Journal of Photochemistry and Photobiology最新文献

Ultraviolet (UV) irradiation has been identified as a key trigger for skin photoaging, characterized by the overproduction of matrix metalloproteinases (MMPs) and reactive oxygen species (ROS), along with the accelerated decomposition of extracellular matrix (ECM) proteins, ultimately contributing to the development of wrinkles. Persicaria senticosa (PS) extracts are recognized for their antioxidative properties and their importance in skin health. Nevertheless, there is a paucity of studies investigating the potential of PS in protecting the skin against photoaging. The present study aimed to assess the effectiveness of PS extracts in preventing photoaging and elucidating the molecular mechanisms involved in using immortalized human keratinocytes (HaCaT) and hairless mice. The major bioactive constituents of PS were identified as p-coumaric acid, isoquercitrin, quercetin-3-O-glucuronide, and quercetin. Aqueous extracts of PS exhibited the ability to mitigate UVB-induced cellular damage and diminished ROS generation in HaCaT cells. Moreover, treatment with PS effectively attenuated the upregulated expression of matrix metalloproteinase-1 (MMP-1) and collagen degradation induced by UVB exposure. The property of PS to counteract photoaging was related to its capacity to inhibit the UVB-induced phosphorylation of mitogen-activated protein kinase (MAPK) and suppress the subsequent activation of activator protein 1 (AP-1) signaling pathways. Moreover, in hairless mice exposed to UVB radiation, the application of PS significantly alleviated the development of skin wrinkles, diminished epidermal thickening, and mitigated collagen degradation. Notably, PS treatment resulted in the downregulation of the UVB-activated MAPK/AP-1/MMP-1 pathway in mouse skin tissues. These findings suggest that PS has the potential to serve as a therapeutic agent for treating photoaging, holding promises in both cosmeceutical and pharmaceutical applications.

Photobiomodulation (PBM) is emerging as a promising non-invasive approach for managing inflammatory skin conditions. However, its precise molecular mechanisms, especially within the green light spectrum, remain elusive. In this study, we investigated the anti-inflammatory mechanisms of 520 nm green light in primary human keratinocytes (KCs) exposed to the contact sensitizer 2,4-dinitrochlorobenzene (DNCB). Our data revealed that green light effectively reduces the mRNA expression of pro-inflammatory cytokines IL-6, IL-8, and TNF-α, comparably to the effect of dexamethasone, a conventional anti-inflammatory agent. As Nuclear factor erythroid-2-related factor 2 (Nrf2) is involved in the red light response, we explored Nrf2′s role in green light anti-inflammatory activity. Green light exposure activated the Nrf2 pathway, leading to Nrf2 increased accumulation in KCs and the induction of Nrf2 target genes, including HO-1 and GCLC. Invalidation of Nrf2 with si-RNA diminished the green light's regulatory effect, indicating Nrf2′s essential role in the green light's anti-inflammatory action. As the Transient Receptor Potential Vanilloid 1 (TRPV1) channel is a potential target for green light, we investigated its role in PBM response. Blocking TRPV1 with capsazepine (CPZ) abolished the anti-inflammatory effect of green light and prevented the upregulation of Nrf2 target genes. This finding highlights TRPV1′s integral role in green light beneficial activity via the activation of the Nrf2 pathway. Overall, our study identifies TRPV1 and Nrf2 as critical players in the green light response, highlighting the versatility of PBM in controlling skin inflammation.

Near-infrared photoimmunotherapy (NIR-PIT) is a recently described method for cancer treatment that utilizes an antibody-conjugated phthalocyanine photosensitizer and NIR light. In NIR-PIT, light of 690 nm wavelength is used to activate a photosensitizer, IR700, while longer-wavelength light penetrates deeper into tissues. Thus, more effective NIR-PIT would be achieved by using photosensitizers that are activated by longer-wavelength light. The absorption wavelength would be red-shifted by destabilizing the highest occupied molecular orbital (HOMO) energy level by introducing electron donating groups at the α positions of a phthalocyanine ring. In this study, we developed a red-shifted photosensitizer for NIR-PIT, KA800, whose absorption wavelength was red-shifted by the introduction of ethoxy groups to IR700. As intended, the absorption maximum of KA800 was red-shifted compared to IR700 by 84 nm. Although phototoxicity of the antibody-KA800 (Ab-KA800) conjugate was observed in cultured cancer cells, no therapeutic effect was observed in mice. This is because the cytotoxicity of Ab-KA800 was mainly due to singlet oxygen, which can be quenched by abundant antioxidants in vivo. KA800 had low reactivity with respect to axial ligand cleavage required for inducing cell death via aggregate formation, a unique cytotoxic mechanism in NIR-PIT. The axial ligand cleavage proceeds via the anion radical formation of the photosensitizer, and KA800 was found to be less likely to receive an electron than IR700. This may be due to the destabilization of the HOMO energy level of KA800. Therefore, our findings suggest that stabilizing the lowest unoccupied molecular orbital (LUMO) energy level would be better than destabilizing the HOMO energy level for developing a red-shifted photosensitizer for NIR-PIT.

