Protective Effect of Djulis (Chenopodium formosanum) Extract against UV- and AGEs-Induced Skin Aging via Alleviating Oxidative Stress and Collagen Degradation.

Skin aging is a complex process involving photoaging and glycation stress, which share some fundamental pathways and have common mediators. They can cause skin damage and collagen degradation by inducing oxidative stress and the accumulation of reactive oxygen species (ROS). Chenopodium formosanum (CF), also known as Djulis, is a traditional cereal in Taiwan. This study investigated the protection mechanisms of CF extract against ultraviolet (UV) radiation and advanced glycation end products (AGEs)-induced stress. The results indicated that CF extract had strong antioxidant and free radical scavenging effects. It could reduce UV-induced intracellular ROS generation and initiate the antioxidant defense system by activating the nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling pathway in human skin fibroblasts. CF extract modulated mitogen-activated protein kinase (MAPK) and transformed growth factor-beta (TGF-ß) signaling pathways to alleviate oxidative stress-induced skin aging. Moreover, the results revealed that CF extract not only promoted collagen synthesis but also improved aging-induced collagen degradation. CF extract attenuated AGEs-induced ROS production and the upregulation of receptor for AGEs (RAGE). The overall results suggest that CF extract provides an effective anti-aging strategy by preventing skin damage from oxidative stress and collagen loss with potent antioxidant, anti-photoaging, and antiglycation activities.

The Anti-Melanogenesis Effect of 3,4-Dihydroxybenzalacetone through Downregulation of Melanosome Maturation and Transportation in B16F10 and Human Epidermal Melanocytes.

The biosynthesis pathway of melanin is a series of oxidative reactions that are catalyzed by melanin-related proteins, including tyrosinase (TYR), tyrosinase-related protein-1 (TRP-1), and tyrosinase-related protein-2 (TRP-2). Reagents or materials with antioxidative or free radical-scavenging activities may be candidates for anti-melanogenesis. 3,4-Dihydroxybenzalacetone (DBL) is a polyphenol isolated from fungi, such as Phellinus obliguus (Persoon) Pilat and P. linteus. In this study, we investigated the effects and mechanisms of DBL on antioxidation and melanogenesis in murine melanoma cells (B16F10) and human epidermal melanocytes (HEMs). The results indicated that DBL scavenged 2,2-diphenyl-1-picrylhydrazyl (DPPH) and hydroxyl radicals, and exhibited potent reducing power, indicating that it displays strong antioxidative activity. DBL also inhibited the expression of TYR, TRP-1, TRP-2, and microphthalmia-related transcription factor (MITF) in both the cells. In addition, DBL inhibited hyperpigmentation in B16F10 and HEMs by regulating the cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA), v-akt murine thymoma viral oncogene homolog (AKT)/glycogen synthase kinase 3 beta (GSK3ß), and mitogen-activated protein kinase kinase (MEK)/extracellular regulated protein kinase (ERK) signaling pathways. DBL not only shortened dendritic melanocytes but also inhibited premelanosome protein 17 (PMEL17) expression, slowing down the maturation of melanosome transportation. These results indicated that DBL promotes anti-melanogenesis by inhibiting the transportation of melanosomes. Therefore, DBL is a potent antioxidant and depigmenting agent that may be used in whitening cosmetics.

(-)-ß-Homoarginine anhydride, a new antioxidant and tyrosinase inhibitor, and further active components from Trichosanthes truncata.

One new amino acid derivative, (-)-ß-homoarginine anhydride 1, as well as nine known compounds were isolated from Trichosanthes truncata. The structures of the isolates were elucidated by spectroscopic methods. Among them, compounds 5 and 11 could notably dose-dependently inhibit ROS productions in HaCaT keratinocyte cells without cytotoxicity in the concentration range of 0.2-20 µM. In cell-free mushroom tyrosinase assay, compounds 1-5, 10 and 11 had more potential anti-tyrosinase activities with IC50 values of 106.9-255.6 µM than arbutin that were similar to predicted values of binding affinity calculated by molecule docking. The most active 2 had hydrogen bonds (Ser77, Glu309, Phe454) and electrostatic charges (Glu309, Glu248) interactions with mushroom tyrosinase, respectively. Our data manifested that T. truncata and its components are potentially to be developed as anti-aging and whitening agents for skin disorders.

