Psoralen

Phytomedicine. 2014 Jun 15;21(7):970-7.

Psoralen reverses docetaxel-induced multidrug resistance in A549/D16 human lung cancer cells lines.[Pubmed: 24703328]

Chemotherapy is the recommended treatment for advanced-stage cancers. However, the emergence of multidrug resistance (MDR), the ability of cancer cells to become simultaneously resistant to different drugs, limits the efficacy of chemotherapy. Previous studies have shown that herbal medicine or natural food may be feasible for various cancers as potent chemopreventive drug. This study aims to explore the capablility of reversing the multidrug resistance of docetaxel (DOC)-resistant A549 cells (A549/D16) of Psoralen and the underlying mechanisms.
METHODS AND RESULTS:
In this study, results showed that the cell viability of A549/D16 subline is decreased when treated with Psoralen plus DOC, while Psoralen has no effect on the cell proliferation on A549 and A549/D16 cells. Furthermore, mRNA and proteins levels of ABCB1 were decreased in the presence of Psoralen, while decreased ABCB1 activity was also revealed by flow cytometry. Based on these results, we believe that Psoralen may be feasible for reversing the multidrug resistance by inhibiting ABCB1 gene and protein expression.
CONCLUSIONS:
Such inhibition will lead to a decrease in ABCB1 activity and anti-cancer drug efflux, which eventually result in drug resistance reversal and therefore, sensitizing drug-resistant cells to death in combination with chemotherapeutic drugs.

Pak J Pharm Sci. 2015 Mar;28(2 Suppl):667-70.

Effects of psoralen on chondrocyte degeneration in lumbar intervertebral disc of rats.[Pubmed: 25796142]

Discuss the internal mechanism of delaying degeneration of lumber intervertebral disc.
METHODS AND RESULTS:
The cartilage of lumbar intervertebral disc of SD rats was selected in vitro, then cultured by tissue explant method, and identified by HE staining, toluidine blue staining and immunofluorescence. The optimal concentration of Psoralen was screened by cell proliferation assay and RT-PCR method. The cells in third generation with good growth situation is selected and placed in 6-well plate at concentration of 1×10(5)/well and its expression was tested. Compared to concentration of 0, the mRNA expression of Col2al (Collagen Ⅱ) secreted by was up regulated chondrocyte of lumbar intervertebral disc at the concentration of 12.5 and 25μM (P<0.0 or P<0.01). The aggrecan mRNA of Psoralen group was higher than blank control group (P<0.01); compared with IL-1β induced group, the mRNA expression of Col2al was significantly increased but the mRNA expression of ADAMTS-5 was significantly decreased in Psoralen group (P<0.01).
CONCLUSIONS:
These findings suggest that, Psoralen can remit the degeneration of lumbar intervertebral disc induced by IL-1β to some extent, and affect the related factors of IL-1β signaling pathway.

Int J Mol Med . 2018 Jun;41(6):3727-3735.

A novel psoralen derivative-MPFC enhances melanogenesis via activation of p38 MAPK and PKA signaling pathways in B16 cells[Pubmed: 29512683]

Abstract As an active compound, Psoralen is present in various Chinese herbal medicines and has exhibited significant activity in skin disease treatment. Its derivative 8-methoxypsoralan (8-MOP) is the most commonly used drug to induce repigmentation of vitiligo. In our previous screening assays, 4-methyl-6-phenyl-2H-furo[3,2-g]chromen-2-one (MPFC), a Psoralen derivative, was identified as more effective tyrosinase and melanin activator than the positive control 8-MOP in consideration of low doses, as well as low toxicity. The overall purpose of this study was to characterize the melanogenic effect and mechanisms of MPFC in B16 cells. The melanin biosynthesis effects of MPFC were determined by examination of cellular melanin contents, tyrosinase activity assay, cyclic adenosinemonophosphate (cAMP) assay, and western blotting of MPFC-stimulated B16 mouse melanoma cells. Our results showed that MPFC enhanced both melanin synthesis and tyrosinase activity in a concentration-dependent manner as well as significantly activated the expression of melanogenic proteins such as tyrosinase, tyrosinase-related protein-1 and tyrosinase-related protein-2. Western blot analysis showed that MPFC increased the phosphorylation of p38 mitogen-activated protein kinase and cAMP response element-binding protein (CREB) as well as the expression of microphthalmia-associated transcription factor (MITF). Moreover, MPFC stimulated intracellular cAMP levels and induced tyrosinase activity and melanin synthesis were attenuated by H89, a protein kinase A inhibitor. These results indicated that MPFC-mediated activation of the p38 MAPK and the protein kinase A (PKA) pathway may shed light on a novel approach for an effective therapy for vitiligo.

Int J Nanomedicine. 2014 Jan 23;9:669-78.

Evaluation of psoralen ethosomes for topical delivery in rats by using in vivo microdialysis.[Pubmed: 24489470]

This study aimed to improve skin permeation and deposition of Psoralen by using ethosomes and to investigate real-time drug release in the deep skin in rats.
METHODS AND RESULTS:
We used a uniform design method to evaluate the effects of different ethosome formulations on entrapment efficiency and drug skin deposition. Using in vitro and in vivo methods, we investigated skin penetration and release from Psoralen-loaded ethosomes in comparison with an ethanol tincture. In in vitro studies, the use of ethosomes was associated with a 6.56-fold greater skin deposition of Psoralen than that achieved with the use of the tincture. In vivo skin microdialysis showed that the peak concentration and area under the curve of Psoralen from ethosomes were approximately 3.37 and 2.34 times higher, respectively, than those of Psoralen from the tincture. Moreover, it revealed that the percutaneous permeability of ethosomes was greater when applied to the abdomen than when applied to the chest or scapulas.
CONCLUSIONS:
Enhanced permeation and skin deposition of Psoralen delivered by ethosomes may help reduce toxicity and improve the efficacy of long-term Psoralen treatment.

