Amino acids disrupt calcium-dependent adhesion of stratum corneum

Reduction of enlarged facial pore using ion-paired amino acid through enhancement in skin permeation and exfoliation: A placebo-controlled in vivo study

BACKGROUND

Serine is a hypoallergenic but inefficient chemical exfoliant. Serine paired with arginine (ion-paired amino acid, IPA) shows enhanced lipophilicity, skin permeation, and exfoliation efficacy.

AIM

This study was conducted to determine whether exfoliation using an emulsion containing IPA could reduce enlarged facial pores and improve the dermis density.

METHODS

IPA formation was validated by spectroscopic analysis. Enhanced permeability and exfoliation efficacy were evaluated ex vivo using porcine skin. In a clinical trial, healthy Korean women aged 20-49 years (mean age ± SD: 35.6 ± 8.6, n = 64) were evaluated, and the right and left sides of the cheeks were randomly chosen. An emulsion containing 4.0% IPA and placebo emulsion were applied to each side for 6 weeks. To evaluate pore sizes following treatment, the number of enlarged facial pores, inner skin structures from the stratum corneum to epidermal-dermal interface, and dermal density on each cheek of the participants were assessed.

RESULTS

IPA showed a significantly increased partition coefficient in n-octanol-water. In porcine skin, permeation of serine after 12 hour was 70% higher for the IPA than for serine alone at the same percent weight concentrations. In the clinical trial, after 6 weeks, the number of enlarged facial pores was changed by -19.317% in the IPA emulsion group (P < .001) and -2.930% in placebo emulsion group (P = .254).

CONCLUSION

Exfoliation with an IPA-containing emulsion reduced enlarged facial pores and increased the dermis density. IPA, effective mild exfoliator, can be used as a major ingredient for the cosmeceutical skincare products in the future.

Integrated targeted serum metabolomic profile and its association with gender, age, disease severity, and pattern identification in acne

Background

Westernized diet and nutritional metabolism are important in acne pathogenesis, especially in adult patients. However, clinical and basic data are lacking. Pattern identification (PI) is a tool that results in a diagnostic conclusion based on a cluster of concurrent symptoms and signs in traditional medicine. Acne can be classified by PI. However, whether the metabolomic profile differs according to the PI of acne is unknown. Metabolomic data would help clarify the pathogenesis of acne.

Methods

We conducted a cross-sectional study involving 40 healthy controls and 60 subjects with acne. We evaluated androgens, serum lipids, essential amino acids, nonessential amino acids, other amino acids, and pro-inflammatory cytokines of all subjects and compared the metabolomic profiles between acne subjects and healthy controls, and in subgroups according to gender, age, severity, and PI.

Results

Dehydroepiandrosterone sulfate and serum fatty acids were significantly higher in female subjects, adolescents, and those with disharmony of the thoroughfare and conception vessels. The total essential and nonessential amino acids were significantly lower in the overall, female, adult, severe, and phlegm-stasis group. The latter group exhibited elevated serum levels of interleukin-1β and -6.

Conclusions

This is the first study to investigate serum lipids, amino acids, and cytokines in subjects with acne. We analyzed the differences between metabolomic profiles to determine the diagnostic value of PI. Prospective studies with more patients are needed to confirm the characteristics of each PI and lipidomic data will enrich knowledge concerning lipid mechanism.