Photochemical & Photobiological Sciences最新文献

Colorectal cancer (CRC) is significantly contributed to global cancer mortality rates. Treating CRC is particularly challenging due to metastasis and drug resistance. There is a pressing need for new treatment strategies against metastatic CRC. Photodynamic therapy (PDT) offers a well-established, minimally invasive treatment option for cancer with limited side effects. Hypericin (HYP), a potent photosensitizer for PDT, has been documented to induce cytotoxicity and apoptosis in various types of cancers. However, there are few reports on the inhibitory effects of HYP-mediated PDT on the metastatic ability of CRC cells. Here, we evaluate the inhibitory effects of HYP-mediated PDT against metastatic CRC cells and define its underlying mechanisms. Wound-healing and Transwell assays show that HYP-mediated PDT suppresses migration and invasion of CRC cells. F-actin visualization assays indicate HYP-mediated PDT decreases F-actin formation in CRC cells. TEM assays reveal HYP-mediated PDT disrupts pseudopodia formation of CRC cells. Mechanistically, immunofluorescence and western blotting results show that HYP-mediated PDT upregulates E-cadherin and downregulates N-cadherin and Vimentin. HYP-mediated PDT also suppresses key EMT regulators, including Snail, MMP9, ZEB1 and α-SMA. Additionally, the expressions of RhoA and ROCK1 are downregulated by HYP-mediated PDT. Together, these findings suggest that HYP-mediated PDT inhibits the migration and invasion of HCT116 and SW620 cells by modulating EMT and RhoA-ROCK1 signaling pathway. Thus, HYP-mediated PDT presents a potential therapeutic option for CRC.

A variety of 3-hydroxy-isoindolin-1-one derivatives were synthesized using the photodecarboxylative addition of carboxylates to phthalimide derivatives in aqueous media. Subsequent acid-catalyzed dehydration furnished 3-(alkyl and aryl)methyleneisoindolin-1-ones with variable E-diastereoselectivity in good to excellent overall yields. Noteworthy, the parent 3-phenylmethyleneisoindolin-1-one underwent isomerization and oxidative decomposition when exposed to light and air. Selected 3-hydroxy-isoindolin-1-one and 3-(alkyl and aryl)methyleneisoindolin-1-one derivatives showed moderate antibacterial activity that justifies future elaboration and study of these important bioactive scaffolds.

Cysteine (Cys) plays an indispensable role as an antioxidant in the maintenance of bioredox homeostasis. We have constructed an efficient fluorescent probe Mito-Cys based on the binding of indole and naphthol. The acrylic ester group serves as a recognition switch for specific detection of Cys, which undergoes Michael addition and intramolecular cyclization reactions, thereby ensuring the chemical kinetics priority of Cys compared to other biothiols. The probe has good water solubility, large Stokes shift (137 nm), with a detection limit of 21.81 nM. In addition, cell imaging experiments have shown that the probe has excellent mitochondrial targeting ability (R = 0.902). The probe can distinguish between Cys, homocysteine (Hcy) and glutathione (GSH), and can detect Cys specifically and quickly (100 s) to ensure accurate quantitative analysis of Cys changes in cells. More importantly, the probe confirms that ferroptosis inducing factors trigger thiol starvation in mitochondria, which helps to gain a deeper understanding of the physiological and pathological functions related to Cys and ferroptosis.

Knowledge of long-term time trends of solar ultraviolet (UV) radiation on ground level is of high scientific interest. For this purpose, precise measurements over a long time are necessary. One of the challenges solar UV monitoring faces is the permanent and gap-free data collection over several decades. Data gaps hamper the formation and comparison of monthly or annual means, and, in the worst case, lead to incorrect conclusions in further data evaluation and trend analysis of UV data. For estimating data to fill gaps in long-term UV data series (daily radiant exposure and highest daily irradiance), we developed three statistical imputation methods: a model-based imputation, considering actual local solar radiation conditions using predictors correlated to the local UV values in an empirical model; an average-based imputation based on a statistical approach of averaging available local UV measurement data without predictors; and a mixture of these two imputation methods. A detailed validation demonstrates the superiority of the model-based imputation method. The combined method can be considered the best one in practice. Furthermore, it has been shown that the model-based imputation method can be used as an useful tool to identify systematic errors at and between calibration steps in long-term erythemal UV data series.

We investigated the effects of daily ultraviolet A1 (UV-A1, 340-400 nm) exposures on mood states (#R19055, approval on 21 October 2020). Based on our earlier findings of the influence of diurnal preference on mood, we investigated further whether diurnal preference plays a role in the influence of UV-A1 on mood states. Forty-one healthy participants aged 19-55 years were randomized to receive either UV-A1 (n = 21) or control (n = 20) exposures (violet light, 390-440 nm). The irradiations were administered on three consecutive mornings on the skin of the buttocks and middle back. Diurnal preference was assessed with the modified 6-item Morningness-Eveningness Questionnaire (mMEQ). Changes in mood were assessed with Total Mood Disturbance (TMD) score of the 40-item Profile of Mood States (POMS) before the first irradiation, immediately after each irradiation and one week after the last irradiation. Mood improved among those subjected to UV-A1 exposures compared with the controls (p = 0.031). Individuals with more pronounced morningness had mood improvement (p = 0.011), whereas those with more pronounced eveningness did not (p = 0.41). At follow-up of one week after the last irradiation the mood improvement had disappeared.

