Thio and Seleno- Psoralens as Efficient Triplet Harvesting Photosensitizers For Photodynamic Therapy.

The Psoralen (Pso) molecule finds extensive applications in photo-chemotherapy, courtesy of its triplet state forming ability. Sulfur and selenium replacement of exocyclic carbonyl oxygen of organic chromophores foster efficient triplet harvesting with near unity triplet quantum yield. These triplet-forming photosensitizers are useful in Photodynamic Therapy (PDT) applications for selective apoptosis of cancer cells. In this work, we have critically assessed the effect of the sulfur and selenium substitution at the exocyclic carbonyl (TPso and SePso, respectively) and endocyclic oxygen positions of Psoralen. It resulted in a significant redshifted absorption spectrum to access the PDT therapeutic window with increased oscillator strength. The reduction in singlet-triplet energy gap and enhancement in the spin-orbit coupling values increase the number of intersystem crossing (ISC) pathways to the triplet manifold, which shortens the ISC lifetime from 10-5 s for Pso to 10-8 s for TPso and 10-9 s for SePso. The intramolecular photo-induced electron transfer process, a competitive pathway to ISC, is also considerably curbed by these exocyclic functionalizations. In addition, a maximum of 115 GM of two-photon absorption (2PA) with IR absorption (660-1050 nm) confirms that the Psoralen skeleton can be effectively tweaked via single chalcogen atom replacement to design a suitable PDT photosensitizer.

The Role of Extracorporeal Photopheresis in the Management of Graft Versus Host Disease: Narrative Review.

Hematopoietic stem cell donation is a method used to treat both blood-related and non-blood-related malignancies. Graft-versus-host disease is a potentially life-threatening complication that can occur following a stem cell transplant from a donor. This happens after the transplanted grafts attack the recipient's body as foreign cells, causing significant morbidity and mortality. Clinically, this condition can be classified as acute or chronic based on onset and pathophysiology. This review aims to provide an overview of recent studies on extracorporeal photopheresis as a treatment strategy option for graft-versus-host-diseased patients. It will explain how it treats graft-versus-host disease, summarize its promising effects, and provide future recommendations for its use in treating this illness. Extracorporeal photopheresis is used to treat graft-versus-host disease by collecting and separating white blood cells from the patient. This blood is fractionated into different parts, and white blood cells undergo treatment with 8-methoxy psoralen, a photoactivable drug, before exposure to ultraviolet light A. Lastly, the cells that have been treated are reinfused into the recipient's body. It prompts the programmed cell death of lymphocytes and the engulfment of cellular debris by host antigen-presenting, leading to a subsequent rise in T regulatory cells. However, more experimental and randomized controlled studies are required to identify the best patient selection requirements, environments, and treatment regimens for graft-versus-host disease.

Comparison of Efficacy of Topical Betamethasone Dipropionate and Topical Minoxidil in Patients With Alopecia Areata.

Background and objective Alopecia areata (AA) is a reiterative and nonscarring type of hair loss that can affect any hairy area of the body, particularly the scalp. It manifests as patchy or confluent hair loss with variations in demographics and ethnicity. There are numerous treatment options available, including topical and systemic steroids, topical minoxidil, dithranol, tacrolimus, psoralen and ultraviolet therapy (PUVA), contact immunotherapy, and oral immunosuppressive drugs. However, no previous contrast for efficacy is present between the topical betamethasone versus topical minoxidil alone in our population. This study aims to compare the efficacy of topical betamethasone dipropionate versus topical minoxidil in patients with AA. Methodology A nonrandomized controlled study was conducted at the Department of Dermatology, Jinnah Hospital Lahore, incorporating the data of patients between July 26, 2016, and January 26, 2017, after obtaining institutional ethical approval. One hundred patients with alopecia, either on the scalp or any other hairy part, from both genders, aged between 18 and 50 years, were included in the study. Two groups were created, and patients were assigned to these groups based on the clinician's choice. Group A patients were administered betamethasone dipropionate (0.05%) lotion twice daily on affected areas for 12 weeks. Group B patients were administered minoxidil (5%) solution twice daily on affected areas for 12 weeks. A four-week follow-up plan was followed. A five-point scale score system was used for alopecia grading. After 12 weeks, the hair regrowth score (RGS) was used to compare the efficacy of treatment between the two groups. Results A total of 100 patients with grades S1 to S3 AA of less than three months duration were enrolled. Two groups were created, with 50 patients in each group. The mean age in Group A was 29.08 ± 6.51 years, while in Group B, it was 29.38 ± 6.62 years. In Group A, there were 76% males and 24% females, while in Group B, there were 74% males and 26% females. Comparison of efficacy of topical betamethasone dipropionate versus topical minoxidil in patients with AA demonstrated a greater efficacy of 74% (Grade 3 and Grade 4 responses) in Group A, while in Group B, only 42% of patients showed efficacy. A statistically significant difference was found, with a P-value of 0.001. No serious side effects were noted. Conclusions Our study concluded that topical betamethasone dipropionate (0.05%) lotion has statistically significantly higher efficacy compared to topical minoxidil (5%) solution in patients with AA.

