODS

Two clinical studies using solar simulators equipped with specific bandpass physical filters were carried out. Volunteers (FSPT III-IV) were exposed on the back to UVA1 + HEV (350-450 nm), UVA1 (350-400 nm), HEV (400-450 nm) or part of UVA1 + HEV (370-450 nm) in Study 1 (n = 27) and to VL (400-700 nm), HEV (400-450 nm), Blue (400-500 nm), Green (500-600 nm) and Green+Red (500-700 nm) domains in Study 2 (n = 25). Pigmentation level was assessed by visual scoring and colorimetry at different time points postexposure, up to Day 43.

RESULTS

Induced pigmentation was detected in all exposed conditions, peaking at 2 h and thereafter progressively decreasing but remaining persistent up to Day 43. In Study 1, UVA1 showed an additive effect with HEV, with a significant contribution coming from the Longest UVA1 rays (370-400 nm). Study 2 demonstrated that 24 h postexposure, the Blue domain accounted for 71% of VL-induced pigmentation, the HEV one for 47%, the Green one for 37% and the Green+Red one for 36%, confirming no significant effect for Red light.

CONCLUSIONS

Altogether, these results underline the need for UVA1 photoprotection up to 400 nm and highlight the importance of protecting the skin from solar VL wavelengths and especially from HEV, Blue and Green light, to limit induced pigmentation.

Maintenance effect of a once-weekly regimen of a Selenium Disulfide-based shampoo in moderate-to-severe scalp seborrheic dermatitis after initial treatment with topical corticosteroid/salicylic acid

INTRODUCTION

Seborrheic dermatitis (SD) is a chronic, relapsing, inflammatory disorder of the head and trunk.

OBJECTIVES

To explore the potential of a 1% Selenium disulphide (SeS2)-based shampoo to prevent relapses of scalp SD (SSD) following corticosteroid/salicylic acid (TCS/SA) treatment.

MATERIALS & METHODS

After a 2-week treatment with TCS/SA, adult patients with moderate-to-severe SSD received either the SeS2-based shampoo or its vehicle for eight weeks in a randomized, double-blinded fashion. Visits took place at baseline, weeks 2, 6 and 10. SSD severity was assessed based on erythema, flakes and pruritus; patients assessed the severity of pruritus. Global investigator and patient satisfaction were assessed at week 10.

RESULTS

Forty-eight adults were included. After four and eight weeks of post TCS/SA maintenance regimen, 8.1% and 16.7% in the SeS2, and 41.7% and 54.2% in the vehicle group relapsed, respectively. First median time-to-relapse in the vehicle group was 56 days; this was not reached for SeS2. After two weeks of TCS/SA, the prevalence of patients with no pruritus was 29.2% in the SeS2 group, and 41.7% in the vehicle group; it increased to 76.2% with SeS2 and to 57.1% with the vehicle at the end of the study. The clinical benefit of treatment with TCS/SCA was maintained in the SeS2 group only. Investigators and patients were highly satisfied with the efficacy of SeS2. Tolerance to SeS2 was excellent, with no reported adverse events.

CONCLUSION

The SeS2-based shampoo significantly reduces the time-to-relapse of moderate-to-severe SSD flares. Its tolerance was excellent, with no reported adverse events.

Tricuspid annulus dynamics in atrial fibrillation compared to sinus rhythm using 3-D echocardiography: relation with tricuspid regurgitation

Funding Acknowledgements

Type of funding sources: None.

Background

Atrial fibrillation (AF) is known to cause dilation in both the mitral (MA) and the tricuspid (TA) annuli. Few studies have investigated MA dynamics and function in AF compared to sinus rhythm (SR). However, no study addressed this issue in TA. Hence, we set forth to describe TA dynamics in AF and SR and its relationship with severity of tricuspid regurgitation (TR).

Methods

3D echocardiographic imaging data were acquired from adult patients in AF or SR with varying degrees of TR between 2018 and 2020. TA was automatically tracked throughout the cardiac cycle using a commercially available software (TomTec 4MV software; Figure 1) over 4-6 cardiac cycles per patient. Time to minimal area as percentage of the R-R interval was recorded in each of the cycles. Absolute change in TA area was calculated as the difference between maximal and minimal TA area in each cardiac cycle and was averaged over 4-6 cycles per patient. This measurement was used to reflect the dynamic range of TA deformation during the cardiac cycle. Right atrial (RA) and right ventricular (RV) volumes and longitudinal strain were also measured (speckle tracking, 4-ch view).

