Recent Developments in (K, Na)NbO3-Based Lead-Free Piezoceramics.

(K0.5Na0.5)NbO3 (KNN)-based ceramics have been extensively investigated as replacements for Pb(Zr, Ti)O3-based ceramics. KNN-based ceramics exhibit an orthorhombic structure at room temperature and a rhombohedral-orthorhombic (R-O) phase transition temperature (TR-O), orthorhombic-tetragonal (O-T) phase transition temperature (TO-T), and Curie temperature of -110, 190, and 420 °C, respectively. Forming KNN-based ceramics with a multistructure that can assist in domain rotation is one technique for enhancing their piezoelectric properties. This review investigates and introduces KNN-based ceramics with various multistructures. A reactive-templated grain growth method that aligns the grains of piezoceramics in a specific orientation is another approach for improving the piezoelectric properties of KNN-modified ceramics. The piezoelectric properties of the [001]-textured KNN-based ceramics are improved because their microstructures are similar to those of the [001]-oriented single crystals. The improvement in the piezoelectric properties after [001] texturing is largely influenced by the crystal structure of the textured ceramics. In this review, [001]-textured KNN-based ceramics with different crystal structures are investigated and systematically summarized.

Ergothioneine alleviates senescence of fibroblasts induced by UVB damage of keratinocytes via activation of the Nrf2/HO-1 pathway and HSP70 in keratinocytes.

Ultraviolet B (UVB) irradiation induces skin damage and photoaging through several deleterious effects, including generation of reactive oxygen species (ROS), apoptosis of epidermal cells, inflammation, and collagen degradation in fibroblasts. Ergothioneine (EGT) is a naturally occurring amino acid with potential biological properties. We evaluated whether EGT protects against UVB-induced photoaging using a keratinocyte/fibroblast co-culture system. Keratinocytes were pretreated with EGT, irradiated with UVB, and co-cultured with fibroblasts. In keratinocytes, ROS production and apoptosis were assessed. We also analyzed the Nrf2/HO-1 pathway, HSP70, proapoptotic proteins, and paracrine cytokines by Western blotting and real-time PCR. Collagen degradation-related genes and senescence were also assessed in fibroblasts. EGT pretreatment of keratinocytes significantly inhibited downregulation of the Nrf2/HO-1 pathway and HSP70, and protected keratinocytes by suppressing production of ROS and cleavage of proapoptotic proteins, including caspase-8 and PARP. Furthermore, EGT significantly reduced the paracrine cytokines, including IL-1ß, IL-6, and TNF-α. In co-cultures of fibroblasts with EGT-treated keratinocytes, the expression levels of collagen degradation-related genes and fibroblast senescence were significantly decreased; however, synthesis of procollagen type I was significantly increased. Our results confirm that EGT suppresses the modification of collagen homeostasis in fibroblasts by preventing downregulation of the Nrf2/HO-1 pathway and HSP70 in keratinocytes following UVB irradiation.

Sulforaphane controls the release of paracrine factors by keratinocytes and thus mitigates particulate matter-induced premature skin aging by suppressing melanogenesis and maintaining collagen homeostasis.

BACKGROUND: Skin aging, potentially caused by exposure to particulate matter (PM)2.5, is characterized by wrinkling, abnormal pigmentation, and skin dryness triggered by several keratinocyte-derived paracrine factors. Sulforaphane (4-methylsulfinylbutyl isothiocyanate, SFN), commonly found in cruciferous vegetables, has diverse biological effects on skin tissue. PURPOSE: In the present study, we have investigated whether SFN may alleviate PM2.5-induced premature skin aging. METHODS: We used keratinocyte/melanocyte or keratinocyte/fibroblast coculture models of skin cells and measured the parameters of melanogenesis, collagen homeostasis and inflammation. RESULTS: SFN inhibited the development of reactive oxygen species in keratinocytes exposed to PM2.5. In keratinocyte/melanocyte cocultures, it significantly inhibited the upregulation of melanogenic paracrine mediators (including endothelin-1 and prostaglandin E2) in keratinocytes exposed to PM2.5; the synthesis of melanogenic proteins including microphthalmia-associated transcription factor, tyrosinase-related protein 1, and tyrosinase; and the levels of melanin in melanocytes. SFN treatment of keratinocyte/fibroblast cocultures significantly reduced the PM2.5-induced expression of NF-κB-mediated cytokines including interleukin-1ß, interleukin-6, tumor necrosis factor α, and cyclooxygenase-2. In fibroblasts of the keratinocyte/fibroblast coculture system, the expression levels of phospho-NF-κB, cysteine-rich protein 61, and matrix metalloproteinase-1 were significantly decreased whereas procollagen type I synthesis was significantly increased. CONCLUSION: Collectively, our results suggest that SFN mitigates PM2.5-induced premature skin aging by suppressing melanogenesis and maintaining collagen homeostasis. It acts by regulating the release of paracrine factors from keratinocytes.

