The Science and (Lost) Art of Psoralen Plus UVA Phototherapy

Methods and applications of genome-wide profiling of DNA damage and rare mutations

DNA damage is a threat to genome integrity and can be a cause of many human diseases, owing to either changes in the chemical structure of DNA or conversion of the damage into a mutation, that is, a permanent change in DNA sequence. Determining the exact positions of DNA damage and ensuing mutations in the genome are important for identifying mechanisms of disease aetiology when characteristic mutations are prevalent and probably causative in a particular disease. However, this approach is challenging particularly when levels of DNA damage are low, for example, as a result of chronic exposure to environmental agents or certain endogenous processes, such as the generation of reactive oxygen species. Over the past few years, a comprehensive toolbox of genome-wide methods has been developed for the detection of DNA damage and rare mutations at single-nucleotide resolution in mammalian cells. Here, we review and compare these methods, describe their current applications and discuss future research questions that can now be addressed.

The phenomenon of phototoxicity and long-term risks of commonly prescribed and structurally diverse drugs

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.

Excimer Laser System: The Revolutionary Way to Treat Psoriasis

Psoriasis is a chronic, autoinflammatory skin disease that affects approximately 100 million people worldwide. It is a systemic disease characterized by scaly, red patches on the skin and can also affect the joints. Psoriasis can significantly affect a person's physical and mental health. The prevalence rate of psoriasis may vary depending on the specific population studied and the diagnostic criteria used. Phototherapy is a safe and effective treatment for psoriasis that involves exposing the affected skin to specific wavelengths of light. It can be used alone or with other treatments for severe psoriasis. However, clinicians must choose the right light source for each type of psoriasis and monitor the patient closely during treatment to avoid adverse events. The 308 nm excimer laser is a widely used device in dermatology for treating several skin conditions, including psoriasis. Although the excimer laser can treat various dermatologic diseases, this study will focus only on its effectiveness in treating psoriasis. This study will review the use of an excimer laser, its protocol, and its side effects.

Extracorporeal Photopheresis in Graft-versus-Host Disease

Graft-versus-host disease (GVHD) is a major cause of mortality and morbidity following allogeneic hematopoietic stem cell transplantation. Extracorporeal photopheresis (ECP), which exposes mononuclear cells to ultraviolet A irradiation in the presence of a photosensitizing agent, has shown efficacy in the treatment of GVHD. Recent observations in molecular and cell biology have revealed the mechanisms by which ECP can reverse GVHD, including lymphocyte apoptosis, differentiation of dendritic cells from circulating monocytes, and modification of the cytokine profile and T cell subpopulations. Technical innovations have made ECP accessible to a broader range of patients; however, logistical constraints may limit its use. In this review, we scrutinize the development of ECP from its origins to recent insights into the biology underlying ECP efficacy. We also review practical aspects that may complicate successful ECP treatment. Finally, we analyze how these theoretical concepts translate into clinical practice, summarizing the published experiences of leading research groups worldwide.

Angelicin impedes the progression of glioblastoma via inactivation of YAP signaling pathway

Glioblastoma (GBM) is a human malignant tumor with low survival and high recurrence rate. Angelicin, an active furanocoumarin compound, has been reported to possess potential antitumor activity towards various malignancies. However, the effect of angelicin on GBM cells and its mechanism are still unclear. In this study, we found that angelicin inhibited the proliferation of GBM by inducing the cell cycle arrested in G1 phase and suppressed the migration of GBM cells in vitro. Mechanically, we found that angelicin downregulated the expression of YAP and decreased the nuclear localization of YAP, and suppressed the expression of β-catenin. Furthermore, overexpression of YAP partially restored the inhibitory effect of angelicin on GBM cells in vitro. Finally, we found that angelicin could inhibit the growth of tumor and reduce the expression of YAP in the subcutaneous xenograft model of GBM in nude mice and the syngeneic intracranial orthotopic model of GBM in C57BL/6 mice. Taken together, our results suggest that the natural product angelicin exerts its anticancer effects on GBM via YAP signaling pathway, and is expected to be a promising compound for the treatment of GBM.

