Effect of oral administration ofHypericum perforatum extract (St. John's Wort) on skin erythema and XXXX induced by UVB, UVA, visible light and solar simulated radiation.

@entity1 @entity308 @entity51198 @entity9335 @entity2118 @entity19486
@entity19486 from St John's wort (Hypericum perforatum L.) is a photosensitizing agent that may cause a severe @entity9335 when higher amounts of St John's wort are ingested by animals. Although Hypericum extracts are widely used in the treatment of @entity308 , only a little information on the photosensitizing capacity of St John's wort in @entity1 is available. In the present prospective randomized study we investigated the effect of the Hypericum extract @entity51198 on skin sensitivity to ultraviolet B (UVB), ultraviolet A (UVA), visible light (VIS) and solar simulated radiation (SIM). Seventy two volunteers of skin types II and III were included and were divided into six groups, each consisting of 12 volunteers. In the single-dose study the volunteers (n = 48) received 6 or 12 coated tablets (5400 or 10 800 microgram hypericin). In the steady-state study the volunteers (n = 24) received an initial dose of 6 tablets (5400 microgram hypericin), and subsequently 3 x 1 tablets (2700 microgram hypericin) per day for 7 days. Phototesting was performed on the volar forearms prior to medication and 6 h after the last administration of Hypericum extract. The erythema-index and melanin-index were evaluated photometrically using a mexameter. After both single-dose and steady-state administration, no significant influence on the erythema-index or melanin-index could be detected, with the exception of a marginal influence on UVB induced @entity2118 (p = 0.0471) in the single-dose study. The results do not provide evidence for a phototoxic potential of the Hypericum extract @entity51198 in @entity1 when administered orally in typical clinical doses up to 1800 mg daily. This is in accordance with previous pharmacokinetic studies that found hypericin serum and skin levels after oral ingestion of Hypericum extract always to be lower than the assumed phototoxic hypericin threshold level of 1000 ng/mL.