Mucormycosis is an extremely aggressive fungal disease with a high mortality rate, especially in people with compromised immune systems. Most cases of mucormycosis are caused by the fungus Rhizopus oryzae. The treatments used are based on high doses of antifungals, associated with surgical resections, when it is possible. However, even with this aggressive treatment, the estimated attributable mortality rate is high. There is therefore a need to develop adjuvant treatments. Photodynamic Inactivation (PDI) may be an auxiliary therapeutic option for mucormycosis. Due to the lack of reports in the literature on the morphology and photodynamic inactivation of R. oryzae, characterization of the fungus using Confocal Microscopy and Transmission Electron Microscopy, and different protocols using Photodithazine® (PDZ), a chlorin e6 compound, as a photosensitizer, were performed. The fungus growth rate under different concentrations and incubation times of the photosensitizer and its association with the surfactant Sodium Dodecyl Sulphate (SDS) was evaluated. For the hyphae, both in the light and dark phases, in the protocols using only PDZ, no effective photodynamic response was observed. Meanwhile with the combination of SDS 0.05% and PDZ, inhibition growth rates of 98% and 72% were achieved for the white and black phase, respectively. In the conidia phase, only a 1.7 log₁₀ reduction of the infective spores was observed. High concentration of melanin and the complex and resistant structures, especially at the black phase, results in a high limitation of the PDI inactivation response. The combined use of the SDS resulted in an improved response, when compared to the one obtained with the amphotericin B treatment.

Double difunctionalization of a vinyl ether tethered hydroxy or carbamoyl group with electron-deficient alkenes such as acrylonitrile or acrylic esters was achieved by visible-light irradiation in a two-molecule photoredox system. Use of anhydrous acetonitrile solution as a solvent promoted both dimerization of the radical cation of electron-rich alkene with electron-rich alkene and intramolecular nucleophilic addition to generate an electron-rich radical that was added to electron-deficient alkene to furnish the double difunctionalized product. A variety of electronically differentiated rich and deficient alkenes were used in the photoreaction; a simple construction of a complex carbon framework containing acetal from simple alkenes was successful under mild conditions.

Paracoccidioidomycosis (PCM) is a systemic mycosis with serious clinical consequences in which the use of antifungal drugs requires long-term treatment. Therefore, we studied the effect of low-level LASER therapy (LLLT) to evaluate its prospects as a complementary treatment for PCM and improve the clinical response to the disease.

Objectives: Our study focused on the resolution of lesions caused by fungal infection using a subcutaneous air pouch model of infection.

Methods: We evaluated cell profile and cytokines, fungi viability, and the presence of fibroblasts and fibrocytes at the site of infection. Inoculation of P. brasiliensis (Pb) was performed using a subcutaneous air pouch model and the LLLT irradiation was performed on alternate days on the rear paws of mice for 10 days, after which the cells from the air pouch were collected and analyzed.

Results: In animals irradiated with LLLT, the influx of cells to the air pouch was reduced, but they were more activated and produced pro-inflammatory (IL-12, IL-17 and TNF-α) and neutrophil (PMN) activating cytokines (IL-8, GM-CSF and γ-IFN). A better resolution of the infection, evidenced by the reduction in the number of viable fungi with preserved morphology in the air pouch, and an increase in the number of fibrocytes, indicating a healing profile were also observed.

Conclusion: LLLT decreased the influx of PMN, but those presents were highly activated, with increased fungicidal activity. LLLT irradiation also resulted in earlier cicatrization at the site of infection, leading to a better outcome of the infection. These data are favorable to the use of LLLT as a complementary therapy in PCM.

Bioluminescence, the emission of light by living organisms, is a captivating and widespread phenomenon with diverse ecological functions. This comprehensive review explores the biodiversity, mechanisms, ecological roles, and conservation challenges of bioluminescent organisms in Brazil, a country known for its vast and diverse ecosystems. From the enchanting glow of fireflies and glow-in-the-dark mushrooms to the mesmerizing displays of marine dinoflagellates and cnidarians, Brazil showcases a remarkable array of bioluminescent species. Understanding the biochemical mechanisms and enzymes involved in bioluminescence enhances our knowledge of their evolutionary adaptations and ecological functions. However, habitat loss, climate change, and photopollution pose significant threats to these bioluminescent organisms. Conservation measures, interdisciplinary collaborations, and responsible lighting practices are crucial for their survival. Future research should focus on identifying endemic species, studying environmental factors influencing bioluminescence, and developing effective conservation strategies. Through interdisciplinary collaborations, advanced technologies, and increased funding, Brazil can unravel the mysteries of its bioluminescent biodiversity, drive scientific advancements, and ensure the long-term preservation of these captivating organisms.

Δ⁹-THC, the psychotropic cannabinoid in Cannabis sativa L., for many years has been the focus of all the pharmacological attention as the main promising principle of the plant. Recently, however, cannabidiol (CBD) has brought a sudden change in the scenario, exponentially increasing the interest in pharmacology as the main non-psychotropic cannabinoid with potential therapeutic, cosmetical and clinical applications. Although the reactivity of CBD and Δ⁹-THC has been considered, little attention has been paid to the possible photodegradation of these cannabinoids in the vegetal matrix and the data available in the literature are, in some cases, contradictory. The aim of the present work is to provide a characterization of the photochemical behaviour of CBD and Δ⁹-THC in three cannabis chemotypes, namely I (Δ⁹-THC 2.50%_w/w), II (CBD:Δ⁹-THC 5.82%_w/w:3.19%_w/w) and III (CBD 3.02%_w/w).