Modulation of the skin microbiome in cutaneous T-cell lymphoma delays tumour growth and increases survival in the murine EL4 model.

Cutaneous T-cell lymphomas (CTCL) are a group of lymphoproliferative disorders of skin-homing T cells causing chronic inflammation. These disorders cause impairment of the immune environment, which leads to severe infections and/or sepsis due to dysbiosis. In this study, we elucidated the host-microbial interaction in CTCL that occurs during the phototherapeutic treatment regime and determined whether modulation of the skin microbiota could beneficially affect the course of CTCL. EL4 T-cell lymphoma cells were intradermally grafted on the back of C57BL/6 mice. Animals were treated with conventional therapeutics such as psoralen + UVA (PUVA) or UVB in the presence or absence of topical antibiotic treatment (neomycin, bacitracin, and polymyxin B sulphate) as an adjuvant. Microbial colonisation of the skin was assessed to correlate with disease severity and tumour growth. Triple antibiotic treatment significantly delayed tumour occurrence (p = 0.026), which prolonged the survival of the mice (p = 0.033). Allocation to phototherapeutic agents PUVA, UVB, or none of these, along with antibiotic intervention, reduced the tumour growth significantly (p = 0.0327, p ≤ 0.0001, p ≤ 0.0001 respectively). The beta diversity indices calculated using the Bray-Curtis model showed that the microbial population significantly differed after antibiotic treatment (p = 0.001). Upon modulating the skin microbiome by antibiotic treatment, we saw an increase in commensal Clostridium species, e.g., Lachnospiraceae sp. (p = 0.0008), Ruminococcaceae sp. (p = 0.0001)., Blautia sp. (p = 0.007) and a significant reduction in facultative pathogens Corynebacterium sp. (p = 0.0009), Pelomonas sp. (p = 0.0306), Streptococcus sp. (p ≥ 0.0001), Pseudomonas sp. (p = 0.0358), and Cutibacterium sp. (p = 0.0237). Intriguingly, we observed a significant decrease in Staphylococcus aureus frequency (p = 0.0001) but an increase in the overall detection frequency of the Staphylococcus genus, indicating that antibiotic treatment helped regain the microbial balance and increased the number of non-pathogenic Staphylococcus populations. These study findings show that modulating microbiota by topical antibiotic treatment helps to restore microbial balance by diminishing the numbers of pathogenic microbes, which, in turn, reduces chronic inflammation, delays tumour growth, and increases survival rates in our CTCL model. These findings support the rationale to modulate the microbial milieu during the disease course of CTCL and indicate its therapeutic potential.

Benzopyrone, a privileged scaffold in drug discovery: An overview of FDA-approved drugs and clinical candidates.

Natural products have always served as an important source of drugs for treating various diseases. Among various privileged natural product scaffolds, the benzopyrone class of compounds has a substantial presence among biologically active compounds. One of the pioneering anticoagulant drugs, warfarin approved in 1954 bears a benzo-α-pyrone (coumarin) nucleus. The widely investigated psoriasis drugs, methoxsalen, and trioxsalen, also contain a benzo-α-pyrone nucleus. Benzo-γ-pyrone (chromone) containing drugs, cromoglic acid, and pranlukast were approved as treatments for asthma in 1982 and 2007, respectively. Numerous other small molecules with a benzopyrone core are under clinical investigation. The present review discusses the discovery, absorption, distribution, metabolism, excretion properties, and synthetic approaches for the Food and Drug Administration-approved and clinical-stage benzopyrone class of compounds. The role of the pyrone core in biological activity has also been discussed. The present review unravels the potential of benzopyrone core in medicinal chemistry and drug development.