Sesamol Inhibited Ultraviolet Radiation-Induced Hyperpigmentation and Damage in C57BL/6 Mouse Skin.

Melanin is synthesized through a series of oxidative reactions initiated with tyrosine and catalyzed by melanogenesis-related proteins such as tyrosinase, tyrosinase-related protein-1 (TRP-1), dopachrome tautomerase (TRP-2), and microphthalmia-associated transcription factor (MITF). Our previous study demonstrated that sesamol inhibited melanin synthesis through the inhibition of the melanocortin 1 receptor (MC1R)/MITF/tyrosinase pathway in B16F10 cells. In this study, sesamol was applied to C57BL/6 mouse skin to understand its activity with respect to skin pigmentation. The results indicated that ultraviolet (UV) B-induced hyperpigmentation in the C57BL/6 mouse skin was significantly reduced by topical application of sesamol for 4 weeks. Sesamol reduced the melanin index and melanin content of the skin. In addition, sesamol elevated the brightness (L* value) of the skin. Sesamol also reduced UVB-induced hyperplasia of epidermis and collagen degradation in dermis. In immunohistochemical staining, topical application of sesamol reduced UVB-induced tyrosinase, TRP-1, TRP-2, and MITF expression in the epidermis of the skin. These results demonstrated that sesamol is a potent depigmenting agent in the animal model.

Protective Effects and Mechanisms of N-Phenethyl Caffeamide from UVA-Induced Skin Damage in Human Epidermal Keratinocytes through Nrf2/HO-1 Regulation.

The skin provides an effective barrier against physical, chemical, and microbial invasion; however, overexposure to ultraviolet (UV) radiation causes excessive cellular oxidative stress, which leads to skin damage, DNA damage, mutations, and skin cancer. This study investigated the protective effects of N-phenethyl caffeamide (K36) from UVA damage on human epidermal keratinocytes. We found that K36 reduced UVA-induced intracellular reactive oxygen species (ROS) production and induced the expression of the intrinsic antioxidant enzyme heme oxygenase-1 (HO-1) by increasing the translocation of nuclear factor erythroid 2⁻related factor 2 (Nrf2). K36 could inhibit the phosphorylation of extracellular-signal-regulated kinase (ERK) and c-Jun N-terminal kinases (JNK) and reduce UVA-induced matrix metalloproteinase (MMP)-1 and MMP-2 overexpression; it could also elevate the expression of tissue inhibitors of metalloproteinases (TIMP). In addition, K36 ameliorated 8-hydroxy-2'-deoxyguanosine (8-OHdG) induced by UVA irradiation. Furthermore, K36 could downregulate the expression of inducible nitric oxide synthase (iNOS) and interleukin-6 (IL-6) and the subsequent production of nitric oxide (NO) and prostaglandin E2 (PGE2). Based on our findings, K36 possessed potent antioxidant, anti-inflammatory, antiphotodamage, and even antiphotocarcinogenesis activities. Thus, K36 has the potential to be used to multifunctional skin care products and drugs.

New diterpenes leojaponins G-L from Leonurus japonicus.

Six new diterpenes, leojaponins G-L (1-6) along with 19 known compounds (7-25) were isolated from Leonurus japonicus. Their structures were elucidated by NMR, MS, IR, UV, and ECD spectroscopic data. Anti-melanogenesis assay indicated that 7 could safely and dose-dependently decrease melanin production in B16F10 melanoma cell with an IC50 value of 59.1 µM, but moderately inhibit tyrosinase activity. Without cytotoxicities at 20 µM, compounds 11, 14, 15, and 17-21 showed significant melanogenesis stimulation activities at the percentages of 7.7-48.2. Antioxidants 19 and 24 could notably inhibit ROS production in a dose-dependent manner with percentages of 24.7-42.2 and 27.9-40.2, respectively among the concentrations of 0.16 to 100 µM. Our results demonstrated L. japonicus and its constituents could be potential botanical resources of cosmeceutical development for treatment and prevention of skin disorders.

Sesamol Inhibited Melanogenesis by Regulating Melanin-Related Signal Transduction in B16F10 Cells.

