Topically applied hypericin exhibits skin penetrability on nude mice

Zhuo-heng LI,Yuan-yuan LI,Lai-chun LU,Xiao-yu XU

(1.College of Pharmaceutical Sciences&Chinese Medicine,Southwest University,Chongqing Key Laboratory of New Drug Screening from Traditional Chinese Medicine,Pharmacology of Chinese Materia Medica-The Key Discipline Constructed by the State Administration of Traditional Chinese Medicine,2.Department of Pharmacy,Institute of Surgery Research,Daping Hospital,Third Military Medical University,Chongqing 400042,China）

T3-9

Topically applied hypericin exhibits skin penetrability on nude mice

Zhuo-heng LI1,Yuan-yuan LI2,Lai-chun LU2,Xiao-yu XU1

(1.College of Pharmaceutical Sciences&Chinese Medicine,Southwest University,Chongqing Key Laboratory of New Drug Screening from Traditional Chinese Medicine,Pharmacology of Chinese Materia Medica-The Key Discipline Constructed by the State Administration of Traditional Chinese Medicine,2.Department of Pharmacy,Institute of Surgery Research,Daping Hospital,Third Military Medical University,Chongqing 400042,China）

OBJECTIVEHypericin,a powerful naturally photosensitizer in photodynamic therapy(PDT),is suitable for treating skin diseases involving excess capillary proliferation.In the present study,we aimed to evaluate the skin penetrability of a topically applied hypericin,expecting reducing the risk of prolonged skin photosensitivity,which often occurs after systemic administration.METHODSThe Franz diffusion cell assay was performed to evaluate different penetration enhancers.In vivo studies,fluorescence microscopy was performed to examine the distribution of hypericin in the skin,macroscopic and microscopic analyses were also carried out to detect pathological changes in the skin after topical hypericin-PDT treatment.Immunohistochemistry was used to determine the expression of PECAM-1 in the treated skin.RESULTS5%menthol facilitated hypericin penetrate the skin of nude mice most.The results of in vivo assays revealed that hypericin penetrated nude mice skin,spread to the dermis,and resulted in obvious photosensitivity reaction on the dermal capillaries.Moreover,skin injured by the photosensitive reaction induced by hypericin was replaced by normal skin 7 d after hypericin-PDT treat⁃ment.CONCLUSIONTopical hypericin could penetrate nude mouse skin well and be great potential in PDT treatment of skin diseases.

hypericin;photosensitizer;skin penetrability;photodynamic therapy

Xiao-yu XU,Tel:13062319833,E-mail：xxy0618@sina.com