Pratol, an O-Methylated Flavone, Induces Melanogenesis in B16F10 Melanoma Cells via p-p38 and p-JNK Upregulation.

Tyrosinase is the rate-limiting enzyme critical for melanin synthesis. It controls pigmentation in the skin. Activation of tyrosinase is currently the most common approach in the development of tanning and haircare products. Pratol is a 7-hydroxy-4-methoxyflavone found in Trifoliumpratense. In this study, we investigated the effects of pratol on melanogenesis. We also studied the mechanism of action of pratol in B16F10 mouse melanoma cells. The cells were treated with various concentrations (6.25, 12.5, 25, and 50 µM) of pratol to observe its effects. The results showed that pratol significantly increased melanin content and tyrosinase activity in the cells without being cytotoxic. In addition, pratol strongly increased the expression of tyrosinase and tyrosinase-related protein-1 and 2 by enhancing the expression of microphthalmia-associated transcription factor. Furthermore, pratol stimulated melanogenesis via the phosphorylation of p38, c-Jun N-terminal kinases (JNK), and extracellular signal-regulated kinase (ERK). The findings from an assay searching for the inhibitor revealed that SB203580 (a specific p38 inhibitor) or SP600125 (a p-JNK inhibitor) attenuated pratol-induced cellular tyrosinase activity whereas PD98059 (an ERK inhibitor) did not. Additionally, pratol interfered with the phosphorylation of p-AKT. We also found that pratol-induced melanogenesis was reversed by H89, which is a specific protein kinase A inhibitor. The results suggest that, owing to its multi-functional properties, pratol may be a potential tanning agent or a therapeutic agent for hair depigmentation in the cosmetic industry.

Pollution and acne: is there a link?

In recent years, the critical role that inflammation may play in the development and progression of acne has become increasingly recognized. The prevalence of acne is similar between Asian and Caucasian women, but Asian women have a higher prevalence of inflammatory acne. They also report their symptoms exacerbate during periods of high air pollution. The objective of this study was to review the current evidence that links air pollution to worsening of acne symptoms. Firstly, a group of five Asian and three European scientists with expertise in Dermatology reviewed the current literature and described current acne treatment practices in their countries. During this activity, they identified the need for further epidemiological and clinical research. Secondly, additional studies ensued which provided evidence that acne symptoms might exacerbate in regions of high ambient air pollution. Based on these findings, the authors suggest that people with acne should protect the natural barrier function of their skin with emollients and ultraviolet (UV)A/UVB protection.

Anti-inflammatory effects of isoketocharbroic acid from brown alga, Sargassum micracanthum.

During our on-going screening program designed to isolate natural compounds from marine environments, we isolated isoketochabrolic acid (IKCA) from Sargassum micracanthum, an important brown algae distributed in Jeju Island, Korea. Furthermore, we evaluated the inhibitory effects of IKCA on nitric oxide (NO) production in lipopolysaccharide (LPS)-triggered macrophages. IKCA strongly inhibited NO production, with an IC50 value of 58.31 µM. Subsequent studies demonstrated that IKCA potently and concentration-dependently reduced prostaglandin E2 (PGE2), tumor necrosis factor-alpha (TNF-α), interleukin (IL)-1ß, and IL-6 cytokine production. In conclusion, to the best of our knowledge, this is the first study to show that IKCA isolated from S. micracanthum has a potent anti-inflammatory activity. Therefore, IKCA might be useful as an anti-inflammatory health supplement or functional cosmetics.

Concomitant use of an infrared fractional laser with low-dose isotretinoin for the treatment of acne and acne scars.