Proc Natl Acad Sci U S A. 1986 Nov;83(21):8211-5.

Psoralens potentiate ultraviolet light-induced inhibition of epidermal growth factor binding.[Pubmed: 3490664 ]

The Psoralens, when activated by ultraviolet light of 320-400 nm (UVA light), are potent modulators of epidermal cell growth and differentiation. Previously, we reported that, in mammalian cells, these compounds bind to specific saturable high-affinity cellular receptor sites.
METHODS AND RESULTS:
In the present studies, we demonstrate that binding of Psoralens to their receptors followed by UVA light activation is associated with inhibition of epidermal growth factor (EGF) receptor binding. Inhibition of EGF binding, which required UVA light, was rapid and dependent on the dose of UVA light (0.5-2.0 J/cm2), as well as the concentration of Psoralens (10 nM to 1 microM). Higher doses of UVA light (2.0-6.0 J/cm2) by themselves were also inhibitory, indicating that Psoralens potentiate the UVA-induced inhibition of EGF binding. A number of biologically active analogs of Psoralen, including 8-methoxyPsoralen, 5-methoxyPsoralen, and 4,5',8-trimethylPsoralen, when activated by UVA light, were found to be inhibitors of binding. Inhibition of EGF binding by Psoralens was observed in a variety of human and mouse cell culture lines known to possess Psoralen receptors. In the epidermal-derived line PAM 212, at least two populations of receptors with different affinities for EGF were found. Psoralens and UVA light selectively inhibited binding to the higher-affinity EGF receptors, an effect analogous to that of the phorbol ester tumor promoters. As observed with phorbol esters, photoactivated Psoralens appeared to inhibit EGF binding by an indirect mechanism.
CONCLUSIONS:
These data demonstrate that the Psoralens and UVA light have direct biological effects on cell-surface membranes. Since EGF is a growth-regulatory peptide, the ability of Psoralens and UVA light to inhibit EGF binding may underlie the biologic effects of these agents in the skin.

Am J Chin Med. 2014;42(3):665-78.

Effects of Psoraleae fructus and its major component psoralen on Th2 response in allergic asthma.[Pubmed: 24871658]

This study is aimed to evaluate the effects of Psoraleae fructus (PF) on Th2 responses in a rat model of asthma in vivo and Psoralen, a major constituent in PF, on Th2 responses in vitro.
METHODS AND RESULTS:
A rat model of asthma was established by sensitization and challenged with ovalbumin (OVA). Airway hyperresponsiveness was detected by direct airway resistance analysis. Lung tissues were examined for cell infiltration and mucus hypersecretion. Bronchoalveolar lavage fluid (BALF) was assessed for cytokine levels. In vitro study, Th2 cytokine production was evaluated in the culture supernatant of D10.G4.1 (D10 cells) followed by the determination of cell viability, meanwhile Th2 transcription factor GATA-3 expression in D10 cells was also determined. The oral administration of PF significantly reduced airway hyperresponsiveness (AHR) to aerosolized methacholine and decreased IL-4 and IL-13 levels in the BALF. Histological studies showed that PF markedly inhibited inflammatory infiltration and mucus secretion in the lung tissues. In vitro study, Psoralen significantly suppressed Th2 cytokines of IL-4, IL-5 and IL-13 by ConA-stimulated D10 cells without inhibitory effect on cell viability. Furthermore, GATA-3 protein expression was also markedly reduced by Psoralen.
CONCLUSIONS:
This study demonstrated that PF exhibited inhibitory effects on hyperresponsiveness and airway inflammation in a rat model of asthma, which was associated with the suppression of Th2 response. Psoralen, a major constituent of PF, has immunomodulatory properties on Th2 response in vitro, which indicated that Psoralen might be a critical component of PF for its therapeutic effects.

Nucleic Acids Res. 1996 Feb 1; 24(3): 509–514.

Psoralen crosslinking between human immunodeficiency virus type 1 RNA and primer tRNA3(Lys).[Reference: WebLink]

Initiation of reverse transcription is a crucial step of retroviral infection. In HIV-1, it involves hybridization of the 18 3′-terminal nucleotides of the primer tRNA3Lys to the primer binding site (PBS) of the viral RNA. Moreover, additional interactions between the two RNAs were recently evidenced [Isel et al. (1995) J. Mol. Biol. 247, 25269–25272].
METHODS AND RESULTS:
To get further information on the topology of the viral RNA/tRNA3Lys complex, we used Psoralen to induce RNA-RNA crosslinking. A defined intermolecular crosslinked complex was obtained. The crosslinked regions were characterized by RNase T1 digestion followed by bi-dimensional gel electrophoresis. The crosslinked residues (nucleotide mcm5S2U34 and U35 in the anticodon loop of tRNA3Lys and UCU154 in the viral RNA upstream of the PBS) were mapped using a retardation method coupled with random hydrolysis. The formation of this crosslink depends on the same elements that are required for the formation of the extended interactions between primer and template RNAs, i.e., the modified bases of the tRNA and a conserved A-rich loop located upstream of the PBS in the genomic RNA.
CONCLUSIONS:
Therefore, the present crosslinking data provide relevant information on the topology of the template/primer binary complex.