The phytochemical study of Dorstenia arifolia Lam. (Moraceae) has led to the identification of 18 triterpenes esterified by fatty acids, five triterpenes without esterification, 12 triterpenes esterified by acetic acid, together with a known furanocoumarin: α-amyrin (1), β-amyrin (2) α-amyrin acetate (3) β-amyrin acetate (4), α-amyrin octanoate (5), β-amyrin octanoate (6), α-amyrin decanoate (7...

Detoxification of host plant defensive compounds by larval Lepidoptera is mediated by cytochrome P450 monooxygenases (P450s) such as CYP6B1, which is expressed in Papilio polyxenes (black swallowtail) larvae in response to xanthotoxin, a linear furanocoumarin. Baculovirus-mediated expression of two cloned CYP6B1 cDNAs in lepidopteran cell lines has demonstrated that CYP6B1 isozymes primarily me...

Lime disease or phytophotodermatitis is a phototoxic inflammatory cutaneous eruption that occurs when skin is exposed to furanocoumarin-containing plants and sunlight. The presentations range from mild erythema to acute blisters or bullae.1 Common causative plants include lime, lemons, figs, parsnips and celery. The diagnosis is clinical and relies on meticulous review of exposure history, corr...

It has been well established that the formation of reactive metabolites of drugs is associated with drug toxicity. Similarly, there are accumulating data suggesting the role of the formation of reactive metabolites/intermediates through bioactivation in herbal toxicity and carcinogenicity. It has been hypothesized that the resultant reactive metabolites following herbal bioactivation covalently...

Several naturally occurring coumarins, to which humans are routinely exposed in the diet, were previously found to inhibit P450-mediated metabolism of benzo[a]pyrene (B[a]P) and 7,12-dimethylbenz[a]anthracene (DMBA) in vitro, block DNA adduct formation in mouse epidermis and inhibit skin tumor initiation by B[a]P and/or DMBA when applied topically to mice. The present study was designed to inve...

Over the past two decades a significant increase in fungal infections has been observed (1). More than any other antifungal class, the azoles have been steadily refined and improved upon over the course of almost 50 years. These antifungal compounds are chemically either an imidazole or a triazole group joined to carbon atom as their functional pharmacophore and working through blocking the act...

Grapefruit juice increases the oral availability of a variety of CYP3A4 substrates. It has been shown that recurrent grapefruit juice ingestion results in a loss of CYP3A4 from the small bowel epithelium. We now show that the reduction in intestinal CYP3A4 concentration is rapid; a 47% decrease occurred in a healthy volunteer within 4 hr after consuming grapefruit juice. To identify the specifi...