BACKGROUND: Acne scarring has lifelong sequelae. Fractional photothermolysis (FP) has been shown to provide fast recovery from acne within a short period, thereby aiding skin rejuvenation. Isotretinoin is a well-known, effective drug for the treatment of severe recalcitrant acne. This study investigated the safety and the efficacy of infrared fractional laser treatment in conjunction with low-dose isotretinoin for the treatment of acne and acne scars. MATERIALS: A 1550 nm Erbium-doped fiber laser was used to treat 35 patients with acne scarring. All the patients had taken isotretinoin (10 mg/day) for more than one month prior to the commencement of the fractional laser treatment. RESULTS: There was no aggravation of acne scars, hypertrophic scars, or keloids. Most of the patients (33 patients) received reduced microthermal damage zone (MTZ) treatment. Eighty percent of the treated patients (28 patients) demonstrated more than a fair improvement. The total average score on the global acne scarring classification before treatment was 13.5, and the score after treatment was 11.2. CONCLUSION: Acne and acne scars can be treated more effectively by concomitant use of an infrared fractional laser with low-dose isotretinoin with reduced MTZ densities. Most patients showed more than a fair improvement, and there was no aggravation of the scars.

Protective effects of fermented Citrus unshiu peel extract against ultraviolet-A-induced photoageing in human dermal fibrobolasts.

The aqueous extracts of Citrus unshiu peel containing flavonoid glycosides was used as co-substrate with Schizophyllum commune mycelia producing ß-glucosidase and its biological activities were studied. ß-glucosidase-produced S. commune mycelia converted the glycosides (narirutin and hesperidin) into aglycones (naringenin and hesperetin). The photoprotective potential of fermented C. unshiu peel extract with S. commune (S-CPE) was tested in human dermal fibroblasts (HDFs) exposed to UVA. It was revealed that S-CPE had an inhibitory effect on human interstitial collagenase (matrix metalloproteinase, MMP-1) expression in UVA-irradiated HDFs. The treatment of UVA-irradiated HDFs with S-CPE resulted in a dose-dependent decrease in the expression level of MMP-1 mRNA. The UVA irradiation raised the proportion of senescence-associated ß-galactosidase (SA-ß-gal) positive cells in comparison with the normal control group. The treatment of UVA-irradiated HDFs with S-CPE was shown to decrease the level of SA-ß-gal (by approximately 45% at an S-CPE concentration 0.1%, w/v) compared with the UVA-irradiated HDFs. It was found that S-CPE containing hesperetin has notable collagen biosynthetic activity for fibroblasts, indicating that S-CPE can be promising cosmetic ingredients.

In vitro antioxidant and in vivo anti-inflammatory activities of Ophioglossum thermale.

Antioxidant fractions from Ophioglossum thermale were extracted with five different polar solvents using a Soxhlet type extractor. The total phenolic content of the extracts was determined by the Folin-Ciocalteu method. The ethyl acetate fraction of O. thermale was found to contain maximum phenolics. The dried fractions were screened for their antioxidant activity potential using in vitro model systems such as 1,1-diphenyl-2-picryl hydrazyl (DPPH), nitroblue tetrazolium (NBT) and lipid-peroxidation reduction at different concentrations. Results revealed that the EtOAc fraction exhibited the best performance in the DPPH assay, NBT assay and lipid peroxidation. All fractions showed more potent antioxidant capacity than green tea extract, a well-known antioxidant. Furthermore, the EtOAc fraction has the highest total phenolic content (475.65 mg of EGCG/g). In addition, the EtOAc fraction at 0.005% and 0.01% (g/100 ml) also significantly inhibited UVB irradiation-induced ROS generation in human dermal fibroblasts (HDFs). In a carrageenan-induced edema model, the EtOAc fraction showed an inhibitory effect (21.5%, p < 0.05) at 200 mg/kg (p.o.) after 300 min administration. Consequently, 3-O-methylquercetin (3MQ) was also isolated from the antioxidative EtOAc fraction. The data obtained using the above in vitro and in vivo tests suggest that the antioxidant activity of O. thermale and its anti-inflammatory effect on carrageenan-induced acute inflammation can be attributed to its ameliorating effect on oxidative damage, and thus it has great potential as a source for natural health products. To the best of our knowledge, this is the first report on the antioxidant activity of different polar extracts from O. thermale.

Inflammatory Acne in the Asian Skin Type III Treated with a Square Pulse, Time Resolved Spectral Distribution IPL System: A Preliminary Study.

