Synthesis of 5-Aminolevulinic Acid-Based ALACELL Possessing Inhibitory Effect against Cutibacterium acnes: Whitening Effect and Protective Effect of UVB-Irradiated Damage Cells.

Five-aminolevulinic acid (5-ALA)-photodynamic therapy combined with infrared radiation is an effective and safe therapy for facial acne. Although there are various available agents for treating acne, therapies for resistant or severe strains have been limited. The aim of this study was to investigate the inhibitory efficacy of ALACELL synthesized by combining 5-ALA with Y-G-G-F-L peptide against Staphylococcus aureus, Bacillus cereus, Escherichia coli, and Yersinia enterocolitica, as well as Cutibacterium acnes. Furthermore, other effects of ALACELL on human skin cells, melanin formation, intracellular tyrosinase activity, and Ultra Violet B (UVB)-irradiated cell death were measured by treatment of ALACELL in vitro. ALACELL particularly showed a growth inhibitory effect on C. acnes and no inhibitory effect on the four bacteria strains. ALACELL reduced melanin formation and intracellular tyrosinase activity by α-melanin cell-stimulating hormone (α-MSH) in B16F10 cells, with no cytotoxicity. ALACELL also improved cell viability in UVB-irradiated HaCaT cells. The results of the experiment show that ALACELL exhibits more efficacy than 5-ALA against antimicrobial activity, melanin formation, intracellular tyrosinase activity, and UVB-irradiated cell death. Therefore, ALACELL is recommended as a candidate for clinical application in the treatment of acne and skin aging and will be further investigated to study the mode of action and in actual situations.