Photochemical reaction to increase melanogenesis using Buddleja officinalis and blue light-emitting diode irradiation in B16F10.

Recently, the incidence of vitiligo has increased because of stresses induced by external environment. Ultraviolet (UV) light therapy is the most commonly used method of treating the disease; however, UV light therapy requires a long treatment period, and prolonged exposure to UV radiation has side effects. The purpose of the present study was to investigate the effects of natural products and LED irradiation (LED-IR) on the synthesis of melanin. It was not possible to effectively increase intracellular melanin production through individual applications of Buddleja officinalis (BO), which is a natural substance selected through screening, or blue light irradiation (Blue-IR). However, when used in combination, these two agents stimulated adenylyl cyclase (AC) and melanin production was induced in the stimulated cells via the CREB/MITF/TYR pathway. Furthermore, the combined treatment with BO and Blue-IR generated low levels of cellular reactive oxygen species (ROS) and induced p38 phosphorylation, which in turn activated MITF in ROS-stimulated synthetic melanocytes, resulting in the promotion of melanogenic pathways other than the CREB/MITF/TYR pathway. In addition, this treatment combination effected melanin transport. These results suggested that the combined therapies can be used to treat melanin-deficiency skin diseases such as vitiligo.

Anti-inflammatory effect of 635 nm irradiations on in vitro direct/indirect irradiation model.

Low-level laser therapy (LLLT) has been promoted for its beneficial effects on tissue healing and pain relief. As during laser treatment it is possible to irradiate only a small area of the surface body or wound and, correspondingly, of a very small volume of the circulating blood, it is necessary to explain how its photomodification can lead to a wide spectrum of therapeutic effects. To establish the experimental model for indirect irradiation, irradiation with 635 nm was performed on immortalized human gingival fibroblasts (IGFs) in the presence of Porphyromonas gingivalis lipopolysaccharides (LPS). The irradiated medium was transferred to non-irradiated IGFs which were compared with direct irradiated IGFs. The protein expressions were assessed by Western blot, and prostaglandin E2 (PGE2 ) was measured using an enzyme-linked immunoassay. Reactive oxygen species (ROS) were measured by DCF-DA; cytokine profiles were assessed using a human inflammation antibody array. Cyclooxygenase-2 (COX-2) protein expression and PGE2 production were significantly increased in the LPS-treated group and decreased in both direct and indirect irradiated IGFs. Unlike direct irradiated IGFs, ROS level in indirect irradiated IGFs was decreased by time-dependent manners. There were significant differences of released granulocyte colony-stimulating factor (G-CSF), regulated on activated normal T-cell expressed and secreted (RANTES), and I-TAC level observed compared with direct and indirect irradiated IGFs. In addition, in the indirect irradiation group, phosphorylations of C-Raf and Erk1/2 increased significantly compared with the direct irradiation group. Thus, we suggest that not only direct exposure with 635 nm light, but also indirect exposure with 635 nm light can inhibit activation of pro-inflammatory mediators and may be clinically useful as an anti-inflammatory tool.

In vitro bactericidal effects of 625, 525, and 425 nm wavelength (red, green, and blue) light-emitting diode irradiation.

OBJECTIVE: The purpose of this study was to evaluate the relationship of 625, 525, and 425 nm wavelengths, providing average power output and effects on three common pathogenic bacteria. BACKGROUND DATA: Ultraviolet (UV) light kills bacteria, but the bactericidal effects of UV may not be unique, as 425 nm produces a similar effect. The bactericidal effects of light-emitting diode (LED) wavelengths such as 625 and 525 nm have not been described. Before conducting clinical trials, the appropriate wavelength with reasonable dose and exposure time should be established. MATERIALS AND METHODS: The bactericidal effects of 625, 525, and 425 nm wavelength LED irradiation were investigated in vitro for the anaerobic bacterium Porphyromonas gingivalis and two aerobes (Staphylococcus aureus and Escherichia coli DH5α). Average power output was 6 mW/cm(2) for 1 h. The bacteria were exposed to LED irradiation for 1, 2, 4, and 8 h (21.6, 43.2, 86.4, and 172.8 J/cm(2), respectively). LED irradiation was performed during growth on agar and in broth. Control bacteria were incubated without LED irradiation. Bacterial growth was expressed in colony-forming units (CFU) and at an optical density at 600 nm in agar and broth. RESULTS: The bactericidal effect of LED phototherapy depended upon wavelength, power density, bacterial viable number, and bacteria species. The bactericidal effect of 425 and 525 nm irradiation varied depending upon the bacterial inoculation, compared with unirradiated samples and samples irradiated with red light. Especially, P. gingivalis and E. coli DH5α were killed by 425 nm, and S. aureus growth was inhibited by 525 nm. However, the wavelength of 625 nm was not bactericidal for P. gingivalis, E. coli DH5α, or S. aureus. CONCLUSIONS: Irradiation at 625 nm light was not bactericidal to S. aureus, E. coli, and P. gingivalis, whereas wavelengths of 425 and 525 nm had bactericidal effects. S. aureus was also killed at 525 nm.

Effect of 635 nm irradiation on high glucose-boosted inflammatory responses in LPS-induced MC3T3-E1 cells.

Hyperglycemia occurs in patients with poorly controlled diabetes mellitus and contributes to bone resorption and increased susceptibility to bacterial infections. Hyperglycemia can incite low-grade inflammation that can contribute to the resorption of bone, especially the periodontal bone. The increased susceptibility to periodontal infections can contribute to bone resorption through the activation of osteoclasts. In this study, the osteoblastic, clonal cell line, MC3T3-E1, was used in an in vitro model of hyperglycemia and lipopolysaccharide-induced reactive oxygen species generation to determine the potential anti-inflammatory effect of 635 nm light-emitting diode (LED) irradiation or whether 635 nm LED irradiation can be a potential anti-inflammatory treatment. LED irradiation of MC3T3-E1 cells stimulated with lipopolysaccharide in a high glucose-containing medium decreased the level of cyclooxygenase gene and protein expression and reduced the level of prostaglandin E2 expression by decreasing the amount of reactive oxygen species generation. LED irradiation also inhibited the osteoclastogenesis in MC3T3-E1 cells by regulating the receptor activator of nuclear factor kappa-B ligand and osteoprotegerin. These findings reveal the mechanisms which are important in the pathogenesis of diabetic periodontitis and highlight the beneficial effects of 635 nm LED irradiation in reducing the adverse effects of diabetic periodontitis.