Current study results from the report, "Highly variable contents of phenolics in St. John's Wort products affect their transport in the human intestinal Caco-2 cell model: pharmaceutical and biopharmaceutical rationale for product standardization," have been published. According to a study from Houston, United States, "The purposes of this study were to determine content uniformity of phenolics in the St. John's wort (SJW) supplements and to demonstrate how variations in the product matrices affect their absorption and efflux."
"LC and LC-MS/MS methods were used to determine the phenolic contents of 12 different products purchased locally or from the Internet. Three representative extracts were further submitted to Caco-2 cell transport experiment, and transport of rutin, hyperoside, and isoquercitrin was evaluated. The results indicated that the 12 different products displayed 12 different HPLC fingerprints, but all products contained the following major compounds: rutin, hyperoside, isoquercitrin, quercitrin, quercetin, and amentoflavone. The content uniformity of these major compounds was poor across products, with the smallest difference in the amounts of amentoflavone (3.6-fold) and largest difference in that of isoquercitrin (28.8-fold). The Caco-2 experiments indicated transport of rutin in products was vectorial, with the permeabilities varied about 3.6-fold in both directions of transport. The vectorial permeabilities of hyperoside and isoquercitrin were similarly different. Use of efflux transporter inhibitor studies suggested that MRP2 was involved in isoquercitrin's efflux and the product matrix affected the extent of its efflux," wrote S. Gao and colleagues, University of Houston (see also Epithelial Cells).
The researchers concluded: "Different SJW supplements had highly variable contents of phenolics, and the variability in product matrix and phytochemical compositions affected the permeabilities of key phenolics across the Caco-2 monolayers, which may further affect their bioavailabilities. Therefore, standardization will be necessary to ensure safe and efficacious using of supplements such as SJW."
Gao and colleagues published their study in the Journal of Agricultural and Food Chemistry (Highly variable contents of phenolics in St. John's Wort products affect their transport in the human intestinal Caco-2 cell model: pharmaceutical and biopharmaceutical rationale for product standardization. Journal of Agricultural and Food Chemistry, 2010;58(11):6650-9).
For more information, contact S. Gao, Dept. of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, 1441 Moursund Street, Houston, Texas 77030, United States.
Keywords: City:Houston, State:Texas, Country:United States, Region:North and Central America, Agricultural, Agriculture, Caco 2 Cells, Chemicals, Epithelial Cells, Food Chemistry.
This article was prepared by Science Letter editors from staff and other reports. Copyright 2011, Science Letter via NewsRx.com.
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