Results

A total of 70 patients were studied (35 AF; 35 SR; 54% males in each group). Patients with AF were older [median (IQR) of 81 (72-86) years vs. 69 (59-78) years in SR, p &lt; 0.001], had larger maximal TA area and circumference (p &lt; 0.001 for both), larger RA size (p &lt; 0.001), lower RA reservoir strain  (p &lt; 0.001) and RV free-wall strain (p &lt; 0.001). Absolute change in TA area was significantly decreased in AF [2.3 (1.7-2.7) cm2] vs. 3.1 (2.3-3.5) cm2 in SR, p = 0.002. Patients with ≥ moderate TR (n = 41, 59%) had lower absolute change in TA area [2.4 (1.7-3.1) cm2 vs. 2.8 (2.2-3.5) cm2 in &lt; moderate TR, p = 0.05]. Female sex was associated with lower absolute change in TA area [2.3 (1.7-3.2) cm2 vs. 2.7 (2.2-3.6) cm2 in males, p = 0.02] on univariate analysis. AF patients had more frequently ≥ moderate TR [28 AF vs. 13 SR, p &lt; 0.001]. On multivariate analysis including sex, rhythm, TR severity, RA and RV strains, and averaged maximal TA area, independent factors associated with lower absolute change in TA area were AF, ≥ moderate TR, and larger maximal TA area (p &lt; 0.05 for all).  Time to minimal TA size was achieved in (0-40%) of the R-R interval in 70% of patients in SR compared to only 41% of patients in AF (Figure 2) and in 73% in patients with &lt; moderate TR compared to 43% in patients with ≥ moderate TR.

Conclusion

AF is associated with blunted TA dynamics resulting in lower decrease in TA size and with a heterogenous timing of minimal TA size throughout the cardiac cycle. The blunted and discoordinated annular contraction may reduce systolic tricuspid valve competence and be involved in the pathophysiology of functional TR. Future studies are needed to confirm this hypothesis and evaluate the effect of restoration of SR on TA dynamics and time to minimal TA size. Abstract Figure 1Abstract Figure 2

Disclosing genetic risk for coronary heart disease: effects on perceived personal control and genetic counseling satisfaction

We investigated whether disclosure of coronary heart disease (CHD) genetic risk influences perceived personal control (PPC) and genetic counseling satisfaction (GCS). Participants (n = 207, age: 45-65 years) were randomized to receive estimated 10-year risk of CHD based on a conventional risk score (CRS) with or without a genetic risk score (GRS). Risk estimates were disclosed by a genetic counselor who also reviewed how GRS altered risk in those randomized to CRS+GRS. Each participant subsequently met with a physician and then completed surveys to assess PPC and GCS. Participants who received CRS+GRS had higher PPC than those who received CRS alone although the absolute difference was small (25.2 ± 2.7 vs 24.1 ± 3.8, p = 0.04). A greater proportion of CRS+GRS participants had higher GCS scores (17.3 ± 5.3 vs 15.9 ± 6.3, p = 0.06). In the CRS+GRS group, PPC and GCS scores were not correlated with GRS. Within both groups, PPC and GCS scores were similar in patients with or without family history (p = NS). In conclusion, patients who received their genetic risk of CHD had higher PPC and tended to have higher GCS. Our findings suggest that disclosure of genetic risk of CHD together with conventional risk estimates is appreciated by patients. Whether this results in improved outcomes needs additional investigation.

Superparamagnetic bifunctional bisphosphonates nanoparticles: a potential MRI contrast agent for osteoporosis therapy and diagnostic

A bone targeting nanosystem is reported here which combined magnetic contrast agent for Magnetic Resonance Imaging (MRI) and a therapeutic agent (bisphosphonates) into one drug delivery system. This new targeting nanoplatform consists of superparamagnetic γFe(2)O(3) nanoparticles conjugated to 1,5-dihydroxy-1,5,5-tris-phosphono-pentyl-phosphonic acid (di-HMBPs) molecules with a bisphosphonate function at the outer of the nanoparticle surface for bone targeting. The as-synthesized nanoparticles were evaluated as a specific MRI contrast agent by adsorption study onto hydroxyapatite and MRI measurment. The strong adsorption of the bisphosphonates nanoparticles to hydroxyapatite and their use as MRI T2(∗) contrast agent were demonstrated. Cellular tests performed on human osteosarcoma cells (MG63) show that γFe(2)O(3)@di-HMBP hybrid nanomaterial has no citoxity effect in cell viability and may act as a diagnostic and therapeutic system.