Methoxsalen (8-methoxypsoralen) is an effective and selective mechanism-based inhibitor of human hepatic cytochrome P-450 (CYP)2A6 in vitro, and may have utility as a clinical probe for CYP2A6-catalyzed xenobiotic metabolism in humans in vivo. This investigation explored single-dose oral methoxsalen effects on human CYP2A6 activity in vivo, assessed by coumarin 7-hydroxylation. Eleven volunteer...

Previously, we demonstrated that 8-methoxypsoralen (methoxsalen), a potent human cytochrome P450 2A6 (CYP2A6) inhibitor, strongly suppresses lung adenoma induction by 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) in female A/J mice. In the present study, we examined the inhibitory effects of methoxsalen on the development of lung adenocarcinomas, as well as on adenomas and alveolar hyper...

BACKGROUND Limited data exist in the literature concerning the characteristics of erythema following psoralen UV-A (PUVA) treatment using topical methoxsalen. To optimize the phototherapeutic regimen and reduce short- and long-term risks, knowledge of such basic information is essential. OBSERVATIONS The characteristics of PUVA erythema following 15- and 5-minute immersion in methoxsalen was ...

Studies were undertaken to examine whether methoxsalen (9-methoxyfuro[3,2-g][1]benzopyran-7-one), a specific and relatively selective inhibitor of human CYP2A6, inhibited CYP2A5-mediated nicotine metabolism in vitro. Furthermore, studies were performed in vivo to determine whether methoxsalen would modulate acute nicotine pharmacokinetics and pharmacological effects (antinociception and hypothe...

INTRODUCTION Coumarins exert many biological effects in humans, animals, and plants, which make the evaluation of their biological activities and study of their role in ethnomedicine highly valued. OBJECTIVES Here, we selected seven plants which have ethnopharmacological use as antimicrobial in Iraq and the aims were to quantify the two structural isomers bergapten and methoxsalen in their se...

Human CYP2A6 has been recognized as being involved in the mutagenic activation of promutagens such as the tobacco-specific nitrosamine, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK). Methoxsalen (8-methoxypsoralen) was reported to inhibit CYP2A6. In the present study, the inhibitory effects of methoxsalen on NNK-induced lung tumorigenesis in female A/J mice were examined. Female A/J mice...

OBJECTIVE Methoxsalen is a natural photoactive compound which is found in many seed plants. A number of epidermal proliferative disorders can be treated by methoxsalen along with long wave ultraviolet A (UVA). MATERIALS AND METHODS In an experimental study, we aimed to demonstrate the effect of methoxsalen, UVA and their combination on oogenesis Balb/C mice. There were two experimental groups...

CYP2A6 is the principle enzyme metabolizing nicotine to its inactive metabolite cotinine. In this study, the selective probe reactions for each major cytochrome P450 (P450) were used to evaluate the specificity and selectivity of the CYP2A6 inhibitors methoxsalen, tranylcypromine, and tryptamine in cDNA-expressing and human liver microsomes. Phenacetin O-deethylation (CYP1A2), coumarin 7-hydrox...

BACKGROUND Different investigation showed that 5-methoxypsoralen and 8- methoxypsoralen reduce birth rates in the rats. OBJECTIVE In this study we worked out the effect of methoxsalen together with ultraviolent A (UVA) radiation on mature Balb/C mice spermatogenesis. MATERIALS AND METHODS The LD50 standard was determined 160 mg/kg and the UVA dose which causes erythema was calculated 0.046 ...