Psoralen: a narrative review of current and future therapeutic uses.

Psoralen is a family of naturally occurring photoactive compounds found in plants that acquire potential cytotoxicity when activated by specific frequencies of electromagnetic waves. Psoralens penetrate the phospholipid cellular membranes and insert themselves between the pyrimidines of deoxyribonucleic acid (DNA). Psoralens are initially biologically inert and acquire photoreactivity when exposed to certain classes of electromagnetic radiation, such as ultraviolet light. Once activated, psoralens form mono- and di-adducts with DNA, leading to marked cell apoptosis. This apoptotic effect is more pronounced in tumor cells due to their high rate of cell division. Moreover, photoactivated psoralen can inhibit tyrosine kinase signaling and influence the immunogenic properties of cells. Thus, the cytotoxicity of photoactivated psoralen holds promising clinical applications from its immunogenic properties to potential anti-cancer treatments. This narrative review aims to provide an overview of the current understanding and research on psoralen and to explore its potential future pharmacotherapeutic benefits in specific diseases.

Furanocoumarin compounds isolated from Dorstenia foetida potentiate irinotecan anticancer activity against colorectal cancer cells.

Although the anticancer activity of Dorstenia foetida was already observed, the chemical entity responsible for this activity remained unidentified. In this study, the cytotoxic activity of two furanocoumarin compounds, i.e., 5-methoxy--3-(3-methyl-2,3-dihydroxybutyl)-psoralen (1) and 5-methoxy-3-(3-methyl-2,3-dihydroxybutyl)-psoralen diacetate (2) isolated from ethyl acetate fraction of D. foetida (whole plant) was investigated in several cancer cell lines including HN22, MDA-MB-231, HCT116, and HT29. The results revealed that compound 2 exhibited cytotoxic activity, particularly against colorectal cancer cell lines HCT116 and HT29. The interplay between compound 2 and irinotecan (Iri) showed synergism against HCT116, which was analyzed by CompuSyn software. The simulation revealed that, at the molar ratio of Iri:2 of 1:40, the concentration predicted to achieve a 90 % inhibitory effect when used in the combination would be ~28- and ~4-fold lower than the concentration of compound 2 and Iri, resp., when used individually. Finally, the percentage of apoptotic cells in the HCT116 line treated with the combination was markedly higher than in the cells treated with the individual agent (60 % apoptotic cells for the combination compared to 17 and 45 % for Iri and compound 2 monotherapy, resp). In conclusion, our results identified compound 2 as a plant-derived compound exhibiting anticancer properties that can act synergistically with Iri and warranted further research to assess the potential of this synergism for colorectal cancer treatment.

Photochemical inactivation as an alternative method to produce a whole-cell vaccine for uropathogenic Escherichia coli (UPEC).

