Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2001-8-22
pubmed:abstractText
Hypericum perforatum extracts are used mainly as oral antidepressants. Depending on source the extracts contain various amounts of phenylpropanes, flavonol derivates, biflavones, proathocyanidines, xanthones, phloroglucinoles, some amino acids, naphtodianthrones (hypericines) and essential oil constituents. The therapeutic use of Hypericum perforatum extracts however is limited by their phototoxic potential. It was the aim of the present study to investigate the phototoxic potential of 3 Hypericum perforatum extracts from different sources as well as some of its main constituents. In order to systematically study the phototoxic potential we established a modified neutral red assay utilizing an immortalized human keratinocyte cell line (HaCaT cells) as substrate and UVA irradiation. This modified neutral red assay was found to be a simple and reliable method for detecting phototoxic effects of reference agents and plant extracts. The validity of this method was demonstrated with known phototoxic compounds like chloropromazine and psoralenes like 5-MOP. Hypericum perforatum extracts demonstrated cytotoxicity and photocytotoxicity in a dose and UVA-dose dependent manner. Hypericine itself also evoked severe phototoxic effects and was thus identified as the main phototoxic constituent. Among the tested flavonoids quercitrin was found to be cytotoxic, while rutin unexpectedly demonstrated phototoxicity whereas quercitrin was effective to control the phototoxic activity of Hypericum perforatum extracts.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0944-7113
pubmed:author
pubmed:issnType
Print
pubmed:volume
8
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
306-9
pubmed:dateRevised
2004-11-17
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
Role of flavonoids in controlling the phototoxicity of Hypericum perforatum extracts.
pubmed:affiliation
proDERM Institute for Applied Dermatological Research GmbH, Schenefeld/Hamburg, Germany.
pubmed:publicationType
Journal Article