Psoralea corylifolia L.: a comprehensive review of its botany, traditional uses, phytochemistry, pharmacology, toxicology, quality control and pharmacokinetics

Psoralea corylifolia L. (PCL), referred to as "Bu-gu-zhi" in Chinese, has great medicinal values since ancient times. PCL is the dried ripe fruit of Psoralea corylifolia L., which has been widely used in traditional Chinese medicine (TCM) for the treatment of kidney-yang deficiency, enuresis and urinary frequency, chills and pain of the waist and knees, dawn diarrhea and vitiligo. In this paper, a systematic of the botany, traditional uses, phytochemistry, pharmacology, toxicology, quality control and pharmacokinetics of PCL was presented, along with future research directions. According to the results, PCL contains approximately 163 chemical components, including coumarins, flavonoids, monoterpene phenols, benzofurans, glycosides, lipids, fatty acids, and volatile oils. PCL and its active ingredients have a variety of pharmacological activities, such as anti-inflammatory, antibacterial, antiviral, antioxidant, antitumor, antiosteoporosis, cardioprotective, neuroprotective, and immunomodulatory. Further study of quality control standards and potential mechanisms of PCL is also needed. In addition, more toxicological studies will also contribute to the progress of clinical trials.

Novel psoralen derivatives as anti-breast cancer agents and their light-activated cytotoxicity against HER2 positive breast cancer cells

Psoralen derivatives are well known for their unique phototoxicity and also exhibits promising anti-breast cancer activity both in the presence and the absence of UVA irradiation. However, the structure–activity relationship on this scaffold remains lacking. Herein, a series of psoralen derivatives with various C-5 substituents were synthesized and evaluated for their in vitro dark and light-activated cytotoxicity against three breast cancer cell lines: MDA-MB-231, T47-D, and SK-BR-3. The type of substituents dramatically impacted the activity, with the 4-bromobenzyl amide derivative (3c) exhibiting the highest dark cytotoxicity against T47-D (IC₅₀ = 10.14 µM), with the activity comparable to those of the reference drugs (doxorubicin, 1.46 µM; tamoxifen citrate, 20.86 µM; lapatinib 9.78 µM). On the other hand, the furanylamide 3g exhibits the highest phototoxicity against SK-BR-3 cells with the IC₅₀ of 2.71 µM, which is almost tenfold increase compared to the parent compound, methoxsalen. Moreover, these derivatives showed exceptional selectivity towards HER2+ (SK-BR-3) over the HER2− (MDA-MB-231) breast cancer cell lines, which correlates well with the results from the molecular docking study, revealing that 3g formed favorable interactions within the active site of the HER2. Additionally, the cell morphology of SK-BR-3 cells suggested that the significant phototoxicity was related to induction of cell apoptosis. Most of the synthesized psoralen derivatives possess acceptable physicochemical properties and are suitable for being further developed as a novel anti-breast cancer agent in the future.

Psoralen Suppresses Lipid Deposition by Alleviating Insulin Resistance and Promoting Autophagy in Oleate-Induced L02 Cells

Non-alcoholic fatty liver disease (NAFLD) held a high global prevalence in recent decades. Hepatic lipid deposition is the major characteristic of NAFLD. We aim to explore the mechanisms of psoralen on lipid deposition in NAFLD. The effects of psoralen on insulin resistance, lipid deposition, the expression and membrane translocation of glucose transporter type 4 (GLUT4), autophagy, and lipogenesis enzymes were determined on sodium oleate-induced L02 cells. Chloroquine and 3-MA were employed. The AMP-activated protein kinase alpha (AMPKα) was knocked down by siRNA. Psoralen alleviated insulin resistance in sodium oleate-induced L02 hepatocytes by upregulating the expression and membrane translocation of GLUT4. Psoralen inhibited lipid accumulation by decreasing the expression of key lipogenesis enzymes. Psoralen promotes autophagy and the autophagic flux to enhance lipolysis. Psoralen promoted the fusion of the autophagosome with the lysosome. Both chloroquine and 3-MA blocked the effects of psoralen on autophagy and lipid accumulation. The AMPKα deficiency attenuated the effects of psoralen on autophagy and lipid accumulation. Our study demonstrated that as an antioxidant, psoralen attenuates NAFLD by alleviating insulin resistance and promoting autophagy via AMPK, suggesting psoralen to be a promising candidate for NAFLD.