Uropathogenic Escherichia coli (UPEC) is the primary causative agent of lower urinary tract infection (UTI). UTI presents a serious health risk and has considerable secondary implications including economic burden, recurring episodes, and overuse of antibiotics. A safe and effective vaccine would address this widespread health problem and emerging antibiotic resistance. Killed, whole-cell vaccines have shown limited efficacy to prevent recurrent UTI in human trials. We explored photochemical inactivation with psoralen drugs and UVA light (PUVA), which crosslinks nucleic acid, as an alternative to protein-damaging methods of inactivation to improve whole-cell UTI vaccines. Exposure of UPEC to the psoralen drug AMT and UVA light resulted in a killed but metabolically active (KBMA) state, as reported previously for other PUVA-inactivated bacteria. The immunogenicity of PUVA-UPEC as compared to formalin-inactivated UPEC was compared in mice. Both generated high UPEC-specific serum IgG titers after intramuscular delivery. However, using functional adherence as a measure of surface protein integrity, we found differences in the properties of PUVA- and formalin-inactivated UPEC. Adhesion mediated by Type-1 and P-fimbriae was severely compromised by formalin but was unaffected by PUVA, indicating that PUVA preserved the functional conformation of fimbrial proteins, which are targets of protective immune responses. In vitro assays indicated that although they retained metabolic activity, PUVA-UPEC lost virulence properties that could negatively impact vaccine safety. Our results imply the potential for PUVA to improve killed, whole-cell UTI vaccines by generating bacteria that more closely resemble their live, infectious counterparts relative to vaccines generated with protein-damaging methods. IMPORTANCE: Lower urinary tract infection (UTI), caused primarily by uropathogenic Escherichia coli, represents a significant health burden, accounting for 7 million primary care and 1 million emergency room visits annually in the United States. Women and the elderly are especially susceptible and recurrent infection (rUTI) is common in those populations. Lower UTI can lead to life-threatening systemic infection. UTI burden is manifested by healthcare dollars spent (1.5 billion annually), quality of life impact, and resistant strains emerging from antibiotic overuse. A safe and effective vaccine to prevent rUTI would address a substantial healthcare issue. Vaccines comprised of inactivated uropathogenic bacteria have yielded encouraging results in clinical trials but improvements that enhance vaccine performance are needed. To that end, we focused on inactivation methodology and provided data to support photochemical inactivation, which targets nucleic acid, as a promising alternative to conventional protein-damaging inactivation methods to improve whole-cell UTI vaccines.

Discovery of psoralen as a quorum sensing inhibitor suppresses Pseudomonas aeruginosa virulence.

Pseudomonas aeruginosa is a common opportunistic pathogen with growing resistance and presents heightened treatment challenges. Quorum sensing (QS) is a cell-to-cell communication system that contributes to the production of a variety of virulence factors and is also related to biofilm formation of P. aeruginosa. Compared to traditional antibiotics which kill bacteria directly, the anti-virulence strategy by targeting QS is a promising strategy for combating pseudomonal infections. In this study, the QS inhibition potential of the compounds derived from the Traditional Chinese Medicines was evaluated by using in silico, in vitro, and in vivo analyses. The results showed that psoralen, a natural furocoumarin compound derived from Psoralea corylifolia L., was capable of simultaneously inhibiting the three main QS regulators, LasR, RhlR, and PqsR of P. aeruginosa. Psoralen had no bactericidal activity but could widely inhibit the production of extracellular proteases, pyocyanin, and biofilm, and the cell motilities of the model and clinical P. aeruginosa strains. RNA-sequencing and quantitative PCR analyses further demonstrated that a majority of QS-activated genes in P. aeruginosa were suppressed by psoralen. The supplementation of psoralen could protect Caenorhabditis elegans from P. aeruginosa challenge, especially for the hypervirulent strain PA14. Moreover, psoralen showed synergistic antibacterial effects with polymyxin B, levofloxacin, and kanamycin. In conclusions, this study identifies the anti-QS and antibiofilm effects of psoralen against P. aeruginosa strains and sheds light on the discovery of anti-pseudomonal drugs among Traditional Chinese Medicines. KEY POINTS: • Psoralen derived from Psoralea corylifolia L. inhibits the virulence-related phenotypes of P. aeruginosa. • Psoralen simultaneously targets the three core regulators of P. aeruginosa QS system and inhibits the expression of a large part of downstream genes. • Psoralen protects C. elegans from P. aeruginosa challenge and enhances the susceptibility of P. aeruginosa to antibiotics.

Synthesis and antibacterial evaluation of novel psoralen derivatives against methicillin-resistant Staphylococcus aureus (MRSA).

Today, the bacterial infections caused by multidrug-resistant pathogens seriously threaten human health. Thereby, there is an urgent need to discover antibacterial drugs with novel mechanism. Here, novel psoralen derivatives had been designed and synthesized by a scaffold hopping strategy. Among these targeted twenty-five compounds, compound ZM631 showed the best antibacterial activity against methicillin-resistant S. aureus (MRSA) with the low MIC of 1 µg/mL which is 2-fold more active than that of the positive drug gepotidacin. Molecular docking study revealed that compound ZM631 fitted well in the active pockets of bacterial S. aureus DNA gyrase and formed a key hydrogen bond binding with the residue ASP-1083. These findings demonstrated that the psoralen scaffold could serve as an antibacterial lead compound for further drug development against multidrug-resistant bacterial infections.

