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Preserved pharmacological activity of hepatocytes-treated extracts of valerian and St. John's wort.
Planta Med 2005; 71(7):592-8PM

Abstract

The two herbal extracts valerian (Valeriana officinalis L.) and St. John's wort (Hypericum perforatum L.) were studied for their metabolic changes upon incubation with freshly prepared rat hepatocytes and subsequently analysed phytochemically as well as pharmacologically in vitro. Quantitative HPLC analysis of valerian extracts revealed considerable metabolic activities with regard to sesquiterpenes and iridoids. The amount of acetoxyvalerenic acid decreased 9-fold, while that of hydroxyvalerenic acid correspondingly increased 9-fold due to O-deacetylation. The valepotriates didrovaltrate, isovaltrate and valtrate decreased 2-, 18- and 16-fold, respectively. However, the binding affinities of the incubated extracts to the benzodiazepine and picrotoxin binding site of the GABA (A) receptor were quite similar to those of the non-incubated extracts. Neither valerenic acids nor valepotriates exhibited any significant effect on the two binding sites when tested as single compounds. Therefore, either other constituents represent the active ones or multiple compounds are necessary for the observed inhibitory and allosteric effects at the GABA (A) receptor. Extracts of St. John's wort were less potently metabolised than valerian. The amount of pseudohypericin and the main flavonoids (hyperoside, rutin, isoquercitrin, quercitrin, quercetin and I3,II8-biapigenin) slightly decreased during the 4-h incubation period. Both the antagonist effect at the corticotropin-releasing factor (CRF) type 1 receptor and the binding inhibition at the 5-HT transporter were attenuated during the metabolic treatment. The reduced antagonist effect correlates with the decreasing amount of pseudohypericin known to be a CRF (1) receptor antagonist. In conclusion, the incubation of plant extracts with freshly prepared rat hepatocytes represents a useful approach to study the pharmacological action of metabolised plant extracts. The consistent pharmacological activity of both valerian and St. John's wort is concordant with the known clinical efficacy of pharmacological activities.

Authors+Show Affiliations

Institute of Pharmaceutical Biology, University of Basel, Basel, Switzerland. usimmen@dtc.chNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

16041642

Citation

Simmen, Urs, et al. "Preserved Pharmacological Activity of Hepatocytes-treated Extracts of Valerian and St. John's Wort." Planta Medica, vol. 71, no. 7, 2005, pp. 592-8.
Simmen U, Saladin C, Kaufmann P, et al. Preserved pharmacological activity of hepatocytes-treated extracts of valerian and St. John's wort. Planta Med. 2005;71(7):592-8.
Simmen, U., Saladin, C., Kaufmann, P., Poddar, M., Wallimann, C., & Schaffner, W. (2005). Preserved pharmacological activity of hepatocytes-treated extracts of valerian and St. John's wort. Planta Medica, 71(7), pp. 592-8.
Simmen U, et al. Preserved Pharmacological Activity of Hepatocytes-treated Extracts of Valerian and St. John's Wort. Planta Med. 2005;71(7):592-8. PubMed PMID: 16041642.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Preserved pharmacological activity of hepatocytes-treated extracts of valerian and St. John's wort. AU - Simmen,Urs, AU - Saladin,Caroline, AU - Kaufmann,Priska, AU - Poddar,Manisha, AU - Wallimann,Christine, AU - Schaffner,Willi, PY - 2005/7/26/pubmed PY - 2005/9/15/medline PY - 2005/7/26/entrez SP - 592 EP - 8 JF - Planta medica JO - Planta Med. VL - 71 IS - 7 N2 - The two herbal extracts valerian (Valeriana officinalis L.) and St. John's wort (Hypericum perforatum L.) were studied for their metabolic changes upon incubation with freshly prepared rat hepatocytes and subsequently analysed phytochemically as well as pharmacologically in vitro. Quantitative HPLC analysis of valerian extracts revealed considerable metabolic activities with regard to sesquiterpenes and iridoids. The amount of acetoxyvalerenic acid decreased 9-fold, while that of hydroxyvalerenic acid correspondingly increased 9-fold due to O-deacetylation. The valepotriates didrovaltrate, isovaltrate and valtrate decreased 2-, 18- and 16-fold, respectively. However, the binding affinities of the incubated extracts to the benzodiazepine and picrotoxin binding site of the GABA (A) receptor were quite similar to those of the non-incubated extracts. Neither valerenic acids nor valepotriates exhibited any significant effect on the two binding sites when tested as single compounds. Therefore, either other constituents represent the active ones or multiple compounds are necessary for the observed inhibitory and allosteric effects at the GABA (A) receptor. Extracts of St. John's wort were less potently metabolised than valerian. The amount of pseudohypericin and the main flavonoids (hyperoside, rutin, isoquercitrin, quercitrin, quercetin and I3,II8-biapigenin) slightly decreased during the 4-h incubation period. Both the antagonist effect at the corticotropin-releasing factor (CRF) type 1 receptor and the binding inhibition at the 5-HT transporter were attenuated during the metabolic treatment. The reduced antagonist effect correlates with the decreasing amount of pseudohypericin known to be a CRF (1) receptor antagonist. In conclusion, the incubation of plant extracts with freshly prepared rat hepatocytes represents a useful approach to study the pharmacological action of metabolised plant extracts. The consistent pharmacological activity of both valerian and St. John's wort is concordant with the known clinical efficacy of pharmacological activities. SN - 0032-0943 UR - https://www.unboundmedicine.com/medline/citation/16041642/Preserved_pharmacological_activity_of_hepatocytes_treated_extracts_of_valerian_and_St__John's_wort_ L2 - http://www.thieme-connect.com/DOI/DOI?10.1055/s-2005-871262 DB - PRIME DP - Unbound Medicine ER -