Fototerapia – metoda wykorzystywana w leczeniu przewlekłych schorzeń dermatologicznych

Wykorzystanie energii świetlnej w terapii schorzeń o różnej etiologii towarzyszy człowiekowi od czasów starożytnych. Elementem decydującym o powodzeniu terapii jest dobranie odpowiedniej długości promieniowania (terapia NB-UVB, BB-UVB i UVA1) lub wystąpienie interakcji między substancją światłoczułą skumulowaną w zmienionej chorobowo tkance a zastosowanym promieniowaniem (terapia PUVA oraz terapia fotodynamiczna). Metody terapeutyczne wykorzystujące energię świetlną są klasyfikowane na podstawie wykorzystywanego zakresu promieniowania. Obecnie wyróżnia się fototerapię UV, wykorzystującą promieniowanie UVA lub UVB oraz terapię fotodynamiczną (PDT; photodynamic therapy), podczas której stosowane jest promieniowanie o długości fali 350-700 nm.

Fototerapia UV wykorzystywana jest do leczenia schorzeń dermatologicznych, takich jak łuszczyca, bielactwo oraz atopowe zapalenie skóry, ze względu na jej działanie immunosupresyjne i antyproliferacyjne. Jest dostępna w postaci terapii PUVA polegającej na wykorzystaniu synergicznego działania promieniowania ultrafioletowego (UVA) oraz związków o działaniu światłouczulającym (8-metoksypsolaren, 5-metoksypsolaren). Ponadto wyróżniono monoterapię promieniowaniem ultrafioletowym A1 (UVA1), szerokozakresowym UVB (BB-UVB) i wąskozakresowym UVB (NB-UVB). Terapia fotodynamiczna obok konwencjonalnych metod leczenia jest nowoczesną i nieinwazyjną alternatywą wykorzystywaną zarówno w diagnostyce, jak i terapii chorób o różnej etiologii. W 90% przypadków PDT jest stosowana w schorzeniach dermatologicznych, takich jak trądzik pospolity czy łuszczyca. Selektywna aktywność cytotoksyczna wykazywana w kierunku złośliwych komórek nowotworowych powoduje, że terapia fotodynamiczna stosowana jest także z powodzeniem w leczeniu zmian onkologicznych. Duży postęp, przejawiający się zarówno w opracowywaniu innowacyjnych substancji światłoczułych, jak i nowych źródeł promieniowania, sprawia, iż zakres stosowalności terapii fotodynamicznej ciągle się poszerza.

W artykule przedstawiono obecnie dostępne formy fototerapii poprzez opis mechanizmu ich działania, zastosowania oraz możliwości powstania skutków niepożądanych.

Oxypeucedanin: Chemotaxonomy, Isolation, and Bioactivities

The present review comprehensively gathered phytochemical, bioactivity, and pharmacokinetic reports on a linear furanocoumarin, namely oxypeucedanin. Oxypeucedanin (OP), which structurally contains an epoxide ring, has been majorly isolated from ethyl acetate-soluble partitions of several genera, particularly Angelica, Ferulago, and Prangos of the Apiaceae family; and Citrus, belonging to the Rutaceae family. The methanolic extract of Angelica dahurica roots has been analytically characterized as the richest natural OP source. This naturally occurring secondary metabolite has been described to possess potent antiproliferative, cytotoxic, anti-influenza, and antiallergic activities, as assessed in preclinical studies. In order to explore potential drug candidates, oxypeucedanin, its derivatives, and semi-synthetically optimized analogues can be considered for the complementary assessments of biological assays.

Nanoliposomes@Transcutol for In Vitro Skin Delivery of 8-Methoxypsoralen

8-methoxypsoralen is the most common drug in psoralen plus ultraviolet light irradiation therapy for the treatment of severe psoriasis. Despite of the efficacy, its classic oral administration leads to several serious adverse effects. However, the topical psoralen application produces a drug skin accumulation lower than that obtained by oral administration, due to the drug low skin permeability. In this paper, 8-methoxypsoralen loaded Penetration Enhancer-containing Vesicles were prepared using soy phosphatidylcholine and the penetration enhancer Transcutol® (5% or 10%) and characterized in terms of size, polydispersity index, zeta potential and encapsulation efficiency. No statistically significant differences in both size (~135 nm) and encapsulation efficiency (~65%) were found for different Transcutol® concentration. Transdermal delivery study assessed by Franz diffusion cells, showed that the 8-methoxypsoralen mainly accumulated into the stratum corneum. Moreover, after Penetration Enhancer-containing Vesicles application, the drug recovered in this layer is almost double of that delivered by conventional liposomes, while no significant difference was found from the different Transcutol® concentrations. Finally, biocompatibility checked by an MTT assay, demonstrated that the incubation of human keratinocytes for 24 h with 8-methoxypsoralen loaded Penetration Enhancer-containing Vesicles did not significantly reduce cell viability.