Psoralen synergies with zinc implants to promote bone repair by regulating ZIP4 in rats with bone defect.

BACKGROUND: The regulation of dose-dependent biological effects induced by biodegradation is a challenge for the production of biodegradable bone-substitute materials, especially biodegradable zinc (Zn) -based materials. Cytotoxicity caused by excess local Zn ions (Zn2+) from degradation is one of the factors limiting the wide application of Zn implants. Given that previous studies have revealed that delayed degradation of Zn materials by surface modification does not reduce cytotoxicity; in the present study, we explore whether preventing the entry of excess Zn2+ into cells may can reduce local Zn toxicity by applying Psoralen (PRL) to Zn implants and assessing its ability to regulate intracellular Zn2+ concentrations. METHODS: The effects of different concentrations of Zn2+ on cellular activity and cytotoxicity were investigated; briefly, we identified natural compounds that regulate Zn transporters, thereby regulating the concentrations of intracellular Zn2+, and applied them to Zn materials. Of these materials, PRL, a natural, tricyclic, coumarin-like aromatic compound that promotes the proliferation and differentiation of osteoblasts and enhances osteogenic activity, was loaded onto the surface of a Zn material using peptides and chitosan (CS), and the surface characteristics, electrochemical properties, and activity of the modified Zn material were evaluated. In addition, the ability of Zn + CS/pPRL implants to promote bone formation and accelerate large-scale bone defect repairs was assessed both in vitro and in vivo. RESULTS: We determined that 180 µM Zn2+ significantly induced pre-osteoblast cytotoxicity, and a 23-fold increase in Zrt- and Irt-like protein 4 (ZIP4) expression. We also found that PRL dynamically regulates the expression of ZIP4 in response to Zn2+ concentration. To address the problem of cytotoxicity caused by excessive Zn2+ in local Zn implants, PRL was loaded onto the surface of Zn implants in vivo using peptides and CS, which dynamically regulated ZIP4 levels, maintained the balance of intracellular Zn2+ concentrations, and enhanced the osteogenic activity of Zn implants. CONCLUSIONS: This study reveals the importance of Zn2+ concentration when using Zn materials to promote bone formation and introduces a natural active ingredient, PRL, that can regulate intracellular Zn2+ levels, and thus may be clinically applicable to Zn implants for the treatment of critical bone defects.

Psoralen synergizes with exosome-loaded SPC25 to alleviate senescence of nucleus pulposus cells in intervertebral disc degeneration.

OBJECTIVE: To explore the mechanism of psoralen synergized with exosomes (exos)-loaded SPC25 on nucleus pulposus (NP) cell senescence in intervertebral disc degeneration (IVDD). METHODS: IVDD cellular models were established on NP cells by tert-butyl hydroperoxide (TBHP) induction, followed by the treatment of psoralen or/and exos from adipose-derived stem cells (ADSCs) transfected with SPC25 overexpression vector (ADSCs-oe-SPC25-Exos). The viability, cell cycle, apoptosis, and senescence of NP cells were examined, accompanied by the expression measurement of aggrecan, COL2A1, Bcl-2, Bax, CDK2, p16, and p21. RESULTS: After TBHP-induced NP cells were treated with psoralen or ADSCs-oe-SPC25-Exos, cell proliferation and the expression of aggrecan, COL2A1, Bcl-2, and CDK2 were promoted; however, the expression of Bax, p16, p21, and inflammatory factors was decreased, and cell senescence, cycle arrest, and apoptosis were inhibited. Of note, psoralen combined with ADSCs-oe-SPC25-Exos further decelerated NP cell senescence and cycle arrest compared to psoralen or ADSCs-oe-SPC25-Exos alone. CONCLUSION: Combined treatment of psoralen and ADSCs-oe-SPC25-Exos exerted an alleviating effect on NP cell senescence, which may provide an insightful idea for IVDD treatment.

