The behaviour of cyclic-3',5'-AMP phosphodiesterase has been studied in the presence of psoralen, 8-methoxy-psoralen (8-MOP), 4,5',8-trimethylpsoralen (TMP) (usually used in PUVA therapy), 4,6,4'-trimethylangelicin (TMA) and khellin recently proposed for the same therapeutical use. TMP and TMA exhibit a significant inhibitory effect on cyclic AMP phosphodiesterase; a light inhibition is produce...

The photoreaction at 3655 Ä between skin-photosensitizing furocoumarins and DNA leads to a photo-C4-cyclo-addition reaction in which the 5 — 6 double bond of the pyrimidine bases and the 3 — 4 or the 4' —5' double bond of the furocoumarins are involved. In continuing the research in this field, the authors have investigated the photoreactions (3655 A) of psoralen, xanthotoxin (8-methoxy-psorale...

High level quantum mechanical methods were used to study the intercalation complexes of psoralen and 8-methoxy psoralen with DNA. The energetics, structures and properties of isolated psoralen and 8-methoxy psoralen have been investigated. Their interactions with DNA bases and base pair were studied aiming to understand more about the nature of the intercalation binding forces between these int...

With the aim of studying the biosynthesis of psoralen and bergapten, two furocoumarins present in the leaves of “Ficus carica” (Moraceae), the Authors, continuing preceding researchs on this topic, have fed the leaves with the following labelled precursors: 4/,5/-dihydropsoralen, 4',5'-dihydrobergapten, 7-hydroxycoumarin, 5,7-dihydroxycoumarin and 5-methoxy-7-hydroxycoumarin. The results obtain...

Previous investigations of H. oreadica reported the presence of a wide spectrum of complex limonoids and dihydrocinnamic acids. Our interest in the Rutaceae motivated a reinvestigation of H. oreadica, H. brasiliana and H. superba searching for other secondary metabolites present in substantial amounts for taxonomic analysis. In a continuation of the investigation of the H. oreadica, three new l...

Background: Palmoplantar eczema is a common clinical problem involving 2% of the population. There are many treatment modalities for palmoplantar eczema, each with specific local and systemic side effects. Objective: To evaluate methoxsalen bath in the treatment of palmoplantar eczema. Patients and Methods: In a randomized, double-blind, placebo controlled clinical trial, 60 patients with palmo...

Angelica dahurica (Fisch. Ex Hoffm) is an important traditional Chinese herb which is widely used in curing acne, ulcers, carbuncles, rheumatism, headaches and toothaches. A systematic antifungal bioassayguided fractionation of the ethyl acetate extract from A. dahurica led to the isolation of six coumarins, namely, suberosin, bergapten, alloimperatorin, xanthotoxol, 5-methoxy-8-hydroxypsoralen...

Objective(s): To observe and determine the effect and mechanism of psoralen on tumor necrosis factor-α (TNF-α)-induced muscle atrophy.Materials and Methods: Three sets of C2C12 cells, including blank control, TNF-α (10 or 20 ng/ml) treatment and a TNF-α (10 or 20 ng/ml) plus psoralen (80 μM) administration were investigated. Cell viabili...

OBJECTIVE To compare the conventional psoralen-ultraviolet A treatment with psoralen-ultraviolet B therapy in the treatment of psoriasis. METHODOLOGY We studied 50 patients of plaque type psoriasis who were selected to receive either conventional psoralen-ultraviolet A or psoralen-ultraviolet B treatment. RESULTS There was no significant difference between the two treatment groups in the nu...

For a better insight of the molecular basis of the photobiological effects of furocoumarins, the relevance of proteins oxydation by singlet oxygen produced by these substrates under irradiation with long u. v. light was studied. Complex oligomeric as well as simple monomeric purified enzymes with high or low molecular weight and different properties and simple amino acids were irradiated under ...