8-methoxypsoralen protects against acetaminophen-induced liver injury by antagonising Cyp2e1 in mice

This study aimed to investigate the effect and mechanism of 8-methoxypsoralen (8-MOP) on acetaminophen (APAP)-induced hepatotoxicity in mice. The study found that one hour after intraperitoneal injection of 300 mg/kg APAP, treatment with 40 mg/kg,80 mg/kg and 120 mg/kg 8-MOP could reduce serum transaminase level and histopathological liver necrosis area. Elevated mRNA expression of liver inflammatory mediators caused by excessive APAP was also reversed. 8-MOP significantly reduced APAP-induced hepatotoxicity dose-dependently, and the highest therapeutic dose of 8-MOP (120 mg/kg) had no harmful effects on the liver. Cocktail probe assay revealed that 8-MOP can inhibit Cyp2e1 enzymatic activities of mice, thereby reducing the production of acetaminophen-cysteine (APAP-CYS), a toxic metabolite of APAP. 8-MOP had no significant effect on the protein and gene expression of Cyp2e1. The three-dimensional structures of mouse Cyp2e1 were constructed by homologous modeling. Molecular docking showed that 8-MOP had a good binding effect on the enzyme activity site of Cyp2e1. In summary, 8-MOP dose-dependently attenuated APAP-induced hepatotoxicity by binding to Cyp2e1 and occupying the active center of the enzyme, thus competitively inhibiting the oxidative metabolism of APAP, and reducing the generation of toxic product APAP-CYS.

Xanthotoxin (8-methoxypsoralen): A review of its chemistry, pharmacology, pharmacokinetics, and toxicity

Xanthotoxin (XAT) is a natural furanocoumarins, a bioactive psoralen isolated from the fruit of the Rutaceae plant Pepper, which has received increasing attention in recent years due to its wide source and low cost. By collecting and compiling literature on XAT, the results show that XAT exhibits significant activity in the treatment of various diseases, including neuroprotection, skin repair, osteoprotection, organ protection, anticancer, antiinflammatory, antioxidative stress and antibacterial. In this paper, we review the pharmacological activity and potential molecular mechanisms of XAT for the treatment of related diseases. The data suggest that XAT can mechanistically induce ROS production and promote apoptosis through mitochondrial or endoplasmic reticulum pathways, regulate NF-κB, MAPK, JAK/STAT, Nrf2/HO-1, MAPK, AKT/mTOR, and ERK1/2 signaling pathways to exert pharmacological effects. In addition, the pharmacokinetics properties and toxicity of XAT are discussed in this paper, further elucidating the relationship between structure and efficacy. It is worth noting that data from clinical studies of XAT are still scarce, limiting the use of XAT in the clinic, and in the future, more in-depth studies are needed to determine the clinical efficacy of XAT.

8-Methoxypsoralen has Anti-inflammatory and Antioxidant Roles in Osteoarthritis Through SIRT1/NF-κB Pathway

Osteoarthritis (OA) is mainly manifested by joint pain, stiffness and mobility disorder, which is the main cause of pain and disability in middle-aged and elderly people. In this study, we aimed to explore the role and mechanism of 8-Methoxypsoralen (8-MOP) in the OA model both in vitro and in vivo. The rat chondrocytes were treated with IL-1β, and the proliferation, apoptosis, inflammatory reactions and oxidative stress responses were determined after treatment with different concentrations of 8-MOP. Real-time quantitative polymerase chain reaction (qRT-PCR) and/or Western blot were implemented to check the AMPK/SIRT1/NF-κB expression in chondrocytes. The NF-κB activity was determined by dual luciferase experiment. The pain threshold of OA rat model dealt with 8-MOP and/or the SIRT1 inhibitor EX527 was measured. Our results revealed that 8-MOP evidently reduced IL-1β-mediated apoptosis and inhibition of proliferation, and mitigated the expression of inflammatory cytokines and oxidative stress factors in chondrocytes. Additionally, 8-MOP promoted phosphorylated level of AMPKα, enhanced SIRT1 expression and inhibited the phosphorylation of NF-κB. After treatment with EX527, 8-MOP-mediated protective effects on chondrocytes were mostly reversed. In vivo, 8-MOP obviously improved the pain threshold in the OA rat model and reduced the injury and apoptosis of chondrocytes in the joints. In addition, 8-MOP relieved inflammatory and oxidative stress responses in the articular cartilage via enhancing SIRT1 and repressing NF-κB activation. After the treatment with EX527, the 8-MOP-mediated protective effects were distinctly weakened. In summary, our study testified that 8-MOP alleviates pain, inflammatory and oxidative stress responses in OA rats through the SIRT1/NF-κB pathway, which is expected to become a new reagent for clinical treatment of OA.

