Showing papers on "Isopimpinellin published in 1993"
TL;DR: The results suggest that the coumarin-type compounds in particular interact with the active sites of Cyp2a-5 and CYP2A6, and the active Sites are structurally different, since a number of compounds inhibited mouse, but not human COH activity.
93 citations
TL;DR: Certain naturally occurring coumarins, to which humans are exposed in the diet, are potent modulators of cytochrome P450, and may be capable of influencing the metabolic activation of other xenobiotics, including chemical carcinogens.
Abstract: The present study was designed to evaluate the effects of a series of natural coumarins on ethoxyresorufin O-dealkylase (EROD) and pentoxyresorufin O-dealkylase (PROD) activities in vitro using hepatic tissues from SENCAR mice. Fifteen different coumarins were examined for potential modulating activities. Several naturally occurring coumarins, found in the human diet, were effective inhibitors of hepatic EROD activity in vitro, including coriandrin, bergamottin, isoimperatorin, and ostruthin. Notably, coriandrin and bergamottin were approximately as potent as 7,8-benzoflavone, a relatively selective inhibitor of cytochrome P450 1A1. Several naturally occurring coumarins were also potent inhibitors of hepatic PROD activity, including imperatorin, bergamottin, isopimpinellin, and angelicin. Kinetic studies of the type of inhibition revealed that these compounds inhibited hepatic EROD and PROD activity by a variety of modes rather than by a uniform one. Furthermore, experiments using a two-stage incubation assay revealed that coriandrin, imperatorin, ostruthin, and several other natural coumarins inactivated hepatic EROD activity (i.e., predominantly cytochrome P450 1A1-mediated) and that isopimpinellin inactivated hepatic PROD activity (i.e., predominantly cytochrome P450 2B1-mediated). Finally, the results indicate that some coumarins had selective inhibitory effects for EROD vs PROD and preliminary analyses suggested a possible structural basis for the observed differences. The current data suggest that certain naturally occurring coumarins, to which humans are exposed in the diet, are potent modulators of cytochrome P450. Furthermore, these compounds may be capable of influencing the metabolic activation of other xenobiotics, including chemical carcinogens.
62 citations
TL;DR: Based on the amounts and types of coumarins, Persian limes appear to be potentially more phototoxic than Key limes, and dermatological interaction assays with psoralen, bergapten, xanthotoxin and limettin should be conducted.
52 citations
TL;DR: Four linear furanocoumarins were identified on the surfaces of callus cells of Ruta graveolens, Ruta pinnata, Daucus carota, and Pastinaca sativa andVariation in the ratios of concentrations of the individual coumarins indicated selective extrusion.
Abstract: Four linear furanocoumarins (psoralen, xanthotoxin, isopimpinellin, and bergapten) were identified on the surfaces of callus cells of Ruta graveolens, Ruta pinnata, Daucus carota, and Pastinaca sat...
10 citations
TL;DR: The total concentration of linear furanocoumarins in glasshouse-grown celery was between 0·6-9·9 μg g-1 fresh mass in virus free plants and 0·9-48·6 μg g/s in virus infected plants, depending on the celery cultivar, virus isolate, and duration of infection.
4 citations