A simple method for obtaining triplet-triplet absorption (TTA) spectra and triplet state (T₁) lifetimes of long-lived triplets is presented and demonstrated with the polycyclic aromatic hydrocarbon coronene (both normal and perdeuterated forms) in a polymer matrix at room temperature. The TTA spectra obtained with a camera flash and a spectrophotometer are noisier but otherwise identical to those obtained with a state-of-the-art flash photolysis apparatus. The triplet lifetimes obtained from transient absorption are identical to the phosphorescence lifetimes of the same samples.

It is known that cell culture micropatterns have the ability to facilitate stem cell differentiation induced by specialized chemical factors and different differentiation directions have different optimal micropattern shapes. In this study, by utilizing extrinsic photobiomodulation (EPM) with verteporfin as photosensitizer and light irradiation of 690 nm wavelength as a universal, unbiased, and synchronizing way of inducing differentiation of human umbilical cord Wharton's Jelly mesenchymal stem cells (WJ-MSCs), the topographic cue for cell type specification conveyed in microislands is investigated. It is found that the topographic cues are encoded in the symmetry and aspect ratio of microislands and conformation of cells to microislands is necessary for acquiring the cue. F-actin vertical columns form and cell thickness increases for cells on microislands, and the two effects are enhanced by EPM and correlate with cell differentiation. EPM treatment poises cells in a stationary state to initiate differentiation and the process of making commitment takes two days. Our findings reveal the way to fully exploit topographic cues for promoting and controlling cell differentiation.

Various integrated technologies have been investigated for the remediation of heavily polluted industrial dye effluent. Also, more than 70 % of these dyes are known to be solely azo dyes used in the textile industry with 5–30 % presence in the effluent as loose dye molecules which are recalcitrant to treatment. These challenges led to the investigation of energy-efficient processes (solar) and the fabrication of high-performance nano-photocatalysts for proficient photocatalysis of dye effluent while mediating the process with Fenton reagents. The study fabricated nanopolymeric catalyst composites (P-AKT) via novel in situ coupling and impregnation of the polyaniline (PANI) with surface-activated TiO₂ NPs. This fabrication is aimed at developing a high-performance catalyst with rapid and proficient photocatalytic activities to photons from sunlight irradiation. The photocatalytic process was mediated using a novel Fenton reagent to enhance the generation of radical species for dye degradation. Various instrumental characterization methods were used to study the structural, molecular, elemental, functional and optoelectronic properties of the fabricated nanocomposite photocatalysts. The result reveals functional groups aiding dye-catalyst bonding and morphological interaction reveal a surface-activated tetragonal crystalline mixture of anatase and rutile from TiO₂⁻Nps embedded in the macromolecular chain of PANI. It also reveals the optimal conditions of 20 mg dosage, 10 mg/L initial concentration with substantial effectiveness at pH of 5 and 7. However, the most efficient photocatalyst recorded was P-AKT-2 % and P-AKT-3 % having 95 % and 94 % efficiencies at 90 min of solar irradiation. The photocatalyst equally demonstrated its capacity for effluent treatability up to 4 cycles of use.

