Epigallocatechin-3-O-(3-O-methyl)-gallate-induced differentiation of human keratinocytes involves klotho-mediated regulation of protein kinase-cAMP responsive element-binding protein signaling.

(-)-Epigallocatechin-3-O-gallate (EGCG) has long been known as a potent inducer of keratinocyte differentiation. Although its molecular mechanisms have been extensively studied, its actions on human skin remain to be elucidated. In this study, we demonstrated that methylated EGCG and EGCG increase the expression of klotho, and that klotho functions as a downstream target of EGCG and methylated EGCG in keratinocyte differentiation. We demonstrated that methylated EGCG3 and EGCG induce morphological changes in normal human epidermal keratinocytes (NHEKs) that are related to up-regulation of klotho expression. We also demonstrated that a klotho-induced keratinocyte differentiation marker in NHEKs is inhibited by H-89, a protein kinase (PKA) inhibitor. These results suggest that methylated EGCG and EGCG may function as inducers of keratinocyte differentiation via transcriptional regulation of the klotho protein.

Autophagy induced by resveratrol suppresses α-MSH-induced melanogenesis.

Autophagy degrades cellular components and organelles through a cooperative process involving autophagosomes and lysosomes. Although autophagy is known to mainly regulate the turnover of cellular components, the role of autophagy in melanogenesis has not been well addressed. Here, we show that inhibition of autophagy suppresses the antimelanogenesis activity of resveratrol (RSV), a well-known antimelanogenic agent. RSV strongly increased autophagy in melanocytes. However, the depletion of ATG5 significantly suppressed RSV-mediated antimelanogenesis as well as RSV-induced autophagy in melanocytes. Moreover, suppression of ATG5 retrieved the RSV-mediated downregulation of tyrosinase and TRP1 in α-MSH-treated cells. Most importantly, electron microscopy analysis revealed that autophagosomes engulfed melanin or melanosomes after combined treatment of α-MSH and RSV. Taken together, these results suggest that RSV-mediated autophagy regulates melanogenesis.

Treatment of Atopic Dermatitis Associated with Malassezia sympodialis by Green Tea Extracts Bath Therapy: A Pilot Study.

Multiple treatment modalities, including topical and systemic corticosteroid and phototherapy, have been used in treatment of patients with atopic dermatitis. However, long-term corticosteroid therapy may have various adverse effects. The purpose of this study was to investigate the therapeutic efficacy and safety of bath therapy using green tea extracts for treatment of patients with atopic dermatitis. A total of four patients with atopic dermatitis were enrolled in this study. A Malassezia multiplex detection kit was used in performance of multiplex PCR on clinical isolates, which confirmed Malassezia sympodialis. Subjects underwent treatment with bath therapy using green tea extracts three times per wk for a period of 4 wk. Assessment using the scoring atopic dermatitis (SCORAD) index, the visual analogue scale for pruritus, and transepidermal water loss was performed weekly. Laboratory tests were performed before and after treatment. All patients showed marked improvement on the mean SCORAD and visual analogue scale, and a significant decrease in the mean values of serum eosinophil counts was observed after treatment. Bath therapy with green tea extract is an effective, safe, and nonsteroidal therapy for treatment of patients with atopic dermatitis associated with Malassezia sympodialis.

Human skin safety test of green tea cell extracts in condition of allergic contact dermatitis.

Various kinds of positive effects of green tea extracts had been studied for long time which included anti-inflammation, anti-aging, and cardiometabolic effects. Although topical steroid and non-steroidal calcineurin inhibitors may control clinical symptoms of allergic contact dermatitis, some of patients also present allergic reaction to these topical agents. Therefore, we have tried green tea extracts for managing this skin disorder with expectation of anti-inflammatory effect without potential side effects including skin irritation and toxic responses. The toxicity test of green tea extract also did not show any sign of irritation in the skin throughout the test period. Moderate severity of allergic contact dermatitis presented satisfactory clinical outcome at second week follow-up which was final visit of outpatient. This result mean that green tea extract has a positive effect for managing allergic contact dermatitis but its potency and efficacy seem to be so not strong enough to control moderate severity allergy skin lesion. In this pilot study, we were able to conclude that green tea cell extracts might be applied for potential anti-inflammatory soaking without skin toxicity.