BACKGROUND AND AIMS: Acne remains a severe problem for both patients and clinicians. Various approaches using photosurgery and phototherapy have been reported with varying degrees of success and robustness of results. An improved intense pulsed light (IPL) system has become available with interesting beam characteristic which might improve IPL treatment of inflammatory acne in the Asian skin, Fitzpatrick type III/IV. SUBJECTS AND METHODS: The 18 study subjects comprised 15 females and 3 males with active mild to moderately severe inflammatory acne (mean age 25.3 ± 7.70 yr, range 17-47 yr, Burton scale 1-4, all Fitzpatrick type III Asian skin). They were treated once (8 subjects) or twice (10 subjects) with an IPL system offering both square pulse and time resolved spectral distribution technologies (420 nm cut-off filter, 30 ms pulse, 8 - 12 J/cm(2), 2-3 passes). Clinical photography was taken at baseline and at 4 weeks after the final treatment. Percentage of acne clearance was assessed by an independent dermatological panel and graded from zero to 5, 5 being total clearance. RESULTS: All subjects completed the study. Post-treatment side effects were mild and transient, with virtually no downtime or postinflammatory hyperpigmentation (PIH) experienced by any subject. All subjects had some improvement and no exacerbation was seen in any subject. Clearance was evaluated by the panel as grade 4 in 5 subjects, grade 3 in 8, grade 2 in 4 and grade 1 in 1, so that 14 of 18 subjects (78%) had clearance of at least 60%. Patient evaluation was in general slightly better than that of the panel. CONCLUSIONS: The special beam characteristics of the IPL system used in the present preliminary study achieved good to very good results in the treatment of acne in the Fitzpatrick type III Asian skin without PIH induction. The results suggested that acne treatment in the Asian skin using this system is both safe and effective, and merits larger population studies to further optimize parameters and standardize top-up treatments.

Xanthelasma palpebrarum treatment with a 1,450-nm-diode laser.

BACKGROUND: Various treatments of xanthelasma palpebrarum have been studied, including surgical excision, treatment with chemicals, and ablative laser therapy, but these methods have some disadvantages. Recently, nonablative laser therapy has been proposed as a treatment for xanthelasma palpebrarum. OBJECTIVE: To investigate the efficacy and safety of a 1,450-nm-diode laser in the treatment of xanthelasma. MATERIALS AND METHODS: Sixteen patients were treated using a 1,450-nm-diode laser. Fluences of 12 J/cm(2) , a 6-mm spot size, and a dynamic cooling device setting of 20 to 30 ms were used. One to four treatments 4 to 6 weeks apart were given to each patient. Photographs were taken before each treatment session and 4 to 6 weeks after the last treatment. RESULTS: Two (12.5%), eight (50%), and four (25%) of the 16 patients were scored as having some (20-40% clearing), moderate (40-60% clearing), and marked (60-80% clearing) improvement, respectively. Focal mild transient hyperpigmentation was noted in five patients. Post-treatment local swelling lasted 3 to 4 days. CONCLUSION: The 1,450-nm-diode laser treatment is a new, valuable treatment option for xanthelasma palpebrarum, offering relatively mild side effects. Studies including long term follow up and a comparison with alternative treatment modalities are necessary to further assess the clinical utility of this treatment. The authors have indicated no significant interest with commercial supporters.

Preparation and characterization of quercetin-loaded polymethyl methacrylate microcapsules using a polyol-in-oil-in-polyol emulsion solvent evaporation method.

Flavonoids and related compounds exhibit a wide range of useful pharmacological properties but present challenges related to their stability and solubility in commonly available solvents. In this study, polymethyl methacrylate (PMMA) microcapsules were prepared using a novel polyol-in-oil-in-polyol (P/O/P) emulsion solvent evaporation method as a means of stabilizing the flavonoids, using quercetin as a model flavonoid drug. The morphology of the microcapsules was evaluated using a scanning electron microscope, revealing a spherical shape with a smooth surface. The cross-section image of the PMMA microcapsules prepared with an amphiphilic polymer in the inner polyol phase showed that the microcapsule was filled with several submicron microspheres. The mean diameter varied from 1.03+/-0.12 microm to 2.39+/-0.42 microm, and the encapsulation efficiency ranged from 12.7% to 26.9%. When free quercetin was stored at 42 degrees C, the residual quercetin content gradually decreased to 18% over 28 days as a result of oxidation. However, when encapsulated in PMMA microcapsules with an amphiphilic polymer in the inner polyol phase, the residual quercetin content decreased to just 82%. In-vitro release studies indicated a sustained release pattern throughout the 36-h study. The release kinetics of the microcapsules with an amphiphilic polymer followed a diffusion-controlled mechanism and the microcapsule without amphiphilic polymer followed an anomalous diffusion behaviour. This study suggests that the novel P/O/P emulsion solvent evaporation method can be applied to the encapsulation of flavonoids.