Potential herbal constituents for psoriasis treatment as protective and effective therapy

Psoriasis is a multifactorial and chronic skin disorder. It is a recurrent disease that requires incessant therapy. Psoriasis treatment includes topical and systemic routes using synthetic drugs that lead to severe unwanted adverse effects. Herbal therapy is widely used for thousands of years in countries like China and India. The use of herbal therapy in the developed region enhanced to a great extent and showed better efficacy towards psoriasis alone or as adjuvant to synthetic therapy. Herbal medicines have gained great attention in the treatment of psoriasis due to their lesser side effects compared to synthetic drugs. In this review, the various plant sources which have been found effective in psoriasis and can be used to develop novel therapeutics have been discussed. The mechanisms by which the phytoconstituents elicit anti-psoriatic activity and various research studies that have proven the effectiveness of these natural products have also been compiled in this review.

The role of UVA radiation in ketoprofen-mediated BRAF-mutant amelanotic melanoma cells death - A study at the cellular and molecular level

Malignant melanoma is the cause of 80% of deaths in skin cancer patients. Treatment of melanoma in the 4th stage of clinical advancement, in which inoperable metastasis occur, does not provide sufficient effects. Ketoprofen has phototoxic properties and it can be used as a new treatment option for skin cancers as a part of photochemotherapy. The present study was designed to investigate whether ketoprofen in combination with UVA induces cytotoxic, anti-proliferative and pro-apoptotic effects on melanoma cells. It was stated that co-treatment with 1.0 mM ketoprofen and UVA irradiation disturbed homeostasis of C32 melanoma cells by lowering its vitality (decrease of GSH level). Contrary to C32 cells, melanocytes showed low sensitivity to ketoprofen and UVA radiation, pointing selectivity in the mode of action towards melanoma cells. Co-treatment with ketoprofen and UVA irradiation has cytotoxic and anti-proliferative and pro-apoptotic effect on C32. The co-treatment triggered the DNA fragmentation and changed the cell cycle in C32 cells. In conclusion, it could be stated that local application of ketoprofen in combination with UVA irradiation may be used to support the treatment of melanoma and creates the possibility of reducing the risk of cancer recurrence and metastasis.

A deep dive into UV-based phototherapy: Mechanisms of action and emerging molecular targets in inflammation and cancer

UV-based phototherapy (including psoralen plus UVA (PUVA), UVB and UVA1) has a long, successful history in the management of numerous cutaneous disorders. Photoresponsive diseases are etiologically diverse, but most involve disturbances in local (and occasionally systemic) inflammatory cells and/or abnormalities in keratinocytes that trigger inflammation. UV-based phototherapy works by regulating the inflammatory component and inducing apoptosis of pathogenic cells. This results in a fascinating and complex network of simultaneous events-immediate transcriptional changes in keratinocytes, immune cells, and pigment cells; the emergence of apoptotic bodies; and the trafficking of antigen-presenting cells in skin-that quickly transform the microenvironment of UV-exposed skin. Molecular elements in this system of UV recognition and response include chromophores, metabolic byproducts, innate immune receptors, neurotransmitters and mediators such as chemokines and cytokines, antimicrobial peptides, and platelet activating factor (PAF) and PAF-like molecules that simultaneously shape the immunomodulatory effects of UV and their interplay with the microbiota of the skin and beyond. Phototherapy's key effects-proapoptotic, immunomodulatory, antipruritic, antifibrotic, propigmentary, and pro-prebiotic-promote clinical improvement in various skin diseases such as psoriasis, atopic dermatitis (AD), graft-versus-host disease (GvHD), vitiligo, scleroderma, and cutaneous T-cell lymphoma (CTCL) as well as prevention of polymorphic light eruption (PLE). As understanding of phototherapy improves, new therapies (UV- and non-UV-based) are being developed that will modify regulatory T-cells (Treg), interact with (resident) memory T-cells and /or utilize agonists and antagonists as well as antibodies targeting soluble molecules such as cytokines and chemokines, transcription factors, and a variety of membrane-associated receptors.