pH-Dependent Photoinduced Interconversion of Furocoumaric and Furocoumarinic Acids

Photo-controlled or photo-regulated molecules, especially biologically active and operating in physiological conditions, are in steady demand. Herein, furocoumaric and furocoumarinic acids being (Z/E)-isomers relative to each other were obtained in two stages starting from psoralen: the alkaline solvolysis of psoralen led to furocoumaric acid, which was further Z → E photoisomerized (365 nm) to furocoumarinic acid. The kinetics of Z → E photoisomerization was monitored by HPLC and UV-vis spectrophotometry. Photophysical characteristics in the aqueous phase for both acids, as well as the reversibility of (Z/E) photoisomerization process, were also assessed. Furocoumarinic acid was found to be visibly fluorescent at pH 2.0-12.0, with the maxima of fluorescence emission spectra being pH-dependent. The reverse E → Z photoisomerization predicted by quantum chemistry calculations as energetically favorable for the monoanionic form of furocoumarinic acid was proved in the experiment while being complicated by pyrone ring closure back to psoralen in acidic and neutral conditions. The preparative synthesis of furocoumarinic acid outlined in this work is particularly valuable in view of a wide range of pharmacological effects previously predicted for this compound.

Further assessment of Salvia haenkei as an innovative strategy to counteract skin photo-aging and restore the barrier integrity

Skin is the essential barrier of the human body which performs multiple functions. Endogenous factors, in concert with external assaults, continuously affect skin integrity, leading to distinct structural changes that influence not only the skin appearance but also its various physiological functions. Alterations of the barrier functions lead to an increased risk of developing disease and side reactions, thus the importance of maintaining the integrity of the epidermal barrier and slowing down the skin aging process is evident.

Salvia haenkei (SH) has been recently identified as a potential anti-senescence agent; its extract is able to decrease the level of senescent cells by affecting the IL1α release and reducing reactive oxygen species (ROS) generation.

In this study, SH extract was tested on human keratinocyte cell line (HaCaT) exposed to stress factors related to premature aging of cells such as free radicals and ultraviolet B radiation. We confirmed that SH acts as scavenger of ROS and found its ability to restore the skin barrier integrity by reinforcing the cytoskeleton structure, sealing the tight junctions and increasing the migration rate of cells.

Given these results, this work becomes relevant, identifying Salvia haenkei as a compound useful for anti-aging skin treatment in clinical performance.

Optimization of an Ultrasound-Assisted Extraction for Simultaneous Determination of Antioxidants in Sesame with Response Surface Methodology

