The transport of the Rooibos tea flavonoid aspalathin across the skin and the intestinal epithelium
Year: 2008
Type: dissertation
Abstract: ABSTRACT \nThe aqueous extract of rooibos has been used for more than three hundred years since its \ndiscovery by the indigenous people. Currently, rooibos is gaining popularity in the \ncosmetic industry and incorporation of rooibos extracts in topical cosmetic formulations \nhas become a fashionable trend. Both topical and intestinal absorption of rooibos tea were \ninvestigated. The transport of aspalathin in the unfermented (green) rooibos aqueous \nextracts and aqueous solution of pure aspalathin were studied. \nThe percutaneous permeation experiments were conducted with vertical Franz diffusion \ncells using human female abdominal skin obtained from patients who underwent \ncosmetic surgery. The green rooibos extract and pure aspalathin solution buffered in \nphosphate buffer system (pH 5.5) were applied to the skin for 12 hours. Samples of the \npermeants were obtained from the receptor fluid phase and from the stratified layers of \nthe skin by using the tape-stripping technique and analysed by HPLC. \nIn vitro intestinal epithelial transport experiments were carried out by using Caco-2 cell \nmonolayers, isolated and cultured from human colonic adenocarcinoma cells, in a \nsix-well transwell system. The green rooibos extract and pure aspalathin solution \nbuffered in phosphate buffer (pH 7.4) were applied on to the cell monolayers and \nincubated for 2 hours. Samples were obtained from the basolateral phase at \npredetermined time intervals and analysed by HPLC. \nLess than 0.1 % of the applied dose of aspalathin permeated the skin. Most of the \npermeated aspalathin accumulated in the stratum corneum. Close to 100 % of aspalathin \nwas transported across the Caco-2 cell monolayers at a concentration dependent manner. \nBetter absorption of aspalathin was observed using the green rooibos extract than with \nthe pure aspalathin solution across the Caco-2 cell monolayers.
Author: Miao-Juei Huang
Language: English
Subfield: Pharmaceutical Science
Domain: Life Sciences
Open Access status: green
Funder: National Research Foundation
OpenAlex ID: W2280871768