Griseofulvin enhances the effect of aminolevulinic acid-based photodynamic therapy in vitro.
OBJECTIVE
In this study, we investigated whether or not griseofulvin (GF), which is an antimycotic widely used for the oral treatment of skin fungal infections, enhanced the effect of aminolevulinic acid-based photodynamic therapy (ALA-PDT) in vitro, using several tumor cell lines.


METHODS
A human squamous cell carcinoma line (KB), two human osteosarcoma cell lines from mandible (HOSM-1, HOSM-2), and the human gingiva-derived fibroblast line (HF), representing normal cells, were used. GF enhancement of ALA-PDT was evaluated by comparing the effect of ALAin combination with GF to the effect of ALAalone (GF enhancement rate of ALA-PDT). Also, the effect of GF on intracellular accumulation of protoporphyrin IX (PpIX) was evaluated by comparing the intracellular accumulation of PpIX in the ALA and GF combined treatment with that of ALA treatment alone (pGF enhancement rate of intracellular PpIX).


RESULTS
GFenhancement rate of ALA-PDT was 2.51 in KB cells, and 1.65 and 1.27 in HOSM-1 and HOSM-2 cells, respectively. GF enhancement rates of intracellular PpIX were 1.94 in KB cells, 1.53 in HOSM-1 cells, and 1.19 in HOSM-2 cells. GF enhancement rate of intracellular PpIX followed the same trends as the levels of GF enhancement rate of ALA-PDT in the different cell types. For HF, a large effect was not revealed in this study.


CONCLUSIONS
The present study, although preliminary, strongly suggests that concomitant treatment with ALAand GF may be very useful to enhance the effect of ALA-PDT.
Nomura
Jouji
J
Department of Oral and Maxillofacial Surgery, Faculty of Medicine, Mie University, Japan. jn@clin.medic.mie-u.ac.jp
Yanase
Shigeaki
S
Tokuda
Tohru
T
Matsumura
Yoshihiko
Y
Sekida
Motoko
M
Tagawa
Toshiro
T
D000622:Aminolevulinic Acid / Q000494:pharmacology*; D000935:Antifungal Agents / Q000494:pharmacology*; D006118:Griseofulvin / Q000494:pharmacology*; D006801:Humans; D010778:Photochemotherapy / Q000379:methods*; D017319:Photosensitizing Agents / Q000494:pharmacology; D011524:Protoporphyrins / Q000032:analysis; D014407:Tumor Cells, Cultured
D000935:Antifungal Agents; D017319:Photosensitizing Agents; D011524:Protoporphyrins; D006118:Griseofulvin; D000622:Aminolevulinic Acid; C028025:protoporphyrin IX