A gene expression profile-based approach to screen the occurrence and predisposed host characteristics of drug-induced liver injury: a case study of Psoralea corylifolia Linn.

Drug-induced liver injury (DILI) is one of the most common causes of a drug being withdrawn, and identifying the culprit drugs and the host factors at risk of causing DILI has become a current challenge. Recent studies have found that immune status plays a considerable role in the development of DILI. In this study, DILI-related differentially expressed genes mediated by immunoinflammatory cytokines were obtained from the Gene Expression Omnibus (GEO) database to predict the occurrence of DILI (named the DILI predictive gene set, DILI_PGS), and the predictability of the DILI_PGS was verified using the Connectivity Map (CMap) and LiverTox platforms. The results obtained DILI_PGS from the GEO database could predict 81.25% of liver injury drugs. In addition, the Coexpedia platform was used to predict the DILI_PGS-related characteristics of common host diseases and found that the DILI_PGS mainly involved immune-related diseases and tumor-related diseases. Then, animal models of immune stress (IS) and immunosuppressive (IP) were selected to simulate the immune status of the above diseases. Meanwhile, psoralen, a main component derived from Psoralea corylifolia Linn. with definite hepatotoxicity, was selected as an experimental drug with highly similar molecular fingerprints to three idiosyncratic hepatotoxic drugs (nefazodone, trovafloxacin, and nimesulide) from the same DILI_PGS dataset. The animal experiment results found a single administration of psoralen could significantly induce liver injury in IS mice, while there was no obvious liver function change in IP mice by repeatedly administering the same dose of psoralen, and the potential mechanism of psoralen-induced liver injury in IS mice may be related to regulating the expression of the TNF-related pathway. In conclusion, this study constructed the DILI_PGS with high accuracy to predict the occurrence of DILI and preliminarily identified the characteristics of host factors inducing DILI.

Psoralen Alleviates Renal Fibrosis by Attenuating Inflammasome-Dependent NLRP3 Activation and Epithelial-Mesenchymal Transition in a Mouse Unilateral Ureteral Obstruction Model.

The role of psoralen (PS), a major active component extracted from Psoralea corylifolia L. seed, in renal fibrosis is still unclear. Thus, the objective of this study was to evaluate the effects of PS on the development and progression of renal fibrosis induced by unilateral ureteral obstruction (UUO) in a mouse model. Mice were divided into four groups: PS (20 mg/kg, i.g., n = 5), PS + sham (n = 5), UUO (n = 10), and PS + UUO (n = 10). PS was intragastrically administered 24 h before UUO and continued afterwards for 7 days. All mice were killed 7 days post UUO. Severe tubular atrophy, tubular injury, and tubulointerstitial fibrosis (TIF) were significantly developed in UUO mice. A higher expression of transforming growth factor-ß1 (TGF-ß1) was accompanied by elevated levels of α-smooth muscle actin (α-SMA) and phosphorylated Smad2/3 (pSmad2/3) at 7 days post UUO. However, PS treatment reduced tubular injury, interstitial fibrosis, and the expression levels of TGF-ß1, α-SMA, and pSmad2/3. Furthermore, the levels of macrophages (represented by F4/80 positive cells) and the inflammasome, reflected by inflammasome markers such as nucleotide-binding and oligomerization domain-like receptors protein 3 (NLRP3) and cleaved caspase1 (cCASP-1), were significantly decreased by PS treatment. These results suggest that PS merits further exploration as a therapeutic agent in the management of chronic kidney disease (CKD).

Phytochemical and Pharmacological Aspects of Psoralen - A Bioactive Furanocoumarin from Psoralea corylifolia Linn.

