Oxidative stress, in which the amount of oxidants exceeds the capacity of antioxidant defense system, is a well-accepted pathogenesis of several human diseases. Light-emitting diode irradiation (LEDI) is an efficient strategy to counteract this condition. The biological effect of phototherapy, using visible light, has attracted recent attention especially in dermatological practice. However, little is known about the molecular mechanism of the anti-oxidant and anti-inflammatory effects of red light irradiation. We evaluated these effects of LEDI in HaCaT human keratinocyte cells under phorbol-12-myristate-13-acetate (PMA) induced reactive oxygen species (ROS). Microarray analysis revealed changes in 309 genes after LEDI. LEDI at 625 nm produced ROS scavenging and anti-inflammatory effects. One of the most important genes identified by microarray analysis was sphingosine kinase-1 (SPHK1), which is a key molecule in sphingolipid metabolism. SPHK1 knock-down drastically reduced ROS scavenging efficiency as well as expression levels of inflammation-related proteins in PMA-treated HaCaT cells. These results not only indicate the potential for the clinical application of 625-nm LEDI in treating skin disorders via ROS and/or inflammation, but also suggest SPHK1 as a potential therapeutic target in phototherapy.

Epidermal inflammation is caused by various bacterial infectious diseases that impair the skin health. Feruloylserotonin (FS) belongs to the hydroxycinnamic acid amides of serotonin, which mainly exists in safflower seeds and has been proven to have anti-inflammatory and antioxidant activities. Human epidermis mainly comprises keratinocytes whose inflammation causes skin problems. This study investigated the protective effects of FS on the keratinocyte with lipopolysaccharides (LPS)-induced human HaCaT cells and elucidated its underlying mechanisms of action. The mechanism was investigated by analyzing cell viability, PGE2 levels, cell apoptosis, nuclear factor erythroid 2-related factor 2 (Nrf2) translocation, and TLR4/NF-κB pathway. The anti-inflammatory effects of FS were assessed by inhibiting the inflammation via down-regulating the TLR4/NF-κB pathway. Additionally, FS promoted Nrf2 translocation to the nucleus, indicating that FS showed anti-oxidative activities. Furthermore, the antioxidative and anti-inflammatory effects of FS were found to benefit each other, but were independent. Thus, FS can be used as a component to manage epidermal inflammation due to its anti-inflammatory and anti-oxidative properties.

Photodynamic therapy (PDT) is generally safer and less invasive than conventional strategies for head and neck cancer treatment. However, currently available photosensitizers have low selectivity for tumor cells, and the burden and side effects are so great that research is needed to develop safe photosensitizers. In this study, it was confirmed that the Buddleja officinalis (BO) extract, used in the treatment of inflammation and vascular diseases, shows fluorescence when activated by LED light, and, based on this, we aimed to develop a new photosensitive agent suitable for PDT. MTT, Diff-Quick® staining, and DCF-DA were performed to measure the effects of treating head and neck cancer cells with BO extract and 625 nm LED light (BO-PDT). Cell cycle, TUNEL, and western blot assays, as well as acridine orange staining, were performed to explore the mechanism of BO-PDT-induced cell death. We found that when the BO extract was irradiated with 625 nm LED light, it showed sufficient fluorescence and stronger intracellular toxicity and ROS effect than the currently commercially available hematoporphyrin. BO-PDT resulted in a decrease of mTOR activity that was correlated with an increase in the levels of ATG5, beclin-1, and LC3-II, which interfere with the formation of autophagosomes. In addition, BO-PDT induced the activation of PARP and led to an increase in the expression of proapoptotic protein Bax and a decrease in the expression of the antiapoptotic protein Bcl-2. Moreover, BO-PDT has been shown to induce the autophagy pathway 4 h after treatment, while apoptosis was induced 16 h after treatment. Finally, we confirmed that BO-PDT caused cell death of head and neck cancer cells via the intrinsic pathway. Therefore, we suggest that BO extract can be used as a new photosensitizer in PDT of head and neck cancer.

The practice of enhancing existing rivers and creating entirely new waterscapes has exploded in China over the past two decades. In our study of 104 randomly selected cities across China, we identified 14 types of river projects based on grey literature reports and their appearance on sequential aerial imagery, falling into three categories: ‘engineering’, ‘waterfront spaces’ and ‘ecological’ projects. ‘Waterfront spaces’ is the most common (60.5%), followed by ‘engineering’ (28.7%) and ‘ecological’ (10.8%). Using multiple stepwise regression, we found that the types of projects undertaken were strongly influenced by factors such as climate, social-economic setting, and ‘Landscape Garden City’ designation. Designation as a ‘Landscape Garden City’ was correlated with ‘waterfront spaces’, but not ‘engineering’ and ‘ecological’ projects. We found that cities in drier climates (as measured by ‘precipitation minus evaporation’) constructed more projects and they included many projects that impounded seasonal rivers to create year-round water bodies. Based on our results, we conclude that Chinese cities are still in the process of ‘decorating’ rivers, and that the ‘Landscape Garden City’ designation promoted such ‘decorating’ projects, especially ‘linear greening’ projects and ‘public spaces along rivers’. The results also demonstrate that the new river projects in China are often at odds with the local climate.