Ex vivo/in vitro absorption of STW 5 (Iberogast) and its extract components

To correlate the pharmacol. effects of the fixed herbal combination STW 5 (Iberogast) contg. nine ext. components with its confirmed clin. efficacy, ex vivo/in vitro absorption tests were performed. For the investigation, the everted gut sac technique and, in a pilot study, the Caco-2-cell model were used. The absorption rate of the exts. was detd. by measuring characteristic marker substances of each of the individual exts. using HPLC or GC techniques. The results allow us to conclude that the investigated substances from STW 5 possess a good bioavailability, which is in accordance with the rapid onset of the therapeutic efficacy and explains its known pharmacol. effects and clin. efficacy in terms of multiple drug action and multi-target therapy, resp

Transport of alkamides from Echinacea species through Caco-2 monolayers

To gain more insights into the human intestinal absorption of alkamides from Echinacea species, transport studies were performed with the human adenocarcinoma colonic cell line Caco-2 (ATCC) as a model to assess the epithelial transport of dodeca-2E,4E,8Z,10E/Z-tetraenoic acid isobutylamides (1/2), 30 min after apical loading of 25 micro g/mL 1/2, about 15% of these alkamides were detectable on the basolateral side. Close monitoring of the transport during 6 h revealed a nearly complete transport to the basolateral side after 4 h and no significant metab. was observable. Transport expts. performed at 4 DegC showed only a slight decrease in transport, which is a strong hint that dodeca-2E,4E,8Z,10E/Z-tetraenoic acid isobutylamides (1/2) cross biol. membranes by passive diffusion. Nearly the same results were obtained after preincubation of the Caco-2 cells with lipopolysaccharides (LPS) or phorbol 12-myristate-13-acetate (PMA) to mimic an inflammatory status. These results support the assumption that the alkamides can be easily transported from the intestine and hence may contribute to the in vivo effects of Echinacea prepns