Since long ago, medicinal plants have played a vital role in drug discovery. Being blessed and rich in chemovars with diverse scaffolds, they have unique characteristics of evolving based on the need. The World Health Organization also mentions that medicinal plants remain at the center for meeting primary healthcare needs as the population relies on them. The plant-derived natural products have remained an attractive choice for drug development owing to their specific biological functions relevant to human health and also the high degree of potency and specificity they offer. In this context, one such esteemed phytoconstituent with inexplicable biological potential is psoralen, a furanocoumarin. Psoralen was the first constituent isolated from the plant Psoralea corylifolia, commonly known as Bauchi. Despite being a life-saver for psoriasis, vitiligo, and leukoderma, it also showed immense anticancer, anti-inflammatory, and anti-osteoporotic potential. This review brings attention to the possible application of psoralen as an attractive target for rational drug design and medicinal chemistry. It discusses the various methods for the total synthesis of psoralen, its extraction, the pharmacological spectrum of psoralen, and the derivatization done on psoralen.

Mechanistic study of cytochrome P450 enzyme-mediated cytotoxicity of psoralen and isopsoralen.

Psoralen and isopsoralen are the major components responsible for Psoraleae Fructus-induced hepatotoxicity. This study explored the role of metabolic activation by cytochrome P450 (CYP) enzymes in psoralen- and isopsoralen-induced cytotoxicity and its potential mechanisms. Inhibitors of CYP1A2, 2C9, 2C19, 2D6, 2E1, and 3A4 were used to screen specific CYP enzymes responsible for the metabolic activation of psoralen and isopsoralen in mouse primary hepatocytes, which was verified using the corresponding transfected cell lines. Network toxicology and transcriptome analyses were performed to explore the mechanisms underlying toxicity. Psoralen and isopsoralen decreased the viability of mouse primary hepatocytes, whereas the inhibition of CYP2C9, 2C19, 2D6, and 2E1 significantly increased their viability. Psoralen-induced cytotoxicity was significantly enhanced by the overexpression of CYP2C19 in Chinese hamster ovary cells, whereas the overexpression of the above CYP enzymes did not affect the cytotoxicity of isopsoralen. Psoralen- and isopsoralen-induced cytotoxic effects were associated with putative core targets (i.e., Fn1, Thbs1, and Tlr2) and multiple signaling pathways (e.g., PI3K-Akt, MAPK, and TNF pathways). Our results demonstrate that the metabolic activation of psoralen and isopsoralen is mediated by CYP enzymes, thereby regulating multiple core targets and signaling pathways and resulting in cytotoxicity.

Synthesis and Antioxidant Properties of Psoralen Derivatives.

Five psoralen derivatives were synthesized and the structures of them were characterized by 1 H-NMR, 13 C-NMR, and IR. The antioxidant properties of the compounds were tested by inhibiting the free radical-initiated DNA oxidation and scavenging the radical reaction. The results showed that the effective stoichiometric factors (n) of the compounds V and IV could reach 2.00 and 2.11 in the system of inhibiting the DNA oxidation reaction initiated by 2,2'-Azobis(2-methylpropionamidine) dihydrochloride (AAPH). In the inhibition of ⋅OH-oxidation of the DNA system, compounds I~V showed antioxidant properties. The thiobarbituric acid absorbance (TBARS) percentages of compounds IV and V were 76.19 % and 78.84 %. Compounds I~V could also inhibit Cu2+ /GSH-oxidation of DNA, and all compounds exhibited good antioxidant properties except compound II (94.00 %). All the five compounds were able to trap diammonium 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonate) salt radical (ABTS+ ⋅), 2,2-diphenyl-1-picrylhydrazyl radical (DPPH⋅) and 2,6-di-tert-butyl-alpha-(3,5-di-tert-butyl-4-oxo-2,5-cyclohexadien-p-tolylox radical (galvinoxyl⋅). The ability of compounds I~V to scavenge those free radicals can be measured by the k values. The k values ranged from 0.07 to 0.82 in scavenging ABTS+ ⋅, galvinoxyl, and DPPH radicals, respectively.

Development and Crosslinking Properties of Psoralen-Conjugated Triplex-Forming Oligonucleotides as Antigene Tools Targeting Genome DNA.