Two CYP71AJ enzymes function as psoralen synthase and angelicin synthase in the biosynthesis of furanocoumarins in Peucedanum praeruptorum Dunn

Psoralen synthase and angelicin synthase responsible for the formation of psoralen and angelicin in Peucedanum praeruptorum Dunn were identified and functionally characterized, respectively. Furanocoumarins were reported to possess several activities such as anticancer, anti-inflammatory and neuroprotective, and function as phytotoxin and allelochemical in plants. Furanocoumarins are the main bioactive ingredient in P. praeruptorum which is a commonly used traditional Chinese medicine. Phenylalanine ammonia lyase (PAL), 4-coumarate: CoA ligase (4CL), p-coumaroyl CoA 2'-hyfroxylase (C2'H) were cloned previously to elucidate the biosynthetic mechanism of coumarin lactone ring. However, the genes involved in complex coumarins in P. praeruptorum have not been explored. Herein, putative psoralen synthase CYP71AJ49 and angelicin synthase CYP71AJ51 were cloned from P. praeruptorum. In vivo and in vitro yeast assays were conducted to confirm their activities. Furthermore, the results of High Performance Liquid Chromatography-Electrospray Ionization Mass Spectrometry (HPLC-ESI-MS) verified that CYP71AJ49 catalyzed the conversion of marmesin to psoralen, and CYP71AJ51 catalyzed columbianetin to angelicin. Subsequently, the expression profile showed that CYP71AJ49 and CYP71AJ51 were easily affected by environmental conditions, especially UV and temperature. The genes tissue-specific expression and compounds tissue-specific distribution pattern indicated the existence of substance transport in P. praeruptorum. Phylogenetic analysis was conducted with 27 CYP71AJs, CYP71AJ49 and CYP71AJ51 were classified in I-4 and I-2, respectively. These results provide further insight to understand the biosynthetic mechanism of complex coumarins.

Prospective pharmacological effects of psoralen photoxidation products and their cycloadducts with aminothiols: chemoinformatic analysis

Psoralens are medicinal photosensitizing furocoumarins which are used in photochemotherapy and photoimmunotherapy of dermatoses. Psoralen photooxidation products may be involved in therapeutic effects, but the possible mechanisms of their action remain unclear. The study was aimed to assess the prospective pharmacological effects and mechanisms of activity for six previously identified ortho–hydroxyformyl-containing psoralen photooxidation products and their cycloadducts with aminothiols, as well as for structurally similar compounds (furocoumaric acid and tucaresol). Chemoinformatic analysis of the prospective pharmacological effects and mechanisms of action of these compounds was performed using the PASS and PharmaExpert software. The predicted pharmacological effects partially confirmed by previous studies highlight the possible involvement of psoralen photooxidation products in the effects of PUVA therapy or photopheresis during the course of dermatoses and proliferative disorders treatment. A broad spectrum of pharmacological effects found for furocoumaric acid and cycloadducts of coumarinic and benzofuranic photoproducts of psoralen with cysteine and homocysteine appoints new directions of research relating to therapeutic use of psoralens.

Extracorporeal Photopheresis in Graft-versus-Host Disease

Background and Summary

Extracorporeal photopheresis (ECP) is a leukapheresis-based procedure used in the therapy of acute and chronic graft-versus-host disease (aGvHD, cGvHD) and other diseases. Based on the substantial efficacy and the excellent safety profile in the absence of immunosuppression ECP has established itself as a major treatment form for steroid-refractory GvHD. Here we review the current literature on ECP as a treatment option for patients with aGvHD as well as cGvHD.

Key Messages

ECP is a well-established second-line therapy for cGvHD. Its role in the treatment of aGvHD is less clear but also points towards an effective second-line therapy option. In the future ECP could play a role in the prevention of GvHD. More experimental and randomized controlled trials are needed to define the best patient selection criteria, settings, and therapy regimens for GvHD.