Although the treatment currently recommended for snakebite accidents is serum therapy using antivenom, a need for adjunctive therapy associated with serum therapy for treating the local effects caused by snakebites is an effort of the WHO to reduce local signals and symptoms. Photobiomodulation with laser or LED therapy is one of the primary examples of adjuvant therapy to serum therapy to lessen these local effects caused by snakebite envenoming. For this purpose, the project aims to study the action of photobiomodulation with LED therapy in isolated thioglycolate-elicited macrophages stimulated with Bothrops jararacussu venom (BjV) and isolated bothropstoxins BthTX-I and BthTX-II focusing on cell dead mechanism such as necrosis and apoptosis, mitochondrial membrane potential, and cytokines [Interleukin (IL)-1β, IL-10, IL-6], and [tumor necrosis factor (TNF)-α] and lipid mediator [prostaglandin (PG)E₂] liberation. Briefly, thioglycollate-elicited macrophages were harvested from Swiss male mice incubated with BjV or BthTXs irradiated or not with LED, and the following parameters were analyzed: necrosis and apoptosis, mitochondrial membrane potential, cytokines, and lipid mediator liberation. Herein, results showed that LED therapy was able to decrease necrosis cell death, caspase-3 activity, and TNF-α liberation. In addition, LED therapy induces mitochondrial membrane potential and modulates gene expression of lipid mediators. In conclusion, the data of this study support the use of phototherapy as an adjuvant therapeutical approach in combination with serum therapy to mitigate the local effects resulting from snakebite envenoming.

Oxidative stress and inflammation in the retinal pigment epithelium (RPE) cells have been identified as significant risk factors in the development and progression of retinal associated diseases including age-related macular degeneration (AMD). In addition, AMD and myopia have been associated with impaired dopamine activity. Treatment of RPE cells with antioxidants or high concentrations of l-DOPA (levodopa), which down-regulates vascular endothelial growth factor (VEGF) via a G-protein-coupled receptor GPR143, slow AMD progression. To develop a targeted and effective treatment aimed at improving the viability of RPE cells we examined small molecular weight thiol-based and levodopa containing molecules. These include the N-acetylcysteine amide (AD4/NACA), SuperDopa-Amide (SDA), and members of the thioredoxin mimetic (TXM) family of peptides, TXM-CB13, TXM-CB30, and SuperDopa (SD). We show that these antioxidant/anti-inflammatory reagents protect ARPE-19 cells from photic stress mediated by rose Bengal (rB) and rhodopsin-rich POS, and from non-photic stress induced by oxidation with sodium iodate. Protection is correlated with a reduction in DPPH radical and singlet-oxygen quenching. Compared to GSH the bimolecular rate-constants of singlet oxygen quenching in aqueous solution by the levodopa derivatives SD and SDA were two-fold higher. Inhibition of auranofin-induced activation of the mitogen-activation-kinases (MAPK's) JNK1/2 and ERK1/2 confirmed the antioxidant/anti-inflammatory activity of the thiol-levodopa derivatives. The antioxidant and radical scavenging activities of TXM-CB13 and TXM-CB30, or SD and SDA, which combine redox activity with elevating cellular levodopa, might offer an efficient protection of RPE cells. These retino-protective peptides are potential drug candidates destined for slowing the onset and/or progression of RPE-related disorders.

Photosensitivity to structurally diverse drugs is a common but under-reported adverse cutaneous reaction and can be classified as phototoxic or photoallergic. Phototoxic reactions occur when the skin is exposed to sunlight after administering topical or systemic medications that exhibit photosensitizing activity. These reactions depend on the dose of medication, degree of exposure to ultraviolet light, type of ultraviolet light, and sufficient skin distribution volume. Accurate prediction of the incidence and phototoxic response severity is challenging due to a paucity of literature, suggesting that phototoxicity may be more frequent than reported. This paper reports an extensive literature review on phototoxic drugs; the review employed pre-determined search criteria that included meta-analyses, systematic reviews, literature reviews, and case reports freely available in full text. Additional reports were identified from reference sections that contributed to the understanding of phototoxicity. The following drugs and/or drug classes are discussed: amiodarone, voriconazole, chlorpromazine, doxycycline, fluoroquinolones, hydrochlorothiazide, nonsteroidal anti-inflammatory drugs, and vemurafenib. In reviewing phototoxic skin reactions, this review highlights drug molecular structures, their reactive pathways, and, as there is a growing association between photosensitizing drugs and the increasing incidence of skin cancer, the consequential long-term implications of photocarcinogenesis.

Today's Western lifestyle leads to increasing rates of skin cancers. Photoprotection behavior has become a hot topic in the last decades. This historical review aims at understanding modern photoprotection advice, considering decades of dermatological and photobiological research. The link between social trends, the main scientific discoveries in the field of photobiology and photoprotection strategies developed by dermatologists and industrials thanks to technological advances is narrated. Photoprotection strategies evolve in response to consumers’ demands and concerns. Here are described many social shifts, from the apparition of retributed holidays to the rise of personalized cosmetic trends. In the discussion, the most up-to-date personalized dermatological advice is presented, according to a panel of dermatologists and photoprotection experts.