Psoralen-conjugated triplex-forming oligonucleotides (Ps-TFOs) have been utilized for genome editing and anti-gene experiments for over thirty years. However, the research on Ps-TFOs employing artificial nucleotides is still limited, and their photo-crosslinking properties have not been thoroughly investigated in relation to biological activities. In this study, we extensively examined the photo-crosslinking properties of Ps-TFOs to provide fundamental insights for future Ps-TFO design. We developed novel Ps-TFOs containing 2'-O,4'-C-methylene-bridged nucleic acids (Ps-LNA-mixmer) and investigated their photo-crosslinking properties using stable cell lines that express firefly luciferase constitutively to evaluate the anti-gene activities of Ps-LNA-mixmer. As a result, Ps-LNA-mixmer successfully demonstrated suppression activity, and we presented the first-ever correlation between photo-crosslinking properties and their activities. Our findings also indicate that the photo-crosslinking process is insufficient under cell irradiation conditions (365 nm, 2 mW/cm2 , 60 min). Therefore, our results highlight the need to develop new psoralen derivatives that are more reactive under cell irradiation conditions.

The Immunogenicity and Properties of a Whole-Cell ETEC Vaccine Inactivated with Psoralen and UVA Light in Comparison to Formalin.

Inactivated whole-cell vaccines present a full repertoire of antigens to the immune system. Formalin treatment, a standard method for microbial inactivation, can modify or destroy protein antigenic epitopes. We tested the hypothesis that photochemical inactivation with psoralen and UVA light (PUVA), which targets nucleic acid, would improve the immunogenicity of an Enterotoxigenic E. coli (ETEC) vaccine relative to a formalin-inactivated counterpart. Exposure of ETEC H10407 to PUVA using the psoralen drug 4'-Aminomethyltrioxsalen hydrochloride (AMT) yielded replication-incompetent bacteria that retained their metabolic activity. CFA/I-mediated mannose-resistant hemagglutination (MRHA) was equivalent for PUVA-inactivated and live ETEC, but was severely reduced for formalin-ETEC, indicating that PUVA preserved fimbrial protein functional integrity. The immunogenicity of PUVA-ETEC and formalin-ETEC was compared in mice ± double mutant heat-labile enterotoxin (dmLT) adjuvant. Two weeks after an intramuscular prime/boost, serum anti-ETEC IgG titers were similar for the two vaccines and were increased by dmLT. However, the IgG responses raised against several conserved ETEC proteins were greater after vaccination with PUVA-ETEC. In addition, PUVA-ETEC generated IgG specific for heat-labile toxin (LT) in the absence of dmLT, which was not a property of formalin-ETEC. These data are consistent with PUVA preserving ETEC protein antigens in their native-like form and justify the further testing of PUVA as a vaccine platform for ETEC using murine challenge models.

Effect of psoralen on the regulation of osteogenic differentiation induced by periodontal stem cell-derived exosomes.

Periodontitis is a chronic inflammatory disease that is the main cause of tooth loss in adults, and the key to periodontitis treatment is the repair and regenerate of periodontal bone tissue. Psoralen is the main component of the Psoralea corylifolia Linn, which shows antibacterial, anti-inflammatoryand osteogenic activities. It promotes the differentiation of periodontal ligament stem cells toward osteogenesis. Exosomes secreted by stem cells play important roles in information transmission during the osteogenic differentiation process. The aim of this paper was to investigate the role of psoralen in regulating osteogenic miRNA information in periodontal stem cells and in periodontal stem cells exosomes and the specific mechanism of its action. Experimental results show that exosomes of human periodontal ligament stem cell origin treated with psoralen (hPDLSCs + Pso-Exos) were not significantly different from untreated exosomes (hPDLSC-Exos) in terms of size and morphology. Thirty-five differentially expressed miRNAs were found to be upregulated and 58 differentially expressed miRNAs were found to be downregulated in the hPDLSCs + Pso-Exos compared to the hPDLSC-Exos (P < 0.05). hsa-miR-125b-5p was associated with osteogenic differentiation. Among them, hsa-miR-125b-5p was associated with osteogenic differentiation. After hsa-miR-125b-5p was inhibited, the osteogenesis level of hPDLSCs was enhanced. In summary, the osteogenic differentiation of hPDLSCs was promoted by psoralen through the downregulation of hsa-miR-125b-5p gene expression in hPDLSCs, and the expression of the hsa-miR-125b-5p gene was also downregulated in exosomes. This finding provides a new therapeutic idea for using psoralen to promote periodontal tissue regeneration.