Melanin is synthesized through a series of interactions catalyzed by melanogenic enzymes such as tyrosinase, dopachrome tautomerase (tyrosinase-related protein-2; TRP-2), and tyrosinase-related protein-1 (TRP-1). Tyrosinase plays a key role in catalysing the initial and limiting steps of melanogenesis. The melanin that results from melanogenesis has the protective effect of absorbing ultraviolet radiation. However, overproduction of melanin, in addition to altering the appearance of skin, may lead to skin disorders such as melasma, solar lentigo, and postinflammatory hyperpigmentation. Previous studies have revealed that sesamol is a strong antioxidant and a free radical scavenger. In this study, we investigated the effects of sesamol on the regulation of melanogenesis and related mechanisms in B16F10 cells. The results indicated that sesamol inhibited tyrosinase activity and melanogenesis induced by α-melanocyte-stimulating hormone (α-MSH) in B16F10 melanoma cells. Sesamol decreased the protein level of melanocortin 1 receptor (MC1R), microphthalmia-associated transcription factor (MITF), tyrosinase, and TRP-1 by downregulating cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA) pathways that had been activated by α-MSH. Sesamol increased glycogen synthase kinase 3 beta (GSK3ß), protein kinase B (AKT), and extracellular signal-related kinase (ERK) phosphorylation, thus inhibiting the transcription of MITF. Sesamol also inhibited melanin synthesis and tyrosinase expression by modulating ERK, phosphoinositide 3-kinase (PI3K)/AKT, p38, and c-Jun amino-terminal kinase (JNK) signalling pathways. These results indicate that sesamol acted as a potent depigmenting agent.

Fisetin Regulates Nrf2 Expression and the Inflammation-Related Signaling Pathway to Prevent UVB-Induced Skin Damage in Hairless Mice.

Chronic ultraviolet (UV) exposure may cause skin damage, disrupt skin barrier function, and promote wrinkle formation. UV induces oxidative stress and inflammation, which results in extracellular matrix degradation in the dermis and epidermal hyperplasia. Our previous study demonstrated that fisetin exerts photoprotective activity by inhibiting mitogen-activated protein kinase/activator protein-1/matrix metalloproteinases (MMPs) activation. In this study, fisetin was applied topically to investigate its antiphotodamage effects in hairless mice. The erythema index (a* values) and transepidermal water loss were evaluated to assess skin damage, and immunohistochemical staining was conducted to elucidate the photoprotective mechanism of fisetin. The results revealed that the topical application of fisetin reduced UVB-induced increase in the a* value and wrinkle formation. In addition, fisetin inhibited epidermal hyperplasia and increased the collagen content in the dermis. Fisetin exerted photoprotective activity by inhibiting the expression of MMP-1, MMP-2, and cyclooxygenase-2 and increasing the expression of nuclear factor erythroid 2-related factor. Furthermore, fisetin increased the expression of filaggrin to prevent UVB-induced barrier function disruption. Altogether, the present results provide evidence of the effects and mechanisms of fisetin's antiphotodamage and antiphotoinflammation activities.

Comparison of E and NS1 antigens capture ELISA to detect dengue viral antigens from mosquitoes.

BACKGROUND & OBJECTIVES: In the absence of an effective vaccine or specific antiviral therapy against dengue infection, the only available control measure remains focusing on the incrimination and reduction of vector (mosquito) populations to suppress virus transmission. Diagnosis of dengue in laboratory can be carried out using several approaches, however, their sensitivity and specificity vary from test-to-test. This study was conducted to evaluate the sensitivity and stability of viral envelope (E) and NS1 antigens detected by ELISA in dengue virus infected mosquitoes. METHODS: An in-house developed E-ELISA to detect dengue E antigens was first characterized by using cross-reactive monoclonal antibody (mAb) 42-3 and rabbit polyclonal antibodies as the capture and detector antibodies, respectively. The sensitivity of E-ELISA was compared with the Platelia Dengue NS1 Ag kit using experimentally infected or field-caught mosquitoes. RESULTS: Our results demonstrated that the E-ELISA was capable of detecting viral antigens with the sensitivity of 69.57, 100, 52.38 and 66.67% for DENV-1 to DENV-4 infected mosquito pools, respectively. This was comparable to the Platelia Dengue NS1 Ag kit, detecting 100% of DENV-1 infected mosquito pools. Among 124 field-collected mosquito pools collected in the vicinity of localized outbreak areas; both E-ELISA and NS1 Ag kit confirmed nine RT-PCR positive samples with sensitivity and concordance rate up to 100%. INTERPRETATION & CONCLUSION: With the future potential of antigen capture ELISA to be used in the resource deprived regions, the study showed that E-ELISA has similar sensitivity and antigen stability as NS1 Ag kit to complement the current established virological surveillance in human. The improvement of the sensitivity in detecting DENV-3/4 will be needed to incorporate this method into routine mosquito surveillance system.