Sesame is a nutritional agricultural product with medicinal properties. Accurate determination of micronutrients is important for the improvement of sesame quality and nutrition assessments. Our previous study showed that 10 antioxidants—d-homoproline, vitamin B₂, coniferyl aldehyde, hesperidin, phloretin, N-acetyl-l-leucine, l-hyoscyamine, ferulic acid, 5-methoxypsoralen, and 8-methoxypsoralen—in sesame were potential characteristic nutrients in sesame. Herein, simultaneous detection of 10 different types of antioxidants was developed by using ultrasound-assisted extraction coupled with liquid chromatography-tandem mass spectrometry (UAE-LC-MS/MS) with the help of response surface methodology. The significant variables and levels were screened and optimized by combining the single factor experiment, Plackett–Burman test, and Box–Behnken design. The optimal conditions for extraction of target antioxidants in sesame were methanol solution of 75.0%, liquid-to-material ratio of 20:1 (mL/g), extraction temperature of 50 °C, extraction power of 410.0 W, extraction time of 65 min. The total yield of targets was 21.74 μg/g under the optimized conditions. The mobile phase used was 0.1% formic acid in acetonitrile and 0.1% formic acid in water, and the column was a Thermo Syncronis C18 reverse phase column (100 mm × 2.1 mm, 3 μm). All targets required only one injection and could be quickly separated and assayed within 7 min. The limits of detection and limits of quantification for these 10 nutritional compounds ranged from 0.01 to 0.11 µg/kg and from 0.04 to 0.34 µg/kg, respectively. The validation results indicated that the method had reasonable linearity (R² ≥ 0.9990), good recoveries (71.1%–118.3%), satisfactory intra-day precision (≤9.6%) and inter-day precision (≤12.9%), and negligible matrix effects (≤13.8%). This simultaneous quantification method was accurate, fast, and robust for the assessment of sesame nutrition.

Photosensitizers for Photodynamic Therapy

As an emerging clinical modality for cancer treatment, photodynamic therapy (PDT) takes advantage of the cytotoxic activity of reactive oxygen species (ROS) that are generated by light irradiating photosensitizers (PSs) in the presence of oxygen (O₂ ). However, further advancements including tumor selectivity and ROS generation efficiency are still required. Substantial efforts are devoted to design and synthesize smart PSs with optimized properties for achieving a desirable therapeutic efficacy. This review summarizes the recent progress in developing intelligent PSs for efficient PDT, ranging from single molecules to delicate nanomaterials. The strategies to improve ROS generation through optimizing photoinduced electron transfer and energy transfer processes of PSs are highlighted. Moreover, the approaches that combine PDT with other therapeutics (e.g., chemotherapy, photothermal therapy, and radiotherapy) and the targeted delivery in cancer cells or tumor tissue are introduced. The main challenges for the clinical application of PSs are also discussed.

4,6,4'-trimethylangelicin shows high anti-proliferative activity on DU145 cells under both UVA and blue light

OBJECTIVES

Furocoumarins (psoralens and angelicins) have been already used under ultraviolet A light (UVA) for the treatment of skin diseases and cutaneous T-cell lymphoma. Besides their high anti-proliferative activity, some severe long-term side effects have been observed, for example genotoxicity and mutagenicity, likely strictly related to the formation of crosslinks. It has been demonstrated that blue light (BL) activation of 8-methoxypsoralen, an FDA-approved drug, leads to less mutagenic monoadducts in the DNA. So far, in this work the less toxic and more penetrating BL is proposed to activate 4,6,4'-trimethylangelicin (TMA), an already known UVA photoactivatable compound.

MATERIALS AND METHODS

Photocleavage, crosslink formation and oxidative damage were detected in pBR322 plasmid DNA treated with 300.0 μmol/L TMA activated with various exposures of BL. Anti-proliferative activity, reactive oxygen species (ROS) formation and activation status of some signalling pathways involved in cell growth and apoptosis were verified on DU145 cells treated with 5.0 μmol/L TMA plus 2.0 J/cm² of BL.

RESULTS

Under BL-TMA, no mutagenic crosslinks, no photocleavage and neither photooxidative lesions were detected on isolated plasmid DNA. TMA showed high anti-proliferative activity on DU145 cells through induction of apoptosis. Besides ROS generation, the proapoptotic effect seemed to be related to activation of p38 and inhibition of p44/42 phosphorylation. Interestingly, the decrease in nuclear β-catenin was coupled with a significant dropping of CD44-positive cells.

CONCLUSION

Overall, our results indicate that TMA can be activated by BL and may be considered for targeted phototherapy of prostate cancer lesions.