Protoporphyrin IX Synthesis Induced by 5-aminolevulinic Acid and Its Esters in Normal Mouse Skin / 대한피부과학회지

BACKGROUND: Photodynamic therapy with using 5-aminolevulinic acid (ALA) is a good noninvasive treatment modality that can treat several cutaneous diseases. Yet hydrophilic ALA is not able to easily penetrate the cellular membrane or the lipid layer of the skin. Thus, various ALA alkyl esters been developed. OBJECTIVE: We studied whether novel ALA unsaturated alkyl esters synthesize more protoporhyrin IX (PpIX) than does ALA in mouse skin tissues. METHODS: We applied 5, 10, 15% ALA and ALA esters ointment to the skin of shaved mice, respectively. We harvested the skin tissue, made a preparation and did quantitative analysis according to the fluorescent spectrum for determining the amount of PpIX synthesized in the skin after the elapse of 1 hour and 3 hours, respectively. RESULTS: No matter what the sort or the concentration of the ALA and ALA ester was, the amount of synthesized PpIX increased more after the elapse of 3 hours than that after 1 hour. ALA (hetenyl-, petenyl-, butenyl-, methyl-) esters tended to produce a much greater amount of PpIX than ALA. According to the results of the comparative study with using 5%, 10% and 15% of ALA and ALA esters ointment, the amount of synthesized PpIX was not proportional to the concentration of the ALA and the ALA esters, even though the ALA esters produced more PpIX than the ALA. CONCLUSION: We found that the ALA unsaturated alkyl esters are a good photosensitizer and they are similar to ALA-me, which is an ALA saturated alkyl ester that induces more PpIX, an actual photosensitizer, than ALA can.

Expression of Protoporphyrin IX by Methyl 5-aminolevulinate in Various Dermatologic Diseases and Cells / 대한피부과학회지

BACKGROUND: 5-aminolevulinic acid (ALA), is the precursor of heme biosynthesis and used in photodynamic therapy (PDT). When applied exogenously, it is converted to protoporphyrin IX (PpIX) that is an immediate photosensitizer. PpIX is accumulated selectively in various cells including tumor cells. Because most of photosensitizers emit fluorescence of a specific wavelength, it is very important to identify the fluorescence in the tissues and cells targeted for therapy. OBJECTIVE: This study was undertaken to identify the presence of PpIX fluorescence image and localization in various dermatologic diseases with methyl 5-aminolevulinate (MAL), that satisfactorily penetrates cutaneous lipid layers and cell membranes. METHODS: Various skin diseases such as basal cell carcinoma (6), squamous cell carcinoma (4), keratoacanthoma (6), malignant melanoma (3), extramammary Paget's disease (4), verruca (5), psoriasis vulgaris (5), rosacea (2), and acne (5) were included. We applied MAL, ALA ester, ointment to cutaneous lesions and perilesional area for at least 3 hours. After that, we identified the fluorescence image with Wood's lamp (wavelength 320~400 nm) and photographed fluorescence image. Also, we performed skin biopsies of fluorescence site and investigated the PpIX fluorescent location with a fluorescence microscope. In addition, we treated three cultured cell lines (HaCaT cells, human dermal fibroblasts, A431 cells) with MAL and investigated PpIX fluorescence. RESULTS: The PpIX fluorescence images were observed significantly in basal cell carcinoma, squamous cell carcinoma, extramammary Paget's disease, keratoacanthoma, psoriasis, rosacea, and acne. In tissues, PpIX fluorescence was expressed mainly in the pilosebaceous unit, abnormal keratinocytes, tumor cells including basal cell carcinoma, and extramammary Paget's disease. In addition, PpIX was expressed in the cytoplasm of HaCaT cells, human dermal fibroblasts, and A431 cells in vitro. CONCLUSION: In applieation of photodynamic therapy, this study is expected to be helpful in enhancement of therapeutic effectiveness and increase of indications of diseases.