A proposal for a spiritual care assessment toolkit for religious volunteers and volunteer service users.

Based on the idea that volunteer services in healthcare settings should focus on the service users' best interests and providing holistic care for the body, mind, and spirit, the aim of this study was to propose an assessment toolkit for assessing the effectiveness of religious volunteers and improving their service. By analyzing and categorizing the results of previous studies, we incorporated effective care goals and methods in the proposed religious and spiritual care assessment toolkit. Two versions of the toolkit were created. The service users' version comprises 10 questions grouped into the following five dimensions: "physical care," "psychological and emotional support," "social relationships," "religious and spiritual care," and "hope restoration." Each question could either be answered with "yes" or "no". The volunteers' version contains 14 specific care goals and 31 care methods, in addition to the 10 care dimensions in the residents' version. A small sample of 25 experts was asked to judge the usefulness of each of the toolkit items for evaluating volunteers' effectiveness. Although some experts questioned the volunteer's capacity, however, to improve the spiritual care capacity and effectiveness provided by volunteers is the main purpose of developing this assessment toolkit. The toolkit developed in this study may not be applicable to other countries, and only addressed patients' general spiritual needs. Volunteers should receive special training in caring for people with special needs.

Religious coping methods of Taiwanese folk religion.

The purpose of this study was to explore religious coping methods employed by Taiwanese folk religious believers. This study applied qualitative research methods in data collection and data analysis by conducting semi-structured interviews with participants and analyzing the interview contents. We have identified fourteen coping methods that can be categorized into five different religious dimensions: belief, ritual, ethical, emotional and material. The findings not only expanded our knowledge about how believers of Taiwanese folk religion employ the religion to cope with difficulties but also discovered that some coping methods employed by them are also reported in Western countries, only in different forms.

Long-term care residents' views about the contributions of Christian-based volunteers in Taiwan: a pilot study.

This pilot study explored the view from six long-term care residents on the contributions of religious volunteers. The findings suggest that religious volunteers may contribute to long-term care residents' religious or spiritual health more than non-religious volunteers. However, since religious volunteers lack professional training and competence to attend to patients' religious needs, they may not afford in-depth spiritual and religious services. Under certain conditions when qualified chaplains are not available, inadequate religious services performed by religious volunteers are still better than no such care at all. However, in order to provide this important aspect of holistic care, we propose that health care policy makers should pay more attention to this topic.

Implementation of an indium-tin-oxide (ITO) direct-Ohmic contact structure on a GaN-based light emitting diode.

A GaN-based light-emitting diode (LED) with a direct-Ohmic contact structure, formed by an indium-tin-oxide (ITO) transparent film and Au thermal-diffused and removed layer, is studied. By depositing an Au metallic film on the Mg-doped GaN layer followed by thermal annealing and removed processes, an ITO direct-Ohmic contact at p-GaN/ITO interface is formed. An enhanced light output power of 18.0% is also found at this condition. This is mainly attributed to the larger and more uniform light-emission area resulted from the improved current spreading capability by the use of an ITO direct-Ohmic contact structure.

Performance investigation of GaN-based light-emitting diodes with tiny misorientation of sapphire substrates.

GaN-based light-emitting diodes (LEDs) grown on c-plane vicinal sapphire substrates are fabricated and characterized. Based on the material quality and electrical properties, the LED with a 0.2 degrees tilt sapphire substrate (device A) exhibits the lowest defect density and high performance, while the LED with a 1.0 degrees tilt sapphire (device D) exhibits the highest one. At 2 mA, the extremely enhanced output power of 23.3% indicates of the reduction of defect-related nonradiative recombination centers in active layers for the device A. At 60 mA, the improved value is up to 45.7%. This is primarily caused by the formation of indium quantum dots in MQW which provides an increased quantum efficiency.