Effect of photobiomodulation on alleviating primary dysmenorrhea caused by PGF2α.

Photobiomodulation (PBM) has attracted widespread attention in suppressing various pain and inflammation. Primary dysmenorrhea (PD) primarily occurs in adolescents and adult females, and the limited effectiveness and side effects of conventional treatments have highlighted the urgent need to develop and identify new adjunct therapeutic strategies. In this work, the results of pain and PGs demonstrated that 850 nm, 630 nm, and 460 nm all exhibited pain inhibition, decreased PGF2α and upregulated PGE2, while 630 nm PBM has better effectiveness. Then to explore the underlying biological mechanisms of red light PBM on PD, we irradiated prostaglandin-F2α induced HUSM cells and found that low-level irradiance can restore intracellular calcium ion, ROS, ATP, and MMP levels to normal levels. And, red light enhanced cell viability and promoted cell proliferation for normal HUSM cells. Therefore, this study proposes that red light PBM may be a promising approach for the future clinical treatment of PD.

Effects of photobiomodulation at various irradiances on normal and dihydrotestosterone-treated human hair dermal papilla cells in vitro.

Androgenetic alopecia (AGA) is the most common type of hair loss caused by dihydrotestosterone (DHT) binding to androgen receptors in dermal papilla cells (DPCs). Photobiomodulation (PBM) is a promising treatment for AGA but suffers from inconsistent outcomes and inconsistent effective light parameters. This study investigated the impact of red light at various irradiances on normal and DHT-treated DPCs. Our results suggested that red light at 8 mW/cm2 was most effective in promoting DPCs growth. Furthermore, a range of irradiances from 2 to 64 mW/cm2 modulated key signaling pathways, including Wnt, FGF, and TGF, in normal and DHT-treated DPCs. Interestingly, 8 mW/cm2 had a greater impact on these pathways in DHT-treated DPCs and altered the Shh pathway, suggesting that the effect of PBM varies with the cellular environment. This study highlights specific factors that influence PBM effectiveness and provides insight into the need for personalized PBM treatment approaches.

Effect of blue light on the cell viability of A549 lung cancer cells and investigations into its possible mechanism.

Blue light has attracted extensive attention as a new potential cancer therapy. Recent studies have indicated that blue light has a significant inhibition effect on A459 cells. However, the effect of light parameters on the treatment of A549 cells and the mechanism of how blue light made the effect was still unclear. This study aimed to investigate A549 cells responses to blue light with varying irradiance and dose-dense, and tried to find out the mechanism of the effects blue light made. The results suggested that the responses of A549 cells to blue light with different irradiance and dose-dense were different and the decrease of cell viability reached saturation when the irradiance reached 3 mW/cm2 and the dose-dense reached 3.6 J/cm2 . It was assumed that blue light suppressed PI3K/AKT pathway and promoted the expression of JNK and p53 to affect the proliferation of A549 cells.

The Parameters Affecting Antimicrobial Efficiency of Antimicrobial Blue Light Therapy: A Review and Prospect.

Antimicrobial blue light (aBL) therapy is a novel non-antibiotic antimicrobial approach which works by generating reactive oxygen species. It has shown excellent antimicrobial ability to various microbial pathogens in many studies. However, due to the variability of aBL parameters (e.g., wavelength, dose), there are differences in the antimicrobial effect across different studies, which makes it difficult to form treatment plans for clinical and industrial application. In this review, we summarize research on aBL from the last six years to provide suggestions for clinical and industrial settings. Furthermore, we discuss the damage mechanism and protection mechanism of aBL therapy, and provide a prospect about valuable research fields related to aBL therapy.

Inhibition of Aspergillus oryzae Mycelium Growth and Conidium Production by Irradiation with Light at Different Wavelengths and Intensities.

Aspergillus oryzae is a safe filamentous fungus widely used in the food, medicine, and feed industries, but there is currently not enough research on the light response of A. oryzae. In this study, 12 different light conditions were set and A. oryzae GDMCC 3.31 was continuously irradiated for 72 h to investigate the effect of light on mycelial growth and conidium production. Specifically, each light condition was the combination of one light wavelength (475, 520, or 630 nm) and one light intensity (20, 40, 60, or 80 µmol photon m-2 s-1). The results show that mycelium growth was inhibited significantly by green light (wavelength of 520 nm and intensities of 20 and 60 µmol photon m-2 s-1) and blue light (wavelength of 475 nm and intensity of 80 µmol photon m-2 s-1). The production of conidia was suppressed only by blue light (wavelength of 475 nm and intensities of 40, 60, and 80 µmol photon m-2 s-1), and those levels of inhibition increased when the intensity of blue light increased. When the strain was irradiated by blue light (80 µmol photon m-2 s-1), the number of conidia was 57.4% less than that of the darkness group. However, within our set range of light intensities, A. oryzae GDMCC 3.31 was insensitive to red light (wavelength of 630 nm) in terms of mycelium growth and conidium production. Moreover, interaction effects between light wavelength and intensity were found to exist in terms of colony diameter and the number of conidia. This research investigated the light response of A. oryzae, which may provide a new method to regulate mixed strains in fermented foods by light. IMPORTANCE Studies on the monochromatic light response of Aspergillus nidulans and Neurospora crassa have gone deep into the molecular mechanism. However, research methods for the light response of A. oryzae remain in the use of white light sources. In this study, we first demonstrated that A. oryzae GDMCC 3.31 was sensitive to light wavelength and intensity. We have observed that blue light inhibited its growth and sporulation and the inhibitory effect increased with intensity. This research not only adds new content to the study of the photoreaction of Aspergillus but also brings new possibilities for the use of light to regulate mixed strains and ultimately improve the flavor quality of fermented foods.

Comparative transcriptome analysis of gene expression patterns on B16F10 melanoma cells under Photobiomodulation of different light modes.

Cutaneous melanoma is one of the aggressive cancers. Recent studies have shown that Photobiomodulation (PBM) can inhibit the proliferation of melanoma cells. However, it is not clear that the effect of PBM light mode on the inhibition of melanoma cells. Herein, we investigated the difference of influence between continuous wave (CW) and Pulse PBM on B16F10 melanoma cells. Our results suggested that Pulse mode had a more significant inhibition on the viability of B16F10 melanoma cells than CW mode under the PBM light parameter of wavelength, dose, and average irradiance at 457 nm, 1.14 J/cm2, and 0.19 mW/cm2. Besides, we revealed the differentially expressed genes of B16F10 melanoma cells under the various treatments of PBM light mode (not PBM treatment, CW mode, and Pulse mode) by RNA sequencing. Together, our data suggested that Pulse-PBM can improve the effect of PBM on cells significantly and there may be different molecular mechanisms between Pulse and CW mode including anti-proliferative and cell necrosis. The study shed new light on investigating the molecular mechanisms of various PBM light modes on B16F10 melanoma cells.